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17 December 2011, Volume 15 Issue 51 Previous Issue    Next Issue

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In vitro degradation mechanism of beta-tricalcium phosphate/alpha-calcium sulfate hemihydrates bone graft Li Peng, Mao Ke-ya, Jiang Tao, Yang Yun, Cui Fu-zhai, Hou Xi-jun, Liang Mao-hua, Du Ming-kui, Wang Ji-fang, Wang Yan 2011, 15 (51):  9501-9504.  doi: 10.3969/j.issn.1673-8225.2011.51.001 Abstract ( 359 )   PDF (1090KB) ( 553 )   Save BACKGROUND: The ideal degradation rate of bone repair materials should be matched with the speed of new bone formation, and the bone repair materials are replaced by new bone gradually via creeping substitution. OBJECTIVE: To investigate the in vitro degradation mechanism and degradation speed of β-tricalcium phosphate/α-calcium sulphate hemihydrates (β-TCP/α-CSH) bone graft. METHODS: β-TCP/α-CSH, β-TCP and α-CSH samples were soaked in PBS liquid. The pH value, degradation rate and compressive stress were examined. RESULTS AND CONCLUSION: In the PBS liquid, the pH value of β-TCP/α-CSH bone graft and α-CSH gradually decreased with the soaked time, but that of β-TCP changed little. After 4 weeks, the pH value of β-TCP/α-CSH bone graft and α-CSH was stabilized to about 5.6. The weight and compressive stress of β-TCP/α-CSH bone graft and α-CSH were gradually decreased with the soaked time in the PBS liquid, but those of β-TCP decreased little. β-TCP/α-CSH bone graft can gradually degrade through physical dissolution in vitro, and the degradation rate is lower than that of β-TCP but higher than that of α-CSH. Related Articles | Metrics

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Platelet-rich plasma combined with deproteinized bone promotes healing of tendon-bone interface at early stage Zhai Wen-liang, Lü Chen-wei, Ding Zhen-qi, Gao Yue-chuan, Zheng Yan-mei 2011, 15 (51):  9505-9508.  doi: 10.3969/j.issn.1673-8225.2011.51.002 Abstract ( 268 )   PDF (1478KB) ( 433 )   Save BACKGROUND: Studies show that the platelet-rich plasma (PRP) gel cannot improve the regeneration of bone and it may be lost or inactivated rapidly by synovial fluid. OBJECTIVE: To observe the effects of PRP combined with deproteinized bone (DPB) on the biomechanical property of tendon-bond interface at the early stage after reconstruction of the anterior cruciate ligament (ACL). METHODS: New Zealand white rabbits were divided into normal group, model group, experimental group, and control group. The later three groups were used to prepare ACL reconstruction model. Nothing was implanted into the bone tunnel of the model group while DPB and PRP+DPB were implanted into the control group and experimental group respectively. RESULTS AND CONCLUSION: At 2 and 4 weeks after surgery, the mainly tensile unload way in each group was that the transplanted tendon was extracted from the bone tunnel. At 8 weeks, the way mainly in the experimental group was tendon tearing, while for the control group and model group, majority of the transplanted tendons were still extracted from the bone tunnels. The differences had statistical significance (P < 0.05). At 12 weeks, tendon tearing was the main reason of tensile unloading for all of the groups. The maximum tensile load in the experimental group was obviously higher than those of the control and model groups at 4 and 8 weeks after surgery (P < 0.05); the differences had no significance at 12 weeks (P > 0.05), however, the difference between the experimental group and the normal group was still significant (P < 0.01). The difference in stiffness of each group was increased as time went on, but the differences between each group were not significant (P > 0.05). PRP+DPB can reinforce the biomechanics strength of the tendon-bond interface in the early stage. Related Articles | Metrics

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Histological changes of bone marrow mesenchymal stem cells combined with heterogeneous deproteinized cancellous bone in repair of bone defects Wang Hao, Wei Dong-xing, Wang Wei 2011, 15 (51):  9509-9512.  doi: 10.3969/j.issn.1673-8225.2011.51.003 Abstract ( 287 )   PDF (1394KB) ( 312 )   Save BACKGROUND: Nowadays, there are so many studies on manmade scaffold combined with cells for repair of bone defects. However, the restoration effects are not ideal because of the manmade scaffold lacking the nature structure of bone. OBJECTIVE: To inoculate the bone marrow mesenchymal stem cells (BMSCs) in the deproteinized cancellous bone in order to repair segmental femoral defects of rats and evaluate the composite application prospect by restoration effects in vivo. METHODS: BMSCs were isolated, cultured, proliferated and marked by BrdU in vitro. At the same time bovine deproteinized cancellous bone was prepared, and then combined with the marked cells in vitro. The bone defect models (5 mm in length) were created at the bilateral femur in rats and divided into three groups. The defects were implanted by BMSCs combined with deproteinized cancellous bone, deproteinized cancellous bone, and BMSCs respectively. RESULTS AND CONCLUSION: The BrdU expressed in all cells of each group, and the expression was decreased as time went on. X-ray scores and hematoxylin-eosin stained histological scores showed that the osteogenic effect of the composite group was better than those of the other groups. Collagen protein-Ⅰ expression in the composite group was obviously increased as time went on and was stronger than the other groups. The osteogenesis ability of the composite of BMSCs and heterogeneous deproteinized cancellous bone is stronger than simple scaffolds. BMSCs have the osteogenesis ability, but they cannot repair segmental bone defects. Related Articles | Metrics

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A type of injectable porous calcium phosphate cement in vivo Zhang Liang, Gao Jian-jun, Dang Xiao-qian 2011, 15 (51):  9513-9517.  doi: 10.3969/j.issn.1673-8225.2011.51.004 Abstract ( 286 )   PDF (1788KB) ( 382 )   Save BACKGROUND: Calcium phosphate cement (CPC) has the disadvantages of brittleness, low waterborne (blood-soluble), poor mechanical property and conductibility which limit its clinical application in some degree. Therefore its modification research is in need. OBJECTIVE: To prepare a type of porous calcium phosphate cement with certain intensity and porosity for the bone growth. METHODS: This study was based on the CPC system. The liquid phase was the weak acidic solution of chitosan which had favorable biocompatibility and high viscosity to achieve injectable of CPC. It could strongly improve the application and comfort of CPC. The solid phase was biphasic calcium phosphate (four calcium phosphate + calcium hydrogen phosphate) system. The pores of mannitol and lactic-co-glycolic acid were added into solid phase to prepare the calcium phosphate scaffold. RESULTS AND CONCLUSION: The aperture of the prepared material could reach to 10-300 μm. The porosity of the solidified CPC could reach to (68.3±1.5)% when the proportion of the porogen was 60%. The increased porosity of CPC decreased the mechanical properties of the material, the compressive strength of CPC without porogen was (53.0±1.4) MPa initially, and dropped to (2.5±0.2) MPa with 60% porogen. The CPC material has better compressive strength and favorable biocompatibility, and can be degraded in vivo and used as a type of injectable scaffold materials. Related Articles | Metrics

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Effect of zinc on titanium implant bone fusion Chen Hai-jun, Zhang An-sheng, Lin Jun-zhou, Qian Qi-chun, Yu Shu-xiang, Nan Fu-qing 2011, 15 (51):  9518-9522.  doi: 10.3969/j.issn.1673-8225.2011.51.005 Abstract ( 309 )   PDF (7464KB) ( 282 )   Save BACKGROUND: Previous research has testified that zinc can improve the healing rate and enhance the fixation strength of implants. OBJECTIVE: To observe the effect of zinc on the morphology of implant-bone interface. METHODS: Forty adult male rabbits were involved and divided into zinc supplement group and control group. The titanium implants were implanted into bilateral tibias at the proximal end to establish animal models of titanium implants. Zinc sulfate of 10 g/L was administered intramuscularly to the animals in the zinc supplement group at the dose of 4 mg/kg once per day, and those in the control group were treated with saline at the same dose. The animals were killed at 1, 2, 4, 8 and 12 weeks after treatment. Stereomicroscope and scanning electron microscopy were used to observe the morphology of the implant-bone interface. RESULTS AND CONCLUSION: Zinc supplement could accelerate the new bone formation on the implant-bone interface at 1-4 weeks after treatment to facilitate the fusion between the implant and bone. It is indicated that amount of zinc supplement can promote the new bone formation and enhance the speed and quality of bone healing. Related Articles | Metrics

