Table of Content

18 January 2019, Volume 23 Issue 2 Previous Issue    Next Issue

For Selected:

Download Citations EndNote Reference Manager ProCite BibTeX RefWorks

Toggle Thumbnails

Select

Titanium-copper alloys with nanotubular coatings increase antibacterial abilities and osteoblast functions Zhang Lei, Zhang Hangzhou, Allieu Kamara 2019, 23 (2):  165-171.  doi: 10.3969/j.issn.2095-4344.0692 Abstract ( 285 )   PDF (727KB) ( 117 )   Save BACKGROUND: Implant infection is still a serious adverse event after orthopedic surgery. Copper (Cu) is a currently known metal that has antibacterial properties. Studies have shown that nanostructured metals prepared by nanotechnology can promote the adhesion, proliferation and osseointegration of osteoblasts in vivo. Staphylococcus aureus, the most common implant-related pathogen in clinical practice, is used to test antibacterial properties of titanium-copper alloy nanotubes. OBJECTIVE: To observe the effect of antibacterial properties of titanium-copper alloy nanotubes on the function of osteoblasts. METHODS: Mouse osteoblasts (MC-3T3-E1) were co-cultured with different materials, including pure titanium, titanium dioxide nanotubes, and titanium-copper alloy nanotubes with a copper content of 5%, for 6 and 24 hours. Cell adhesion and proliferation on the scaffold were observed. Antibacterial properties of titanium-copper alloy nanotubes, titanium dioxide nanotubes and pure titanium were compared. Biocompatibility of osteoblasts co-cultured on different material surfaces was detected, and antibacterial properties of different materials to Staphylococcus aureus were measured. RESULTS AND CONCLUSION: (1) Under scanning electron microscope, we observed good cell adhesion onto the surface of titanium dioxide nanotubes and titanium-copper alloy nanotubes, and the adherent cells had good cell morphology and regular arrangement. Cell proliferation of osteoblasts was better in the two nanotube groups than in the pure titanium group, but there was no significant difference between the titanium-copper alloy nanotube and titanium dioxide nanotube groups. (2) Higher bacteria counts were observed in the pure titanium and titanium dioxide nanotube groups than the titanium-copper alloy nanotube group. In conclusion, the titanium-copper alloy nanotubes have good inhibitory effect on bacterial adhesion, and have no influence on the bio-functions of osteoblasts.  中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Kummell disease: bone cement leakage during kyphoplasty Lu Wenchao, Wang Yupeng, Zhan Chuan 2019, 23 (2):  172-177.  doi: 10.3969/j.issn.2095-4344.0691 Abstract ( 504 )   PDF (603KB) ( 145 )   Save BACKGROUND: Kummell disease has certain correlation with osteoporotic vertebral fracture morphology and magnetic resonance imaging manifestations; however, few reports focus on the correlation between the severity of osteoporotic vertebral fracture and Kummell disease. OBJECTIVE: To analyze the correlation between Genant classification and Kummell disease in osteoporotic vertebral fractures, and to investigate the prevention and treatment of bone cement complications during percutaneous kyphoplasty for the treatment of Kummell disease. METHODS: Eighty-four elderly patients with osteoporotic vertebral compression fractures undergoing conservative treatment were selected. A total of 109 cases of vertebral bodies were involved. The T9-L4 vertebral body segments were involved in fractures. Fracture vertebral bodies were graded according to the Genant semi-quantitative assessment method (48 cases of mild malformation, 34 cases of moderate malformation, and 27 cases of severe malformation). After 6 months of conservative treatment, they were referred again. MRI imaging was performed to observe the occurrence of fractured vertebral body segmental cleft, to determine Kummell disease, and to assess the severity of disease (type I, II, III). For patients diagnosed with Kummell disease, kyphoplasty with bone cement was performed. The bone cement leakage was observed by X-ray. The pain, lumbar back function, height of anterior vertebral body and recovery of Cobb angle were observed after treatment. RESULTS AND CONCLUSION: (1) Of the 184 patients, intervertebral vacuum cleft sign was found in 23 cases (mostly in the T12 segment), and its incidence with mild, moderate, and severe malformations was 3%, 6%, and 12%, respectively. (2) After kyphoplasty with bone cement, 1 case of intervertebral disc leakage and 1 case of paravertebral leakage were found in the 6 cases of type I Kummell disease; 2 cases of cemented intervertebral disc leakage and 1 case of paravertebral leakage were found in the 14 cases of type II Kummell disease; and 1 case of cemented intervertebral disc leakage and 1 case of paravertebral leakage were found in the 3 cases of type III Kummell disease. There was no difference in the incidence of intervertebral disc leakage and paravertebral leakage between different subtypes. (3) The pain, lumbar back function, anterior vertebral height and Cobb angle were significantly improved in 23 patients with Kummell disease at the 6-month follow-up (P < 0.05). These results reveal that with the increasing of Genant grading, the incidence of Kummell disease increases. The rate of bone cement leakage after kyphoplasty for Kummell disease is at a high level, and intradiscal leakage tends to occur in most cases.  中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Three-dimensional finite element analysis of dental implant combined with residual tooth after hemisection under dynamic loads Zou Yingnan, Wang Yibo, Ding Chao, Pan Xinyu, Shi Jiuhui 2019, 23 (2):  178-183.  doi: 10.3969/j.issn.2095-4344.1504 Abstract ( 283 )   PDF (848KB) ( 184 )   Save BACKGROUND: The traditional treatment options after tooth hemisection are harmful to the abutment tooth. In recent years, with the development of oral implantology technique, combination of dental implant and residual tooth after hemisection provides a new way for mandibular molar restoration. OBJECTIVE: To compare the biomechanical properties of implant-residual tooth supported prosthesis, single implant and double implants in the mandibular molar restoration under dynamic loads. METHODS: Three-dimensional finite element models in which implant-residual tooth supported prosthesis, single implant and double implants were used to restore the mandibular first molar were established. A dynamic load of 0.875 s as a chewing cycle was applied on the restorations. Stress distributions of the implant, natural tooth and its surrounding bone tissues during the chewing cycle were analyzed. RESULTS AND CONCLUSION: (1) At different stages of one chewing cycle, the stresses of the implant, cortical bone and cancellous bone changed as follows: lingual-buccal loading > buccal-lingual loading > vertical loading; the stress of the natural tooth changed as follows: vertical loading > buccal-lingual loading > lingual-buccal loading. (2) At the end of the chewing cycle, the stress distribution of the implant, cortical bone and cancellous bone was ranked as follows: the implant-residual tooth model > double-implant model > single-implant model. (3) The safety factor at the implant-abutment junction was lowest, which was the most dangerous area of fatigue failure. The implant-residual tooth supported prosthesis had a service life enough to bear chewing pressures in the oral cavity, but not developing fatigue fracture. All these results suggest that dental implant combined with residual tooth after hemisection follows the principle of bionics and plays an important role in the regulation of occlusal force, which is an acceptable treatment from a biomechanical perspective.   