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08 October 2021, Volume 25 Issue 28 Previous Issue    Next Issue

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Screening and optimization of three-dimensional scaffolds for the construction of bioartificial liver bioreactor Chen Li, Huang Lei, Yu Mengyao, Zhang Guoying, Zhang Shichang 2021, 25 (28):  4429-4434.  doi: 10.12307/2021.053 Abstract ( 813 )   PDF (904KB) ( 588 )   Save BACKGROUND: Bioreactor is the core part of bioartificial liver, and its performance determines the effect of bioartificial liver support therapy. The application of scaffolds in hollow fiber bioreactor is expected to solve the problem of insufficient support for hepatocyte culture. OBJECTIVE: To screen three-dimensional scaffolds for the development of bioartificial liver reactor. METHODS: The porosity of polyurethane, chitosan and poly(DL-lactide-co-glycolide) scaffolds was detected. HL-7702 human hepatocytes were seeded on three kinds of scaffolds respectively, and the cell inoculation rate was detected at 4 hours; the cell viability and lactate dehydrogenase leakage were detected at 24 hours; and the intracellular albumin synthesis was detected at 3 days. According to the above experimental results, polyurethane was selected in the following experiment. In the rat tail collagen coating group, material was inoculated with rat tail collagen solution and then inoculated with HL-7702 human hepatocyte suspension. In the fibrin gel group, HL-7702 human hepatocytes were resuspended in fibrinogen culture medium, and then inoculated on the scaffold. In the polyurethane control group, material was inoculated with HL-7702 human hepatocyte suspension directly. After 1, 3, 5, and 7 days of culture, cell viability, lactate dehydrogenase leakage and albumin synthesis were detected.  RESULTS AND CONCLUSION: (1) The three kinds of scaffolds were porous. Polyurethane and chitosan scaffolds had good elasticity, but poly(DL-lactide-co-glycolide) scaffold was hard. The porosity of polyurethane and chitosan scaffolds was significantly higher than that of poly(DL-lactide-co-glycolide) scaffold (P < 0.05). (2) The inoculation rate of cells in polyurethane scaffold was significantly higher than that in poly(DL-lactide-co-glycolide) scaffold (P < 0.05), and significantly lower than that in chitosan scaffold (P < 0.05). The cell viability and albumin synthesis of cells cultured in polyurethane and chitosan scaffolds were significantly higher than that of poly(DL-lactide-co-glycolide) scaffold (P < 0.05). There was no significant difference in lactate dehydrogenase leakage among the three groups (P > 0.05). (3) The cell distribution of fibrin gel group was more homogeneous than that of polyurethane control group and rat tail collagen coating group. The cell viability and albumin content at 3, 5, and 7 days after culture were higher than those of polyurethane control group and rat tail collagen coating group (P < 0.05). The lactate dehydrogenase leakage amount at 3, 5, and 7 days of culture was lower than that of polyurethane control group and rat tail collagen coating group (P < 0.05). (4) Our results suggested that fibrin gel optimized polyurethane scaffolds could be used in the construction of bioartificial liver reactor. Figures and Tables | References | Related Articles | Metrics

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Kummell’s disease treated by intra-pedicle bone cement perfusion combined with kyphoplasty: To enhance the stability of bone cement mass in the vertebral body Yao Rubin, Wang Shiyong, Yang Kaishun 2021, 25 (28):  4435-4440.  doi: 10.12307/2021.054 Abstract ( 426 )   PDF (1117KB) ( 523 )   Save BACKGROUND: Percutaneous kyphoplasty is one of the effective measures for the treatment of Kummell’s disease, but there is a displacement of bone cement mass after operation, which leads to pain and even failure, so some scholars have proposed to reduce the pain that may be aggravated by pedicle injection of bone cement, but its curative effect is not clear.  OBJECTIVE: To explore the clinical effect of transpedicular bone cement perfusion combined with percutaneous kyphoplasty in the treatment of Kummell’s disease.  METHODS: From January 1, 2015 to December 31, 2018, 27 patients with Kummell’s disease, including 7 males and 20 females, aged mean (70.44±6.44) years, who were treated in the Department of Spinal Surgery, the First Affiliated Hospital of Dali University, were retrospectively analyzed. All patients were followed up from 8 to 36 months. All patients were treated with percutaneous kyphoplasty operation. Gelatin sponge and high viscosity bone cement were used to reduce the leakage of bone cement; bone cement perfusion in the pedicle was performed. The visual analogue scale score and Oswestry disability index of back pain before and after treatment and the last follow-up were recorded, and the anterior and posterior vertebral height and wedge angle were measured before and after operation. CT scanning was used to observe the leakage of bone cement and the bone cement in the pedicle after operation, and the displacement of bone cement during the follow-up period.  RESULTS AND CONCLUSION: (1) A total of 29 diseased vertebrae of 27 patients were included in the study. The average operation time was (49.46±14.8) minutes and the average amount of bone cement injection was (4.32±1.72) mL. Cement leakage was found in a total of three diseased vertebrae, all of which were transcortical defect leakage (type C). (2) The visual analogue scale score and Oswestry disability index on the first day and the last follow-up were significantly better than those before operation (P < 0.05). Oswestry disability index during the last follow-up was significantly improved than that on the first day after operation (P < 0.05). (3) The wedge angle of the diseased vertebrae after operation was significantly lower than that before operation; anterior vertebral height and posterior vertebral height of the diseased vertebrae after operation were significantly higher than those before operation, and the difference was statistically significant (P < 0.05). (4) It is concluded that intrapedicular bone cement infusion combined with percutaneous kyphoplasty can connect the vertebral body and pedicle bone cement into one, and enhance the stability of bone cement mass, and effectively prevent the displacement of bone cement in vertebral body, which is an effective technique for the treatment of Kummell’s disease. Figures and Tables | References | Related Articles | Metrics

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Three-dimensional printed porous titanium alloy scaffolds with different apertures in repair of femoral defects in rabbits: 600 μm aperture is more conducive to osseointegration Wang Qing, Weng Yiping, Liu Hongwei, Zhang Wen, Shi Qin, Zhang Runze, Jiang Junfeng, Wang Caimei 2021, 25 (28):  4441-4446.  doi: 10.12307/2021.055 Abstract ( 499 )   PDF (1164KB) ( 159 )   Save BACKGROUND: The microporous structure of a porous titanium alloy can not only provide sufficient space for the proliferation and migration of osteoblasts, but also promote the angiogenesis of mesenchymal stem cells, affect the expression of osteogenic genes and the differentiation of osteoblasts, which is an important factor for bone integration. OBJECTIVE: To analyze the osseointegration ability of three-dimensional printed porous titanium alloy scaffolds with different apertures in repairing rabbit femoral condyle defect. METHODS: Totally 40 hind legs of 20 New Zealand rabbits were randomly divided into group A, group B, group C, and group D. A 5 mm×5 mm bone defect model was established. Groups A, B, and C were implanted with porous titanium alloy scaffolds with a diameter of 200, 600, and 1 000 μm, while group D was not implanted. X-ray films were taken at 4 and 8 weeks after operation to observe whether there was displacement, prolapse and osteolysis, and osteonecrosis around the implants. At 8 weeks after operation, the trabecular thickness, trabecular number, trabecular volume, bone surface area density, and trabecular separation were detected by micro CT. The osseointegration was observed by histology. The experimental protocol was approved by the Animal Experiment Ethics Committee of Soochow University.  RESULTS AND CONCLUSION: (1) X-ray films showed that the implants were in good position, without obvious displacement or falling off, and the bone around the materials was good, without osteolysis, osteonecrosis or other bad phenomena. (2) Micro-CT examination showed that bone tissue existed in the pores and around the implants in three groups. The number of trabeculae and bone surface area density in group B were significantly higher than those in the groups A and C (P < 0.05). The trabecular thickness of micropores in the group A was significantly higher than that in the groups B and C (P < 0.05). (3) Toluidine blue staining showed that the new bone tissue grew into almost all the surface micropores in group B, and some of the new bone extended into the deep pores of the experimental scaffold, closely combined with the porous structure, forming mechanical interlocking. Groups A and C had only a small amount of new bone tissues in surface micropores, and there was not new bone tissues in deep pores. The combination of new bone and implant was poor. (4) The results showed that the three-dimensional printed porous titanium alloy scaffold with 600 μm aperture was more conducive to new bone formation compared with 200 μm and 1 000 μm aperture. Figures and Tables | References | Related Articles | Metrics