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Application of glue-like E-matrix in posterolateral spinal fusion of rats Wu Gui-zhong, Yang Hui-lin, Sun Zhi-yong, Chen Kang-wu, Gu Yong 2011, 15 (51):  9523-9526.  doi: 10.3969/j.issn.1673-8225.2011.51.006 Abstract ( 311 )   PDF (1120KB) ( 389 )   Save BACKGROUND: Various animal models and clinical trials show that the recombinant human bone morphogenetic protein (rhBMP) has the capacity of bone induction. OBJECTIVE: To study the effect of glue-like E-matrix as a new type of carrier for rhBMP-2 on posterolateral spinal fusion of rats. METHODS: Posterolateral fusion models were established in 105 male Lewis rats. Absorbable gelatin sponge and rhBMP-2 with different qualities were implanted into the L4-5 intertransverse of rats under the same conditions. Observation of adding glue-like E-matrix or not into groups was performed. RESULTS AND CONCLUSIONS: Fusion rates of the rats with 10 μg rhBMP-2 and 3 μg rhBMP-2 were 100%, and those of the rats with 1 μg, 0.5 μg and 0.1 μg of rhBMP-2 were 40%, 10% and 0% respectively. In the adding glue-like E-matrix groups, the fusion rate of rats with > 0.5 μg rhBMP-2 was 100%, but no fusion was observed in the rats with 0.1 μg and 0.05 μg rhBMP-2. The micro-CT results revealed that the amount of the new bone created in the 10 μg rhBMP-2 + E-matrix group and the 3 μg rhBMP-2+E-matrix group were similar. However, there was no new bone created in the 0.1 μg and 0.05 μg rhBMP-2 groups containing E-matrix or not. E-matrix can enhance the fusion rate of rhBMP-2 significantly in posterolateral spinal fusion. However, the expected fusion cannot be achieved by E-matrix if the dose of rhBMP-2 is too small. Related Articles | Metrics

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In vitro cytotoxicity evaluation of a new type anticalcification bovine jugular venous conduit Lin Xi, Zhang Wei-da, Zhang Hong-bin, Li Jie, Wang Xiao-li 2011, 15 (51):  9527-9530.  doi: 10.3969/j.issn.1673-8225.2011.51.007 Abstract ( 299 )   PDF (1261KB) ( 350 )   Save BACKGROUND: Triton X-100 and epoxy chloropropane modification with glutaraldehyde-treated bovine jugular venous conduit is a new type anticalcification valved conduit for right ventricular outflow tract reconstruction. There are few reports on the biocompatibility research. OBJECTIVE: To evaluate the cytotoxicity of the new type anticalcification bovine jugular venous conduit in vitro. METHODS: The cytotoxicity of the new type anticalcification bovine jugular venous conduit (experimental group) and only glutaraldehyde treated bovine jugular venous conduit extracts (control group) was detected by CCK-8. The relative growth rate was calculated and the toxicity was graded at days 2 and 4. RESULTS AND CONCLUSION: CCK-8 test results showed that the relative growth rate of the experimental group was more than 85%. The toxicity grade was 1, and there was non-cytotoxicity, which were significantly better than those in the control group (P < 0.05). It was indicated that Triton X-100 and epoxy chloropropane modification with glutaraldehyde-treated bovine jugular venous conduit had no cytotoxicity and should be a safe implanted material. Related Articles | Metrics

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Preparation and degradation property of composite membrane of porous poly (3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate Wu Yue-heng, Zhang Ling-min, Zeng Xiang-jun, Mai Li-ping, Wu Chang-li, Tang Shun-qing, Yu Xi-yong 2011, 15 (51):  9531-9534.  doi: 10.3969/j.issn.1673-8225.2011.51.008 Abstract ( 333 )   PDF (1251KB) ( 542 )   Save BACKGROUND: Degradation properties of scaffold are closely related to the adhering of seed cells to its surface. OBJECTIVE: To prepare the composite membrane of porous poly (3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate (P (3HB-co-4HB)/CMP) and observe its degradation properties in vitro. METHODS: The raw material ratio of P (3HB-co-4HB)/CMP was 50/50, and the P (3HB-co-4HB)/CMP was mixed uniformly and dissolved in chloroform and dumped in a Petri dish. After drying, the porous composite membranes were obtained. The porous composite membranes were put in the circulation device, the flow rate of which was 0.30 m/s, the channel was filled with 50 mL 37 ℃ physiological saline. RESULTS AND CONCLUSION: Weight loss rates of the composite membrane at 2, 4, 8, 16, 24 hours under flow field were 4.5%, 5.6%, 6.9%, 9.6% and 10.6% respectively; scanning electron microscopy showed that the partial calcium phosphate particles on the surfaces were complete depredated or lost, the concave particles were kept, 2 μm porous on the surfaces could not be seen, 30-50 μm porous did not change but the edge was smooth; the water absorption, porosity and density of the composite membrane were 40.6%, 46.3%, and 1.14 g/cm3 respectively before depredation, and 51.6%, 54.1%, 1.05 g/cm3 after that. During the preparation of P (3HB-co-4HB)/CMP, the depredation of the composite membrane in the early stage is the partial calcium phosphate depredation, and the microfilament is prone to be depredated and facture during the depredation. Related Articles | Metrics

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Feasibility of biodegradable polyurethane in construction of tissue engineering anterior cruciate ligament Liu Long-fei, Zhang Wen-tao, Huang Wei, Zhang Xin-tao, Xiao De-ming 2011, 15 (51):  9535-9538.  doi: 10.3969/j.issn.1673-8225.2011.51.009 Abstract ( 315 )   PDF (1157KB) ( 333 )   Save BACKGROUND: The anterior cruciate ligament (ACL) of the knee joint is the common site of injury. Tissue engineering has achieved much progress in the past 10 years for ACL, but none of the ideal scaffolds. OBJECTIVE: To investigate the feasibility of biodegradable polyurethane in construction of tissue engineering ACL. METHODS: Leaching liquor of polyurethane composed of biodegradable polyurethane fibers was prepared on DMEM medium containing fetal bovine serum. NIH3T3 cells were cultured in DMEM medium with 100%, 50%, 25%, and 12.5% of leaching liquor. The cytotoxicity of polyurethane was detected by CCK-8 agent. Rabbit ACL cells and NIH3T3 cells were isolated and cultured in vitro, and seeded onto the surface of the polyurethane scaffold to observe their growth. The biomechanical properties of the polyurethane scaffold were measured and analyzed with electronic tensile machine. RESULTS AND CONCLUSION: The braided polyurethane scaffold materials had no cytotoxicity; ACL and NIH3T3 cells adhered, grew and proliferated well on the surface of the braided polyurethane scaffold materials. The Young’s modulus, ultimate tensile stress and elongation at break were (41.2±2.1) MPa, (51.0±1.5) MPa and (600±60)% respectively. The polyurethane scaffold materials possess good biomechanical properties and biological safety. Related Articles | Metrics

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Repair of mechanical damage of rabbit nasal mucosa by collagen spray Zhao Peng, Lei Jing, Chen Dan-chang, Huang Dong-jing 2011, 15 (51):  9539-9543.  doi: 10.3969/j.issn.1673-8225.2011.51.010 Abstract ( 389 )   PDF (1490KB) ( 702 )   Save BACKGROUND: Collagen is a kind of natural material, which has a low immune, good cell compatibility and tissue compatibility. It can promote the generation of vascular and plays an extremely important role in cell differentiation, tissue repair and the normal nutrition to organs. OBJECTIVE: To evaluate the repair function of collagen spray on mechanical damaged nasal mucosa in rabbits. METHODS: Nasal mucosa mechanical damage model was prepared. Collagen sprays were given to the treatment group in the left nose, and the left nose of model group was treated with the same amount of saline. The repair situation and pathomorphology of the wounded tissue were observed. RESULTS AND CONCLUSION: Collagen spray had no excitant. The goblet cell count and submucosal glands in the treatment group were slightly decreased than the model group. The rate of submucosal edema in the treatment group was significantly different from that in the model group (P < 0.01). Under light microscope, there was a decrease of fresh repaired epithelial goblet cells, the submucosal glands were small and well-regulated, and its secretion was unobstructed; there were no obvious edema, and the glands were dense; none of the above could be seen in the control group. The collagen spray had a clear repair function on mucosal injury, the infiltrating phenomenon of inflammatory cells was reduced in the mucosal lamina propria, the performance of diffuse submucosal edema was not obvious, and the glandular secretion was in good condition. Related Articles | Metrics

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Subcutaneous implantation of bone marrow mesenchymal stem cells-polyglycolic acid scaffold complex to construct small diameter tissue-engineered blood vessels Gao Guo-liang, Song Jian-fei, Wang Hai-yong, Zheng Min, Wang Wei, Jiang Yi-yao, Du Zhen-zong 2011, 15 (51):  9544-9548.  doi: 10.3969/j.issn.1673-8225.2011.51.011 Abstract ( 214 )   PDF (424KB) ( 368 )   Save BACKGROUND: Our former studies have shown that bone marrow mesenchymal stem cells (BMMSCs) can be induced differentiation to vascular smooth muscle-like cells (VSMLCs) and vascular endothelium-like cells (VELCs), which are compatible with collagen-embedded polyglycolic acid scaffolds. OBJECTIVE: To investigate the possibility of constructing small diameter tissue-engineered blood vessels via subcutaneous implantation. METHODS: The cells-scaffold complex was produced by separately seeding VSMLCs and VELCs derived from BMMSCs on polyglycolic acid collagen scaffolds. The two layers were separated by ECMgel. The cells-scaffold complex was subcutaneous implanted into small diameter tissue-engineered blood vessels. RESULTS AND CONCLUSION: Histological analysis of the small diameter tissue-engineered blood vessel walls revealed a typical artery structure, which was similar to natural vessels. The tissue-engineered blood vessels were not broken down under a force of 26.6 kPa. Eight weeks after implantation, the Brdu-labeled seed cells were found in the three layers of the vessel walls. The results revealed that the subcutaneous tissue was a good bioreactor to construct small diameter tissue-engineered blood vessels. Related Articles | Metrics