中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Polyetheretherketone/biphasic bioceramic composite coated with vascular endothelial growth factor to repair mandibular defects Yu Hedong, Chen Yongji, Mao Min, Chen Shaojuan, Ni Xiaobing, Leng Weidong, Luo Jie 2019, 23 (2):  184-189.  doi: 10.3969/j.issn.2095-4344.1505 Abstract ( 268 )   PDF (964KB) ( 114 )   Save BACKGROUND: Previous studies have confirmed that polyetheretherketone/biphasic bioceramic composites have good biocompatibility, ideal porosity and mechanical properties, which can meet the repair requirements of non-load bearing bone defects. OBJECTIVE: To further observe the effect of polyetheretherketone/biphasic bioceramic composite coated with vascular endothelial growth factor in the repair of mandibular defects. METHODS: Thirty-six New Zealand white rabbits were randomly divided into four groups, nine in each group. The control group did not undergo any treatment. A mandibular defect model was made in the model group. The sham operation group only replicated the surgical procedure of the model group but did not make bone defects. In the scaffold group, the polyetheretherketone/biphasic bioceramic composite coated with vascular endothelial growth factor was implanted into the mandibular defect site. Mandibular specimens were taken at 4, 8, and 16 weeks after operation. Hematoxylin-eosin staining and Van Gieson staining were performed to observe the repair of bone defects. The expression of vascular endothelial growth factor was detected by PCR, western blot and immunofluorescence. RESULTS AND CONCLUSION: (1) Hematoxylin-eosin staining results showed that the bone structure was intact in the control group and the sham operation group, and the bone defect in the model group did not change markedly within 16 weeks after operation; at 8 and 16 weeks after operation, osteoblasts appeared at the scaffold edge of the scaffold group. (2) Van Gieson staining results showed that the bone structure was intact in the control group and the sham operation group, and there was no significant change in the bone defect within 16 weeks after operation; at 8 and 16 weeks after operation, osteoblasts appeared at the scaffold edge of the scaffold group, but not collagen fibers produced. (3) At 4 weeks after operation, there was no difference in the expression of vascular endothelial growth factor among the three groups; at 8 and 16 weeks after operation, the expression of vascular endothelial growth factor in the control group was higher than that in model group (P < 0.05), but lower than that in the scaffold group (P < 0.05). In conclusion, polyetheretherketone/biphasic bioceramic composites coated with vascular endothelial growth factor to repair mandibular defects can increase the expression of vascular endothelial growth factor and promote bone regeneration.  中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Effect of gelatin sponge/beta-tricalcium phosphate composite with different doses of basic fibroblast growth factor on bone regeneration Cui Tingting, Qiu Zewen, Gui Lin, Zhong Weijian, Ma Guowu 2019, 23 (2):  190-195.  doi: 10.3969/j.issn.2095-4344.1506 Abstract ( 354 )   PDF (1652KB) ( 168 )   Save BACKGROUND: The current method of improving tissue regeneration is to combine growth factors with scaffold materials. Therefore, more and more attention has been paid to the gene-enhanced tissue engineering method. OBJECTIVE: To evaluate the effect of gelatin sponge/β-tricalcium phosphate composite mixed with different doses of basic fibroblast growth factor on bone regeneration. METHODS: Forty male Sprague-Dawley rats were selected to prepare skull defect models. Rat models were randomly divided into four groups, and implanted with gelatin sponge/β-tricalcium phosphate composite, gelatin sponge carrying 10, 100 and 200 ng of basic fibroblast growth factor/β-tricalcium phosphate composite. After 8 weeks of implantation, bone formation was observed by gross and histological observations. RESULTS AND CONCLUSION: In each group, the gelatin sponge/β-tricalcium phosphate composite was encapsulated by a large number of fibrous connective tissues, a large number of neovascularization and lymphocytes distributed in the fibrous connective tissue, and macrophages were visible around β-tricalcium phosphate granules. β-tricalcium phosphate granules were not obviously absorbed, and there was new bone formation between β-tricalcium phosphate and the skull. Many active bone cells existed among the new bone trabeculae, with disordered woven bone structure, the mature lamellar bone underneath the woven bone, and the undamaged original skull. The most active new bone formation was found in the basic fibroblast growth factor 100 ng+gelatin sponge/β-tricalcium phosphate composite group, and the new bone volume was the least in the solely used gelatin sponge/β-tricalcium phosphate composite. In conclusion, the combination of basic fibroblast growth factor with gelatin sponge/β-tricalcium phosphate composite can promote bone regeneration in the bone defect, and the best effect on bone regeneration is observed when 100 ng basic fibroblast growth factor is used.   中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Cytocompatibility of injectable glycol chitosan/dibenzaldehyde-terminated poly-ethyleneglycol hydrogel Jing Xiaoguang, Liu Shuyun, Guo Weimin, Li Xu, Lü Ao, Liu Shichen, Meng Haoye, Chen Mingxue, Zhang Xueliang, Zhang Zengzeng, Liu Xuejian, Gao Chao, Wang Zehao, Zhang Bin, Shen Shi, Tao Lei, Yang Jianhua, Guo Quanyi 2019, 23 (2):  196-203.  doi: 10.3969/j.issn.2095-4344.1507 Abstract ( 376 )   PDF (1079KB) ( 180 )   Save  BACKGROUND: Our research group independently developed an injectable glycol chitosan/dibenzaldehyde-terminated poly-ethyleneglycol (GCS/DF-PEG) hydrogel, which has good injectability and self-healing properties. OBJECTIVE: To test the physical properties and cytocompatibility of the GCS/DF-PEG hydrogel. METHODS: The injectable GCS/DF-PEG hydrogel was prepared by mixing GCS solution at a mass fraction of 1.5% with an equal volume of DF-PEG solution at a mass fraction of 2%, 4%, and 8%, respectively. Their moduli of elasticity were measured. Three groups of injectable hydrogels were immersed in PBS for 4 weeks to detect the in vitro degradation of the hydrogels. Passage 2 adipose-derived mesenchymal stem cells from Sprague-Dawley neonatal rats were cultured in injectable GCS/DF-PEG hydrogel leaching solution as experimental group or cultured routinely as control group. MTT assay was used to detect the cell proliferation. Passage 2 adipose-derived mesenchymal stem cells from Sprague-Dawley neonatal rats were mixed with 3% GCS solution, and then mixed with 4% DF-PEG solution. On the 1st and 5th days of culture, the cell survival and death in the hydrogel were tested by live/dead staining. Passage 2 adipose-derived mesenchymal stem cells from Sprague-Dawley neonatal rats were mixed with 3% GCS solution, and then mixed with 2%, 4% and 8% DF-PEG solution, respectively. MTT method was used for testing the cell proliferation. RESULTS AND CONCLUSION: (1) The moduli of elasticity of GCS/DF-PEG hydrogel with 2%, 4%, 8% DF-PEG were 13.48, 22.21 and 33.19 kPa, respectively. (2) In vitro degradation experiments showed that GCS/DF-PEG hydrogels gradually degraded in PBS over time. And the degradation rate of the 2% DF-PEG hydrogel was significantly faster than the other two groups. (3) Within 7 days of culture, there was no difference in the cell proliferation between the experimental and control groups. (4) Live/dead staining results showed that adipose-derived mesenchymal stem cells were spherical in the hydrogel, the survival rate was over 90%, and the number of cells increased significantly with time. (5) Over time, the number of adipose-derived mesenchymal stem cells in the GCS/DF-PEG hydrogel with different mass fractions gradually increased. And the cell proliferation in the hydrogel containing 2% DF-PEG was faster than 4% and 8% groups (P < 0.05). In conclusion, the injectable GCS/DF-PEG hydrogel has good cytocompatibility, mechanical strength and degradation, and it is expected to be a good carrier for stem cell transplantation in cartilage tissue engineering.   