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    08 August 2021, Volume 25 Issue 22 Previous Issue    Next Issue
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    Effects of hemostasis and promoting wound healing of ozone sustained-release hydrogel
    Liu Fang, Shan Zhengming, Tang Yulei, Wu Xiaomin, Tian Weiqun
    2021, 25 (22):  3445-3449.  doi: 10.3969/j.issn.2095-4344.3182
    Abstract ( 692 )   PDF (999KB) ( 48 )   Save
    BACKGROUND: Ozone has good bacteriostatic and hemostatic effects, but its poor stability and easy decomposition limit its application and promotion.
    OBJECTIVE: To prepare ozone sustained-release hydrogel, and to evaluate its stability and hemostasis and promoting effect on wound healing.
    METHODS: (1) With carbomer as the substrate, the ozone sustained-release hydrogels with ozone concentrations of (3.4±0.2)×10-6, (2.3±1.8)×10-6, (7.20±0.5)×10-6, (7.0 ±3.0)×10-6, (16.4±1.2)×10-6, and (15.0±5.0)×10-6 were prepared by controlling the ozone penetration time, and the stability of ozone in the ozone sustained-release hydrogel was tested. (2) A total of 15 Sprague-Dawley rats were used to make liver hemorrhage models. They were randomly divided into five groups: the blank control group used ordinary clean gauze to stop bleeding; the positive control group used Celox hemostatic powder to stop bleeding; the low-, medium- and high-concentration ozone gel groups were covered with ozone sustained-release hydrogel containing ozone concentrations of (3.4±0.2)×10-6, (7.20±0.5)×10-6, and (16.4±1.2)×10-6, and the time of hemostasis was recorded. (3) A total of 15 Sprague-Dawley rats were used to make a model of the back skin wound. They were randomly divided into five groups: the blank control group was not treated; the positive control group was coated with Beijing Wanhong ointment; the low-, medium- and high-concentration ozone gel groups were covered with the ozone sustained-release hydrogel containing ozone concentrations of (2.3±1.8)×10-6, (7.0±3.0)×10-6, and (15.0±5.0)×10-6, and wound healing was observed within 14 days. The experimental project was approved by the animal experimental ethics committee of Wuhan University (approval No. 2019010019). 
    RESULTS AND CONCLUSION: (1) Ozone had good stability in hydrogels, which could last for about 2 weeks. (2) In the liver hemostasis experiment, compared with the blank control group, the medium- and high-concentration ozone sustained-release hydrogel and hemostatic powder could shorten the hemostatic time (P < 0.01), and the hemostatic time of the high-concentration ozone sustained-release hydrogel was shorter than that of hemostatic powder (P < 0.05). (3) In the skin wound experiment, compared with the blank control group, medium- and high-concentration ozone sustained-release hydrogel could improve the wound healing rate at 4 days (P < 0.05, P < 0.01); at 14 days, there was no significant difference in wound healing rate among five groups. (4) Ozone sustained-release hydrogel has good stability, can promote hemostasis and wound healing.
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    How does bone cement dispersion affect the early outcome of percutaneous vertebroplasty
    Feng Guancheng, Fang Jianming, Lü Haoran, Zhang Dongsheng, Wei Jiadong, Yu Bingbing
    2021, 25 (22):  3450-3457.  doi: 10.3969/j.issn.2095-4344.3180
    Abstract ( 320 )   PDF (1793KB) ( 38 )   Save
    BACKGROUND: Percutaneous vertebroplasty for osteoporotic vertebral compression fractures can stabilize the vertebral body immediately, relieve pain effectively, and improve the quality of life of patients. However, the relationship between the dispersion pattern of bone cement and its curative effect is still controversial.
    OBJECTIVE: To analyze the influence of different types of bone cement dispersion distribution on the early curative effect after percutaneous vertebroplasty.