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Three-dimensional printed artificial bone loaded with anti-tuberculosis drugs and bone morphogenetic protein 2 sustained-release microspheres can promote osteogenesis of bone marrow mesenchymal stem cells Liu Changhao, Zheng Jianping, Shi Jiandang, Zhu Xi, Zhou Zhanwen, Zhang Xu 2021, 25 (28):  4447-4453.  doi: 10.12307/2021.056 Abstract ( 558 )   PDF (2522KB) ( 224 )   Save BACKGROUND: Insufficient local effective drug concentration after debridement of spinal tuberculosis lesions and repair of residual bone defects are the current problems in the treatment of spinal tuberculosis. New anti-tuberculosis drugs combined with bone morphogenetic protein 2 (BMP-2) have become a new idea to solve this problem, which can effectively promote bone defect repair. OBJECTIVE: To observe the effect of PA-824, moxifloxacin and pyrazinamide (PaMZ)/BMP-2/nano-hydroxyapatite (nHA) anti-tuberculosis artificial bone on osteogenic differentiation and adhesion of rabbit bone marrow mesenchymal stem cells. METHODS: Rabbit bone marrow mesenchymal stem cells were extracted and purified. The nHA was used to fabricate the three-dimensional printed artificial bone containing anti-tuberculosis drugs PA-824, moxifloxacin, pyrazinamide and BMP sustained-release microspheres (PaMZ/BMP-2/nHA), and co-cultured with the third generation of bone marrow mesenchymal stem cells as the experimental group. BMP-2 was co-cultured with bone marrow mesenchymal stem cells as a positive control group. Bone marrow mesenchymal stem cells were cultured separately as blank control group. The proliferation, osteogenesis and cell adhesion effects of rabbit bone marrow mesenchymal stem cells were respectively tested at 1, 3, 7, 14, and 21 days of culture to evaluate the influence of the artificial bone on the osteogenic differentiation of rabbit bone marrow mesenchymal stem cells. The cell proliferation and cytotoxicity were detected by CCK-8 assay. The degree of calcium nodule deposition and alkaline phosphatase expression activity were measured to evaluate the influence of osteogenic differentiation. Fluorescence quantitative PCR and western blot assay were used to detect the expression levels of osteogenicgenes and proteins, respectively. The adhesion characteristics of cells were observed by scanning electron microscopy.  RESULTS AND CONCLUSION: (1) The newly synthesized anti-tuberculosis artificial bone showed good spatial microstructure, which was conducive to cell attachment. (2) CCK-8 assay showed that the cells in each group proliferated well. Among them, the experimental group and the positive control group showed a proliferation state for 14 days, and the blank control group became stable after 7 days, indicating that the artificial bone had good biocompatibility. (3) The alkaline phosphatase activity appeared a trend of increasing first and then decreasing, reaching a peak at 14 days. At 7 and 14 days, the alkaline phosphatase activity of the positive control group was higher than that of the experimental group (P < 0.05), but the activity of the experimental group was higher than that in the positive control group at 21 days. The change was not obvious in the blank control group at each time point. (4) Alizarin red staining experiments revealed that calcium nodules were formed in the experimental group and the positive control group, and the differences in the number and size of calcium nodules between the experimental group and the positive control group were not obvious. The expression levels of bone-related genes and proteins (Runx2 and collagen I) were higher in the two groups than those in the blank control group (P < 0.05). (5) Under the scanning electron microscope, it was observed that the cells adhered tightly to the scaffold and showed “Eight Claws” or long fusiform growth. (6) It is concluded that the newly synthesized anti-tuberculosis artificial bone has a unique spatial structure and good biocompatibility, which can promote the proliferation and osteogenesis of bone marrow mesenchymal stem cells, and is an ideal bone tissue engineering material. Figures and Tables | References | Related Articles | Metrics

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A hydrogel based on acellular decalcified bone matrix/erythropoietin promotes osteogenesis and angiogenesis Zhou Jianwei, Zhou Jing, Li Mao, Chi Cheng, Wang Fei 2021, 25 (28):  4454-4459.  doi: 10.12307/2021.057 Abstract ( 550 )   PDF (1624KB) ( 143 )   Save BACKGROUND: In recent years, acellular decalcified bone matrix (ADBM) exhibits tremendous potential and application prospects in bone defect repair due to its favorable biocompatibility and biomechanics. Erythropoietin (EPO) can promote the formation of local blood vessels and thus indirectly regulate bone repair owing to crucial role in angiogenesis of bone repair. OBJECTIVE: To investigate the effects of acellular decalcified bone matrix/erythropoietin (ADBM-EPO) hydrogel on osteogenesis and angiogenesis. METHODS:  ADBM hydrogel and ADBM-EPO hydrogel were constructed. Human bone marrow mesenchymal stem cells and human umbilical vein endothelial cells were respectively seeded on the two hydrogels, and the conventionally cultured cells were used as the control group. The effects on the migration ability of two kinds of cells were detected through cell transmembrane invasion and cell scratch migration experiments. The effects of the two hydrogels on osteogenic differentiation of bone marrow mesenchymal stem cells were determined by alkaline phosphatase and alizarin red staining.   RESULTS AND CONCLUSION:  (1) Compared with the control group, ADBM hydrogel and ADBM-EPO hydrogel could promote the migration of bone marrow mesenchymal stem cells or umbilical vein endothelial cells. Moreover, the ADBM-EPO hydrogel had better migration ability than that of ADBM hydrogel. (2) Compared with the control group, both ADBM and ADBM-EPO hydrogels could reduce the scratch distance of human bone marrow mesenchymal stem cells or human umbilical vein endothelial cells. Of them, ADBM-EPO hydrogel was more effective than ADBM hydrogel. (3) Compared with the control group, both ADBM and ADBM-EPO hydrogels could increase the alkaline phosphatase activity and the number of calcium nodules in bone marrow mesenchymal stem cells. Moreover, the ADBM-EPO hydrogel had better ability than that of ADBM hydrogel. (4) The above experimental results showed that the ADBM-EPO hydrogel had a bidirectional role in promoting osteogenesis and angiogenesis. Figures and Tables | References | Related Articles | Metrics

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Biological characteristics of hydroxyapatite/chitosan combined with metformin for bone defect in rats Li Rui 2021, 25 (28):  4460-4464.  doi: 10.12307/2021.058 Abstract ( 519 )   PDF (1054KB) ( 108 )   Save BACKGROUND: Metformin can stimulate the osteogenic differentiation of stem cells and promote the regeneration and repair of bone tissue. OBJECTIVE: To observe the restorative effect of hydroxyapatite/chitosan combined with metformin on skull defects in rats. METHODS: The hydroxyapatite/chitosan/metformin composite was prepared by dissolving chitosan into metformin deionized water solution and adding hydroxyapatite with certain mass ratio. Hydroxyapatite/chitosan composite was prepared by the same method. The hydroxyapatite/chitosan/metformin composite was immersed in cell culture medium, and the release rate of metformin in the composite was detected in vitro. Thirty 8-week-old male Sprague-Dawley rats were used to make skull defects at a diameter of 5 mm. Samples were randomly divided into three groups. No material was implanted in the blank group. The control group and experimental group were implanted with hydroxyapatite/chitosan composite and hydroxyapatite/chitosan/metformin composite respectively. At 3 months after operation, X-ray, micro CT and histological examination were performed. The animal experiment was approved by the Ethics Committee of Hubei Medical University (approval No. 20170539). RESULTS AND CONCLUSION: (1) Hydroxyapatite/chitosan/metformin composite sustained release of metformin in the cell culture medium, and the cumulative release of metformin was (95.37±4.31)% at 21 days, which showed that metformin continued to release throughout the induction and differentiation of osteoblasts. (2) X-ray and micro-CT results showed that the skull bone defects of the three groups were repaired to different degrees, and the fracture line was fuzzy. The area and volume of new bone in the experimental group were larger than those in the control group and blank group, and those in the experimental group were significantly larger compared with the control group. (3) Hematoxylin-eosin staining results showed that in the experimental group and the control group, the materials were degraded in different degrees. The new bone was mainly filled in the gap between the scaffold materials, with a small number of fiber cells around. The percentage and density of new bone area in the experimental group and the control group were significantly higher than those in the blank group (P < 0.05), while the percentage and density of new bone area in the experimental group were significantly higher than those in the control group (P < 0.05). (4) The results indicate that hydroxyapatite/chitosan/metformin composite biomaterial has a good osteogenic promoting effect. Figures and Tables | References | Related Articles | Metrics