中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Preparation and characterization of novel porous polymethyl methacrylate bone cements Gao Shan, Zhou Fang, Lü Yang, Yuan Liang, Li Ailing, Qiu Dong 2019, 23 (2):  204-210.  doi: 10.3969/j.issn.2095-4344.1508 Abstract ( 388 )   PDF (848KB) ( 228 )   Save BACKGROUND: Porous tricalcium phosphate/polymethyl methacrylate bone cement can overcome the poor osteoconduction of traditional polymethyl methacrylate bone cement. But the addition of porogens may cause a significant reduction in the mechanical properties of composite bone cements. OBJECTIVE: To improve the mechanical properties of porous tricalcium phosphate/polymethyl methacrylate at different proportions, and to observe the mechanical properties, agglomeration, porosity and biosafety of composite bone cements. METHODS: Different groups of composite bone cements were prepared by adding different contents of tricalcium phosphate (40%, 50%, 60%) in solid phase and hydroxyethyl methylacrylate (0%, 5%, 10%, 15%, 20%) in liquid phase. The compressive strength, bending strength, maximum setting temperature, and setting time were measured, and screened the optimal ratio preliminarily. Then the pore formation properties of the optimal specimens were observed by scanning electron microscopy at 12 weeks after soaking in simulated body fluid. The osteogenic precursor cells were co-cultured with the preferred composite bone cement extract for 24 hours. The absorbance was then measured by cell counting kit-8 assay, and the cell viability was calculated. RESULTS AND CONCLUSION: The compressive strength of composite bone cement was increased when adding 40% and 50% of tricalcium phosphate in solid phase, but decreased when tricalcium phosphate concentration reached 60%. The bending strength was significantly decreased after adding tricalcium phosphate, showing a linear relationship. Addition of hydroxyethyl methylacrylate in liquid phase could strengthen the compressive strength and bending strength of composite bone cements, but no longer enhanced the mechanical properties when the concentration exceeded 15%. The maximum setting temperature of the composite bone cement was about 80 oC, regardless of the contents of tricalcium phosphate and hydroxyethyl methylacrylate. The setting time prolonged with the increasing of tricalcium phosphate and shortened with the increasing of hydroxyethyl methylacrylate. The formulas containing 50% tricalcium phosphate in the solid phase and 0%, 5% and 10% hydroxyethyl methylacrylate, respectively in liquid phase were chosen as preferable groups. After immersing in the simulated body fluid for 12 weeks, there was porous structure whose pore size was approximately 100 μm formed on the surface of composite bone cement. The cell viabilities of the preferable composite bone cement extract were all more than 75%, showing there was no cytotoxicity. In conclusion, the addition of 50% tricalcium phosphate in solid phase and 10% hydroxyethyl methylacrylate A in liquid phase into polymethyl methacrylate from the optimal composite bone cement formulation.  中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Orthogonal optimization of vancomycin/poly(lactic-co-glycolic acid) microspheres: preparation and drug release in vitro Liu Yazhen, Qiu Xiaoming, Li Songkai 2019, 23 (2):  211-217.  doi: 10.3969/j.issn.2095-4344.1509 Abstract ( 431 )   PDF (1040KB) ( 227 )   Save BACKGROUND: Despite the advances in modern antibiotics and surgical techniques, the long-term systemic use of antibiotics for deep soft tissue infections or bone infections, especially methicillin-resistant Staphylococcus aureus infections, is susceptible to nephrotoxicity, ototoxicity and toxic and side effects on the gastrointestinal tract. Moreover, it is expensive and its efficacy is uncertain. The local drug delivery system can achieve sustained-release of high concentrations of antibiotics in the local infection, thereby more effectively controlling and treating infections, and significantly reducing the side effects of systemic antibiotic treatment. Vancomycin is encapsulated into poly(lactic-co-glycolic acid) copolymer microspheres carrying vancomycin are gradually degraded and absorbed in the body, and the effective inhibitory concentration of vancomycin can be maintained for a long time at the infection site to achieve local anti-infection effects. OBJECTIVE: To optimize the preparation process of vancomycin/poly(lactic-co-glycolic acid) microspheres by orthogonal design experiments, then to prepare the vancomycin/poly(lactic-co-glycolic acid) sustained-release microspheres with uniform particle size, and to test their drug release and antibacterial properties in vitro at the same time. METHODS: Using double-emulsion solvent evaporation method, taking the drug loading rate and entrapment efficiency of microspheres as the main indicators, the orthogonal experiments of four factors and three levels were carried out under four different process conditions, including the concentration of poly(lactic-co-glycolic acid) solution, the concentration of internal water phase, the polyvinyl alcohol concentration of external water phase and the speed of agitation. RESULTS AND CONCLUSION: The optimum conditions were as follows: oil phase 9 mL: poly(lactic-co-glycolic acid) 500 mg, internal water phase 1 mL vancomycin 300 mg, external water phase: polyvinyl alcohol concentration was 3%, the speed: 400 r/min. When the other three factors were unchanged and the stirring rate was 400, 800 and 1 200 r/min, the microspheres with the particle size of (232±26), (157±23), (102±37) µm were prepared. For the microspheres with an average particle size of (102±37) µm, the drug loading rate was (17.40±1.87)% and the entrapment efficiency was (35.12±3.65)%. The drug release in vitro showed that the release rate of the microspheres on the 1st day was (17.91±2.41)%, and there was a certain burst of release. After 2 days, the release rate gradually decreased and slowed down, the cumulative release was (58.78±1.54)% at the 12th day, the average daily release was 1.41% from the 12th to the 24th day, and the total release was (75.31±1.02)% at the 24th day. These findings indicate that using the optimal preparation process, we can prepare vancomycin/ poly(lactic-co-glycolic acid) sustained-release microspheres with uniform particle size and smooth drug release.   中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Superparamagnetic chitosan gelatin microspheres as sustained-release gene carrier: magnetofection and release in vitro Cen Chaode, Zhang Yong, Luo Cong, Yang Xiaolan, Wu Jun, Wu Shengzhong, Liu Fuyao 2019, 23 (2):  218-225.  