    METHODS: 155 patients with osteoporotic vertebral compression fracture of single vertebral body were selected from January 2018 to December 2019. The distribution of bone cement was determined by X-ray after percutaneous vertebroplasty. The patients were divided into two groups: bone cement separation group (n=77, 22 cases of thoracic vertebra fracture and 55 cases of lumbar vertebra fracture) and bone cement fusion group (n=78, 39 cases of thoracic vertebra fracture and 39 cases of lumbar vertebra fracture). At the time of preoperatively, 2 days postoperatively and final follow-up, bone cement leakage, visual analogue scale score, Oswestry dysfunction index score, vertebral height recovery, and local kyphosis Cobb angle change were compared between the two groups. Simultaneously, the differences in above indexes between thoracic fracture and lumbar fracture were compared between the two groups.
    RESULTS AND CONCLUSION: (1) The visual analogue scale score and Oswestry dysfunction index of the bone cement separation group and the bone cement fusion group were lower after surgery than those before surgery (P < 0.05). The visual analogue scale score of the bone cement separation group was lower than that of the bone cement fusion group during final follow-up (P < 0.05). The relative height of anterior edge and midline of the injured vertebra was higher after surgery than that before surgery (P < 0.05), and the local kyphotic Cobb angle was lower than that before surgery (P < 0.05). There was no significant difference between the two groups in the changes of anterior and midline relative height and local kyphosis Cobb angle (P > 0.05). (2) Under the type of bone cement separation distribution, the recovery of anterior edge height in thoracic fracture group was lower than that in lumbar fracture group at 2 days postoperatively and final follow-up (P < 0.05), and the visual analogue scale score in thoracic fracture group was lower than that in lumbar fracture group at 2 days after operation (P < 0.05). There was no significant difference between the two groups in the relative height of anterior edge and midline and the change of local kyphosis Cobb angle (P > 0.05). (3) Under the distribution type of bone cement fusion, the visual analogue scale score of thoracic fracture group was higher than that of lumbar fracture group at the last follow-up (P < 0.05). There was no significant difference between the two groups in the recovery of anterior and midline height and the change of local kyphosis Cobb angle (P > 0.05). (4) Results suggest that two kinds of bone cement dispersion distribution all can obtain satisfactory early postoperative results.
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    Effects of bone marrow mesenchymal stem cells and human umbilical vein endothelial cells combined with hydroxyapatite-tricalcium phosphate scaffolds on early angiogenesis in skull defect repair in rats
    Chen Siqi, Xian Debin, Xu Rongsheng, Qin Zhongjie, Zhang Lei, Xia Delin
    2021, 25 (22):  3458-3465.  doi: 10.3969/j.issn.2095-4344.3207
    Abstract ( 364 )   PDF (1682KB) ( 33 )   Save
    BACKGROUND: Tissue-engineered bone provides a new direction for the repair of large bone defects, but the survival of tissue-engineered bone grafts in vivo can be guaranteed only if the capillary network is formed in the early stage. Therefore, vascularization of early tissue-engineered bone is the key to its clinical application.
    OBJECTIVE: To explore the effect of bone marrow mesenchymal stem cells and human umbilical vein endothelial cells combined with hydroxyapatite-tricalcium phosphate scaffolds on early angiogenesis in skull defect repair in rats. 
    METHODS: (1) The hydroxyapatite-tricalcium phosphate scaffold was divided into four groups: Group A was added with DMEM culture medium and extracellular matrix culture medium with volume ratio of 1:1. Group B was added with bone marrow mesenchymal stem cells suspension and human umbilical vein endothelial cells suspension with a volume ratio of 1:1. Group C was cultured with DMEM culture medium and human umbilical vein endothelial cells suspension with a volume ratio of 1:1. Group D was cultured with bone marrow mesenchymal stem cells suspension and extracellular matrix medium with a volume ratio of 1:1 for 21 days for in vivo implantation experiment. (2) Bone defects with a diameter of 1 cm were made in the skull of adult SD rats, and materials of groups A, B, C and D were implanted respectively. Skull micro-CT and skull scaffold complex gross, histomorphology, CD31/CD34 immunohistochemical staining, CD31/CD34 molecular content, and vascular endothelial growth factor A protein were detected respectively 4, 8 and 12 weeks after the operation. Animal experiment was approved by the Animal Ethics Committee of Southwest Medical University. 
