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    15 July 2016, Volume 20 Issue 30 Previous Issue    Next Issue
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    Biomechanical analysis of mandibular body reconstruction using titanium plate
    Chen Biao, Fan Xu-hui, Liu Yao-qiang, Yue Lei, Zhang Rui, Qu Peng-fei, Jia Zhi-yu, Zhao Yun-zhuan, Yang Wei
    2016, 20 (30):  4413-4418.  doi: 10.3969/j.issn.2095-4344.2016.30.001
    Abstract ( 422 )   PDF (971KB) ( 253 )   Save

    BACKGROUND: Three-dimensional finite element has been widely used in the oral cavity field, but little is reported on the three-dimensional finite element reconstruction of the mandibular body using titanium plate.
    OBJECTIVE: To study the biomechanical characteristics of reconstructing the mandibular body using titanium plate.
    METHODS: We established a three-dimensional finite element model of mandibular body defect undergoing reconstruction using bicortical titanium screws and titanium plate. Under the simulated normal occlusion state, a 200 N vertical load was added to the central fossa of the occlusal surface of the right mandible first molar. Then, stress distribution and maximum displacement of the mandible, titanium screw, and titanium plate were analyzed.
    RESULTS AND CONCLUSION: Under the simulated normal occlusion state, mandible stress was concentrated in the mandibular body and mandibular branch, especially in the anterior and posterior edges of the mandibular branch and the lower edge of the mandible. The stress in the posterior edge of the mandible was lower than that in the anterior edge of the mandible, and moreover, the contact site between the titanium plate and the mandible also presented a concentration of stress. The maximum stress of the bicortical titanium screws appeared near the screw cap, and the stress was also concentrated at the contact site between the titanium screw and the titanium plate. The maximum stress of the titanium screw at the ascending branch of the mandible was higher than that of the titanium screw at the anterior end of the defect. For the titanium plate, the stress was mainly concentrated at the fixed site of the titanium screws; the peak stress of the anterior and posterior edges of the titanium plate was found at the contact site between the anterior end of mandibular defect and the titanium stress as well as between the ascending branch of the mandible and the titanium screw. After mandibular body reconstruction using the titanium plate, a displacement was likely to occur at the contact site between the anterior end of mandibular defect and the titanium plate. In conclusion, these findings indicate that mandibular body reconstruction using bicortical titanium screws and titanium plate is relatively stable, but the titanium plate fixed at the anterior part of the mandibular angle is prone to breakage.

     

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    Effects of different dental implant systems on the peri-implant bone absorption
    Zhu Yan, Wan Peng-bo, Zhao Wei, Wang Xiao-ling, Liu Jin, Wei Kang-kang, Liu Jun-xiang
    2016, 20 (30):  4419-4424.  doi: 10.3969/j.issn.2095-4344.2016.30.002
    Abstract ( 464 )   PDF (1055KB) ( 244 )   Save

    BACKGROUND: The peri-implant bone absorption is closely related to the repair effect.
    OBJECTIVE: To compare the effects of three kinds of dental implant systems on the peri-implant bone absorption.
    METHODS: 116 patients who underwent the dental implant systems were collected, including 46 cases with 3I implant system, 40 cases with ITI implant system and 30 cases with BLB implant system. The peri-implant bone absorption, sulcus bleeding index and periodontal probing depth of three groups were detected at 1, 3, 6, 9 and 12 months after implantation, respectively.
    RESULTS AND CONCLUSION: The peri-implant bone absorption of three groups within 1 year after implantation was in a rise, and the bone absorption of BLB group was significantly higher than that of ITI and 3I groups at 3 and 12 months after implantation (P < 0.05). Compared with the natural teeth, the gingival sulcus bleeding index of three groups were all increased at different time points after implantation; the gingival sulcus bleeding index of BLB group was significantly higher than that of natural teeth at 6 months after implantation (P < 0.05); the gingival sulcus bleeding index of three groups were significantly higher than that of natural teeth at 9 months after implantation (P < 0.05). The periodontal probing depth of three groups showed an ascending trend at 6 months after implantation; the periodontal probing depth of three groups was higher than that of natural teeth at different time points after implantation, which exhibited significant differences at 6 and 9 months after implantation (P < 0.05). In conclusion, three kinds of dental implant systems exhibit differet effects on the peri-implant bone absorption, but all achieve excellent clinical efficacies.

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    Construction of folate-modified nanoparticles as ultrasound contrast agent targeting breast cancer
    Chen Yuan-yuan, Xu Feng, Yang Hui, Liu Ting, Zhou Jian-qiao, Cai Chen-lei, Ye Yuan-yuan,Liu Pei-feng, Han Bao-san
    2016, 20 (30):  4425-4433.  doi: 10.3969/j.issn.2095-4344.2016.30.003
    Abstract ( 405 )   PDF (6019KB) ( 209 )   Save