doi: 10.3969/j.issn.2095-4344.1510 Abstract ( 413 )   PDF (1121KB) ( 289 )   Save BACKGROUND: The transfection of angiogenic genes into cells by slow-release technology is the key to adequate vascularization of tissue engineered bone, and it is most important to select the safe and effective gene carrier. OBJECTIVE: To prepare and characterize superparamagnetic iron oxide chitosan nanoparticles (SPIOCN) and superparamagnetic chitosan plasmid gelatin microspheres (SPCPGM). METHODS: SPIOCN was prepared by dehydration condensation reaction, and the molecular structure, morphology and particles size, saturation magnetization, ζ potential and DNA binding ability were respectively characterized. SPIOCN solution was incubated with MG-63 cells for 24 hours, and cell phagocytosis of SPIOCN was observed by transmission electron microscope. SPCPGM and non-magnetic chitosan gelatin microspheres were prepared, which were filled in the porous cage, and the plasmid release of SPCPGM intended for implantation in the porous cage in the presence of and absence of oscillating magnetic fields was carried out in 0.01 mol/L phosphate buffer at 37 oC (pH=7.4). MG-63 cells and human umbilical vein endothelial cells were selected as target cells for transfection, which were divided into four groups and respectively intervened by PolyMag200 (commercial magnetic transfection reagent)/Pdna+the static magnetic field, SPIOCN/pDNA+the static magnetic field, SPIOCN/pDNA and naked pDNA. The transfection efficiency was then detected by inverted fluorescence microscope and flow cytometry after 24 hours. Human umbilical vein endothelial cells were cultured in four groups: PolyMag200/pDNA+the static magnetic field group, SPIOCN/pDNA+the magnetic field group, SPIOCN/pDNA group and naked pDNA group (control group). Cell viability was detected after 24, 48 and 72 hours of culture. RESULTS AND CONCLUSION: (1) The average particle size of SPIOCN was (187±24) nm, the saturation magnetization was (20.3±4.5) emu/g and the zeta potential was (9.5±2.4) mV, indicating that SPIOCN endows the combination ability with plasmid DNA transfected into MG-63 cells and human umbilical vein endothelial cells. (2) SPIOCN was attached to the cell membrane and entered into the cells through intracellular endocytosis pathway. SPIOCN swallowed as endosomes were dispersed in the cytoplasm. (3) The releasing plasmid amount of SPCPGM implanted in the porous cage in the presence of magnetic field was significantly higher than that of non-magnetic chitosan gelatin microspheres implanted in the porosity cage (P < 0.05). (4) The transfection efficiency of PolyMag200/pDNA+the static magnetic field group was higher than that of the other three groups (P < 0.05), and the transfection efficiency of SPIOCN/pDNA+the static magnetic field group was higher than that of SPIOCN/pDNA group and naked pDNA group (P < 0.05). (5) Compared with the naked pDNA group, the cell survival rate of SPIOCN/pDNA+the static magnetic field group and PolyMag200/pDNA+the static magnetic field group decreased at different time points  (P < 0.05), while the cell survival rate of SPIOCN/pDNA group showed no significant changes. The cell survival rate of SPIOCN/ pDNA+ static magnetic field group at different time points was higher than that of PolyMag200/pDNA+the static magnetic field group (P < 0.05). To conclude, SPIOCN has the characteristics of small particle size, good dispersibility, low toxicity, superparamagnetism and combined protection of DNA transfected cells. The oscillating magnetic field integrated with SPCPGM is an ideal system of slow-release gene carriers.   中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Effects of adventitial glutaraldehyde cross-linking on biomechanical properties of human saphenous vein graft Fang Ying, Liu Changcheng, Gu Chengxiong, Yu Yang, Li Zhenfeng, Xu Huanming, Chen Duanduan 2019, 23 (2):  226-231.  doi: 10.3969/j.issn.2095-4344.0690 Abstract ( 351 )   PDF (823KB) ( 183 )   Save BACKGROUND: Poor venous wall is one of the inducing factors causing saphenous vein failure after coronary artery bypass grafting (CABG). OBJECTIVE: To explore the effects of adventitial glutaraldehyde cross-linking on the biomechanical properties of human saphenous vein graft (SVG). METHODS: Forty residual segments of SVG were collected from the patients undergoing CABG. Those segments were randomly divided into group A (n=20) and group B (n=20). Adventitial cross-linking was performed with 0.3% glutaraldehyde solution. Each SVG segment in group A was equally subdivided into two parts: one for adventitial cross-linking 5 minutes and the other as self-control. Each SVG segment in group B was also equally subdivided into two parts: one for adventitial cross-linking 10 minutes and the other as self-control. The ultra-structural changes of the venous wall with or without cross-linking were observed by fluorescence microscope and scanning electron microscope. The SVG segments in two groups underwent the uniaxial stretch test to detect the stress-strain relationship, Young’s elastic modulus and breaking strength of SVG segments receiving different processing. RESULTS AND CONCLUSION: (1) Fluorescence microscope: Compared with the SVGs of self-control, cross-linked SVGs mainly presented with compacted adventitial monomer of collagen and increased density of type I collagen, without obvious ultra-structural changes in the lumen surface. (2) Scanning electron microscope: The adventitial collagen fibers in the self-control segments showed a typical wavy loose arrangement, while the adventitial collagen fibers in the cross-linked segment appeared to have a dense fibrous network. (3) Uniaxial stretch test: Compared with the self-control parts, the stress-stretch ratio curve in the cross-linked parts in the two groups was shifted to the left remarkably, and in the high strain region (stretch ratio 1.3-1.5), the Young’s elastic modulus was also increased significantly (P < 0.05). Compared with the SVGs in the cross-linking 5 minutes, the stress-stretch ratio curve in the SVGs in the cross-linking 10 minutes was shifted to the left remarkably, and in the high strain region (stretch ratio 1.3-1.5), the Young’s elastic modulus was also increased significantly (P < 0.05). The breaking strength of cross-linked SVGs was higher than that of self-control SVGs in the two groups (P < 0.05). To conclude, adventitial glutaraldehyde cross-linking reinforces venous wall and reduces the ductility of human SVG.   中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Reparation of femoral defects with a Ca-P coated magnesium alloy scaffold carrying sustained release microspheres Lu Yanqin, Yi Fang, Ju Wei, Li Wenjie, Lei Lei 2019, 23 (2):  232-238.  doi: 10.3969/j.issn.2095-4344.0689 Abstract ( 332 )   PDF (951KB) ( 196 )   Save BACKGROUND: Previous studies often discuss that magnesium alloy or core-shell microspheres containing growth factors can promote bone regeneration, but there are no relevant reports on the bone regeneration effect of magnesium alloy scaffolds combined with core-shell microspheres containing fibroblast growth factor-2 (FGF-2) and bone morphogenetic protein-2 (BMP-2). OBJECTIVE: To investigate the effect of Ca-P coated ZK60 magnesium alloy scaffolds combined with core-shell microspheres in the rats with femoral defects. METHODS: The poly(lactic-co-glycolic acid) and poly-L-lactic acid core-shell sustained release microspheres loaded with FGF-2 and BMP-2 were prepared by means of coaxial electrostatic spraying, and they were filled into the hollow tubular scaffolds of ZK60 magnesium alloy. Ca-P coating was applied to the surface of the magnesium alloy. The Ca-P coated ZK60 magnesium alloy scaffolds and uncoated ZK60 magnesium alloy scaffolds were immersed in Hanks solution for 30 days, and then the corrosion resistance of the alloys was tested. Eighteen Sprague-Dawley rats were randomly divided into six groups, and the model of femoral defects was established in each rat. The defects were implanted with nothing (Blank group), Ca-P coating ZK60 magnesium (ZK group), Ca-P coating ZK60+FGF microspheres (FGF group), Ca-P coating ZK60+BMP microspheres (BMP group), Ca-P coating ZK60+FGF+BMP microspheres (DUAL group, release of the