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Application of a memory alloy elastic metal stent in reconstruction of tracheal defects by pulmonary tissue flaps in dogs Ji Zi-zhao, Chen Gang, Zhang Su-ning, Shi Wen-jun 2011, 15 (51):  9549-9552.  doi: 10.3969/j.issn.1673-8225.2011.51.012 Abstract ( 303 )   PDF (1221KB) ( 426 )   Save BACKGROUND: Lined stent containing good biocompatibility is the key of successful repair of tracheal defect by pulmonary tissue flap. Memory alloy stent is the research hotspot now. OBJECTIVE: To explore the possibility of autologous pulmonary tissue flap lined with elastic metal stent in replacing tracheal defect. METHODS: Fourteen hybrid adult dogs came from animal laboratory of Shengjing Hospital of China Medical University were involved. Eight dogs were male and six ones were female with weight of 12-26 kg. The entire trachea of 3 cm or 5 cm was removed in all dogs. Thoracic tracheal reconstruction was performed with autologous pulmonary tissue flap lined with elastic metal stent to replace the tracheal defect. RESULTS AND CONCLUSION: Four dogs died of the complications and other reasons. Ten dogs survived, and their stomas were good and the barium flux was unobstructed. The replacement of tracheal defect by autologous pulmonary tissue flap lined with elastic metal stent is a possible tracheal reconstruction method. Related Articles | Metrics

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Cytocompatibility of magnesium alloys after surface fluoridation tested by human bone marrow mesenchymal cells Jiang Hai-ying, Yan Zheng-bin, Zhang Zhao, Ai Hong-jun 2011, 15 (51):  9553-9556.  doi: 10.3969/j.issn.1673-8225.2011.51.013 Abstract ( 231 )   PDF (1135KB) ( 616 )   Save BACKGROUND: AZ31B magnesium alloy with surface flouridization is a new type of magnesium alloy developed by Institute of Metal Research, Chinese Academy of Sciences. Its biocompatibility is unclear.  OBJECTIVE: To observe the cytocompatibility of magnesium alloys with surface fluoridation tested by human bone marrow mesenchymal cells (BMSCs). METHODS: Human BMSCs were identified and cultured. The AZ31B magnesium alloy was taken as control and the AZ31B magnesium alloy with surface fluoridation was experimental group. Human BMSCs were the test cells. Leaching liquor of the alloy in both groups was used for cell compatibility experiments in vitro in order to evaluate the biocompatibility of AZ31B magnesium alloy. RESULTS AND CONCLUSION: The cell survival rate of AZ31B magnesium alloys with surface fluoridation was significantly higher than AZ31B magnesium alloys without surface fluoridation. The toxicity of cells in the leaching liquor of AZ31B magnesium alloys with surface fluoridation was Grade 1 and was non-toxic to the basic cell growth. The biocompatibility of the AZ31B magnesium alloys with surface fluoridation is superior to the AZ31B magnesium alloys without surface fluoridation. Related Articles | Metrics

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Antibacterial properties of LZB-GC nano-silver-filled antibacterial agents used in alginate impression materials Liu Wen-juan, Wang Yi, Zhao Hong-mei, Liu Bin, Han Jian, Zhou Wei, Wang Meng 2011, 15 (51):  9557-9560.  doi: 10.3969/j.issn.1673-8225.2011.51.014 Abstract ( 310 )   PDF (1589KB) ( 360 )   Save BACKGROUND: The disinfection method of alginates impression materials has been controversial.    OBJECTIVE: To analyze the appropriate ratio of the LZB-GC nano-silver-filled antibacterial agent to the alginate impression material. METHODS: The LZB-GC antibacterial agents were added into the alginate impression materials according to different contents, including 0.125, 0.25%, 0.5%, 1%, 1.5%, 2% and 2.5%. The alginate impression materials without the LZB-GC antibacterial agents served as a control. Their antibacterial activities were tested by film adhesion method, including Staphylococcus aureus and Escherichia coli. RESULTS AND CONCLUSION: The antibacterial efficiency was increased as the adding ratios of antibacterial agent against two tested bacteria strains increased (P < 0.05). The antibacterial efficiency was beyond 99% when the adding ratio of antibacterial agent was 0.5% or beyond 0.5%. It was indicated that the best adding ratio of the LZB-GC antibacterial agent in the alginate impression material was 0.5%. Related Articles | Metrics

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Repair of skin defect with collagen-chitosan compound nanofiber membrane Yu Pei-jun, Wang Lu-ping, Guo Yu, Chen Wei, Mo Xiu-mei 2011, 15 (51):  9561-9564.  doi: 10.3969/j.issn.1673-8225.2011.51.015 Abstract ( 310 )   PDF (1174KB) ( 443 )   Save BACKGROUND: Studies in vitro have confirmed that collagen-chitosan (80:20) compound nanofiber membranes have excellent mechanical properties, biocompatibility and biodegradability. However, there are few researches in vivo about the materials. OBJECTIVE: To observe the effect of collagen-chitosan compound nanofiber membranes on repair of full-thickness skin defect on the back of Sprague Dawley (SD) rats. METHODS: Thirty SD rats with full-thickness skin defects on the back were divided into two groups randomly by lottery method. SD rats treated with collogen-chitosan (80:20) compound nanofiber membrane and oily gauzes on the defects were taken as the experimental group, while those treated with oily gauzes only as the control group. The defects of all rats were fixed with dry gauze bandage at the margin of outer packaging. RESULTS AND CONCLUSION: The wounds healed basically in the experimental group at 14 days after the repair; hematoxylin-eosin staining showed that the numbers of capillaries were reduced and the content of fibers was increased. While in the control group, wound healed irregularly, and the wound was larger than that in the experimental group; hematoxylin-eosin staining showed that there were more obvious dilated capillaries and a large number of inflammatory cells. The above results indicated that collagen-chitosan compound nanofiber membrane is superior to ordinary gauze in promoting the tissue repair and wound healing of skin defects. Related Articles | Metrics

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Preparation of nano-hydroxyapatite/aliphatic polyester-amide electrospun ultrafine fiber and its biocompatibility Deng Xia, Xia Xi, Chen Zhi-qing 2011, 15 (51):  9565-9569.  doi: 10.3969/j.issn.1673-8225.2011.51.016 Abstract ( 377 )   PDF (2141KB) ( 594 )   Save BACKGROUND: Bioactive ceramics can be introduced into ultrafine fibers by electrospinning method. The electrospun composite which simulates the structure and biological function of native extracellular matrix is a new branch in bone tissue engineering research.  OBJECTIVE: To prepare the nano-hydroxyapatite/aliphatic polyester-amide electrospun ultrafine fibers (nHA/PEA) and to evaluate the biocompatibility. METHODS: The nHA/PEA scaffold was prepared by electrospinning technology and characterized with X-ray diffraction, scanning electron microscope and energy-dispersive X-ray spectroscopy. Moreover, osteoblasts were cultured on the surface of nHA/PEA scaffold and the morphology of osteoblasts was investigated.  RESULTS AND CONCLUSION: Good cell adhesion and proliferation manner was observed on the fibrous scaffold, indicating that the cellular biocompatibility of the composite scaffold is preliminarily confirmed. It is expected that the electrospun nHA/PEA composite scaffold can be a potential biomimetic extracellular matrix biomaterial for bone tissue engineering. Related Articles | Metrics

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Effect of glucose on eliminating activity and adhesion of Staphylococcus epidermidis in Tupaia belangeri Xu Yu-shan, Wang Xi, Xu Yun-min, Lei Yu-jie, He Meng, Huang Yun-chao 2011, 15 (51):  9570-9574.  doi: 10.3969/j.issn.1673-8225.2011.51.017 Abstract ( 301 )   PDF (476KB) ( 387 )   Save BACKGROUND: High-concentration glucose can induce the formation of biofilms in Staphylococcus epidermidis. OBJECTIVE: To investigate the effect of high-concentration glucose on eliminating ability and adhesion of Staphylococcus epidermidis in Tupaia belangeri. METHODS: Tupaia belangeri models of hyperglycaemia (≥11.1 mmoL/L) were induced by intraperitoneal injection of Streptozocin. PVC catheters were inserted into the left femoral vein, and Staphylococcus epidermidis with or without formation of biofilms was inoculated into the catheters. RESULTS AND CONCLUSION: Following transfection of Staphylococcus epidermidis with formation of biofilms, there were higher rates of bacterial infection as well as higher bacterium colony number in the serum, heart, liver, kidney and pancreas of Tupai belangeri in hyperglycemia group (≥11.1 mmoL/L) as compared with the control group (P < 0.05). Detected by scanning electronic microscope, biofilm formation was remarkable in hyperglycemia group (≥11.1 mmoL/L) (P < 0.05). However, there was no formation of biofilms in hyperglycemia or control groups following transfection of Staphylococcus epidermidis without formation of biofilms. Hyperglycemia can induce the decreasing ability of eliminating bacteria and the increasing formation of biofilms on the surface of biomaterials transfected with Staphylococcus epidermidis. Related Articles | Metrics