    RESULTS AND CONCLUSION: (1) Micro-CT showed that 8 weeks after operation, the mass of new bone in group B was higher than that in the other three groups, and the mass of new bone in groups C and D was higher than that in group A. At 12 weeks after surgery, the new bone mass was from high to low: group B>group C>group D>group A. (2) Gross observation showed that the bone crawling area on the scaffold of group B was higher than that of the other three groups, and that of groups C and D was higher than that of group A. At the same time point, the amount of bloody exudate was from most to least: group B>group C>group D>group A. (3) Histological observation showed that at 4 weeks after the operation, the bone regeneration amount from high to low was: group B>group C>group D>group A. At other time points, the bone regeneration amount from high to low was: group B>group D>group C>group A. (4) Immunohistochemical staining showed that at the same time point, the microvascular density of CD31/CD34 was from high to low successively: group B>group C>group D>group A. Except for groups C and D, there was no significant difference (P > 0.05), and the difference between the other groups was significant (P < 0.05). (5) Western blot assay showed that at the same time point, the protein expression of vascular endothelial growth factor A was in descending order from high to low: group B>group C>group D >group A, except for no significant difference between groups C and D (P > 0.05), and the difference between the other groups was significant (P < 0.05). (6) The results showed that bone marrow mesenchymal stem cells and human umbilical vein endothelial cells combined with hydroxyapatite-tricalcium phosphate scaffold materials had strong early vascularization ability in repairing skull defects in rats. 

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    Preparation and properties of poly3-hydroxybutyrate 4-hydroxybutyrate/polyethylene glycol/graphene oxide tissue-engineered scaffolds
    Liu Jun, Yang Long, Wang Weiyu, Zhou Yuhu, Wu Ying, Lu Tao, Shu Liping, Ma Minxian, Ye Chuan
    2021, 25 (22):  3466-3472.  doi: 10.3969/j.issn.2095-4344.3177
    Abstract ( 284 )   PDF (2017KB) ( 78 )   Save
    BACKGROUND: The application of poly3-hydroxybutyrate 4-hydroxybutyrate (P34HB) scaffolds in tissue engineering has been limited due to lacking hydrophilicity.   
    OBJECTIVE: To explore the physicochemical properties and biocompatibility of P34HB as well as polyethylene glycol (PEG) co-solvent mixed graphene oxide (GO) electroplating scaffolds. 
    METHODS: The scaffolds of P34HB, P34HB/PEG and P34HB/PEG/GO had been prepared by electrospinning technology. The three-dimensional structure of the scaffold had been observed by scanning electron microscopy. The contact angle of water droplets on the scaffold had been measured by optical measuring instrument. The tensile stress, strain and elastic modulus of electrospinning frame were analyzed by mechanical tester. The three kinds of scaffolds had been co-cultured with rat bone marrow mesenchymal stem cells respectively. Cell adhesion had been detected by MTT assay. Cell proliferation was detected by Alamar blue assay. Cell survival rate had been observed by Live/Dead fluorescence staining. Cell morphology had been observed by scanning electron microscopy.   
    RESULTS AND CONCLUSION: (1) Scanning electron microscopy had showed random distribution of scaffold fibers in the three groups, and the fiber diameters of P34HB, P34HB/PEG, and P34HB/PEG/GO groups gradually decreased. (2) The contact angles of P34HB/PEG and P34HB/PEG/GO scaffolds were smaller than that of the P34HB scaffold (P < 0.01). (3) The strain rates of P34HB/PEG and P34HB/PEG/GO scaffolds were lower than that of P34HB scaffold (P < 0.05 or 
    P < 0.01), and the elastic modulus of P34HB/PEG/GO scaffolds was higher than that of P34HB/PEG scaffold (P < 0.05). There was no significant difference in the tensile strength among the three groups (P > 0.05). (4) At 1, 3, and 6 hours of co-culture, the number of cell adhesion in the P34HB/PEG/GO group was higher than that in the P34HB and P34HB/PEG groups (P < 0.01), and the number of cell adhesion in the P34HB/PEG group was higher than that in the P34HB group
    (P < 0.01). (5) At 4 and 7 days of co-culture, the proliferation of cells in the P34HB/PEG/GO group was faster than that in the P34HB group and P34HB/PEG group (P < 0.05 or P < 0.01). (6) After 7 days of co-culture, scanning electron microscopy showed that the surface cell volume of P34HB/PEG/GO scaffold was largest and best spread, and the cell survival rate of Live/Dead fluorescence staining group was highest. (7) The results have showed that P34HB/PEG/GO electrospinning scaffold had certain mechanical properties and good hydrophilicity, and could effectively promote cell proliferation and adhesion. 