    BACKGROUND: Studies have testified that nano-ultrasound contrast agents have a strong permeability, making it possible to image the targeted tissues outside blood vessels and overcome the limitation that micron contrast agents are only available for the blood pool imaging.
    OBJECTIVE: To construct the folate-modified nanoparticles targeting breast cancer as ultrasound contrast agents, as well as to observe their ability to specifically bind to cells and imaging effect in vitro.
    METHODS: Both contrast agents, pegylated lactic acid-glycolic acid copolymer wrapping liquid fluorocarbon formed nanoparticles (mPP/PFOB) and folate modified pegylated lactic acid-glycolic acid wrapping liquid fluorocarbon formed nanoparticles (mPPF/PFOB), were constructed by phacoemulsification-evaporation method. (1)Biocompatibility detection: HFF-1 and MCF-7 cells in the logarithmic phase were cultivated with various concentrations (0, 0.005, 0.01, 0.02, 0.05, 0.1, 0.2 and 1 g/L) of mPP/PFOB or mPPF/PFOB for 24 hours respectively, and then the cell viability was measured. (2)Targeting ability detection in vitro: HFF-1 and MCF-7 cells in the logarithmic phase were divided into three groups. Cy5-labled mPP/PFOB and mPPF/PFOB were added into groups A and B, respectively; the cells in group C were pretreated with folate for 2 hours, and sequentially Cy5-labled mPPF/PFOB was added into group C. Fluorescence intensity was detected by flow cytometry after 0.5 hours of culture. The distribution of contrast agents in cells was observed using confocal microscopy after 20 minutes of culture. (3)Ultrasound imaging in vitro: there were three groups: saline was as group A; the suspension of saline and mPPF/PFOB nanoparticles was prepared as group B; MCF-7 cells were resuspended with the mixture of saline and mPPF/PFOB nanoparticles to prepare the suspension of nanoparticles and cells as group C. In each group, the suspension was added into latex gloves, that were then tightened and immersed in water. Finally, the ultrasound was use to detect the ultrasound imaging effect in vitro.
    RESULTS AND CONCLUSION: Neither nanoparticles were with significant cytotoxicity. The flow cytometry showed that the mean fluorescence intensity in MCF-7 cells of group B was significantly higher than that of groups A and C. But there were no significant differences in the mean fluorescence intensity in HFF-1 cells among the three groups. It was observed that mPPF/PFOB mainly gathered around the MCF-7 cell membrane, while mPP/PFOB randomly distributed in the cytoplasm. After mPPF/PFOB binding to MCF-7 cells, they could enhance ultrasound echo in vitro. These findings indicate that the targeted nanoparticles mPPF/PFOB have good biocompatibility and can specifically bind to breast cancer MCF-7 cells in vitro and enhance the imaging capability.

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    A novel biodegradable scaffold: biological properties and application in bile duct repair
    Ma Li-feng, Kang Jian-sheng, Li Tao, Zhang Li-chao, Liu Guo-chao, Wang Jian-long
    2016, 20 (30):  4434-4441.  doi: 10.3969/j.issn.2095-4344.2016.30.004
    Abstract ( 498 )   PDF (2177KB) ( 179 )   Save

    BACKGROUND: A variety of factors contribute to biliary injury that is difficult to be repaired. Stent implantation is extensively used for bile duct injury, but either scaffolds made by metal or plastics can lead to certain adverse reactions.
    OBJECTIVE: To explore the biological characteristics of a novel biodegradable scaffold and its repair effects on bile duct injury.
    METHODS: The biological characteristics of the novel biodegradable scaffold were detected by fresh bile, and its degradation was observed at different time points. Thirty Bama mini pigs were included and were randomly divided into observation group (n=15) and control group (n=15). After bile duct injury models were prepared, the control group was subjected to the bile duct interrupted suture, while the observation group was subjected to the novel biodegradable scaffold combined with omentum majus. The biological properties of the scaffolds were observed. Hepatic enzymes and serum total bilirubin levels were detected, as well as hematoxylin-eosin staining, Masson staining and immunohistochemistry detection of α-smooth muscle actin were performed.
    RESULTS AND CONCLUSION: Before and 1, 3 and 6 months after surgery, hepatic enzymes and total bilirubin of two groups were detected, and neither intra-group nor intergroup comparisons had significant differences (P > 0.05). Hematoxylin-eosin staining and Masson staining revealed that inflammatory reactions and fiber hyperplasia at the anastomotic site in the observation group were lighter than those in the control group at different time points after surgery. The α-smooth muscle actin-positive scores in both two groups were in a rise at 1 and 3 months after surgery, and peaked at the 3rd month, and then began to decline. Moreover, the α-smooth muscle actin-positive scores in the observation group were significantly lower than those in the control group at 3 and 6 months after surgery (P < 0.05). These results show that the novel biodegradable scaffold has good biological characteristics and can obtain ideal repair effects in the bile duct injury.

    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

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     Guided bone regeneration with acellular dermal matrix as a barrier for bone defects
    Jia Ren-jie, Ren Yu-qing, Xu Hao, Wang Wei-ying, Yi Zhong-ping, Zhao Bao-dong
    2016, 20 (30):  4442-4448.  doi: 10.3969/j.issn.2095-4344.2016.30.005
    Abstract ( 312 )   PDF (3977KB) ( 205 )   Save

    BACKGROUND: Acellular dermal matrix has good biocompatibility and absorbability and exhibits superiority in the guided bone regeneration.
    OBJECTIVE: To compare the histological changes and osteogenic effects in bone defects after guided bone regeneration with acellular dermal matrix and Bio-Gide membrane.
    METHODS: Mandibular second, third and fourth premolars and the first molars bilaterally were extracted from 12 beagle dogs. Three months later, four three-wall bone defect models in the mandible of each dog were made, and randomized into acellular dermal matrix plus bone graft group (acellular dermal matrix group), Bio-Gide plus bone graft group (Bio-Gide group), bone graft group, and blank control group (no treatment). In the former two groups, acellular dermal matrix and Bio-Gide were used to cover the bone grafts, respectively.
    RESULTS AND CONCLUSION: After surgery, all the beagle dogs recovered well. All the groups except the control group showed dramatical improvement in histological changes and percentage of new bone area, and this improvement was more significant in the Bio-Gide and acellular dermal matrix groups. Moreover, there was no significant difference between the Bio-Gide and acellular dermal matrix groups. Therefore, the acellular dermal matrix can be a candidate for bone repair instead of Bio-Gide membrane in the clinical practice.