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Preparation of platelet-derived growth factor loaded three-dimensional bio-printed Meniscus scaffold 李 浩, 杨 振, 高仓健, 付力伟, 苑志国, 眭 翔, 刘舒云, 郭全义 2021, 25 (28):  4465-4472.  doi: 10.12307/2021.059 Abstract ( 384 )   PDF (2525KB) ( 222 )   Save BACKGROUND: Based on the need of in situ tissue engineering regeneration in the field of meniscus regeneration, three-dimensional (3D) bioprinting technology can be used to construct a scaffold which can effectively combine recruitment bioactive factors and excellent materials. OBJECTIVE: To optimize the preparation process of polycaprolactone/methacrylate anhydride gelatin/meniscus extracellular matrix (PCL/GelMA/MECM) 3D bioprinting scaffold loaded with platelets derived growth factor-BB (PDGF-BB), and to test the sustained release properties of the growth factor and its effect on the migration and proliferation of the synovial mesenchymal stem cells.  METHODS: Photosensitive bio-ink was prepared by GelMA/MECM. PCL scaffold and PCL/GelMA/MECM bio-scaffold were prepared by 3D bioprinting technology. Finally, PDGF-BB was loaded to fabricate functional bioprinting PCL/GelMA/MECM/PDGF scaffold, and then its mechanical properties and sustained release properties were tested. New Zealand white rabbit synovial mesenchymal stem cells were isolated and cultured. Transwell and CCK-8 assays were used to explore the effects of PCL scaffold, PCL/GelMA/MECM scaffold and PCL/GelMA/MECM/PDGF scaffold on the migration and proliferation of synovial mesenchymal stem cells, and single medium cultured cells were used as negative control. The third passage of synovial mesenchymal stem cells was inoculated on PCL scaffold, PCL/GelMA/MECM scaffold and PCL/GelMA/MECM/PDGF scaffold respectively. The viability, adhesion and growth of the cells on the three scaffolds were observed by confocal microscope and scanning electron microscope. RESULTS AND CONCLUSION: (1) There was no significant difference in tensile modulus and compression modulus between PCL/GelMA/MECM scaffolds and PCL scaffolds (P > 0.05). (2) PCL/GelMA/MECM/PDGF scaffolds had good sustained release performance, and PDGF-BB could be released continuously for up to 28 days. (3) Compared with the negative control group, PCL/GelMA/MECM scaffolds and PCL/GelMA/MECM/PDGF scaffolds could promote the migration of synovial mesenchymal stem cells, among which PCL/GelMA/MECM/PDGF scaffolds were more effective. (4) Compared with the negative control group, the cells cultured with PCL/GelMA/MECM scaffolds and PCL/GelMA/MECM/PDGF scaffolds proliferated faster after 4 and 7 days (P < 0.001), and the proliferative effect of PCL/GelMA/MECM/PDGF scaffolds was more obvious. (5) Dead/Live staining showed that the cells in each group had good activity, and the number of cells on the PCL/GelMA/MECM/PDGF scaffold was the highest. (6) Scanning electron microscope showed that the cells were attached to the surface of the three groups of scaffolds, and the cells on PCL/GelMA/MECM scaffolds and PCL/GelMA/MECM/PDGF scaffolds adhered to a large number of cells and secreted a large amount of extracellular matrix. (7) These results showed that the 3D bioprinted meniscus scaffold loaded with PDGF-BB had good mechanical properties and biocompatibility and could promote the migration and proliferation of synovial mesenchymal stem cells. Figures and Tables | References | Related Articles | Metrics

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Preparation of alginate-gelatin-adipose-derived stem cells microspheres by electrospray and feasibility on repairing articular cartilage injury Liao Sida, Meng Haoye, Li Junkang, Xu Yichi, Li Huo, Tian Xiaoyu, Feng Yong, Wang Aiyuan, Peng Jiang 2021, 25 (28):  4473-4479.  doi: 10.12307/2021.060 Abstract ( 599 )   PDF (2242KB) ( 307 )   Save BACKGROUND: Microsphere can be used as a cell delivery system to localize cells in cartilage injury site and regenerate them by injection or combined with other scaffolds. OBJECTIVE: To produce adipose-derived stem cells (ADSCs)-embedded alginate-gelatin microspheres for cartilage tissue engineering by electrospray, and to evaluate cell viability, proliferation and chondrogenic differentiation ability of microspheres.  METHODS: The electrospray technology was used to produce alginate-gelatin microspheres with different gelatin concentrations (0, 5, 15, 25 g/L). The morphology of microspheres could be observed under the optical microscope. The mass concentration of gelatin to form complete microspheres was selected for the following experiments. Alginate-gelatin-ADSCs microspheres and alginate-ADSCs microspheres were produced by electrospray. The spherical effect was observed under the optical microscope. Two kinds of microspheres containing cells were cultured in rotating cell culture system. The proliferation ability, viability and chondrogenic ability of the cells in the microspheres were detected at the set time point. RESULTS AND CONCLUSION: (1) Intact microspheres could be produced by adding 0, 5 g/L gelatin. The diameter of the microspheres was (365.85±16.88) or (358.85±23.97) μm. There was no significant difference in the diameter of the two kinds of microspheres (P > 0.05). The mass concentration of gelatin as 5 g/L was selected for subsequent experiments. (2) The addition of ADSCs did not affect the spheroidization and the diameter of alginate microspheres and alginate microspheres-gelatin microspheres. (3) The number of cell proliferation and the proportion of living cells at 7 and 14 days were higher in the alginate-gelatin-ADSCs microspheres than those without alginate-ADSCs microspheres (P < 0.05). (4) The content of glycosaminoglycan was higher in alginate-gelatin-ADSCs microspheres than that in alginate-ADSCs microspheres at 7, 14, and 21 days after chondrogenic differentiation (P < 0.05). (5) It is concluded that alginate-gelatin-ADSCs microspheres are prone to promote proliferation and keep cell viability, and are a kind of biomaterials with great potential in the field of cartilage tissue engineering. Figures and Tables | References | Related Articles | Metrics