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    Decellularized porcine skin matrix for tissue-engineered meniscus scaffold
    Wang Hao, Chen Mingxue, Li Junkang, Luo Xujiang, Peng Liqing, Li Huo, Huang Bo, Tian Guangzhao, Liu Shuyun, Sui Xiang, Huang Jingxiang, Guo Quanyi, Lu Xiaobo
    2021, 25 (22):  3473-3478.  doi: 10.3969/j.issn.2095-4344.3173
    Abstract ( 340 )   PDF (1420KB) ( 49 )   Save
    BACKGROUND: Regeneration and repair of the injured meniscus remain scientific challenges. It is of significance to construct a tissue-engineered scaffold with good biomechanical performance and cytocompatibility.
    OBJECTIVE: To prepare decellularized porcine skin matrix scaffold and evaluate its biomechanical properties and cytocompatibility.
    METHODS: Porcine skin was decellularized with the combination of trypsin, Triton X-100 and sodium dodecyl sulfate to obtain decellularized porcine skin matrix. DAPI staining was used to observe whether the cells were well removed and scanning electron microscope to observe its microstructure. The decellularized porcine skin matrix was compared with natural meniscus in term of histological staining, contents of collagen and glycosaminoglycans, and biomechanical properties. The third-generation bone marrow mesenchymal stem cells were seeded on the decellularized porcine skin matrix. After 3 days of culture, the scanning electron microscopy, dead/live cell staining and phalloidin staining were used to observe cytocompatibility of the decellularized porcine skin matrix.
    RESULTS AND CONCLUSION: (1) DAPI staining showed that no cell nucleus was found in the decellularized porcine skin matrix. Scanning electron microscopy showed that the surface of the decellularized porcine skin matrix was rough, and the surface fibers showed a topological structure. (2) Histological staining showed that the natural meniscus tissue was rich in extracellular matrix, and the meniscus cells were evenly distributed in the matrix. The collagen fibers were dense and arranged regularly, and the collagen composition was mainly type I collagen fibers and contained glycosaminoglycan components. The decellularized porcine skin matrix had no cell nucleus and was in the shape of loose fiber strips with more pore structure, and its collagen component was mainly type I collagen fiber and contained glycosaminoglycan components. (3) There was no significant difference in collagen content and tensile modulus between decellularized porcine skin matrix and natural meniscus (P > 0.05), while the glycosaminoglycan content and compression modulus were lower than those of the natural meniscus (P < 0.05). The biomechanical properties of the decellularized porcine skin matrix are sufficient to bear the load of the knee joint and maintain the integrity of the scaffold. (4) Scanning electron microscope showed that bone marrow mesenchymal stem cells adhered to the pore structure of porcine skin matrix, and the cells were elliptical and grew in clusters. (5) Dead/live cell staining showed that the bone marrow mesenchymal stem cells on the decellularized porcine skin matrix had high activity (94.0±3.8)%. (6) Phalloidin/DAPI staining showed that bone marrow mesenchymal stem cells showed good spreading on the decellularized porcine skin matrix. (7) The results showed that decellularized porcine skin matrix has similar collagen components as the natural meniscus, and presents good biomechanical performance and cytocompatibility, and is conducive to cell adhesion and growth.
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    Forming prevascularized cell sheets and the expression of angiogenesis-related factors
    Mo Jianling, He Shaoru, Feng Bowen, Jian Minqiao, Zhang Xiaohui, Liu Caisheng, Liang Yijing, Liu Yumei, Chen Liang, Zhou Haiyu, Liu Yanhui
    2021, 25 (22):  3479-3486.  doi: 10.3969/j.issn.2095-4344.3160
    Abstract ( 265 )   PDF (1118KB) ( 45 )   Save
    BACKGROUND: It is difficult to solve the problem of vascularization in tissue engineering, which has become the key to restrict its clinical application.