growth factor at the same time), or Ca-P coating ZK60+FGF/BMP microspheres (SEQ group, sequential release). The rats were sacrificed at 8 weeks postoperatively. The defects were evaluated by gross observation, Micro-CT and bone tissue pathological observation. RESULTS AND CONCLUSION: (1) After 30 days of immersion in Hanks solution, there was a significant corrosion pit on the surface of uncoated ZK60 magnesium alloy, while only corrosion cracks were visible on the surface of Ca-P coated ZK60 magnesium alloy. (2) The Micro-CT results showed that the bone defect of the BLANK group was obvious, and was only covered with a layer of soft tissue. The defect site of ZK group was repaired, but not completely. The repair of FGF group was better than that of the ZK group, but the repair was still incomplete. The defects of BMP and DUAL groups were filled with new tissues, and the tissue density was higher in the DUAL group than the BMP group. The repair effect of SEQ group was the best with the highest density of the new tissues. (3) The histopathological sections of bone tissues showed that the bone defect was obvious in the BLANK group, and the defect was somewhat repaired in the ZK group. The defect repair of FGF group, BMP group and DUAL group was better than that of ZK group, and the repair effect of SEQ group was the best. To conclude, Ca-P coated magnesium alloy scaffolds carrying sustained release FGF-2/BMP-2 microspheres can promote bone regeneration.  中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Simvastatin sustained-release microspheres promote osteogenesis of bone tissue engineering in vitro Qing Wei, Dai Yanjun, Huang Lijuan, Ren Jing, Zheng Jiajun, Tuo Qiang, Ren Xiaohua, Mu Yandong 2019, 23 (2):  239-244.  doi: 10.3969/j.issn.2095-4344.1511 Abstract ( 379 )   PDF (1635KB) ( 179 )   Save  BACKGROUND: In recent years, domestic and foreign studies have assembled simvastatin sustained-release microspheres onto scaffold materials. It has been found that simvastatin can be used to repair bone defects and good results have been obtained. OBJECTIVE: To investigate the effect of simvastatin sustained-release microspheres on tissue engineering osteogenesis. METHODS: Nanoliposome simvastatin sustained-release microspheres were prepared by thin-film dispersion method. The particle size, polydispersity coefficient and encapsulation efficiency were measured. The sustained release properties of free simvastatin solution and simvastatin sustained-release microsphere solution were measured by dialysis device. The third generation of human placental mesenchymal stem cells was inoculated on porous hydroxyapatite ceramic scaffolds. The cells were cultured in two groups after adherent growth. The experimental group was treated with simvastatin sustained-release microspheres, and the normal medium was added to the blank group. Transcriptome sequencing was carried out after 7, 14, 21 days. The expression levels of osteogenic genes were verified by real-time fluorescence quantitative PCR. RESULTS AND CONCLUSION: (1) The average particle size of simvastatin sustained-release microspheres was (77.27±6.4) nm, the polydispersity coefficient was 0.131±0.040, and the encapsulation efficiency was 85.6%. (2) The rapid release of free simvastatin solution exceeded 80% total dose in the first 3 days. While the simvastatin sustained-release microsphere solution released only about 40% of the drug in the first 3 days, and had been slowly released until the 14th day, and the cumulative release at the 14th day was close to 80%. (3) Transcriptome sequencing showed that the osteogenesis-related genes such as bone morphogenetic protein 2, bone morphogenetic protein 4 and vascular endothelial growth factor were enriched and expressed in the experimental group. (4) Real-time quantitative PCR showed that the mRNA levels of bone morphogenetic protein 2, bone morphogenetic protein 4 and vascular endothelial growth factor were significantly higher in the experimental group than the blank group at 7, 14 and 21 days (P < 0.05). These results indicate that simvastatin sustained-release microspheres can promote osteogenic performance for tissue engineering.  中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

3D bioprinted nozzle for skin scaffolds: CFD simulation and experiments Chen Dongdong, Zhang Qi, Zhang Pengfei, Zhou Jiping, Jiang Yani 2019, 23 (2):  245-250.  doi: 10.3969/j.issn.2095-4344.1512 Abstract ( 489 )   PDF (1623KB) ( 310 )   Save BACKGROUND: With the development of tissue engineering, 3D bioprinting technology is used to prepare skin scaffolds. The process parameters are however unclear, and stacking and discontinuities often occur during the printing process. OBJECTIVE: To conduct the numerical simulation by 3D bio-printer and finite element software Fluent so as to obtain reasonable extrusion pressure, viscosity, nozzle walking speed, nozzle diameter and temperature parameters to solve the problem of accumulation and discontinuity in the printing process of gelatin fibers. METHODS: Using 5% gelatin cellulose solution as the printing material, the numerical simulation was carried out by using 3D bio-printer and software Fluent. The printing temperature was set at 5, 15, 25 oC, and the printing pressure was 0.16, 0.18, 0.2 MPa, respectively. The flow rate and flow at the tip of the nozzle were measured at 0.21, 0.26, and 0.41 mm. The gelatin fiber skin bio-scaffold was 3D-printed with appropriate parameters, and the scaffold structure was observed by scanning electron microscopy. RESULTS AND CONCLUSION: When the printing temperature was set at 15 oC, the nozzle walking speed was 30 mm/s, the pressure was 0.18 MPa, and the nozzle diameter was 0.21 mm, the gelatin fiber material could be continuously extruded but not stacked or broken. Under the above printing conditions, the width of printed filament was about 1 400 μm. For the biological scaffold printed under this condition, the row and column distribution of the scaffold was more uniform shown by the scanning electron microscope, and the bonding site between the layers was firmly bonded and not easily deformed. The porosity of the scaffold was about 57%.  中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Effect of fluid shear force from a fluid flow device simulating mechanical motion on RANKL expression in myeloma cells, osteocytes and osteoclasts Wang Xiaotao, Tian Shen, He Yuchan, Wu Chunye, Zhang Junyan, Yang Shaofang, Wang Hangfei, You Lidan 2019, 23 (2):  251-256.  doi: 10.3969/j.issn.2095-4344.0608 Abstract ( 346 )   PDF (742KB) ( 154 )   Save BACKGROUND: Myeloma patients have less movement because of bone pain and osteolytic destruction, which result in bone loss and disease aggravation. OBJECTIVE: To explore the effect of myeloma cells (U266 cells) on osteocytes (Y4 cells), osteoblasts and osteoclasts as well as RANKL secreted by osteocytes under fluid shear stress simulating human mechanical movement by a fluid flow devise. METHODS: A flow and no-flow model was established. U266 cell culture fluid was used in the experimental group and Y4 standard culture fluid was used in the flow and control groups. Myeloma cell line U266 and mouse osteocytes cell line Y4 were cultured and passaged in vitro. Y4 cells were allotted and cultured for 48 hours, and the morphology of osteocytes and osteoclasts was observed and counted under microscope. The level of RANKL was quantitatively determined by ELISA and western blot assay. The RANKL, sample and standard culture system was established, RAW264.7 cells were cultured in vitro, and induced by RANKL. Number and morphology of RAW264.7 cells differentiating into osteoclasts were observed by TRAP staining. RESULTS AND CONCLUSION: Compared with the control group, Y4 cells in U266 culture supernatant exhibited morphological changes and their number was significantly decreased. The number of TRAP-positive osteoclasts was increased and the expression of RANKL protein in Y4 cells was significantly up-regulated (P < 0.05). Comparison between the flow model and the no-flow model showed that the number of Y4 cells was significantly increased, the expression of RANKL protein decreased and the number of TRAP-positive osteoclasts was significantly reduced (P < 0.05). Our study indicates that myeloma cells can inhibit the growth of normal osteocyte and might promote the expression of RANKL protein and the growth of osteoclasts. Compared with static state, fluid shear stress may promote the proliferation of osteocytes and might inhibit the expression of RANKL protein and the growth of osteoclasts. So, we hypothesize that mild exercise may prevent the progression of myeloma bone disease.  中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