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    Preparation of an acellular porcine corneal stroma scaffold and its biocompatibility
    Huo Yin-ping, Zhou Li-xiao, Sun Cheng-lin
    2016, 20 (30):  4449-4455.  doi: 10.3969/j.issn.2095-4344.2016.30.006
    Abstract ( 437 )   PDF (4083KB) ( 264 )   Save

    BACKGROUND: Studies have found that a variety of biological materials can be used for preparing corneal stroma scaffolds that have good biocompatibility, but research on preparation and biocompatibility of the acellular porcine corneal stroma scaffold is little.
    OBJECTIVE: To explore the preparation and biocompatibility of the acellular porcine corneal stroma scaffold.
    METHODS: Acellular porcine corneal stroma scaffold and its extract were prepared. Well-grown human corneal stromal cells were selected and cultured in the extract of acellular porcine corneal stroma scaffold (experimental group) or in the complete medium (control group), respectively. After 1, 2 and 3 days of culture, the proliferation ability of human corneal stromal cells was detected by MTT assay. In the meanwhile, human corneal cells were directly seeded onto the acellular porcine corneal stroma scaffold, and then the cell growth on the scaffold was detected using immunochemical method.
    RESULTS AND CONCLUSION: The number of human corneal stromal cells was in a rise with time in the two groups, and absorbance values had no significant difference between two groups at different time points of culture. Human corneal stromal cells grew well on the scaffold, and were positive for cell integrin β1, vimentin, aldehyde dehydrogenase 3A1, as well as CD34, CDK2 and K-Ras. These results show that the acellular porcine corneal stroma scaffold has no cytotoxicity, and has good biocompatibility.

     

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    Biodegradable AZ31 magnesium alloy stent in rabbit aorta: degradation time and effect
    Zhang Xiao-qing, Li Xin
    2016, 20 (30):  4456-4462.  doi: 10.3969/j.issn.2095-4344.2016.30.007
    Abstract ( 360 )   PDF (4037KB) ( 216 )   Save

    BACKGROUND: Stent implantation is a common treatment for various cardiovascular diseases. Biodegradable AZ31 magnesium alloy stent is a new kind of biodegradable stent, but its degradation time and effect are still rarely reported.
    OBJECTIVE: To investigate the degradation time and effect of AZ31 magnesium alloy stent in the rabbit aorta.
    METHODS: Twenty New Zealand white rabbits were subjected to implantation of biodegradable AZ31 magnesium alloy stents into the abdominal aorta. After implantation, the animals were grossly observed, and five animals were sacrificed under anesthesia at 1, 2, 3 and 4 months respectively for X-ray and histological observations. The number of residual struts was calculated under microscope.
    RESULTS AND CONCLUSION: X-ray findings showed that the implanted stent was found to be in complete form at 1 month after implantation, and its degradation was elicited at 2 months, indicating the stent lost its supporting role gradually. The stent was degraded mostly at 3 months and degraded completely at 4 months. After implantation, the degradation rate of the stent was increased over time, which was confirmed by the X-ray findings. The number of residual struts was correlated with the time of degradation (r=-0.943, P < 0.05). The slope of the linear regression equation was -0.12, based on which, the total time of the stent degradation was calculated to be 105 days. These results show that the AZ31 magnesium alloy stent implanted in the rabbit aorta is gradually degraded with time, and the number of its residual struts exhibits an association with the degradation time. Given that the average number of degraded struts per day is 0.12, the complete stent is expected to be degraded within 105 days after implantation.

    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

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    Effects of static pressure on the cytocompatibility of adipose-derived stem cells on electrospun nanofibers
    Chen Liang, Bai Yi, Liu Kai, Zhang Wei
    2016, 20 (30):  4463-4468.  doi: 10.3969/j.issn.2095-4344.2016.30.008
    Abstract ( 383 )   PDF (5454KB) ( 206 )   Save