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Effect of excess resin adhesive removal method on the marginal integrity of all-ceramic crowns with different marginal gaps Zhang Haiyang, Liu Jianzhang, Kan Na, Li Hongxia, Wang Junfeng, Jiang Haiwei, Qiu Chengyu, Xiao Zhen 2021, 25 (28):  4480-4484.  doi: 10.12307/2021.061 Abstract ( 472 )   PDF (1125KB) ( 335 )   Save BACKGROUND: There are many studies on the marginal integrity of all ceramic crowns with different resin adhesives, or different shoulder, different polymerization angles, but there is no research on whether different methods of redundant bonding will affect the marginal integrity of all ceramic crowns.  OBJECTIVE: To analyze the effect of removing excess resin adhesive on the marginal integrity of all ceramic crowns with different marginal gaps.  METHODS: Totally 40 extracted third molars were prepared with all ceramic crowns and randomly divided into groups A, B, C, and D (10 teeth in each group). After the model scanning was completed, the edges of restoration in groups A, B and C were lifted at 30, 60 and 90 µm respectively by computer control, while those in group D were not raised. Procera alumina CAD-CAM all ceramic crowns were made. Then, the four groups of groups A, B, C and D were randomly divided into two subgroups. In one subgroup, a large amount of excess resin adhesive was removed with a small brush, and then the light was illuminated for 40 seconds after the full crown bonding. Subsequently, a small amount of resin adhesive was scraped off with sickle scalpel (small brush group). The sample in the other subgroup was exposed to light for 2 seconds, scraped off with sickle scalpel, and then illuminated for 40 seconds (sickle group). The marginal integrity and surface quality of the adhesive were observed by scanning electron microscope. RESULTS AND CONCLUSION: (1) Scanning electron microscope showed that the continuity of the bonding interface was better in the small brush group. Different degrees of adhesive defects were found in the sickle group. Under the same marginal gap, the defect rate of cement in the small brush group was lower than that in the sickle group (P < 0.05). Under the same adhesive removal method, there was no significant difference in the defect rate of cement between groups A, B, C, and D (P > 0.05). (2) Results indicate that the method of using small brush to remove excess adhesive, then lighting for 40 seconds, and finally using sickle scalpel to remove the remaining small amount of adhesive is more suitable for clinical practice. Figures and Tables | References | Related Articles | Metrics

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Effect of dynamic compression combined with insulin-like growth factor-1 gene transfection on chondrogenic differentiation of rabbit adipose-derived mesenchymal stem cells in chitosan/gelatin scaffolds Zhang Chuanhui, Li Jianjun, Yang Jun 2021, 25 (28):  4485-4491.  doi: 10.12307/2021.062 Abstract ( 382 )   PDF (1709KB) ( 219 )   Save BACKGROUND:  It is a new idea that the application of bioreactor to simulate the biomechanical environment of human body, and the combination with gene transfection technology to construct tissue-engineered cartilage in vitro in the field of tissue engineering research. At present, there is no conclusion about the action mechanism of mechanical stress promoting the chondrogenic differentiation of adipose-derived mesenchymal stem cells at home and abroad. OBJECTIVE: To investigate the comparative and interactive effects of dynamic compression and insulin-like growth factor-1 on the chondrogenesis of rabbit adipose-derived mesenchymal stem cells in chitosan/gelatin scaffolds.  METHODS: Chitosan/gelatin composite scaffolds were placed in a six-well culture plate and divided into four groups. In group A, rabbit adipose-derived mesenchymal stem cells were added into the complete medium for 9 days after incubation for 4 hours. In group B, rabbit adipose-derived mesenchymal stem cells transfected with insulin-like growth factor-1 were incubated for 4 hours and then cultured in complete medium for 9 days. In group C, rabbit adipose-derived mesenchymal stem cells with insulin-like growth factor-1 had been cultured in chitosan/gelatin scaffolds for 2 days before dynamic compression after incubation for 4 hours. The cells/scaffold constructs were subjected to cyclic compression with 2% strain and 1 Hz, pressure for 20 minutes, interval of 20 minutes, 6 cycles per day for 7 consecutive days. In group D, adipose-derived mesenchymal stem cells transfected with insulin-like growth factor-1 were incubated for 4 hours in chitosan/gelatin scaffolds and then cultured in complete medium for 2 days, followed by dynamic pressure culture for 7 days. After the trial intervention, the cell proliferation rate, total glycosaminoglycan content, calcium content and cartilage related gene expression (insulin-like growth factor 1, Sox-9, type II collagen, aggrecan and type X collagen) were quantified. RESULTS AND CONCLUSION: (1) All the cells in each group had good proliferative ability, and the proliferative speed from fast to slow was group D, group B, group C, and group A. (2) The total glycosaminoglycan and calcium ion contents of groups B, C and D were higher than those of group A (P < 0.01), those of group D were higher than those of groups B and C (P < 0.01), and those of group B were higher than those of group C (P < 0.01). (3) There was no difference in the expression of type X collagen mRNA among the four groups (P > 0.05). The mRNA expression levels of insulin-like growth factor-1, Sox-9, type II collagen, and aggrecan in groups B, C and D were higher than those in group A (P < 0.01), higher in group D than in groups B and C (P < 0.01), and higher in group B than in group C (P < 0.01). (4) Our results suggest that dynamic compression combined with insulin-like growth factor-1 overexpression induced chondrogenic differentiation of adipose-derived mesenchymal stem cells on chitosan/gelatin composite scaffold. Figures and Tables | References | Related Articles | Metrics

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Effects of targeted graphene oxide loaded with atractylenolide-I on apoptosis and cell cycle of ovarian cancer cells Gan Fang 2021, 25 (28):  4492-4496.  doi: 10.12307/2021.063 Abstract ( 314 )   PDF (837KB) ( 105 )   Save BACKGROUND: Atractylolide I (AT-I) has a variety of pharmacological and biological activities, such as anti-inflammatory, anti-oxidation, and anti-tumor, but it has poor water solubility, light instability, low permeability, and low bioavailability. OBJECTIVE: To prepare a novel AT-I vector targeting ovarian cancer cells and evaluate its physicochemical properties and biological activities.  METHODS: We functionalized graphene oxide (GO) to obtain arginine glycine aspartate-graphene oxide conjugated structure (RGD@GO), which is stable and biocompatible in a variety of biological solutions, then loaded with hydrophobic molecule AT-I. AT-I loaded RGD@GO nanoparticles (RGD@GO-AT-I) was prepared by emulsion solvent diffusion method. The drug loading and in vitro release properties of the nanoparticles were determined. The human ovarian cancer cell A2780 was co-cultured with GO-AT-I solution, RGD@GO-AT-I solution, RGD@GO solution, and AT-I solution, and co-culture with PBS was set as the control. Cell viability was detected by MTT method after 24 and 48 hours. Human ovarian cancer cell A2780 was co-cultured with GO-AT-I solution and RGD@GO-AT-I solution, and co-culture with PBS was set as the control. Cell cycle and apoptosis were detected after 48 hours of culture.  RESULTS AND CONCLUSION: (1) The highest drug load of RGD@GO-AT-I was (28.09±0.17)%; RGD@GO-AT-I showed a good drug release curve within 30 hours in vitro. (2) After culture for 24 and 48 hours, the cell survival rate of GO-AT-I group and RGD@GO-AT-I group was lower than that of control group (P < 0.01). The cell survival rate of RGD@GO-AT-I group was lower than that of GO-AT-I group (P < 0.01). (3) The proportion of cells in sub-G1  phase in GO-AT-I group and RGD@GO-AT-I group was higher than that in the control group (P < 0.01), and the proportion of cells in G0/G1  phase was lower than that in the control group (P < 0.01). The proportion of cells in the sub-G1  phase in RGD@GO-AT-I group was higher than that in GO-AT-I group (P < 0.01). The proportion of cells in G0/G1  phase was lower than that in GO-AT-I group (P < 0.01). (4) The apoptosis rates of GO-AT-I group and RGD@GO-AT-I group were higher than that of control group (P < 0.01). The apoptosis rate of RGD@GO-AT-I group was higher than that of GO-AT-I group (P < 0.01). (5) The results showed that targeting RGD@GO-AT-I inhibited cell proliferation by inhibiting the G0/G1 phase of A2780 cells and inducing apoptosis, and significantly enhanced the anti-cancer activity of AT-I. Figures and Tables | References | Related Articles | Metrics