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Biological security of nano-hydroxyapatite wisker and β-tricalcium phosphate composited bone substitute Hu Hong-tao, Xu Guo-hua, Liu Ji-chun, Jiang Yu-quan, Tang De-zhi, Zan Qing-feng, Ye Xiao-jian 2011, 15 (51):  9575-9578.  doi: 10.3969/j.issn.1673-8225.2011.51.018 Abstract ( 349 )   PDF (1667KB) ( 590 )   Save BACKGROUND: The technique, which reinforces porous calcium phosphate scaffold by nano hydroxylapatite whisker in situ, can enhance the strength and toughness of scaffold. OBJECTIVE: To evaluate the biocompatibility of the nano-hydroxyapatite wisker and β-tricalcium phosphate (nHAW/β-TCP) as tissue engineered vascular scaffold in vitro. METHODS: The acute systemic toxicity test: Totally 30 mice were divided into intravenous injection group, intra-abdominal injection group and control group. Mice in the three groups were injected by leaching liquor and saline respectively, then the general state of the mice was recorded at the 24, 48 and 72 hours. Test of hemolysis: Dissolution of red blood cells were observed in the mixed liquids of leaching liquor and diluted blood, and the A value was detected at optical density 545 nm then the hemolytic rare was calculated. The sensitization test: Sixteen guinea pigs were randomly divided into experimental group, negative control group and postive control group. Leaching liquor from nHAW/β-TCP, normal saline and 2% dinitrofluorobenzene were injected intradermally into each side of the backbone of each guinea pig. The erythema and edema were recorded at immediate, 24, 48, 72 hours. Test of cytotoxicity: The cells were cultured in the special L-DMEM that nHAW/β-TCP were dipped in and then general morphology of cells and cell activity were observed through microscope and CCK-8. RESULTS AND CONCLUSION: The acute systemic toxicity test: After intravenous and intra-abdominal injection of soaked of materal, there were no changes in breath, appetite, body weight of mice and no death. Test of hemolysis: The haemolytic rates of nHAW/β-TCP were less than 5% of international standard organization requirements, suggesting these materaials had no haematolysis effect. The sensitization test: No allergic reaction were found in guinea pig after endodermal injection. Test of cytotoxicity: Test of CCK-8 colormetry showed that the different densities leaching liquor had no cytotoxicity. nHAW/β-TCP does not cause acute whole body toxic reaction, haematolysis effect, allergic reaction and no cytotoxity. The materials have a good biocompatibility and meet the application requirements for tissue engineered vascular scaffold. Related Articles | Metrics

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Preparation and characterization of biocompatible Fe3O4@SiO2 nanoparticals Sun Peng-fei, Xie Ke-rong, Zhang Feng-wei, Jiao Zong-xian, Cao Xiang-rong 2011, 15 (51):  9579-9582.  doi: 10.3969/j.issn.1673-8225.2011.51.019 Abstract ( 525 )   PDF (1393KB) ( 607 )   Save BACKGROUND: Fe3O4 nanoparticles have good magnetic properties, SiO2 has good biocompatibility, and Fe3O4@SiO2 composite nanoparticles are expected to become the carrier of targeted therapy. OBJECTIVE: To prepare the biocompatible Fe3O4@SiO2 nanoparticles via a reverse microemulsion. METHODS: Firstly, hydrophobicity Fe3O4 nanoparticle modified oleic acid were prepared via a one-pot chemical coprecipitation with FeCl3•6H2O, FeCl2•4H2O, oleic acid and NH3•H2O. Subsequently, Fe3O4 nanoparticles stabilized with oleic acid were dispersed in cyclohexane, and then Triton-X100, hexylalcohol and H2O were added into the above solution and stirred to form stable reverse microemulsion; In the reverse microemulsion, using ammonia solution as a catalyst, tetraethyl orthosilicate (TEOS) was hydrolyzed and condensed to form Fe3O4@SiO2 compound nanoparticles. RESULTS AND CONCLUSION: ①The structure of Fe3O4 nanopartides prepared by a one-pot chemical coprecipitation was spinel, having a mean diameter of 3.5 nm; Through microemulsion methods, SiO2 were coated successfully on the surface of Fe3O4 nanopartides, and the uniform Fe3O4@SiO2 nanoparticles with a mean diameter of 40 nm were obtained. ②Although the saturation magnetization decreased after Fe3O4 nanopartides being coated, the coercivity of magnetic nanoparticles was near zero before and after encapsulation, revealing Fe3O4 and Fe3O4@SiO2 nanoparticles are of superparamagnetic properties.③After EA. hy926 cells were cultured accompanied with Fe3O4@SiO2 nanoparticals, the absorbance value of Fe3O4@SiO2 nanoparticles was markedly higher than that of control group (P < 0.05); At 48 and 72 hours of cell culture, no significant difference was found in the absorbance value between the two group (P > 0.05). The results showed Fe3O4@SiO2 compound nanoparticle using a reverse microemulsion is a kind of excellent biomaterial because of its stable, dispersive and superparamagnetic properties. Related Articles | Metrics

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Characterization and pharmacodynamic evaluation in vitro of 9-nitro-camptothecin-loaded folate-conjugated polymer micelles as tumor-targeted drug delivery system Xu Jin-jun, Han Xue, Ni Jing-man, Lu Wei-yue 2011, 15 (51):  9583-9586.  doi: 10.3969/j.issn.1673-8225.2011.51.020 Abstract ( 387 )   PDF (1191KB) ( 423 )   Save BACKGROUND: Recently, the increasing attention has been focused on amphiphilic polymer micelles as carriers for poorly soluble drugs and folate-mediated tumor targeted drug delivery system in the field of pharmaceutics. OBJECTIVE: To prepare 9-nitro-camptothecin (9-NC)-loaded folate-conjugated polymer micelles and investigate its characterization and antituomor activity in vitro. METHODS: The 9-NC-loaded folate-conjugated polymer micelles were prepared by film-hydration method; micelles size and drug loading capacity were determined by laser particle size analyzer and reversed-phase high-performance liquid chromatography respectively. The dialysis method was used in vitro release study. Pharmacodynamic evaluation in vitro was performed using cellular uptake and cell growth inhibition tests. RESULTS AND CONCLUSION: The diameter of the formulated 9-NC-loaded folate-conjugated micelles was about 24-26 nm. The encapsulation efficiency and drug loading capacity were 95.7% and 3.24% respectively. And the accumulative release percentage in 24 hours of drug-loaded micelles was about 90%. Besides, the folate-conjugated micelles had higher binding affinity with tumor cells and significantly stronger antitumor activity in vitro than normal micelles. The results indicated that the folate-conjugated micelles can provide a type of tumor-targeted nano drug delivery system with good prospect for insoluble drugs. Related Articles | Metrics

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Cellular compatibility of Fe3O4 nanoparticles Gong Jun-zuo, Tu Zhong-qi, Duan Hong, Zhou Shao-bing 2011, 15 (51):  9587-9592.  doi: 10.3969/j.issn.1673-8225.2011.51.021 Abstract ( 384 )   PDF (1806KB) ( 439 )   Save BACKGROUND: Whether as chemotherapy or as a medium of thermotherapy in malignant tumor, the effect and microstructure of Fe3O4 nanoparticles need further studies. OBJECTIVE: To analyze the cellular compatibility of Fe3O4 nanoparticles and to investigate the application and problems of Fe3O4 nanoparticles as drug carriers in the chemotherapy of malignant bone tumors. METHODS: According to the evaluate criteria and requirement of GB/T 16886. 5-2003 (Part V: cytotoxicity test in vitro, Biological Evaluation for Medical Instrument), the colloidal solution of Fe3O4 nanoparticles conjugated with cetrimonium bromide or polyethylene glycol or sodium oleate was co-cultured with osteosarcoma UMR-16 cells and human fibroblast cells, respectively, hence to assess the cytotoxicity characteristics. RESULTS AND CONCLUSION: According the criteria of GB/T16886.5-2003, Fe3O4 nanoparticles conjugated with sodium oleate had good cellular compatibility, whereas, the cellular compatibility of Fe3O4nanoparticles conjugated with cetrimonium bromide was poor, which were not considered as a drug carrier of chemotherapy drug using in clinical practice. Fe3O4 nanoparticles conjugated with polyethylene glycol had a certain cellular compatibility, which needed further studies used as drug carriers. Related Articles | Metrics

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Biocompatibility of pure titanium implant surface micro-arc oxidation coating Zhang Qiang, Wang Jian-ping, Hu Mei-ling, Meng Xiang-cai, Wang Jing 2011, 15 (51):  9593-9597.  doi: 10.3969/j.issn.1673-8225.2011.51.022 Abstract ( 332 )   PDF (1701KB) ( 425 )   Save BACKGROUND: Biological effects of various pure titanium implant surface micro-arc oxidation coatings are different. OBJECTIVE: To study the effects of three different micro-arc oxidation coating palatal implant titanium tablets on mouse osteoblast cell proliferation, alkaline phosphatase activity and beta 1-integrin gene expression level. METHODS: Using international common mice lines (MC3T3-E1), three different coated titanium pieces were used as influencing factors, pure titanium group as control group. MTT method and electron microscopic observation were conducted for cell adhesion and cell proliferation, PNPP was used for determination of alkaline phosphatase activity, RT-PCR method to detect beta 1-integrin expression in mouse osteoblasts. RESULTS AND CONCLUSION: The MTT value, alkaline phosphatase activity, beta 1-integrin gene expression level and electron microscopic observation showed calcium, phosphorus, magnesium, zinc coated titanium pieces of titanium dioxide had the best biocompatibility, titanium dioxide coating titanium containing calcium containing phosphorus salt was secondary, and titanium dioxide coated titanium slice was the worst. The results showed that mouse osteoblasts on the porous of calcium, phosphorus, magnesium, zinc coated titanium pieces had the best adhesion and proliferative abilities. Related Articles | Metrics