    OBJECTIVE: To investigate the feasibility of forming a prevascularized cell sheet by co-culturing of rabbit umbilical vein endothelial cells and stem cell sheet, and to analyze the gene expression of angiogenesis related factors.
    METHODS: Rabbit bone marrow mesenchymal stem cells were isolated and cultured in vitro, forming stem cell sheet by ascorbic acid. Prevascularized cell sheet was prepared by co-culture rabbit umbilical vein endothelial cells with stem cell sheet in the experimental group. Rabbit umbilical vein endothelial cells cultured separately were used as control group. At 3, 7, and 14 days, morphological and histological changes were observed by light microscopy and hematoxylin-eosin staining. mRNA expression of angiogenesis related factors was detected by RT-PCR, and the structure of vascularized network was observed by immunohistochemical staining.
    RESULTS AND CONCLUSION: (1) The light microscopy showed that the cells of the experimental group migrated and rearranged at 3 days after culture. Rabbit umbilical vein endothelial cells "connected" and formed a network structure at 7 days. The network structure was more obvious at 14 days. The cell density of the control group increased continuously, forming a cell mass. No rearrangement or migration of cells was observed to form a network structure. (2) Hematoxylin-eosin staining showed that the cells in the experimental group were not uniformly arranged at 3 days, and the cells were arranged in cords at 7 days and reticulated at 14 days. The cells in the control group showed the accumulation of paving stones and the density increased continuously, without cords or reticular structures. (3) RT-PCR showed that mRNA expression of vascular endothelial growth factor was higher in the experimental group than in the control group at 7 days (P < 0.05). The mRNA expression of basic fibroblast growth factor was higher in the experimental group than that of the control group at 14 days (P < 0.05). The mRNA expression of Ang1 was higher in the experimental group than that of the control group at 7 and 14 days (P < 0.05). The mRNA expression of Ang2 was higher in the experimental group than that of the control group at 3, 7, and 14 days (P < 0.05). (4) Immunohistochemical staining of CD31 showed that the vascular network was formed in the experimental group, while no network was formed in the control group. (5) The results showed that rabbit umbilical vein endothelial cells co-cultured with stem cell membrane can successfully construct the pre-vascularized cell sheet, significantly expressing angiogenesis-related genes.
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    In vitro evaluation of adipose-derived stromal vascular fraction combined with osteochondral integrated scaffold
    Chen Lei, Zheng Rui, Jie Yongsheng, Qi Hui, Sun Lei, Shu Xiong
    2021, 25 (22):  3487-3492.  doi: 10.3969/j.issn.2095-4344.3230
    Abstract ( 249 )   PDF (1290KB) ( 39 )   Save
    BACKGROUND: A large number of animal and clinical experiments have confirmed that local transplantation of adipose-derived stromal vascular fraction can promote articular cartilage repair. 
    OBJECTIVE: To explore the feasibility of constructing tissue-engineered cartilage with acellular dermal matrix/biomineralized collagen integrated bone cartilage scaffold combined with autologous adipose-derived stromal vascular fraction.  
    METHODS: The groin fat pads of both sides of the female rabbit were taken out under sterile conditions, and the stromal vascular fraction was obtained by enzyme digestion. Flow cytometry was used to detect the surface specific protein and observe the ability of adipogenic, osteogenic and chondrogenic differentiation. Adipose-derived stromal vascular fraction (experimental group), adipose-derived mesenchymal stem cells containing transforming growth factor-β3 (cartilage induction group) and adipose-derived mesenchymal stem cells containing 10% fetal bovine serum (control group) were co-cultured on acellular dermal matrix/biomineralized collagen scaffold. CCK8 assay was used to detect cell proliferation. The number of cells was observed under fluorescence microscope. Real time-quantitative PCR detection was used to detect cartilage related gene expression. The content of glycosaminoglycan in extracellular matrix was determined by dimethylmethylene blue colorimetry. 