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Preparation and in vitro biocompatibility of egg white/polyvinyl alcohol/graphene oxide composite fiber scaffolds based on electrospinning Wang Weiyu, Liu Jun, Yang Yong, Lu Tao, Liu Yin, Zhu Kunzhi, Shu Liping, Ye Chuan 2021, 25 (28):  4497-4503.  doi: 10.12307/2021.064 Abstract ( 578 )   PDF (1285KB) ( 497 )   Save BACKGROUND: Relevant studies have shown that adding an appropriate amount of graphene oxide can improve the mechanical properties, hydrophilicity, and cell compatibility of the fiber scaffold, and has a certain ability to promote bone formation. OBJECTIVE: To prepare egg white/polyvinyl alcohol/graphene oxide composite fiber scaffolds with different concentrations of graphene oxide and preliminary explore the biocompatibility of composite fiber scaffold in vitro. METHODS: Electrospinning was used to prepare egg white/polyvinyl alcohol/graphene oxide composite fiber scaffolds containing 0, 0.5, 1, and 1.5 g/L graphene oxid. The morphology of the scaffold was observed by scanning electron microscope, and the mechanical properties, contact angle and equilibrium swelling ratio of the scaffold were also tested. Human umbilical vein endothelial cells and human bone marrow mesenchymal stem cells were respectively inoculated on the surface of four groups of scaffolds. The CCK-8 assay was used to detect the proliferation of the two types of cells. Live/Dead fluorescent staining was used to observe the viability of the two types of cells. The scratch test and rhodamine phalloidin staining were used to observe the migration and morphology of human umbilical vein endothelial cells. RESULTS AND CONCLUSION: (1) Scanning electron microscope showed that with the increase of graphene oxid content, the fiber diameter of the composite scaffold increased. (2) With the increase of graphene oxid content, the hydrophilicity of the composite scaffold first decreased and then increased, and the hydrophilicity of the composite scaffold containing 0.5 g/L graphene oxid was the lowest. (3) With the increase of graphene oxid content, the Young's modulus and tensile strength of the composite scaffold first increased and then decreased, and the Young's modulus and tensile strength of the composite scaffold containing 0.5 g/L graphene oxid were the largest. (4) CCK-8 assay showed that the proliferation rate of human bone marrow mesenchymal stem cells on the composite scaffold containing 1.5 g/L graphene oxid was faster than that of the other three groups of scaffold (P < 0.05), and the proliferation rate of human umbilical vein endothelial cells on the composite scaffold containing 1 g/L graphene oxid was faster than the other three groups of scaffolds (P < 0.05). (5) With the increase of graphene oxid content, the survival rate of human bone marrow mesenchymal stem cells on the composite scaffold increased; the survival rate of human umbilical vein endothelial cells on the composite scaffold containing 1 g/L graphene oxid was the highest. (6) Scratch experiment and rhodamine phalloidin staining proved that the composite scaffold containing 1 g/L graphene oxid was most conducive to the migration and morphological expansion of human umbilical vein endothelial cells. (7) The results show that the egg white/polyvinyl alcohol/graphene oxide fiber scaffold containing 1 g/L graphene oxid has excellent fiber structure, hydrophilicity, mechanical properties and cell compatibility. Figures and Tables | References | Related Articles | Metrics

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Fractographic analysis on fracture failure behavior of all-ceramic crowns Bao Xinlian, Su Yi 2021, 25 (28):  4504-4509.  doi: 10.12307/2021.065 Abstract ( 527 )   PDF (1158KB) ( 153 )   Save BACKGROUND: In recent years, fractographic analysis has been applied to the study of fracture mechanics of ceramics. At present, most studies focus on the analysis of crack origin and propagation path of clinical fracture of all-ceramic crowns by using the typical crack characteristics of fractographic analysis, as well as the analysis of cyclic fatigue damage mode of all-ceramic crowns in vitro simulation state.  OBJECTIVE: The fractographic analysis was used to analyze the crack origin and related defects of all-ceramic  crowns. METHODS: From October 2018 to September 2019, a total of 12 patients with all-ceramic crowns fracture after failure in clinical use were selected from the Department of Stomatology, Eye&ENT Hospital of Fudan University. The stereomicroscope was used to observe the overall morphology of all-ceramic fracture section. The scanning electron microscope was used to observe the crack, surface damage and structural defects. The origin and propagation path of crack were deduced by the fractographic analysis. This trial was approved by the Ethics Committee of Eye & ENT Hospital of Fudan University. RESULTS AND CONCLUSION: (1) Cyclic fatigue was an important reason for the fracture of all-ceramic restorations. Different types of cyclic fatigue damage modes could be observed in 12 fractured pieces of all-ceramic crowns, such as cone crack, veneer chipping, veneer delamination, radial crack, and surface defects. Different all-ceramic crowns had different dominant fatigue damage modes. (2) Cyclic fatigue damage was an important reason for the failure of all-ceramic crowns, among which radial crack was the main mode. The thickness of porcelain layer and core/veneer thickness ratio have a close influence on its occurrence. The interface between veneer and core is the weak link of double-layer all-ceramic restorations. Structural defects and stress concentration caused by abnormal occlusion are potential risk factors for failure of all-ceramic crowns. Figures and Tables | References | Related Articles | Metrics

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Biological effect of magnetic fields to promote bone responses to biomaterials Li Ruozhen, Tian Yaping, Wen Ning 2021, 25 (28):  4510-4515.  doi: 10.12307/2021.066 Abstract ( 419 )   PDF (850KB) ( 155 )   Save BACKGROUND: The regeneration of bone tissue not only needs biomaterials, but also depends on the self-healing ability of the body. However, due to age-related physiological and pathological changes, the regeneration ability of bone tissue will be weakened. Therefore, magnetic field as an auxiliary treatment has been concerned. OBJECTIVE: To introduce the biological effect of magnetic field and the progress of magnetic field used to promote the bone responses to metal implants, bioceramic scaffolds and polymer composites. METHODS: The English literature search was performed in PubMed, EMBASE and EI databases from 2014 to 2020. The keywords were “magnetic fields, magnetic nanoparticles, implant, bioceramic scaffold, calcium phosphate scaffolds, hydroxyapatite, polymer materials, bone growth, bone regeneration, osseointegration, bone remodeling, osteoblasts, osteoclasts, mesenchymal stem cells, signaling pathways”. Totally 52 articles were finally selected for analysis.  RESULTS AND CONCLUSION:  (1) Magnetic field can regulate the proliferation and differentiation of osteoblasts, osteoclasts and mesenchymal stem cells, playing the role of osteogenic induction. (2) Wnt, RANK, MAPK and other signaling pathways play critical roles in magnetic field-mediated osteogenesis. Magnetic field affects bone metabolism by regulating the expression of osteogenic markers on these pathways. (3) Magnetic field can promote bone responses to implants, bioceramic scaffolds, and polymer materials. Thus, the combination of magnetic field and these biomaterials can improve bone regeneration and repair. (4) The best conditions for magnetic field to promote osteogenesis is not confirmed, and the magnetic field parameters should be carefully chosen in clinical practice. In addition, there are many theories about the mechanism of magnetic field-induced bone formation, and the detailed mechanism requires to be further studied.  Figures and Tables | References | Related Articles | Metrics

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Influence of plasma spraying and electrochemical deposition of hydroxyapatite coating morphology on bone marrow mesenchymal stem cells Sun Yang, Luo Mingran, Zheng Li, Hu Weifan, Yuan Feng 2021, 25 (28):  4516-4522.  doi: 10.12307/2021.067 Abstract ( 452 )   PDF (1153KB) ( 115 )   Save BACKGROUND: With its excellent biocompatibility and osteoconductivity, hydroxyapatite is widely used as a material coating in tissue engineering, and its biological properties are strongly associated with the morphology caused by the manufacturing process.  OBJECTIVE: To investigate the effects of plasma spraying and electrochemical deposition on the stent of hydroxyapatite coating on the proliferation, adhesion and osteogenic differentiation of bone marrow mesenchymal stem cells.   METHODS: Hydroxyapatite coating was prepared on titanium stent using plasma spraying and electrochemical deposition. The titanium stent without coating was used as a control. Rat bone marrow mesenchymal stem cells were cocultured with three kinds of stents for 1, 3, 5, and 7 days. Cell proliferation was detected using CCK-8 assay for 5 days. Cell adhesion was observed using scanning electron microscope and confocal laser microscope. At 14 days, alkaline phosphatase staining was conducted; at 21 days, alizarin red staining was performed. At 14 and 21 days, real-time quantitative fluorescent polymerase chain reaction was conducted to analyze osteogenic differentiation of bone marrow mesenchymal stem cells.  RESULTS AND CONCLUSION: (1) With the extension of the culture time, the cell proliferation rate of each group increased. The cell proliferation rate of the plasma spraying group was higher than that of the electrochemical deposition group and the control group (P < 0.05). (2) Scanning electron microscopy showed that cell adhesion was seen on the stents in the three groups. The plasma spraying group had the largest cell spreading area, and the control group had the smallest cell spreading area. The laser confocal microscope showed that the actin fibers in the plasma spraying group were the densest and the cells were in good extension; the electrochemical deposition group was relatively dense and the cells were in normal extension. In the control group, cytotactin was relatively sparse and the cells were not fully extended. (3) The alkaline phosphatase activity of the plasma spraying group was higher than that of the electrochemical deposition group and the control group, and calcium nodules were formed more than that of the electrochemical deposition group and the control group. (4) Real-time quantitative fluorescent polymerase chain reaction showed that the expression levels of osteopontin, type I collagen, osteocalcin and Runx2 mRNA in plasma spraying group were higher than those in electrochemical deposition group at the same time except that there was no difference between osteocalcin mRNA expression at 7 days and Runx2 mRNA expression at 14 days (P < 0.05). (5) The results showed that the morphology of plasma sprayed hydroxyapatite coating is more conducive to proliferation, adhesion and osteogenic differentiation of bone marrow mesenchymal stem cells. Figures and Tables | References | Related Articles | Metrics