In situ repair of full-thickness skin defects by handheld electrospun biodegradable nanofibers Chen Hongrang, Zhang Haitao, Deng Kunxue, Li Yongsheng, Shen Yun, Xu Tao, Zhang Xinqiong 2019, 23 (2):  257-264.  doi: 10.3969/j.issn.2095-4344.1513 Abstract ( 437 )   PDF (1324KB) ( 365 )   Save BACKGROUND: The traditional electrospinning nanofiber manufacturing process is relatively complicated, which requires high manufacturing conditions and cannot meet the needs of rapid tissue repair in emergency events such as trauma and burn/scald. OBJECTIVE: To observe the effect of handheld electrospun polylactic acid/gelatin degradable nanofiber membrane on the in situ repair of mouse skin defects. METHODS: Handheld electrospun polylactic acid/gelatin degradable nanofiber membranes were prepared by self-made 3D printing handheld electrospinning device, and the contact angle and water vapor transmission rate were then measured. Fetal rat fibroblasts were cultured with 100%, 50%, 20% polylactic acid/gelatin degradable nanofiber membrane extracts, and the residual solvent toxicity of the materials was evaluated by cell counting kit-8 cytotoxicity assay. Fetal rat fibroblasts were co-cultured with polylactic acid/gelatin degradable nanofiber membrane (experimental group), and cells cultured alone were set as control. Cell proliferation was detected by Alamar blue method, cell viability was observed by live/dead staining, and cell morphology was observed by scanning electron microscope. A full-thickness skin defect of 2 cm in diameter was made on the back of 18 Balb/c mice. The experimental group was inlaid with handheld electrospun polylactic acid/gelatin degradable nanofiber membrane for in situ repair followed by gauze dressing. The control group was treated with gauze dressing at the defect site. Eight weeks after operation, hematoxylin-eosin and Masson staining were used to observe the repair of skin defects. RESULTS AND CONCLUSION: (1) The contact angle of polylactic acid/gelatin degradable nanofiber membrane was (32.68±5.68)°, indicating a hydrophilic material suitable for cell adhesion. The 24-hour water vapor transmission rate was (4.21±0.11)×103 g/m2, which met the requirements of external skin dressing. Different concentrations of polylactic acid/gelatin degradable nanofiber membrane extract had no obvious cytotoxicity. (2) In the experimental group, fetal rat fibroblasts had the cell viability equivalent to control cells, but exhibited faster proliferation rate and longer proliferation time. (3) Results from the hematoxylin-eosin and Masson staining showed that the full-thickness skin defect healed in the experimental group, with the material being completely degraded and the hair follicles being regenerated. In the control group, the defect healed incompletely. To conclude, handheld electrospun polylactic acid/gelatin degradable nanofibers can implement the in situ repair of mouse full-thickness skin defects.   中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Bioprinting of 3D structure with micro-network fluidic channels Zou Qiang, Sun Yu, Li Xuanze, Wu Zhanyu, Yang Long, Wang Jianji, Liu Qin, Ma Minxian, Ye Chuan 2019, 23 (2):  265-271.  doi: 10.3969/j.issn.2095-4344.0688 Abstract ( 433 )   PDF (1000KB) ( 218 )   Save BACKGROUND: Constructing a three-dimensional pre-vascularization system plays a decisive role in the survival and functional expression of cells in large and complex three-dimensional structures. Therefore, seeking a suitable pre-vascularization strategy has become a problem to be solved urgently in the 3D bio-printing of large size and complex three-dimensional tissue. OBJECTIVE: To make a preliminary exploration on the 3D bioprinting of large-scale and pre-vascularized three-dimensional structure. METHODS: Catia as a reverse engineering software was used to design a three-dimensional biological print blueprint. A modified desktop-grade dual-head 3D printer was used as a biological printer and polyvinyl alcohol as a sacrificial material to print a sacrificial skeleton. The mixture of rat bone marrow mesenchymal stem cells, sodium alginate, agarose and nano-cellulose solution was used as cell biological ink. According to the pre-designed parameters for printing, the tissue engineering three-dimensional structure with three-dimensional fluid channel was constructed. The three-dimensional structure obtained by printing was observed to evaluate the cell activity after printing as well as after material dissolution. The printed structure was cultured in vitro and the proliferation of cells in the three-dimensional structure was detected by Alamar Blue kit. RESULTS AND CONCLUSION: A double-nozzle printing model with micro-porous outer wall and interlaced microtubules was designed by using Catia software. The three-dimensional biometric printing technology was used to construct the three-dimensional structure with self-defined size (especially its height) and pre-vascularization. The survival rate of the cells in the printed structure within 12 hours was (95.47±0.54)%, and as the in vitro culture time prolonged, the cell survival rate decreased but still exceeded 80%. Over time, the cell proliferation showed an increasing tendency. These findings indicate that this biometric printing method can be used to produce three-dimensional structures with different characteristics by using various bio-hydrogel materials, and has potential in the biofabrication of complex tissues and organs with clinically-related dimensions of pre-vascularization. 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Barrier materials for postoperative abdonimal adhesion: biological characteristics, merits and demerits Yang Lili, Bian Yaoyao, Zhao Min, Wang Yetong, Tang Shengjin, Li Wenlin, Zeng Li 2019, 23 (2):  272-277.  doi: 10.3969/j.issn.2095-4344.1514 Abstract ( 455 )   PDF (704KB) ( 212 )   Save BACKGROUND: Postoperative abdominal adhesion is one of the most urgent surgical problems. In view of the complicated pathological mechanisms and various risk factors of postoperative adhesion, surgical techniques and barrier materials have increasingly become the focus of postoperative prevention of adhesion. OBJECTIVE: To summarize the pathological mechanisms and risk factors of postoperative abdominal adhesions and to review the material source, biological characteristics, current research status, and potential deficiencies of different types of barrier materials. METHODS: We retrieved PubMed, CNKI, WanFang and VIP databases from their inception dates to January 2018, and “postoperative abdominal adhesion, etiology and pathogenesis, risk factors, preventive measures, barrier materials” were used as the keywords in English and Chinese, respectively. Fifty-four articles were included in final analysis. RESULTS AND CONCLUSION: Anti-adhesion materials can isolate the injured area and peripheral tissues through physical barriers in the early stage of adhesion formation, and thus prevent the formation of abdominal adhesion. There are three types of anti-adhesion barrier material at present, including solution, gel and membrane agents. Each kind of material has its own advantages and disadvantages. Therefore, we explore the pathological process of postoperative abdominal adhesions, predict the risk factors of postoperative adhesions, improve surgical skills and select appropriate anti-adhesion barrier materials according to actual conditions, which are expected to reduce the formation of postoperative abdominal adhesions. 