    BACKGROUND: Electrospun polylactic acid/polycaprolactone nanofibers (ENF) are a kind of self-synthesized biodegradable material. Our preliminary studies have indicated that the biomaterial exhibits excellent biocompatibility; however, the research about its mechanics is still little.
    OBJECTIVE: To explore the effects of static pressure on the cytocompatibility of adipose-derived stem cells on the ENF scaffold.
    METHODS: Adipose-derived stem cells were seeded onto the ENF scaffold, and then cultured in the low-glucose DMEM supplemented with 10% fetal bovine serum. The mixed constructs were submitted to the static pressure at 0, 15, 30, and 45 kPa for 4 hours using a static pressure device, respectively. Subsequently, the proliferation, adhesion and viability of adipose-derived stem cells on the ENF scaffold were detected using MTT assay and living/dead staining to evaluate the cytocompatibility.
    RESULTS AND CONCLUSION: MTT assay showed that there were significant differences in absorbance values among groups by one-way analysis of variance after 4 hours of loading with different static pressures in vitro. Under 0-30 kPa static pressure, the absorbance values increased with static pressure, but the absorbance values declined until the pressure reached 45 kPa, and multiple comparisons between groups showed significant difference. The significant differences in the cell attachment percentage by MTT assay could be found among groups. The living/dead staining results supported the above findings. Furthermore, the significant differences in percentage of living cells among groups were shown using either one-way analysis of variance or paired t test. In conclusion, the appropriate static pressure can promote the cytocompatibility, proliferation, adhesion and viability of adipose-derived stem cells on the ENF scaffold. But the excessive pressure is likely to inhibit the cellular biological behaviors, thus affecting cytocompatibility of adipose-derived stem cells with the ENF scaffold.

     

    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

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    Autologous oxygen-delivering biomimetic nanoscaffold composited with chondrocytes reconstructs the temporomandibular joint
    Wang Hong, Liao Tian-an, Wang Tao, Fu Liang-bin, Hu Guang-wei, Deng Wei
    2016, 20 (30):  4469-4475.  doi: 10.3969/j.issn.2095-4344.2016.30.009
    Abstract ( 331 )   PDF (1177KB) ( 236 )   Save

    BACKGROUND: The autologous oxygen-delivering biomimetic nanoscaffold is composited with chondrocytes in simulated microgravity to construct the active tissue-engineered bone, which not only has excellent osteogenic potential characteristics, but also has autologous releasing oxygen, and additionally can effectively prevent early transplant failure caused by sufficient revascularization and hypoxia.
    OBJECTIVE: To investigate the effects of autologous oxygen-delivering biomimetic nanoscaffold composited with chondrocytes on repairing different types of temporomandibular joint condylar fractures.
    METHODS: Totally 30 Sprague-Dawley rats were randomly divided into control group, experimental groups 1 and 2 (n=10 per group). The autologous oxygen-delivering nano-hydroxyapatite/chitosan scaffold composited with chondrocytes were transplanted into rats with temporomandibular joint condylar longitudinal fracture in the experimental group 1 and those with temporomandibular joint condylar transverse fracture in the experimental group 2, respectively. At 1, 3 and 6 weeks after transplantation, the number of proliferating cell nuclear antigen-positive cells was detected by immunofluorescence assay; the chondrocyte apoptosis was detected using TUNEL method, and expressions of collagen type II, Sox9 and vascular endothelial growth factor were observed by RT-PCR technology.
    RESULTS AND CONCLUSION: The number of proliferating cell nuclear antigen-positive cells in the experimental groups 1 and 2 were significantly higher than that in the control group at different time points after transplantation (P < 0.05). At 3 and 6 weeks after transplantation, the number of apoptotic chondrocytes in the experimental groups 1 and 2 was significantly lower than that in the control group (P < 0.05); significantly higher and highest expressions of collagen type II, Sox9 and vascular endothelial growth factor were found in the experimental groups 2 and 1 compared with the control group, respectively (P < 0.05). Additionally, compared with the experimental group 2, the number of proliferating cell nuclear antigen-positive cells was significantly lower in the experimental group 1 at 3 and 6 weeks after transplantation (P < 0.05); the number of apoptotic chondrocytes was significantly lower in the experimental group 1 at 3 weeks after transplantation (P < 0.05). These results indicate that autologous oxygen-delivering biomimetic nanoscaffold composited with chondrocytes to repair different types of temporomandibular joint condylar fractures presents some different outcomes.

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     Protective effect of nano-carbon tracers on the parathyroid glands
    Chen yong, Shan Wei-ying
    2016, 20 (30):  4476-4482.  doi: 10.3969/j.issn.2095-4344.2016.30.010
    Abstract ( 425 )   PDF (1191KB) ( 234 )   Save

    BACKGROUND: So far there are many studies about the uses of nano-carbon tracers in the diagnosis and treatment of malignancies. However, little has been reported on the mechanism underlying protective effect of nano-carbon tracers on the parathyroid glands during thyroid cancer surgery.
    OBJECTIVE: To study the protective effect of nano-carbon tracers on the parathyroid in thyroid cancer surgery.
    METHODS: 180 cases of thyroid cancer were randomly divided into nano-carbon and control groups (n=90 per group): patients in the nano-carbon group were injected with nano-carbon tracers into the thyroid before surgery, and those in the control group underwent routine thyroid cancer surgery. Then comparisons of the operating time, incision length, blood loss, postoperative hospital stay, number of lymph node dissection, lymph node metastasis as well as hypoparathyroidism rate were performed between two groups. Besides, levels of serum calcium and parathyroid hormone in the two groups were detected at 3 days after surgery.
    RESULTS AND CONCLUSION: There were no significant differences in the operating time, incision length, blood loss, postoperative hospital stay and lymph node metastasis between the two groups (P > 0.05). The number of dissected lymph nodes of nano-carbon group was significantly higher than that of control group (P < 0.05); the mis-resection rate of parathyroid and hypoparathyroidism of nano-carbon group were significantly lower than those of control group (P < 0.05). Furthermore, the incidences of hypocalcemia and low parathyroid hormone of nano-carbon group were significantly lower than those of control group (P < 0.05). These results suggest that the nano-carbon tracer plays a protective role on the parathyroid glands in thyroid cancer surgery, which can reduce the mis-resection rate of parathyroid, as well as the incidences of hypoparathyroidism, hypocalcemia and low-level parathyroid hormone.