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Application of MXene in biosensors, antibacterial drug loading and biological imaging Gao Wei, Xing Wenge, Guo Yaping, Zhang Yongguang, Li Mingjun, Yang Lei, Liang Chunyong 2021, 25 (28):  4523-4530.  doi: 10.12307/2021.068 Abstract ( 1286 )   PDF (1112KB) ( 386 )   Save BACKGROUND: The emerging two-dimensional materials have become a research hotspot in many research fields, among which MXene two-dimensional materials have been widely used in energy, catalysis, biology and other related fields due to their excellent physicochemical properties. OBJECTIVE: To summarize the current development and future prospects of MXene in the biological field. METHODS: A computer-based online search of Web of Science, CNKI, and Wanfang databases was performed to retrieve studies regarding MXene in the biological field published between March 2011 and May 2020 with the search terms of “Biomedical MXene, MXene Biosensor, MXene Synergistic Therapy” in English and Chinese. RESULTS AND CONCLUSION: Low cytotoxicity, high surface area, and strong and wide Near Infrared (NIR) absorption make the MXene family one of the most promising materials for biomedical applications. MXene structure contains abundant oxygen-containing groups which have a high degree of functionalization capability, enabling MXene nanosheets good performance in biomedical field. Therefore, MXenes are currently expanding their usage territory from mechanical, optical, and electronic fields toward biomedical areas. MXenes possess a unique potential for diagnostic imaging, antimicrobial agents, biosensor, and drug delivery. Although the present studies have shown desirable short-term biocompatibility of the MXenes, systematic assessment of long-term in vivo biosafety is essential for the expansion of their biomedical applications. By future investigations, it is expected to observe a rapid growing in the synthesis of new families of MXenes and their bright perspective in biomedical sciences. Figures and Tables | References | Related Articles | Metrics

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Artificial blood vessel materials with nitric oxide release function Shen Ruiqiu, Liu Zhiming, Song Junyi, Hu Biru 2021, 25 (28):  4531-4538.  doi: 10.12307/2021.069 Abstract ( 563 )   PDF (1419KB) ( 231 )   Save BACKGROUND: The stable and controllable release of nitric oxide from artificial blood vessel materials at the physiological level is not only the key technology to inhibit the formation of thrombus on small-diameter artificial blood vessel inner walls, but also is of great significance for developing novel artificial blood vessel materials.  OBJECTIVE: To review the research and application progress of artificial blood vessel materials in recent years, and focus on introducing nitric oxide-releasing artificial blood vessel materials. METHODS: CNKI, Wanfang, Google Scholar, and PubMed databases were searched with key words such as “vascular graft, blood vessel, catalytic nitric oxide, tissue engineering” in English, “artificial blood vessel, catalytic NO” in Chinese from January 2000 to July 2020 for relevant articles. The retrieved articles were screened and summarized. RESULTS AND CONCLUSION: A series of polymer materials, coating materials and nano composite materials exhibited similar nitric oxide production flux and release rate with natural endothelial tissues. Among them, artificial blood vessel materials loaded with organic selenium, copper ions, keratin, and nano-noble metals have shown great potentialities in the treatment of cardiovascular diseases. The artificial blood vessel materials loaded with organic selenium had long catalytic durations, good biocompatibilities, and excellent mechanical properties. The artificial blood vessel materials loaded with copper had good biological safeties and strong anti-thrombotic abilities. The performance of artificial blood vessel materials loaded with organic selenium and copper ions showed long-term and stable catalytic abilities and selective enhancement abilities of endothelial cell activities. Artificial blood vessel materials containing keratin showed excellent cell compatibility and functional expansibilities. The other artificial blood vessel materials containing substances that could catalyze nitric oxide production also exhibited good potential developments in the future. Up to now, the effects of pre-clinical development or post-clinical trials of implantable biomaterials that release nitric oxide are still unclear, and some important technical issues such as the release time of nitric oxide and the effects on endothelial cells need to be resolved. Figures and Tables | References | Related Articles | Metrics

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Role and characteristics of tissue-engineered cartilage in the treatment of growth plate injuries Wang Xianggang, Wan Qian, Liu He, Li Ronghang, Zhang Yan, Li Zuhao, Wang Jincheng 2021, 25 (28):  4539-4545.  doi: 10.12307/2021.070 Abstract ( 647 )   PDF (1316KB) ( 449 )   Save BACKGROUND: The growth plate regulates the longitudinal growth of long bones. Once damaged and replaced by bony bar formation, it will cause length discrepancy and angular deformity. Considering the unsatisfactory outcome of clinical treatments, it is potential for cartilage tissue engineering scaffolds in treatment of growth plate injuries. OBJECTIVE: To introduce the physiological structure and functions of the growth plate, and discuss and summarize the progress of cartilage tissue engineering technology in the treatment of growth plate injury.  METHODS: The databases of PubMed, Web of Science, CNKI, and Wanfang were retrieved with “growth plate, physis, physeal, scaffold, cartilage tissue engineering” as key words in English and Chinese to collect relevant articles published from 2000 to 2020. Initially, 292 articles were retrieved, and 65 articles were selected for further analysis.  RESULTS AND CONCLUSION: Cartilage tissue engineering scaffolds perform well in treatment of growth plate injuries in animal models. The bioactive scaffold not only fills the defect, inhibits the formation of bone bridge, reduces angular deformity of the affected limb, but also induces the differentiation of mesenchymal stem cells into chondrocytes which are arranged in a columnar regular structure similar to natural growth plates. Many experimental results have found that the application of mesenchymal stem cells combined with appropriate cartilage inducing factors, such as transforming growth factor-β, insulin-like growth factor-1, can promote chondrocytes regeneration and arrange them in order. Regenerated cartilage tissue plays the normal function of growth plate and allows long bone to grow up. In addition, as the carrier of cells and growth factors, the scaffold in cartilage tissue engineering requires suitable mechanical strength and good biocompatibility. Since there are some shortcomings when natural biomaterials or synthetic polymer materials used alone, it is more effective to use scaffolds made of composite materials. However, to be applied to clinical treatment, more experimental researches are required in the future. Figures and Tables | References | Related Articles | Metrics