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Applications of single cell nanoencapsulation: single cell catalysis, cell protection and treatment Xie Wenjia, Wang Jian, Pei Xibo 2019, 23 (2):  278-283.  doi: 10.3969/j.issn.2095-4344.1515 Abstract ( 508 )   PDF (1516KB) ( 171 )   Save BACKGROUND: Single cell nanoencapsulation refers to coating single cells with ultrathin (< 100 nm) layers and it has been widely used in medical and biological areas. OBJECTIVE: To review the development and applications of single cell nanoencapsulation. METHODS: The literature search was performed in PubMed, CNKI and WanFang database, and the keywords were “single cell, nano-coating, nano-encapsulation, cell-in-shell structure” in English and Chinese, respectively. According to the inclusion and exclusion criteria, 52 articles were finally reviewed. RESULTS AND CONCLUSION: The layer-by-layer deposition technique is most widely used due to their versatile processing and tunable properties. And many other materials, like polyphenols and surface-induced hydrogelator have been also utilized as organic cell-coating materials. Besides, bioinspired mineralization and crystallization were utilized for creating inorganic nanoshells. Single cell nanoencapsulation has been widely used in many important areas, including cell biocatalysis, cell therapy, cytoprotection and cell-based biology. Extensive adhesion of polyphenols and self-assembling of some organic materials have been also utilized to form nanoencapsulation of single cells. Besides, bioinspired mineralization and crystallization have been utilized for creating inorganic nanoshells. Nanoencapsulated single cells have been widely used in many important areas, including cell biocatalysis, cell therapy, cytoprotection and cell-based biology. The application of encapsulated cells will make a more important part in the selection of nanocoating materials in future research. 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Biological characteristics of tannic acid and its application value in medicine and stomatology Bian Yuqing, Ma Yidan, Dai Dongyue, Su Ping, Jia Mengqi, Zhan Desong, Fu Jiale 2019, 23 (2):  284-290.  doi: 10.3969/j.issn.2095-4344.1516 Abstract ( 920 )   PDF (1639KB) ( 150 )   Save BACKGROUND: Tannic acid has strong activity in biology and pharmacology, which has been used in industry, medical treatment and etc. Research focusing on tannic acid is in the ascendant, and tannic acid has been considered as a promising material with high research value. OBJECTIVE: To analyze the biological activity and chemical characteristics of tannic acid, and to review its application and prospect in industry, medicine and dentistry. METHODS: We searched the articles about tannic acid in PubMed database, WanFang database, CNKI database and VIP database with the key words of “tannic acid and chemical property, tannic acid and biological activity, tannin and antioxidant activity, tannin and industry, tannin and medicine, tannin and dentistry, tannin and dentin, tannin and tooth decay, tannin and bond strength” in English and Chinese, respectively. RESULTS AND CONCLUSION: As a complex polymer polyphenol, tannic acid has strong functional and biological activity and has been widely used in industry. In medicine, tannic acid not only has bacteriostatic, antiviral, anti-inflammatory, anti-oxidation effects and physiological activities, such as, lowering blood sugar, blood pressure, lipid and so on, but is also able to inhibit the growth of cancer and tumor. In dentistry, tannic acid can inhibit the growth of cariogenic bacteria and the formation of dental plaque biofilm, protect periodontal membrane, prevent the surface demineralization of enamel and promote the re-mineralization of the enamel. As the known biological characteristics of tannic acid, it still has a huge scientific research value in the prevention and treatment of cardiovascular disease and caries as well as in anesthesia. 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Effects of stress on degradation of biodegradable metal for vascular stent application: a review Lu Yun, Gu Xuenan, Fan Yubo 2019, 23 (2):  291-297.  doi: 10.3969/j.issn.2095-4344.0653 Abstract ( 469 )   PDF (830KB) ( 272 )   Save BACKGROUND: The combined action of physiological stress and corrosion may cause stress-assisted corrosion and cracking of biodegradable vascular stents, and even lead to early failure of the stents. OBJECTIVE: To review the degradation of biodegradable metal stents under physiological stress environment and the relevant mechanisms. METHODS: PubMed and CNKI databases were searched for relevant articles published from 2000 to 2018, using the keywords of “biodegradable, degradation, stress” in English and Chinese, respectively. RESULTS AND CONCLUSION: Magnesium, iron and zinc are the representatives of biodegradable metal materials, which have shown good application prospects in the field of vascular stents. Biodegradable stents work via balloon dilatation, and then support vessels until the complete revascularization under complex stresses, including tensile stress, compressive stress, shear stress and cyclic loading. We cannot ignore the effects of stress on the degradation of biodegradable metals; otherwise, the implantation of biodegradable metal stents may fail due to fastened attenuation of mechanical performance or stent fracture. To explore the effect of stress on biodegradable metal stent degradation and its relevant mechanism is crucial to the modification, configuration design and optimization of vascular stent materials. 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Reconstructive implants for defects in bone tuberculous surgery Fang Xu, Dong Junfeng, Zhao Hongwei, Chen Haidan 2019, 23 (2):  298-303.  doi: 10.3969/j.issn.2095-4344.1517 Abstract ( 361 )   PDF (816KB) ( 206 )   Save BACKGROUND: Successful repair of tuberculous bone defects is very important in the surgical treatment of osteoarticular tuberculosis. There are many kinds of repair materials for tuberculous bone defects available in surgery; however, none of them meet the needs of clinical practice nowadays. OBJECTIVE: To review the application of repair materials for tuberculous bone defects. METHODS: The first author searched the articles related to tuberculous bone defect repair in PubMed, CNKI, WanFang, CQVIP databases published from 2000 to 2018. The priority was the articles published recently or in authoritative journals. The search keywords were “spinal tuberculosis; bone defect; biomaterials; scaffold; bone grafting material” in Chinese and English. Ninety-one articles were initially searched, and 48 of them were finally selected for review. RESULTS AND CONCLUSION: Successful repair of tuberculous bone defect is absolutely vital to the surgical treatment of osteoarticular tuberculosis. There are many kinds of repair materials for tuberculous bone defects available in surgery, including autologous bone and allogeneic bone, artificial bone material, artificial vertebral body, titanium mesh, polymethyl methacrylate bone cement, and anti-tuberculosis active implant materials. However, none of them allow for complete bone reconstruction. For example, the source of autologous bone and allogeneic bone is limited; the use of artificial bone materials lacks long-term follow-up data; artificial vertebral bodies and titanium mesh have not been confirmed by the authoritative safety assessment for use in the treatment of local tuberculosis; polymethyl methacrylate does not have bioactivity; and new anti-tuberculosis active materials with sustained release function have no full match between bone induction time and degradation time, and moreover, the mechanical properties of related materials need to be improved and are still unable to fully meet the needs of clinical use. Further research on a new repair material for tuberculous bone defects is warranted. 