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Improvement of surface hydrophilicity of silastic/ferrous nanoparticle composites by air dielectric barrier glow discharge Wu Xing, Tian Hong-jun, Yin Shi-heng, Chen Jian-yun, Li Jun 2011, 15 (51):  9598-9602.  doi: 10.3969/j.issn.1673-8225.2011.51.023 Abstract ( 305 )   PDF (1366KB) ( 444 )   Save BACKGROUND: The inherent disadvantages of medical silicone rubber are the poor performance of X-ray imaging visibility and surface hydrophobicity. X-ray radiopacity of silicone rubber can be achieved by adding with ferrous nanoparticles as radiopaque agents; however, the changes of surface wettability of silicone rubber caused by nanoparticles are still unclear. It is envisaged to improve the hydrophily of those composites by surface treatment. OBJECTIVE: To investigate the surface wettability, hydrophilic modification and characterization of silastic/ferrous nanoparticle composites. METHODS: Both pre-prepared iron nanoparticle enhanced silicone rubber (INESR) and carbon-coated ferric nanoparticle enhanced silicone rubber (Fe/CESR) with formula ratios of 95:5, 90:10 and 85:15 were modified by air dielectric barrier glow discharge (ADBGD). The methyl vinyl silicone rubber (MVSR) was used as control. RESULTS AND CONCLUSION: Surface water contact angles of both INESR and Fe/CESR slightly decreased than that of MVSR, which indicated that their surface hydrophobic had no significant improvement. After treated by ADBGD, the water contact angles of both INESR with different formula ratios and Fe/CESR decreased (P < 0.05). Scanning electron microscope images showed that the specimen surfaces were etched and more rough, but no holes and cracks occurred. X-ray photoelectron spectroscope images displayed that the chemical composition changed on the treated surfaces, on which oxygen-contained groups significantly increased, while the carbon-based ones significantly reduced, silicon-based groups slightly increased, and nitrogen groups emerged. These results showed that nitrogen was combined with the surfaces. Hydrophlic surfaces of MVSR/ferric nanoparticle composites can be builded through ADBGB modification. Related Articles | Metrics

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In vivo distribution and metabolism of 188Re-iodized oil-carboxymethyl chitosan-nanoparticles in the S180 tumor-bearing mice Wang Hong-zhen, Jia Zheng-ping, Hao Yan-ming, Qian Rong-xun, Dong Qi-rong, Xu You-jia 2011, 15 (51):  9603-9607.  doi: 10.3969/j.issn.1673-8225.2011.51.024 Abstract ( 390 )   PDF (1351KB) ( 412 )   Save BACKGROUND: 188Re labeled radiopharmaceuticals in body occur Re nuclear cable off which will not cause serious radiation damage of the body. 188Re-iodized oil may become a kind of clinical application of drugs within the radiation treatment of cancer. OBJECTIVE: To study preparation of drug-loaded nano-carboxymethyl chitosan microspheres and in vivo distribution and metabolism in the S180 tumor-bearing mice. METHODS: 188Re-lipiodol was wrapped by carboxymethyl chitosan nanoparticles, the wrapped 188Re-lipiodol was injected into the mice bearing S180 sarcoma. Imaging of 188Re-iodized oil-carboxymethyl chitosan-nanoparticles in the tumor-bearing mice was observed by single photon emission computed tomography. RESULTS AND CONCLUSION: Labeling rate of 188Re-lipiodol which labeled by carboxymethyl chitosan-nanoparticles was (94.9±0.2)%. 188Re-iodized oil-carboxymethyl chitosan was distributed in liver and kidney; and the intake decreased with time in bone, muscle, small intestine and other organs. Radiation was not measured in brain, and the ratio increased with time, and imaging agent reached to peak at 6 to10 hours after injecting. It is indicated that wrapped effect of 188Re by carboxymethyl chitosan-nanoparticles package is well. 188Re-iodized oil-carboxymethyl chitosan-Nanoparticles in normal bone, muscle and  small intestine is almost not uptaked, but 188Re-iodized oil-carboxymethyl chitosan-Nanoparticles can uptake in sarcoma tissue within 48 hours and the radioactivity ratio of the tumor and spleen, stomach, intestine, femur, muscle and adipose tissue is high. Related Articles | Metrics

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Preparation and characterization of rifampicin-loaded poly(lactic-co-glycolic acid)  microspheres Ye Xiang-yang, Sun Xiang, Jia Hui-wen, Tang Li-xin, Zhao Yu-guo, Zhen Ping 2011, 15 (51):  9608-9612.  doi: 10.3969/j.issn.1673-8225.2011.51.025 Abstract ( 434 )   PDF (1398KB) ( 554 )   Save BACKGROUND: Some scholars prepared rifampicin-loaded poly (lactic-co-glycolic acid) (PLGA) microspheres with diameter of 10μm which was not suitable to be combined with calcium phosphate cement to prepare repair materials with good degradation. OBJECTIVE: To conduct the preparation of rifampicin-loaded PLGA microspheres with large size and to study the physicochemical characteristics of the microspheres and the characteristics of drug release in vitro. METHODS: Rifampicin-loaded microspheres of biodegradable PLGA were prepared using a double-emulsion solvent-extraction [(water-in-oil)-in-water] technique. The morphology of the microspheres was observed by scanning electron microscope and light microscope. Their average diameter and the span were measured. Their envelopment rate and drug-carried rate were determined by high performance liquid chromatography. Their release characteristics were studied in vitro by dissolution method. The curve of drug release in vitro was fitted and the equation of the curve was established. RESULTS AND CONCLUSION: Rifampicin-loaded PLGA microspheres presented complete globe, good dispersibility and no obviously aggregation. Their average diameter was (80.0±9.4) μm, drug-carried rate was (33.18±1.36)% and envelopment rate was (54.79±1.13)%. In vitro release property of the microspheres was good. In the burst release phase, the rate of drug release in vitro was (14.66±0.18)%, and rose to (18.09±0.45)% and (92.17±1.23)% 3 and 42 days later. Rifampicin-loaded PLGA microspheres have the characteristics of slowing antituberculosis drugs releasing. Related Articles | Metrics

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Effects of the xenotransplantation of microencapsulated olfactory bulb cell suspension on the expression of nuclear factor-kappa B in rats after spinal cord injury Wu Jiang-feng, Feng Gang, Shi Hui, Zhang Qiao-juan, Wang Xiao-lian 2011, 15 (51):  9613-9616.  doi: 10.3969/j.issn.1673-8225.2011.51.026 Abstract ( 471 )   PDF (1477KB) ( 372 )   Save BACKGROUND: Studies show that the microencapsulated heterogeneous olfactory bulb cells can reduce the immunological rejection and improve the functional recovery of spinal cord injury. However, the mechanism is unclear. OBJECTIVE: To investigate the effects of the xenotransplantation of microencapsulated olfactory bulb cells into rats on the expression and activity of nuclear factor-kappa B (NF-κB) after spinal cord injury. METHODS: Rabbits were used to prepare the heterogeneous olfactory bulb cell suspension. Sprague Dawley rats were randomly divided into four groups: the sham operation group, the microcapsule group, the cell group and the simple injury group. The rats in the later three groups were prepared for spinal cord hemisection model and transplanted with gelatin sponge sticking 10 μL microencapsulated olfactory bulb cell suspension, 10 μL microencapsulated olfactory bulb cell suspension, and 10 μL physiological saline respectively. The pathological changes of spinal tissues were observed by haematoxylin-eosin staining, and the expressions of NF-κB were observed by immunohistochemical staining.  RESULTS AND CONCLUSION: The expressions of NF-κB in the cytoplasm and cytoblast of neurons were increased in rats after spinal cord injury. The expression level reached a peak at 24 hours, gradually decreased after 3 days, and returned to the normal level after 7 days. The NF-κB+ cells in the microcapsule group were obviously fewer than that in the cell and simple injury groups (P < 0.05). The xenotransplantation of microencapsulated olfactory bulb cells can inhibit the expression and activity of NF-κB to mitigate the NF-κB modified inflammatory reaction after spinal cord injury. Related Articles | Metrics