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    Gelatin sponge containing prednisolone acetate relieves radicular pain following posterior lumbar interbody fusion
    Yao Zhen-song, Chen Kang, Jiang Xiao-bing, Liang De, Tang Jing-jing
    2016, 20 (30):  4483-4488.  doi: 10.3969/j.issn.2095-4344.2016.30.011
    Abstract ( 505 )   PDF (2233KB) ( 238 )   Save

    BACKGROUND: Posterior lumbar interbody fusion can thoroughly decompress the central canal, which is the common surgical technique for the central type of lumbar disc herniation with intervertebral instability at low lumbar segment. However, due to the regular traction on dural sac and nerve root in the operation, lower limb radicular pain in the early stage is inevitable.
    OBJECTIVE: To evaluate the effect of local use of gelatin sponge containing prednisolone acetate around the nerve roots after posterior lumbar interbody fusion on lower limb radicular pain.
    METHED: Sixty-three cases of lumbar disc herniation with degenerative instability were devided into treatment group (n=21) and control group (n=42) based on the type of implants. Gelatin sponge containing prednisolone acetate was implanted into patients in the treatment group after posterior lumbar interbody fusion, while pure gelatin sponge was implanted into patients in the control group.
    RESULTS AND CONCLUSION: Compared with the control group, radicular pain in the treatment group was significantly relieved within 1 week after surgery. The visual analog scale score and Oswestry disability index score were similar between the two groups. There were three cases of radicular pain recurrence in the control group, but no incision infection and epidural hematoma after surgery in both two groups. In conclusion, local use of gelatin sponge containing prednisolone acetate around the nerve roots can significantly relieve lower limb radicular pain in the early stage after posterior lumbar interbody fusion in lumbar disc herniation, contributing to early rehabilitation exercise and patient satisfaction outcomes.

    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

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    Long-circulating methotrexate-loaded liposomes exhibit an antitumor effect on human osteosarcoma in vitro
    Qin Ying-zhou, Chen Han, Zhang Yang, Zhang Qi-qing, Liu Ling-rong
    2016, 20 (30):  4489-4495.  doi: 10.3969/j.issn.2095-4344.2016.30.012
    Abstract ( 343 )   PDF (1303KB) ( 251 )   Save

    BACKGROUND: Liposomes as a new drug delivery system are characterized by few adverse reactions, no immunogenicity and biodegradation. Furthermore, methotrexate-loaded liposomes can significantly reduce drug toxicity and improve anti-tumor effect.
    OBJECTIVE: To prepare long-circulating methotrexate-loaded liposomes and to evaluate its antitumor activity in MG-63 in vitro.
    METHODS: The methotrexate-loaded liposomes were prepared using the film dispersion method, and the long-circulating ones were prepared using the post-insertion method. The initial concentrations of methotrexate were 9.1, 1.82, 0.364 g/L. The ultracentrifugation method and spin column method with Sephadex G-10 or G-50 as packing were employed to separate free drugs from the methotrexate-loaded liposomes. Their recovery, size, morphology, encapsulation efficiency and drug-to-lipid ratio were evaluated. The cytotoxity of the long-circulating methotrexate-loaded liposomes purified with ultracentrifugation method and spin column G-50 method under three dose levels (0, 1, 5, 25 mg/L) were determined by MTS method.
    RESULTS AND CONCLUSION: According to the recovery rates of three methods, the spin column G-50 method was considered as optimal for the long-circulating methotrexate-loaded liposomes. The long-circulating liposomes were spherical or ellipsoidal under transmission electron microscope, about  200 nm in size. At the certain initial concentration of methotrexate, the encapsulation efficiency and drug-to-lipid ratio of the liposomes purified using the spin column G-50 method were remarkably higher than those purified using the other two methods. At the same mass concentration, the cytotoxity of the liposomes purified with ultracentrifugation or spin column G-50 was significantly higher than that of free methotrexate, and furthermore, the cytotoxity of the liposomes purified with spin column G-50 was higher than that of the liposomes purified with ultracentrifugation method. To conclude, the long-circulating methotrexate-loaded liposomes show a higher antitumor activity than free methotrexate in MG-63 cells in vitro, providing the basis for further investigation of its antitumor effect on human osteosarcoma in vivo.

    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

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    Biological properties of acellular dermal matrix derived from mature scar tissue versus normal skin
    Wang Yang-yang, Li Xiao-jing, Bu Shou-shan
    2016, 20 (30):  4496-4502.  doi: 10.3969/j.issn.2095-4344.2016.30.013
    Abstract ( 520 )   PDF (1638KB) ( 240 )   Save