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Application of graphene in bone tissue engineering Zhang Jun, You Qi, Xiong Huazhang, Zou Gang, Jin Ying, Ge Zhen, Liu Yi 2019, 23 (2):  304-309.  doi: 10.3969/j.issn.2095-4344.0656 Abstract ( 396 )   PDF (702KB) ( 169 )   Save BACKGROUND: Graphene has good biocompatibility and high mechanical strength, which has been widely used in tissue engineering. OBJECTIVE: To review the general properties, degraded properties, biocompatibility, and application of graphene in bone tissue engineering METHODS: A computer-based search of CNKI, PubMed, and Elsevier was performed for retrieving articles concerning the application of graphene in bone tissue engineering published from January 2000 to April 2018. The keywords were “grapheme, graphene derivatives, tissue engineering, bone tissue engineering” in Chinese and English, respectively. The preliminary screening was carried out by reading titles and abstracts, and according to inclusion and exclusion criteria, 65 articles were finally included for result analysis after removal of unrelated articles. RESULTS AND CONCLUSION: (1) Graphene has good biocompatibility, degradability, weak cytotoxicity, and has no obvious effect on cell proliferation. Therefore, graphene can be used as a tissue engineering scaffold to carry cells that can grow on the scaffold surface. (2) Graphene and its derivatives can promote the growth and osteogenic differentiation of mesenchymal stem cells, and have a significant role in the repair of bone defects and bone regeneration. Therefore, they can be applied in bone tissue engineering. (3) Graphene combined with other polymers, minerals or metals can improve their performance, and can further promote the osteogenic differentiation. 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Self-assembling peptide hydrogel: hemostatic effect and mechanism Wei Wei, Liu Yanfei, Zhang Ling, Xiong Na 2019, 23 (2):  310-316.  doi: 10.3969/j.issn.2095-4344.0651 Abstract ( 562 )   PDF (838KB) ( 253 )   Save BACKGROUND: As a new type of biomaterial, self-assembling peptide hydrogel is widely used in tissue engineering, drug release, hemostasis and antibacterial agents. OBJECTIVE: To summarize the hemostatic effect and mechanism of self-assembling peptide hydrogel materials in different bleeding models. METHODS: Using “self-assembling peptide, hydrogel, hemostasis, trauma” as the key words in Chinese and English, respectively, we retrieved the related literatures published from 2000 to 2018 in PubMed, CNKI, WanFang databases. RESULTS AND CONCLUSION: Self-assembling peptide materials are characterized as programmability, good viscoelasticity, high biocompatibility and low immunogenicity. The short peptides can self-assemble into nanofiber hydrogels and exhibit good biocompatibility. In different surgical wounds, hydrogels can form physical barriers to exert hemostasis without interacting with the clotting cascade or being coagulated, which can quickly and effectively control bleeding without harm to surrounding tissues or cells. Reasonable use of short peptides that have antibacterial and drug sustained-release properties can ensure rapid hemostatic effect, and meanwhile improve wound microenvironment. Self-assembling peptide hydrogel combined with bioactive molecules to promote wound healing is one of the key research directions of self-assembling short peptide materials at this stage. 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Collagen as a medical biomaterial in tissue repair, regeneration and reconstruction Hu Kang, Zhang Wei 2019, 23 (2):  317-322.  doi: 10.3969/j.issn.2095-4344.0650 Abstract ( 825 )   PDF (769KB) ( 1079 )   Save BACKGROUND: Collagen has been widely used as a medical biomaterial due to its low immunogenicity, good biocompatibility and biodegradability. OBJECTIVE: To summarize the sources, bioactivity, modification of collagen and its application as a medical biomaterial in recent years. METHODS: The first author searched related articles in PubMed, Elsevier, Springerlink, and CNKI from 2010 to 2018. The key words were “collagen, crosslinking, immunogenicity, biocompatibility, tissue engineering” in English and Chinese, respectively. RESULTS AND CONCLUSION: Collagen is mainly extracted from animal tendon, skin, tail and other soft tissues. It has low immunogenicity, good biocompatibility and biodegradability, but has insufficient mechanical strength. Crosslinking modification or combination with other biomaterials can both improve the mechanical properties of collagen. Nowadays, collagen is widely used as hemostatic and wound dressing, biological repair patches, bone repairing materials, drug release carriers and tissue engineering scaffolds, which has a significant role in the clinical repair, regeneration and reconstruction of tissue defects.   中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics

Select

Effect of silver dressing on diabetic foot ulcer: a Meta-analysis Huang Ruina, Huang Ruijia, Niu Caili, Qiu Wenbo, Wu Xiaowan, Wang Xiaojun, Wang Haijiao, Yang Chaojie 2019, 23 (2):  323-328.  doi: 10.3969/j.issn.2095-4344.1518 Abstract ( 571 )   PDF (853KB) ( 151 )   Save BACKGROUND: Various kinds of dressings for diabetic foot have been developed, among which, silver dressing has been widely used, but no conclusion has been reached yet. OBJECTIVE: To evaluate the effects of silver dressing in the treatment of diabetic foot ulcers by a Meta-analysis. METHODS: A systematic search of literatures in PubMed, Embase, Elsevier, CNKI, CBM, VIP and WanFang from inception to March 2018 was conducted. The quality of the literatures was appraised and data were extracted by two researchers independently. Meta-analysis was then conducted for the included literatures. RESULTS AND CONCLUSION: A total of 7 randomized controlled trials involving 642 patients were included. The meta-analysis results showed that the wound healing rate of silver dressing group was significantly higher than that of the other dressing groups [odds ratio (OR)=2.34, 95% confidence interval (CI) (1.57, 3.48), P < 0.000 1], epithelial formation time was significantly shorter than that of other dressing groups [mean difference (MD)=-2.22, 95% CI (-2.77, -1.66), P < 0.000 01], occurrence time of granulation tissue was significantly shorter than that of the other dressing groups[MD=-2.84, 95% CI (-3.26, -2.41), P < 0.000 01], wound healing time was significantly shorter than that of the other dressing groups [MD=-11.13, 95% CI (-19.87, -2.39), P=0.01]. Overall, silver dressing can promote the healing of diabetic foot ulcers. 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程 Figures and Tables | References | Related Articles | Metrics