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Galvanic corrosion between Ti implants and implant superstructure dental alloys Tang Ya, Wang Guo-ping 2011, 15 (51):  9617-9620.  doi: 10.3969/j.issn.1673-8225.2011.51.027 Abstract ( 340 )   PDF (310KB) ( 658 )   Save BACKGROUND: Most of the dental metal repair materials contacting Ti implants will cause galvanic corrosion and local environment with positive electricity on the implant interface, which directly affects the status of the tissues, especially bone resorption. OBJECTIVE: To evaluate the galvanic corrosion of commercially pure Ti (TA2 type) coupled with Au alloy, CoCr alloy, Ti alloy, and NiCr alloy in vitro. METHODS: Circuit of commercially pure Ti contacting with Au alloy, CoCr alloy, Ti alloy, and NiCr alloy was simulated in vitro in artificial saliva, and the common potential and galvanic current in 15 hours were recorded to draw current-time curves. RESULTS AND CONCLUSION: The galvanic current became stable after 8 hours of contacting. The galvanic current was the greatest in Ti/Au, followed by Ti/CoCr, Ti/Ti alloy, and then Ti/NiCr. Results indicated that the galvanic corrosion of the couple of Ti and Au alloy is the lowest. Au alloy is the most suitable material for implant superstructure. The galvanic corrosion of the couple of Ti and NiCr alloy is the highest, so NiCr alloy is not acceptable for implant superstructure. Related Articles | Metrics

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Effect of different manufacture techniques on the colour of gold alloy-porcelain crown’s incisal ridge Liu Li, Gu Wei-ping 2011, 15 (51):  9621-9624.  doi: 10.3969/j.issn.1673-8225.2011.51.028 Abstract ( 316 )   PDF (1131KB) ( 386 )   Save BACKGROUND: The color, neck edge staining and the edge microleakage of high gold alloy-porcelain crowns is better than that of other alloy-porcelain crowns. However, many factors can influence the color of the restoration, and the manufacture has a greater impact on the aesthetic effect of all-ceramic crown restorations.  OBJECTIVE: To study the effect of sintering process following body cut-back on the color of anterior gold alloy-porcelain crown’s incisal ridge. METHODS: Gold alloy-porcelain crowns samples of 2M2 shade were fabricated by the DeguDent porcelain system. After body cut-back, samples of experimental group were sintered first then spread with enamel layer and sintered again, while the control group were directly spread with enamel layer and sintered. Compared with the 2M2 shade guide, the L＊, a＊, b＊ values were measured and color difference (△E) of two groups were obtained. The color changes were analyzed as well. RESULTS AND CONCLUSION: The L＊ value of experimental group was the highest, and there were no significant difference to compare with shade guide (P > 0.05); The a＊ value of experimental group was higher than that of control group and shade guide obviously (P < 0.05); The b＊ value of shade guide was the highest and there were no significant difference to compare with other two groups (P > 0.05). The color difference between experimental group and shade guide was △E=0.39<1.5 and the color difference between control group and shade guide was △E=3.08>1.5, and the color difference between experimental group and control group was △E=3.88. The fabrication process of sintering following body cut-back can present better color of anterior gold alloy-porcelain crown’s incisal ridge. The color is much more similar to natural teeth. Related Articles | Metrics

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Bending mechanical properties of the thermoplastic materials Zou Jian-ming, Zhu Fang-yong, Chen Yu-hua 2011, 15 (51):  9625-9628.  doi: 10.3969/j.issn.1673-8225.2011.51.029 Abstract ( 306 )   PDF (1022KB) ( 459 )   Save BACKGROUND: With the development of the thermoplastic technology, the thermoplastic materials modified appliance becomes being used in orthodontics. OBJECTIVE: To observe the differences of bending mechanical properties among the thermoplastic materials with different thicknesses. METHODS: The experiment was performed at room temperature of 25 ℃, and the thermoplastic material Simona with thickness of 1.0 mm, 1.2 mm, 1.5 mm, and 2.0 mm were involved, 10 pieces of each type. The Simona were tested by universal testing machine before treatment (area was 40 mm×25 mm) and after formation with different rectangle moulds (volume was 50 mm×  10 mm×5 mm) in order to compare their bending mechanical properties. RESULTS ANS CONCLUSION: The modulus, yield strength and the maximum stress of the Simona 2.0 mm were the highest with different treatment (P < 0.05), and there was no fracture. The materials with different thicknesses and shapes have different mechanical properties. The Simona 2.0 mm is suitable for functional appliance base on its high mechanical properties. Related Articles | Metrics

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Modification experiment of poly-L-lactic acid for biodegradable stent Chen Bao-ai, Gu Xue-lian 2011, 15 (51):  9629-9632.  doi: 10.3969/j.issn.1673-8225.2011.51.030 Abstract ( 361 )   PDF (1415KB) ( 388 )   Save BACKGROUND: Current, metal stents mostly used in clinic will permanently stay in the human body, and they can provide potentially risks to human body. OBJECTIVE: To observe the effects of modification on poly-L-lactic acid (PLLA) and the feasibility of preparation of biodegradable stents with modified materials.  METHODS: PLLA, polylactic acid/polycaprolactone (PLCL-J) and PLLA/polycaprolactone (PLCL-H) films were prepared by solution method with the modification ratio of PLLA/polycaprolactone of 95/05. Comparative observation of changes in mechanical property, intrinsic viscosity and mass loss, and changes in surface morphology of PLLA, PLCL-H and PLCL-J was performed with film degradation test.  RESULTS AND CONCLUSION: Mechanical property test showed that the brittleness of PLLA materials was significantly increased after 3 months. The materials were easy to break, and this was a major defect in preparing stents; the mechanical properties of PLCL-J lost too fast, its yield completely disappeared at 3 weeks, its tensile strength began to decline sharply at 4 weeks, and its mechanical property completely disappeared at 10 weeks; PLCL-J material not only had high initial breaking elongation, but also kept a high flexibility during the degradation process. Intrinsic viscosity detection and surface morphology observation showed that PLCL-J material was not suitable for stent preparation based on its fast degradation rate, while the degradation rates of PLLA and PLCL-H materials were uniform, and the degradation rate of PLCL-H material was increased compared with PLLA material. The blending material of PLLA and polycaprolactone with modification ratio of 95/05 can not only ensure the mechanical strength of stents, but also increase breaking elongation of stents, and these make it can be used as a new type of material for preparation of biodegradable stents through an increase in plasticization and degradation rate of the material. Related Articles | Metrics

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Synthesis of cholesterol-modified pullulan and its self-assembled behavior Tao Xiao-jun, Tang Hong-bo, Ling Kai, Wang Yan, Zhang Qi-qing 2011, 15 (51):  9633-9636.  doi: 10.3969/j.issn.1673-8225.2011.51.031 Abstract ( 323 )   PDF (1297KB) ( 372 )   Save BACKGROUND: Carboxyl group is introduced to hydrophobically modify polysaccharides, which could self-aggregate to nanoparticles with some surface charges, and it is beneficial to improving their stability and performing the good properties as a drug carrier. OBJECTIVE: To synthesis cholesterol hydrophobically modified carboxyethyl pullulan (CHS-CEP), and to study their self-aggregated behavior in aqueous solution and characteristics of CHS-CEP nanoparticles. METHODS: Acrylic acid and pullulan polysaccharides could form carboxyethyl pullulan (CEP) by additive reaction. Objective material could be obtained by catalyzing CEP and CSN. The synthesized material was characterized using proton magnetic resonance (1H-NMR). The nanoparticles were prepared by dialysis to characterize the morphology, size and zeta potential by transmission electron microscopy (TEM) and dynamic laser scattering (DLS). RESULTS AND COUCLUSION: By 1H-NMR analysis, it showed that CHS-CEP was successfully synthesized and this material could self-aggregate to form nanoparticles with opalescence. The diameter of CHS-CEP nanoparticles was about 148.6 nm and their zeta potential was -19.9 mV. They could act as drug carrier due to many excellent properties such as a good dispersity in aqueous solution, even distribution and long-term stability. Related Articles | Metrics

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Application of moiré interferometry method in measurement of displacement of metal-porcelain restorations Mi Hong-lin 2011, 15 (51):  9637-9640.  doi: 10.3969/j.issn.1673-8225.2011.51.032 Abstract ( 425 )   PDF (544KB) ( 412 )   Save BACKGROUND: Moiré interferometry method which belongs to the range of experiment mechanics is a modern photo-mechanics test technique. On the other hand, metal-porcelain restorations characterized as beautiful, compatible and stable properties are widely used in oral medicine domain. Moiré interferometry technique is applied in the oral restoration and some mechanics data can be obtained. It can be realized in discipline complementation and interaction between mechanics and bio-medicine engineering. OBJECTIVE: To introduce the moiré interferometry technique in details, and to study the displacement of metal-porcelain restorations under different loads by using the moiré interferometry technique as it is found that porcelains often flake off from the base of restorations in oral clinic. METHODS: The horizontal and vertical displacement of metal-porcelain restorations were measured by using the moiré interferometry method which is sensitive and easy to operate, and suitable for in-plane displacement measurement. The displacement was shown in the form of interferometry patterns. RESULTS and CONCLUSION: The interferometry patterns which represented the in-plane displacement of specimens were obtained and the displacement was linearly related with the loading changes. Moiré interferometry method can be used in measuring the displacement of restorations. Operation is simple and results are shown by interferometry patterns. Related Articles | Metrics