    BACKGROUND: It is necessary to carry out multiple operations to remove the scar in patients with large area of scar, and whether the scar tissue can be recycled has become the focus of the study.
    OBJECTIVE: To compare the tissue structure, biomechanical properties and biocompatibility of the acellular dermal matrix of mature scar tissue and normal skin.
    METHODS: The acellular dermal matrix was prepared from the human mature scar tissue and the normal skin around the scar. Subsequently, histological and scanning electron microscope observations were performed, and biomechanical properties were detected using universal tensile testing machine. Then, the acellular dermal matrix from mature scar tissue and normal skin was co-cultured with fibroblasts for 10 days, respectively, and the cell growth curve was drawn. Additionally, the acellular dermal matrix from mature scar tissue and normal skin was subcutaneously implanted into the dorsal tissue of Sprague-Dawley rats, respectively and histological observation was conducted at 4, 8 and 12 weeks after implantation.
    RESULTS AND CONCLUSION: There were many gaps but no cellular components in the acellular dermal matrix, in both two groups. Collagen fibers of the acellular dermal matrix derived from mature scar were looser than that of the normal skin, and arranged slightly irregularly; the biomechanical properties of the acellular dermal matrix derived from mature scar were similar to that of the normal skin, which exhibited appropriate flexibility and strength. There was no significant difference in the growth state of the two kinds of acellular dermal matrix, and the growth curve was basically consistent. After 4 weeks of implantation, more inflammatory cells infiltration could be found in the mature scar group, and in contrast, only a few inflammatory cells infiltration appeared in the normal skin group, These inflammatory reactions disappeared with time in both two groups. Besides, collagen fibers arranged in neat, and small vessels grew into the implants in both two groups. In conclusion, the tissue structure, biomechanical properties and biocompatibility of the acellular dermal matrix derived from scar tissue are almost consistent with those of the human normal skin.

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     Use of the Y-shaped mesh in functional repair of the pelvic floor in women
    Zhang Yu-di, Lu Dan, Zheng Ping, Wu Xia, Li Hui, Liu Ju-hong
    2016, 20 (30):  4503-4508.  doi: 10.3969/j.issn.2095-4344.2016.30.014
    Abstract ( 419 )   PDF (1047KB) ( 192 )   Save

    BACKGROUND: The Y-shaped mesh graft material weaved using lightweight polypropylen has the appropriate porosity, which not only can make the vaginal tissues grow and fuse rapidly on the mesh, but also can maintain good biological strength to ensure the fixed strength for the presacral suspension.
    OBJECTIVE: To retrospectively analyze the clinical effect of Y-shaped mesh for the biological function reconstruction of the female pelvic floor.
    METHODS: Ten female cases of pelvic floor dysfunction were enrolled, aged 37-73 years, and all were given the treatment of sacral colposuspension under laparoscopy. Then perioperative complications were recorded; patients were followed up regularly to record the Pelvic Organ Prolapse Quantification (POP-Q) score at different time points; and the subjective satisfaction was investigated using the Pelvic Floor Impact Questionnaire (PFIQ-7).
    RESULTS AND CONCLUSION: After at least 6-month follow-up, no postoperative pelvic infection, nerve damage and complications appeared, the patients healed well, and no mesh erosion, infection and other adverse reactions occurred. The POP-Q and PFIQ-7 scores at 1, 3 and 6 months after repair were significantly improved than those before repair (P < 0.05). These results suggest that the Y-shaped biological mesh repairing female midpelvic floor dysfunction has good biocompatibility, and can restore the anatomy of the pelvic floor.

    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

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    Implant fixation with titanium alloy repairs spinal tuberculosis: its biocompatibility and mechanical properties
    Zhuang Yong, Shang Xian-wen, Zhang Hao, Liu Miao, Xu Shun-en
    2016, 20 (30):  4509-4514.  doi: 10.3969/j.issn.2095-4344.2016.30.015
    Abstract ( 360 )   PDF (1087KB) ( 229 )   Save

    BACKGROUND: Currently, surgical implant fixation is mainly applied for spinal tuberculosis. How to choose implant materials, however, is still under discussion.
    OBJECTIVE: To compare the biocompatibility and mechanical properties of titanium alloy and stainless steel for rabbit spinal tuberculosis.
    METHODS: Thirty rabbits were chosen to prepare spinal tuberculosis models. Then, the rabbits were equivalently randomized into two groups, which underwent implant fixation with stainless steel or titanium alloy, respectively. At 30 days after implantation, biocompatibility and biomechanical properties of the two materials in the repaired region of spine were observed and detected, respectively.
    RESULTS AND CONCLUSION: In view of the biocompatibility, infection and immunological rejection could not been found in the titanium alloy group; in contrast, infection appeared in three rabbits of the stainless steel group. Flexion, extension and lateral bending displacements under the spinal loading in the titanium alloy group were significantly less than those in the stainless steel group (P < 0.05); axial pull-out strength in the titanium alloy group was significantly higher than that in the stainless steel group (P < 0.05); flexion, extension, lateral bending and axial compression in the titanium alloy group were significantly greater than those in the stainless steel group (P < 0.05). In conclusion, titanium alloy material has good biocompatibility that can be used to restore and maintain the spinal stability.