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Application of chitosan in nano drug delivery system Yang Menglu, Zhang Na, Wang Fangyuan, Liu Jianguo 2021, 25 (28):  4546-4552.  doi: 10.12307/2021.071 Abstract ( 990 )   PDF (753KB) ( 352 )   Save BACKGROUND: Polycationic chitosan drug carriers have shown good prospects in improving the effectiveness, utilization and security of existing drug delivery methods. OBJECTIVE: To review the research progress of chitosan-based nano drug carriers in recent years. METHODS: Computer was utilized to retrieve recently published articles in PubMed, CNKI and Elsevier Science Direct databases with key words “chitosan, nano, drug delivery, carrier” in Chinese and English. The time of publication was limited from 1994 to October 2020. The articles were primarily screened by reading and analyzing to exclude duplicate and low-relevance articles, and finally 54 articles were selected for result analysis. RESULTS AND CONCLUSION: At present, the research of chitosan as a drug delivery carrier has made significant progress. Both in vitro cell experiments and animal experiments have confirmed that it has a good drug encapsulation rate and can effectively release drugs, with the help of chitosan’s good bioadhesive properties, it can achieve drug delivery across the barrier (such as the blood-brain barrier), and achieve targeted drug delivery to a certain extent. According to different needs, the chitosan-based composites are different in molecular weight, shape, particle size distribution, encapsulation efficiency and drug loading. Even if it coated with the same drug, due to different manufacturing process or operation, there may also be differences in drug encapsulation rate, drug loading and release rate. Therefore, most of these carriers cannot be mass-produced at present. There is still a lot of work to be done for the chitosan-based nanomedicine carrier in a wide range of clinical applications, but in future research, its excellent biomedical properties may further expand its application potential. Figures and Tables | References | Related Articles | Metrics

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Progress and challenges of bone tissue engineering scaffolds Liao Xinyu, Wang Fuke, Wang Guoliang 2021, 25 (28):  4553-4560.  doi: 10.12307/2021.072 Abstract ( 1510 )   PDF (1029KB) ( 996 )   Save BACKGROUND: Bone tissue engineering scaffolds are considered as a potential alternative to traditional bone grafting due to their unlimited supply and lack of disease transmission. However, bone tissue engineering scaffolds have not entered clinical practice due to some limitations or challenges. OBJECTIVE: To discuss the clinical and mechanical requirements of bone scaffolds, summarize the biomaterials used in various scaffolds and the challenges and future trends in the field of bone tissue engineering scaffolds. METHODS: Search words were “bone tissue engineering, bone scaffolding, biomaterials, bone histology, bone defect, bone repair” in English and Chinese. Relevant literature on bone tissue engineering scaffolds published from 2005 to 2020 was searched by computer in CNKI, Wanfang database, and PubMed database. Systematic summary, summary and analysis were conducted to comprehensively describe the new progress and challenges in the research on bone tissue engineering scaffolds.  RESULTS AND CONCLUSION: At present, natural derived biomaterials, synthetic biomaterials and metal materials are mainly used in the preparation of bone tissue engineering scaffolds. These materials have been used in the manufacture of bionic scaffolds to support the growth and regeneration of bone tissue. Although great progress has been made in the research of scaffold materials for bone tissue engineering, there are still many key obstacles to be cleared for the real application of bone tissue engineering in clinical practice. The future research focus is to find some materials similar to human autogenous bone tissue structure and performance, and carry out bionic design on them, so as to develop tissue engineered artificial bone similar to human autogenous bone structure and performance. Figures and Tables | References | Related Articles | Metrics

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Progress and main application of fish skin collagen in tissue engineering Zhu Bikang, Luo Shanchao, Luo Shixing 2021, 25 (28):  4561-4566.  doi: 10.12307/2021.073 Abstract ( 601 )   PDF (1063KB) ( 297 )   Save BACKGROUND: Collagen is one of the widely used scaffold materials in tissue engineering, but commercial collagen is mainly derived from pigskin, cowhide, and other mammals, and there are some zoonotic diseases risks, and religious restrictions. Nowadays, fish skin collagen biomaterials with many functional properties without disease or religious restrictions have become a research hotspot in tissue engineering. OBJECTIVE: To review the extraction, functional modification of fish skin collagen, and its research progress, and main applications in tissue engineering. METHODS: The first author retrieved the literature related to tissue engineering and fish skin collagen included in PubMed, CNKI, Wanfang, and other databases from 2005 to 2020 and selected articles in highly relevant and authoritative journals. The English and Chinese search terms were “fish skin collagen; tissue engineering”. RESULTS AND CONCLUSION: Fish skin collagen has good physical and chemical properties, mechanical strength, and biocompatibility. It is expected to replace mammalian collagen and has attracted the attention of biomedical researchers. It is widely used in various tissue engineering, such as skin wound healing, bone and cartilage tissue engineering, blood vessel and nerve regeneration. However, there are many problems in transforming basic research into clinical application, such as: which extraction method is more fast and efficient for fish skin collagen factory production; and which functional modification scheme for fish skin collagen to achieve composite construction of grafts; the standard of how to improve the mechanical properties and degradation properties of fish skin collagen-based materials to support the regeneration and repair of bone and cartilage tissue; how to construct scaffold materials to improve the perfect and rapid repair of skin trauma. Figures and Tables | References | Related Articles | Metrics

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Effects of different peritoneal dialysis catheterization techniques on the prognosis of patients: a meta-analysis Du Yuan, Jiang Hongwei, Li Chunqing, Xie Yan 2021, 25 (28):  4567-4572.  doi: 10.12307/2021.074 Abstract ( 448 )   PDF (816KB) ( 161 )   Save OBJECTIVE: For peritoneal dialysis patients, the more therapeutic way of insertion catheterization techniques is controversial. There is no evidence of high-grade evidence-based medicine. This study systemically assessed influence of different insertion catheterization techniques on the prognosis of peritoneal dialysis patients, and reviewed the clinical value of percutaneous insertion catheterization in peritoneal dialysis.  METHODS: The PubMed, EMbase, the Cochrane Library, CNKI, VIP, and Wanfang databases of cohort study literature on the comparison of percutaneous technique and surgical incision technique for peritoneal dialysis catheterization published from inception to October 30, 2019 were searched by computer. The effective data were selected and the Newcastle-Ottawa Scale was used to evaluate the quality. Primary outcomes were infection complications, mechanical complications, 1-year peritoneal dialysis tube survival rate, and extubation rate caused by complications. The odds ratio (OR) was the effect indicator. Meta-analysis was performed using RevMan 5.3 software. RESULTS: (1) A total of 12 studies were included, including 2 prospective cohort studies and 10 retrospective cohort studies. A total of 2 203 patients were enrolled, including 1 164 patients in the percutaneous puncture group and 1 039 patients in the peritoneal incision group. (2) The incidence of infection complications, the incidence of mechanical complications, and the 1-year catheter survival rate were not statistically significant between the percutaneous puncture group and the peritoneal incision group (OR=0.57, 95%CI:0.31-1.04, P=0.07: OR=0.88, 95%CI:0.77-1.09, P=0.25; OR=1.05, 95%CI:0.68-1.64, P=0.81). (3) The extubation rate caused by complications in the percutaneous puncture group was lower than in the peritoneal incision group (OR=0.59, 95%CI:0.47-0.74, P < 0.000 1). (4) Subgroup analysis results of cases of infection complications group and 1-year catheter survival rate group according to the type of study suggested that heterogeneity mainly came from retrospective study subgroups, and the meta-analysis results in each subgroup showed there was no significant difference between the two groups. (5) Funnel diagram analysis results showed mild publication bias in dialysis tube infection complications and 1-year survival rate of the included articles. CONCLUSION: It is safe and effective to apply the peritoneal dialysis catheterization with a percutaneous insertion technique, and its clinical effects and prognosis are similar with the traditional open surgical technique. The percutaneous insertion technique could be an ideal alternative to the traditional one.  Figures and Tables | References | Related Articles | Metrics