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Application and role of chitosan in tumor radiotherapy Liu Bin, Zhang Bao-ping, Zhang Hong, Li Zhi-ge, Pan Xiao-jing 2011, 15 (51):  9643-9647.  doi: 10.3969/j.issn.1673-8225.2011.51.034 Abstract ( 427 )   PDF (1906KB) ( 379 )   Save BACKGROUND: Currently, the improvement in the effect of radiation therapy by sensitizer is one of the hotspot in tumor radiotherapy field. Chitosan has a good biocompatibility and biodegradability, and can be used as a kind of multi-functional sensitizer to apply in radiotherapy for synergy therapy. OBJECTIVE: To summarize the research status, application principle and development of chitosan applied in tumor radiotherapy at home and abroad recently. METHODS: A computer-based online search of literatures related to biological effect of chitosan published between 1995 and 2009 in CNKI database, VIP database, Wanfang database, China Biology Medicine disc, Elsevier database and PubMed database was performed. Totally 194 articles in Chinese and in English were collected. 48 of them were chosen to summarize according to inclusion criteria. The anti-tumor effect, radiation sensitizing effect and protective effect on the normal tissues of chitosan were analyzed to summarize its radiosensitivity. RESULTS AND CONCLUSION: Chitosan has been proved to be a kind of multi-functional sensitizer for radiotherapy by the experiments of the anti-tumor effect, radiation sensitizing effect and protective effect on the normal tissues of chitosan. Related Articles | Metrics

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Biocompatibility and clinical application of silk fibroin Zhao Guang-jian, Zhao Yao 2011, 15 (51):  9648-9650.  doi: 10.3969/j.issn.1673-8225.2011.51.035 Abstract ( 289 )   PDF (1155KB) ( 399 )   Save BACKGROUND: Repair and reconstruction after skin injury are difficult. It is an ideal approach to repair defects using skin cells to restore tissue and organ appearance and function. However, this problem remains resolving in clinic. OBJECTIVE: To summarize biocompatibility and application advances in silk fibroin to search the optimal artificial skin. METHODS: A computer-based online search of CNKI and PubMed database was performed for articles related to biocompatibility of silk fibroin and its application in tissue engineered skin and biomaterials, with key words “silk fibroin; biocompatibility; tissue engineering; biological materials; application” in Chinese and English. Articles published recently in authoritative journals regarding biocompatibility and application of silk fibroin were selected. 215 articles were collected and 22 were included. RESULTS AND CONCLUSION: Understanding of properties and application of silk fibroin can benefit repair and reconstruction after skin injury. Repairing defects using skin cells to restore tissue and organ appearance and function exhibits mechanical performance and physiochemical properties, as well as biocompatibility. Moreover, it can promote epidermic cell growth. However, some issues need to resolve for clinical treatment. Related Articles | Metrics

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Application of tracheal prosthesis and tracheal scaffold Zhang Ru-feng, Chen Li-ping 2011, 15 (51):  9651-9654.  doi: 10.3969/j.issn.1673-8225.2011.51.036 Abstract ( 361 )   PDF (1459KB) ( 813 )   Save BACKGROUND: Central airway stenosis is often treated by surgery in the past. However, some patients are not qualified for surgery, and the operation scar may lead to airway restenosis. Therefore, stent implantation becomes one of the most important means to cure central airway stenosis. OBJECTIVE: To summarize the clinical application progress of tracheal prosthesis and tracheal scaffold. METHODS: An online search of PubMed database and CNKI was performed by title-and-summary search method for relevant articles, using keywords of “tissue engineering scaffolds, artificial trachea, trachea scaffolds” in English and Chinese respectively. A total of 22 articles were retained according to inclusion criteria. RESULTS AND CONCLUSION: With the popularization and development of tissue engineering in recent years, research on biological tissue-engineered trachea achieved some progress. At present, tissue-engineered trachea similar to autologous trachea can be constructed using chondrocytes or bone marrow stromal cells as seed cells. Composite tissue-engineered trachea with tracheal mucosal epithelium can be constructed using chondrocytes and epithelial cells. But the long-term activities and psychological functions of tissue-engineered tracheas transplanted in vivo remain to be seen in further experiments. Related Articles | Metrics

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Value of bone repair materials in the treatment of fractures and bone defects Zhai Xi 2011, 15 (51):  9655-9658.  doi: 10.3969/j.issn.1673-8225.2011.51.037 Abstract ( 294 )   PDF (1569KB) ( 804 )   Save BACKGROUND: Using artificial bone materials as bone graft substitutes to repair bone defects is one of the important research subjects in medical and biomaterial fields. OBJECTIVE: To summarize the recent application status of bone repair materials in the treatment of fracture and bone defect. METHODS: An online search of VIP database was performed for articles related to the application of bone repair materials in the treatment of fractures and bone defects published between January 1998 and October 2009, with the key words of “fracture”, “bone repair”, “prosthetic replacement” and “material”. Articles with a high level of correlation were included. Repetitive studies were excluded. The collected articles were analyzed. The references of each article were checked. A total of 26 articles were retained in the end. RESULTS AND CONCLUSION: The recent researches on bone repair materials are focused on nano-hydroxyapatite/ polyamides-66, demineralized bone matrix, calcium sulfate particles and nanometer crystal hydroxyapatite/ collagen composite. Nano tissue-engineered bone material is a new kind of material using nanotechnology. It is based on nano structured units or with the magnitude of 1 to 100 nm. Experiments on animals confirm that the developed nano-hydroxyapatite/ collagen have better biocompatibility and bioactivity than regular hydroxyapatite. It promotes and accelerates bone wound healing. Related Articles | Metrics

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Biodegradable materials in clinical ophthalmology Zhao Ling 2011, 15 (51):  9659-9662.  doi: 10.3969/j.issn.1673-8225.2011.51.038 Abstract ( 354 )   PDF (1519KB) ( 535 )   Save BACKGROUND: Tissue-engineered materials are rarely applied in ophthalmology, especially in ocular surface reconstruction. Most materials are still in animal testing, and there are many urgent problems. OBJECTIVE: To assess the application of biodegradable materials in ophthalmology in order to find the rational ophthalmic materials. METHODS: A computer-based search of Wanfang (http://www.wanfangdata.com.cn/) and PubMed (http://www.ncbi.nlm.nih.gov/ pubmed) was performed to retrieve articles published 1999-01/2009-12 addressing the clinical application of biodegradable materials in ophthalmology. The key words were “tissue engineering, ophthalmology, biomaterial” in Chinese and English. Repetitive articles and Meta analyses were excluded, and finally 17 articles were included in result analysis. RESULTS AND CONCLUSION: Biodegradable materials functioned as biological barriers can promote epithelial cell growth, inhibit fibroblast growth, reduce collagen synthesis, reduce surgical wound bleeding so as to prevent adhesion, as well as have antibacterial function, enhance immunity, and promote wound healing. Therefore, the biodegradable materials can be used alone to treat postoperative inflammation and fibrous proliferative lesions, and they can be also applied for eye surgery. With the further integration of biomedicine and materials science, the application of biodegradable materials is increasingly prevalent in ophthalmic research. It is conceivable that once the biodegradable materials are industrialized, they will have very broad application prospects in biomedicine. Related Articles | Metrics

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Clinical advanced research of biological materials for repairing retinal detachment Jin Dong, Zhang Guo-zhong 2011, 15 (51):  9663-9666.  doi: 10.3969/j.issn.1673-8225.2011.51.039 Abstract ( 471 )   PDF (1620KB) ( 504 )   Save BACKGROUND: Designing various biomaterials for intraocular lens can provide better image quality and myopia/hyperopia function for retinal detachment. OBJECTIVE: To evaluate the effectiveness of different biomaterials in the repair after retinal detachment. METHODS: A computer-based online retrieval of Wanfang database from January 1999 to December 2009 was performed for studies regarding the retinal detachment, with key words of “retinal detachment; materials” in Chinese. RESULTS AND CONCLUSION: Many studies have investigated the clinical reports of biomaterials in the treatment of retinal detachment. With the application of micro-surgery in ophthalmology and the development of micro-surgical instruments in recent 20 years, the materials and technique for the production of intraocular lens have been greatly improved, cataract treatment combined with posterior chamber intraocular lens implantation has become widely used to regain the eyesight, considering as an important advanced progress of ophthalmology. The new folding, injectable materials such as acrylic ester and silicone gel, can reduce the immune rejection and complications such as posterior capsule opacification, reported as many studies. There are many material candidates for retinal detachment, we should make a choice according to the actual situation of patients, thus achieving the satisfactory results. Related Articles | Metrics

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Biological coating materials of intravascular stent surface and intravascular restenosis Xu Hai-feng 2011, 15 (51):  9667-9670.  doi: 10.3969/j.issn.1673-8225.2011.51.040 Abstract ( 307 )   PDF (1467KB) ( 389 )   Save BACKGROUND: Cardiopathy is one of the most important causes of disease which threaten human health. Every year, about  15 million patients with coronary heart disease around the world need percutaneous puncture coronary angioplasty therapy. But about 10% of them develop acute and subacute artery occlusion; 20% to 50% of them develop intravascular restenosis in six months. Restenosis has already become one of the most critical factors that restrict the development of percutaneous puncture coronary angioplasty. OBJECTIVE: To discuss the long-term clinical effects of drug-eluting stent in stent restenosis. METHODS: An online search of Chinese Journal Full-text Database was performed for articles with the key words of “drug-eluting stent”, “obstruction” and “restenosis”. Meta analysis and repetitive studies were excluded. A total of 25 articles were retained, involving the progress of stent placement, the prevention of stent stenosis and the effects of different stent types, materials on recanalizing rate and recanalizing time. RESULTS AND CONCLUSION: Using drug-loading technology and controlled drug release technology, the drug-eluting stent mechanically support the lesion vessels; in the mean time, drugs that inhibit the proliferation of vascular smooth muscle cells release slowly from the stent surface, act on the vascular walls touching the stent. Thereby, problems of elastic recoil and intima hyperplasia are solved. With the improvement and innovation of interventional equipments for coronary, drug-eluting stent technology is maturing and developing. The design concept of the emerging drug-eluting stent technology is based on drug screening and controlled drug release system. It is believed that drug-eluting stents will be used in a wide range of complex vascular lesions (especially venous diseases and vascular injuries) and other organ diseases. Related Articles | Metrics