     

    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

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    Surface construction and biocompatibility of polymer materials as cardiovascular devices: modified tissue-engineered endothelial cells on the surface of polymeric biomaterials
    Chen Bao-lin, Wang Dong-an
    2016, 20 (30):  4515-4523.  doi: 10.3969/j.issn.2095-4344.2016.30.016
    Abstract ( 375 )   PDF (854KB) ( 233 )   Save

    BACKGROUND: As the cardiovascular device, biomaterials applied under the blood-contact conditions should have anti-thrombotic, anti-biodegradable and anti-infective properties.
    OBJECTIVE: To review the research progression in polymer materials for implantation and intervention in cardiovascular tissue engineering and to explore the biocompatibility, blood compatibility and cytocompatibility of the surface-modified polymer biomaterials based on the surface endothelialization using tissue engineering techniques.
    METHODS: We retrieved PubMed and Wanfang databases for relevant articles publishing from 1963 to 2015. The key words were “Biocompatibility, Blood compatibility, Biomedical Materials, Biomedical polymer materials” in English and Chinese, respectively. Those unrelated, outdated and repetitive papers were excluded. Literatures addressing the blood compatibility, biocompatibility, and cytocompatibility of the surface-modified polymer biomaterials based on the surface endothelialization using tissue engineering techniques were investigated by summarizing function of vascular endothelial cells, tissue-engineered endothelial cells on the implant surface, fixation of cell growth-promoting factor on the surface of polymeric biomaterials, and endothelialization of the material surface.
    RESULTS AND CONCLUSION: Totally 71 relevant articles were included. The tissue-engineered modification of endothelial cells on the surface of polymer biomaterials and their biocompatibility and cell compatibility are crucial for developing novel polymer materials for implantation and intervention in cardiovascular tissue engineering. Through in-depth studies of the types and applications of polymer biomaterials, cardiovascular medical devices and implantable soft tissue substitutes, the differences between the surface and the body will be reflected in the many layers of molecules extending from the surface to the body. Two major factors, surface energy and molecular mobility, determine the body/surface behaviors that include body/surface differences and phase separation. Considering the difference between the body/surface composition, an additional determinant is indispensable, that is, the crystallization behavior of each component.

    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

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    Morpholine-2, 5-dione and its derivatives: the valuable biodegradable polymer materials
    Zhou Qun-hua, Yang Li-qun, Zhang Wei, Li Miao
    2016, 20 (30):  4524-4531.  doi: 10.3969/j.issn.2095-4344.2016.30.017
    Abstract ( 395 )   PDF (1063KB) ( 289 )   Save

    BACKGROUND: Currently, biodegradable polymer materials such as poly(morpholine-2, 5-dione) and its derivatives have been widely used in biomedical field to fabricate nerve catheters, tissue engineering and drug control release carriers. Therefore, many research has focused on the synthesis of poly(morpholine-2, 5-dione) and its derivatives.
    OBJECTIVE: To review the synthesis methods of monomeric and polymeric morpholine-2, 5-dione and its derivatives, and to explore its advantages and shortcomings.
    METHODS: A computer-based search of databases of Wanfang, CNKI, SCI and PubMed was performed for relevant articles published from 1982 to 2015. And the keywords were “morpholine-2, 5-dion, biodegradable” in Chinese and English, respectively.
    RESULTS AND CONCLUSION: So far, acylation reactions of α-amino acids and α-halogen halide, the intramolecular esterifications and intramolecular condensation reactions are the key methods for the synthesis of morpholine-2, 5-dione and its derivatives. A modified approach is needed to overcome the existed disadvantages. Ring-opening polymerization of morpholine-2, 5-dione is a preferred method of synthetic polyester-amide, but low molecular weight and conversion of polymers are produced. Polymerization catalyzed via metal compounds and enzymes are the best strategy for the synthesis of poly(morpholine-2, 5-dione). Furthermore, as a valuable biodegradable polymer material, poly(morpholine-2, 5-dione) has been extensively applied in the medical field.

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    Sustained-release carriers of insulin: applications and existing problems
    Chen Guo-chang, Gao Hong
    2016, 20 (30):  4532-4538.  doi: 10.3969/j.issn.2095-4344.2016.30.018
    Abstract ( 416 )   PDF (1078KB) ( 253 )   Save

    BACKGROUND: Sustained-release carriers of insulin shaped as microspheres made of different biomaterials have become an issue of concern.
    OBJECTIVE: To summarize the carrier materials and methods to prepare sustained-release microspheres of insulin.
    METHODS: Wanfang and PubMed databases were retrieved by computer for articles related to sustained-release carriers of insulin published from 1997 to 2015. The search terms were “insulin, controlled-release carrier, biomaterials” in Chinese and English, respectively.
    RESULTS AND CONCLUSION: Natural biodegradable polymer materials are preferred to prepare sustained-release microspheres of insulin, including gelatin, alginate, chitosan and its derivatives. These natural materials have good biocompatibility, degradability, film-forming and microsphere-forming abilities. Synthetic biodegradable polymer materials as carrier materials can promote drug stability and effective utilization, and realize targeted drug delivery. According to different physicochemical properties of materials, sustained-release carriers of insulin that meet different requirements can be prepared using emulsion-chemical crosslinking, spray drying and solvent evaporation methods. This review provides new insight into the development of stable drug carriers.