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Meta-analysis of hyaluronic acid in the treatment of rotator cuff injury Zhao Guoyuan, Hu Weijian, Guo Siyin, Wei Hewei, Wan Lei, Zheng Weipeng, Liu Zhijun, Liao Zhihao, Chen Sheng 2021, 25 (28):  4573-4579.  doi: 10.12307/2021.075 Abstract ( 542 )   PDF (2329KB) ( 130 )   Save OBJECTIVE: Although studies have reported the efficacy of hyaluronic acid in promoting tendon-bone healing, many sports medicine physicians are still controversial and skeptical about the clinical efficacy of hyaluronic acid in the treatment of rotator cuff injuries due to limitations in methods, follow-up, and study design. The efficacy and safety of hyaluronic acid in the treatment of rotator cuff injury compared with conventional treatment or saline control were evaluated by meta-analysis. METHODS: The Cochrane Library, EMBASE, PubMed, Wanfang, CNKI and VIP databases were used to search and collect randomized controlled clinical trials of hyaluronic acid versus conventional treatment or blank control treatment for rotator cuff injuries. Two reviewers independently evaluated the quality of the included studies through the Cochrane Evaluation Manual and the Jadad score, extracted and cross-checked the data, and meta-analyzed the collected data using RevMan 5.3 software. The main outcome indicators analyzed were continuous variables, such as visual analogue scale score, Constant score, and University of California at Los Angeles score; dichotomous variables, such as satisfaction. RESULTS: (1) A total of eight randomized controlled clinical trials were selected for meta-analysis, including three of general quality, five of medium quality and high quality. A total of 541 patients were selected, including 255 patients treated with subacromial injection of hyaluronic acid for supplementary treatment and 286 patients treated with conventional or blank control. (2) Meta-analysis results showed that visual analogue scale pain scores of the hyaluronic acid group were better than those of the control group at 1, 2, 3 and 4 weeks after treatment (MD=-1.34, 95%CI:-1.73 to-0.95, P < 0.05; MD=-1.80, 95%CI:-2.28 to-1.32, P < 0.05; MD=-0.70, 95%CI:-1.12 to-0.29, P < 0.05; MD=-2.55, 95%CI:-5.00 to -0.09, P < 0.05). There was no significant difference in visual analogue scale pain score between the hyaluronic acid group and the control group at 12 and 24 weeks after treatment (MD=-2.09, 95%CI:-4.52-0.35, P > 0.05; MD=-0.04, 95%CI:-0.36-0.29, P > 0.05). Constant scores of the hyaluronic acid group at 2 and 12 weeks after treatment were better than those of the control group (MD=3.23, 95%CI:2.34-4.11, P < 0.05; MD=20.28, 95%CI:0.54-40.03, P < 0.05). The University of California at Los Angeles scores of the hyaluronic acid group at 24 weeks after treatment were all better than that in the control group (MD=0.69, 95%CI:0.20-1.18, P < 0.05). There was no significant difference in patient satisfaction in the last follow-up after treatment between the hyaluronic acid group and the control group (OR=1.82, 95%CI:0.93-3.55, P > 0.05).  CONCLUSION: The treatment of rotator cuff injury with hyaluronic acid could reduce pain, increase activity function and improve daily life quality, and the pain relief effect was particularly obvious in the short term. It is effective and safe to treat rotator cuff injury with hyaluronic acid. However, more large-scale, multi-center, high-quality randomized controlled trials are needed to verify this. Figures and Tables | References | Related Articles | Metrics

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Meta-analysis of coracoclavicular ligament reconstruction with autologous or allogeneic tendon and clavicular hook plate in the treatment of acromioclavicular joint dislocation Yang Kun, Fei Chen, Wang Pengfei, Zhang Binfei, Yang Na, Tian Ding, Zhuang Yan, Zhang Kun 2021, 25 (28):  4580-4586.  doi: 10.12307/2021.076 Abstract ( 463 )   PDF (859KB) ( 138 )   Save OBJECTIVE: At present, tendon reconstruction of coracoclavicular ligament is still in the initial stage. In each study, the number of cases involving tendon reconstruction of coracoclavicular ligament versus clavicular hook plate is less. For this, the clinical effect comparison of the two treatment schemes is still uncertain. This paper compared the efficacy of coracoclavicular ligament reconstruction with autologous or allogeneic tendon and clavicular hook plate in the treatment of acromioclavicular joint dislocation. METHODS: A computer was used to retrieve the PubMed, Embase, Cochrane Library, CNKI, Wanfang, and Weipu database. The retrieval time was from the inception of the database to July 2020. Domestic and foreign literature on comparative study of coracoclavicular ligament reconstruction with autologous or allogeneic tendon and clavicular hook plate in the treatment of acromioclavicular joint dislocation was retrieved. Two researchers independently screened the literature according to the inclusion and exclusion criteria, extracted data, and evaluated the risk of bias in the literature. The operation time, intraoperative blood loss, hospital stay, function score, and complications were meta-analyzed with RevMan 5.3 software. According to the treatment, the patients were divided into two groups: autogenous or allogeneic tendon reconstruction coracoclavicular ligament group and clavicular hook plate group.  RESULTS: Finally, eight articles met the inclusion criteria, including three randomized controlled studies, five retrospective cohort studies and eight articles with high quality, with 382 patients. There were 189 cases of autogenous or allogeneic tendon reconstruction coracoclavicular ligament group and 193 cases of clavicular hook plate group. The longest postoperative follow-up period was about 2.5 years and the shortest was about 6 months. Meta-analysis showed that postoperative Constant-Murley score (MD=3.44, 95%CI: 2.23-4.66), effective rate (OR=9.92, 95%CI: 2.74-35.84), and total postoperative complications (OR=0.11, 95%CI:0.04-0.32) were significantly better in the autogenous or allogeneic tendon reconstruction coracoclavicular ligament group than those in the clavicular hook plate group(P < 0.05). However, operation time (MD=-2.01, 95%CI: -15.96-11.95), intraoperative blood loss (MD=-7.37, 95%CI:-20.00-5.27), and hospital stay (MD=-1.54,  95%CI: -4.22-1.13) and the visual analogue scale score (MD=0.10, 95%CI:-0.02-0.23) had no significant difference between the two groups (P > 0.05). CONCLUSION: According to the comparison of limited literature, the effect of coracoclavicular ligament reconstruction with autologous or allogeneic tendon in the treatment of acromioclavicular joint dislocation was better than that of clavicular hook plate group in short-term follow-up, and the success rate of acromioclavicular joint dislocation was improved. The occurrence of postoperative complications was reduced, and it was more conducive to promote the recovery of acromioclavicular joint function.  Figures and Tables | References | Related Articles | Metrics

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Efficacy of absorbable collagen suture for type I and II surgical incisions: a meta-analysis Peng Yifan, Wang Chong, Shan Yuanfei, Lu Wenli 2021, 25 (28):  4587-4592.  doi: 10.12307/2021.077 Abstract ( 568 )   PDF (1554KB) ( 85 )   Save OBJECTIVE: Absorbable collagen suture has been reported to improve the healing effect for patients with type I and II surgical incisions. However, these studies are single-center small-sample trials, and the results are not clear. This study investigated the efficacy of absorbable collagen suture for type I and II surgical incisions. METHODS: Databases of PubMed, Web of Science, Cochrane Library, CNKI, Wanfang,and VIP were searched to retrieve the randomized controlled trials concerning the effects of absorbable collagen suture. The modified Jadad scale was used to evaluate the quality of the included research literature. The main outcome indicators were wound healing grades, wound leveling, and wound healing time. The secondary indicators were wound pain, incisional red swelling, and wound bleeding. Meta-analysis was conducted using Stata 16.0 software. RESULTS: (1) Eleven articles were included, and the median Jadad score was 3.0. There were 1 720 patients, including 887 patients in the trial group and 833 patients in the control group. (2) Meta-analysis results revealed that compared with the control group, in the trial group, incision healing level was improved (RR=1.44, 95%CI:1.02-1.86, P=0.00), and incision flatness was improved (RR=1.11, 95%CI:0.70-1.52, P=0.002); incision healing time was significantly reduced (WMD=-7.44, 95%CI:-8.09 to -6.79, P=0.00); incision pain was significantly reduced (RR=1.95, 95%CI:1.44-2.46, P=0.00); incision bleeding was significantly reduced (RR=-2.63, 95%CI:-4.65 to -0.61, P=0.01); incisional swelling was significantly reduced (RR=-1.00, 95%CI:-1.78 to-0.22, P=0.01). CONCLUSION: The efficacy of absorbable collagen thread for type I and II surgical incisions was better than that of the silk thread and ordinary absorbable suture.  Figures and Tables | References | Related Articles | Metrics