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Advances in various biomaterials for hemostasis and clinical application of compound materials for hemostasis Li Xue-jun, Sun Yuan-yuan 2011, 15 (51):  9671-9674.  doi: 10.3969/j.issn.1673-8225.2011.51.041 Abstract ( 581 )   PDF (1750KB) ( 1210 )   Save BACKGROUND: With development of biomedical polymers, such as cellulose, chitin, polyvinyl alcohol and collagen, the application of materials for hemostasis has advanced. OBJECTIVE: To summarize advances in dressing materials for hemostasis and evaluate their clinical values. METHODS: A computer-based online search of Wanfang and PubMed database was performed for articles regarding medical polymer dressing materials for hemostasis published between January 1996 and December 2010 with key words “materials for hemostasis, fibrin, polymers, collagen, gelatin sponge” in Chinese or “biological; occlude the flow of blood; gelatin sponge; fibrae sanguis”. Articles published recently in authoritative journals of the same domain were selected. 126 articles were collected, and 28 were included for review analysis. RESULTS AND CONCLUSION: In recently, absorbable materials for hemostasis, including chitosan, fibrin glue, absorbable gelatin sponge, microfiber collagen, alginate and hydrocolloid. Different materials have various mechanisms and hemostasis effects. Comparisons in the effects of various compound materials for hemostasis showed that the pathways and mechanisms of different materials for hemostasis require further investigation to develop more effective and convenient materials for hemostasis. Related Articles | Metrics

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Applications of digital shaping titanium armor plate in skull defect repair Bian Ai-miao 2011, 15 (51):  9675-9678.  doi: 10.3969/j.issn.1673-8225.2011.51.042 Abstract ( 374 )   PDF (1773KB) ( 448 )   Save BACKGROUND: A wide range of materials with varying repair effects are applicated in skull repair. How to perfecting the skull defect repair and how to choose the right repair materials are the research hotspots for researchers in the world. OBJECTIVE: To explore the clinical application of digital three-dimensional shaping titanium armor plate in skull defect repair. METHODS: An online search of Medline database (2000/2011-06) and CNKI was performed for relevant articles, using keywords of “tissue engineering, craniocerebral trauma, CAD/CAM, titanium armor plate” in English and Chinese, respectively. Articles with high pertinence published in recent years were included in the study. As to the identical field, the articles published recently or in authoritative magazines were selected. Outdated documents and articles repetitive to conventional materials and methods for skull defect repair were excluded. Articles involved the latest research progress and clinical application with practice value were thoroughly analyzed and summarized. RESULTS AND CONCLUSION: A total of 236 articles were collected in the initial search, and 27 of them were retained. Conventional repair methods for skull defect exposed many problems, while titanium armor plate, as skull repair materials widely used in clinic recently, has many advantages. Especially with the wide application of digital technology, repair material which is well match with the defect can be manufactured based on head CT scan, simulation of defect skull shape and curvature by three-dimensional reconstruction, individual design of titanium patch for defect skull. Patients’ head shape reinstate anatomically after skull defect repair. Satisfactory effects are received in appearance and compatibility. Related Articles | Metrics

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Long-term clinical effect of artificial mesh application in the repair of abdominal malignant tumor in vivo Wang Gang-cheng, Liu Lin-bo, Ren Ying-kun, Zhang Xue-lei, Han Guang-sen 2011, 15 (51):  9679-9682.  doi: 10.3969/j.issn.1673-8225.2011.51.043 Abstract ( 348 )   PDF (1433KB) ( 335 )   Save BACKGROUND: Artificial mesh is easily adhesive with the abdominal bowel and even lead to intestinal obstruction. This may bring great difficulty to re-operation of the recurrence tumor. OBJECTIVE: To evaluate the long-term clinical effect of artificial mesh on repairing abdominal wall defect after abdominal malignant tumor resection. METHODS: Twenty-six abdominal wall defect patients resulted in abdominal malignant tumor resections were involved for retrospective analysis. Sixteen of them in the artificial mesh group were repaired by polypropylene mesh, expanded polytetrafluoroethylene mesh, and composite mesh. Others repaired by suturing subcutaneous tissue and skin without artificial meshes were taken as suture group. The occurrences of lateral ventral syndrome, bowel obstruction and re-operation of these two groups were analyzed. RESULTS AND CONCLUSION: During the 2-10 years follow-up, none of the artificial mesh group got lateral ventral syndrome. On the contrary, all cases in the suture group got lateral ventral syndrome. Six cases (3 of polypropylene mesh, 1 of expanded polytetrafluoroethylene mesh, and 2 of composite mesh) of the former group got trouble with bowel obstruction and 7 cases (4 of polypropylene mesh, 1 of expanded polytetrafluoroethylene mesh, and 2 of composite mesh) underwent re-operation because of tumor recurrence. In the re-operations, meshes were greatly adhesive with the bowels, which brought trouble to entering abdomen. Four cases of the latter group underwent re-operation because of tumor recurrence, and the re-operation went on well for the adhesion was not serious. Using artificial mesh to repair the abdominal wall defect after abdominal malignant tumor resection can efficiently prevent the occurrence of lateral ventral syndrome. However, it also can lead to abdominal adhesions, which may bring trouble to re-operation when tumor reoccurs. Related Articles | Metrics

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Comparison of digital three-dimensional reconstructed titanium mesh and manual reconstructed titanium mesh in cranioplasty Liu Hui-quan, Chen Zi-xiang, Liu Xing-jun, Wang Jian 2011, 15 (51):  9683-9686.  doi: 10.3969/j.issn.1673-8225.2011.51.044 Abstract ( 253 )   PDF (1523KB) ( 441 )   Save BACKGROUND: Digital three-dimensional reconstructed titanium mesh can achieve the best physiologic and anatomical molding in skull defect cranioplasty. OBJECTIVE: To compare the clinical effects of digital three-dimensional reconstructed titanium mesh and manual reconstructed titanium mesh for cranioplasty of skull defect. METHODS: A total of 84 patients with skull defect were divided into two groups randomly. Forty-three patients were repaired with manual reconstructed titanium mesh, and 41 patients with digital three-dimensional reconstructed titanium mesh. Titanium mesh was made into individual skull prosthetic replacement by computer three-dimensional reconstruction. RESULTS AND CONCLUSION: In the digital three-dimensional reconstructed group, the operation time was shorter and the incidence rate of complication was fewer, while the degree of molding satisfaction was significantly higher than the manual reconstructed group (P < 0.05). Biocompatibility was better but the cost of mesh was higher than the manual reconstructed group. Results show that the digital three-dimensional reconstructed titanium mesh can save surgical duration, have less postoperative complications, have high satisfaction, and cost more money in cranioplasty. Related Articles | Metrics

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Application of bone morphogenetic protein-2 combined with granulo-β-tricalcium phosphate in alveolar cleft reconstruction Wang Si-ming, Sun Yuan 2011, 15 (51):  9687-9690.  doi: 10.3969/j.issn.1673-8225.2011.51.045 Abstract ( 359 )   PDF (1393KB) ( 468 )   Save BACKGROUND: Repair of alveolar cleft is an important part of treatment of cleft lip and palate. Composite artificial bone prepared by optimal combination based on the carrier of artificial bone has a highly osteoinductive activity and can greatly improve the treatment effect in repair of bone defects in clinic. OBJECTIVE: To evaluate the combined effects of bone morphogenetic protein-2 (BMP-2) and β–tricalcium phosphate (β-TCP) in alveolar cleft reconstruction. METHODS: Twenty-four alveolar cleft patients from Department of Stomatology, Lianyungang Second People’s Hospital were divided into experimental group and control group randomly. The experimental group was repaired with BMP-2/β-TCP. The control group was repaired with autogenous iliac cancellous bone. RESULTS AND CONCLUSION: Incisions in both groups were with primary healing and without implant extrusion. All of the patients were followed-up for 3-6 months. Three months after surgery, bone concrescence was seen on X-ray. Part of the artificial bone was replaced by autologous bone and the bone resorption was not obvious in the experimental group after 1 year of surgery, while the bone resorption in the control group was obvious. Enemar grading standard showed that the efficacy rates of grade Ⅰ in the experimental group and control group were 84% and 17% respectively, and the difference was significant (P < 0.05). It is indicated that the granulo-β-TCP/BMP-2 has the advantages of an accurate shape recovery and a low repair trauma in alveolar cleft reconstruction; the implant has a good biocompatibility, osteocondutibility and degradability, so as can be completely replaced by autologous bone and well used in alveolar cleft reconstruction. Related Articles | Metrics