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    Functional bone tissue engineering scaffold used to repair tuberculosis bone defect
    Sun Xiao-hu, Yuan Jing, Zhang Yu, Qiao Yong-jie, Cao Xue-fei, Meng Lei3 Gao Zhan-wang, Meng Lei, Gao Zhan-wang, Zhen Ping
    2016, 20 (30):  4539-4546.  doi: 10.3969/j.issn.2095-4344.2016.30.019
    Abstract ( 448 )   PDF (1412KB) ( 258 )   Save

    BACKGROUND: Repairing tuberculosis bone defect has become a research focus with the development of anti-tuberculosis functional bone tissue engineering scaffold.
    OBJECTIVE: To evaluate the preparation, drug release performance and osteogenic properties of the anti-tuberculosis functional bone tissue engineering scaffold.
    METHODS: PubMed, Chinese Journal Full-text Database, Wanfang databases were searched by computer for articles addressing functional bone tissue engineering scaffold for repair of tuberculosis bone defect. The keywords were “bone tissue engineering scaffold; tuberculosis; bone defect” in English and Chinese. RESULTS AND CONCLUSION: The anti-tuberculosis functional bone tissue engineering scaffold has good drug delivery, biocompatibility, osteogenic properties and anti-tuberculosis properties. As a good choice to avert bone defect relapse, the scaffold enables a long and stable drug release into bone defects to enhance the therapeutic efficacy of anti-tuberculosis drugs topically. Given the technical deficiencies, we can only combine two drugs with the anti-tuberculosis bone tissue engineering scaffold, although the combined use of three or four anti-tuberculosis drugs is preferred. Additionally, a complete course of anti-tuberculosis treatment often lasts for 6-12 months, which cannot be achieved by the existing anti-tuberculosis bone tissue engineering scaffold. Up to now, the effect of this scaffold has not yet been confirmed in animal models, although how to prepare this scaffold has been reported.

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    Hydroxyapatite/zirconia gradient composite scaffolds for bone tissue engineering: current uses and perspectives
    Shao Rong-xue, Huang Xiao-long, Hu Hua-hui, Quan Ren-fu, Xie Shang-ju, Li Xi
    2016, 20 (30):  4547-4553.  doi: 10.3969/j.issn.2095-4344.2016.30.020
    Abstract ( 477 )   PDF (1123KB) ( 173 )   Save

    BACKGROUND: Porous gradient hydroxyapatite/zirconia composite, which can adhere to a variety of cells, such as osteoblasts, bone marrow mesenchymal stem cells and chondrocytes, can induce and promote fracture healing or replace bone defects.
    OBJECTIVE: To review the development and application of porous gradient hydroxyapatite/zirconia composite in bone tissue engineering.
    METHODS: Articles related to porous gradient hydroxyapatite/zirconia composite in bone tissue engineering were retrieved in CNKI and PubMed databases (1971-01/2014-12). The key words were “porous bioceramic, bone tissue engineering, bone morphogenetic protein-2, induced pluripotent stem cells” in Chinese and English, respectively. A total of 54 articles based on inclusion criteria and exclusion criteria were obtained for the review.
    RESULTS AND CONCLUSION: Porous gradient hydroxyapatite/zirconia composite can provide a scaffold to induce naturally forming bone growing to fill the three-dimensional pores, thus realizing the perfect integration of tissue-engineered bone material and host-bone tissue. As zirconia functions as an enhancer of hydroxyapatite, high-quality artificial bone materials, which have elastic modulus, fracture toughness and structure similar to human bone, can be prepared by adjusting the proportion and porosity of materials. Additionally, the new hydroxyapatite/zirconia foamed ceramics as tissue-engineered bone carrying bone morphogenetic protein-2/chitosan gel sustained release system and bone marrow mesenchymal stem cells derived from induced pluripotent stem cells will be expected to increase bone formation and bone fusion rates significantly in the future.

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     Use of the Smart nitinol stent system for the treatment of severe atherosclerotic carotid stenosis: study protocol for a retrospective non-randomized controlled trial
    Ma Zhi-gang, Sun Yu-heng, Peng Xiao-xin, Hu Hong-tao
    2016, 20 (30):  4554-4560.  doi: 10.3969/j.issn.2095-4344.2016.20.021
    Abstract ( 480 )   PDF (1324KB) ( 204 )   Save

    BACKGROUND: The self-expanding Smart nitinol stent system is a popular treatment for carotid artery stenosis, because it is easy to manipulate and deploy, and endothelialization is rapid.
    OBJECTIVE: To assess the efficacy of Smart nitinol stent system for the treatment of severe atherosclerotic carotid stenosis.
    METHODS: We conducted a retrospective, single-center, non-randomized, parallel controlled trial. A cohort of 103 patients with severe atherosclerotic carotid stenosis was included in the analysis after obtaining written informed consent from participants or their guardians. Treatment was undertaken according to each patient’s wishes after weighing the options: a Smart nitinol stent system (Cordis Corporation, Miami, FL, USA) was used in 40 patients, while 63 were managed conservatively with antiplatelet drugs. The primary outcome is the degree of disability of dependence 2 years after treatment, assessed by the modified Rankin Scale. The secondary outcomes are mRS scores 90 days and 1 year after treatment, recurrence of cerebrovascular events, and severity of neurologic deficit measured using the National Institutes of Health Stroke Scale 1 and 2 years after treatment. The study protocol was approved by the Ethics Committee of Beijing Jishuitan Hospital, China (approval number: 201605-01) and conducted in accordance with the guidelines of the Declaration of Helsinki, formulated by the World Medical Association. This trial was registered at ClinicalTrial.gov (NCT02800174).
    DISCUSSION: Previous studies of the Smart nitinol stent system for the treatment of carotid stenosis are mostly self-controlled case series or small cohort studies with short follow-up periods. Consequently, the long-term influence of Smart nitinol stent deployment on the risk of cerebrovascular events and long-term outcomes are not known. This trial illuminates the therapeutic benefits of the Smart nitinol stent system in a 2-year follow-up study involving a large cohort of patients with severe atherosclerotic carotid stenosis.

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