    RESULTS AND CONCLUSION: (1) The results of flow cytometry showed that the adipose-derived stromal vascular fraction had high expression of CD44, CD105 and CD90, and low expression of CD14, CD19 and CD45. Adipose-derived stromal vascular fraction had the ability to differentiate into adipocytes, osteoblasts and chondrocytes. (2) CCK8 assay showed that with the extension of culture time, the number of three kinds of cells on the acellular dermal matrix/biomineralized collagen scaffold increased, and the number of cells in the experimental group was higher than that in the other two groups (P < 0.05). Under the fluorescence microscope, the number of cells in the experimental group was more than that in the other two groups at 7 days after culture. (3) Real time-quantitative PCR results showed that at 21 days after culture, the mRNA expression levels of Sox9, proteoglycan and type II collagen in the experimental group were higher than those in the other two groups (P < 0.05). (4) Dimethylmethylene blue colorimetry results demonstrated that at 7, 14, and 21 days, the content of glycosaminoglycan in the experimental group was higher than that in the other two groups (P < 0.05). (5) The results showed that adipose-derived stromal vascular fraction combined with acellular dermal matrix / biomineralized collagen scaffold could effectively support cartilage formation in vitro. 
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    Effect of modification of β-tricalcium phosphate/chitosan hydrogel on growth and mineralization of dental pulp stem cells
    Li Xinping, Cui Qiuju, Zeng Shuguang, Ran Gaoying, Zhang Zhaoqiang, Liu Xianwen, Fang Wei, Xu Shuaimei
    2021, 25 (22):  3493-3499.  doi: 10.3969/j.issn.2095-4344.3240
    Abstract ( 285 )   PDF (1422KB) ( 57 )   Save
    BACKGROUND: Using the two materials of genipin crosslinking β-tricalcium phosphate and chitosan, we explored an effective and simple synthetic method to form a stable hydrogel material with good biocompatibility. This will lay a foundation for the application of tissue engineering in bone defect repair in the future.
    OBJECTIVE: To investigate the effects of β-tricalcium phosphate modified chitosan hydrogel on the growth and mineralization of dental pulp stem cells.
    METHODS: Chitosan and β-tricalcium phosphate were selected as raw materials to construct biomimetic bone tissue engineering hydrogel with different ratios. The physical and chemical properties of the hydrogel were tested, including morphology, porosity and release of calcium in the extract. The human dental pulp stem cells were then co-cultured with hydrogel to observe their growth, adhesion and mineralization.
    RESULTS AND CONCLUSION: (1) The chitosan hydrogel with β-tricalcium phosphate was more uniform in pore size and more stable in morphology. The hydrogel could release calcium continuously. (2) The hydrogel added with β-tricalcium phosphate showed good biocompatibility after co-culture with dental pulp stem cells, and was able to induce mineralization of dental pulp stem cells without adding osteogenic inducer. (3) The hydrogel obtained in this experiment has good biocompatibility and certain osteoinductivity, which provides a new idea for the preparation of new tissue engineering materials. 
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    Effect of cinnamaldehyde on osteoblasts in high glucose environment with the electrospinning membrane as a carrier
    Liu Keke, Duan Xin, Ma Xiangrui, Zhang Yuntao
    2021, 25 (22):  3500-3504.  doi: 10.3969/j.issn.2095-4344.3229
    Abstract ( 271 )   PDF (1062KB) ( 41 )   Save
    BACKGROUND:  Previous studies have found that cinnamaldehyde can promote the biological properties of osteoblasts in high glucose environment.
    OBJECTIVE: To observe the effect of cinnamaldehyde on proliferation and differentiation of osteoblasts under high glucose with electrospinning membrane as carrier. 
    METHODS: The polycaprolactone membranes were prepared by electrospinning. MC3T3-E1 cells in logarithmic growth phase were divided into four groups: blank control group was added with high glucose medium. Polycaprolactone group was added with polycaprolactone membrane scaffold and high glucose medium. Drug group was added with high glucose medium containing cinnamaldehyde. Combined group was added with polycaprolactone membrane and high glucose medium containing cinnamaldehyde. CCK-8 method was used to detect cell proliferation and alkaline phosphatase kit was used to detect alkaline phosphatase activity at 1, 4 and 7 days of culture. RT-qPCR was used to detect the expression of osteocalcin mRNA at 7 days.
    RESULTS AND CONCLUSION: (1) CCK-8 assay showed that the cell proliferation of polycaprolactone group, drug group and combined group was faster than that of blank control group at each time point (P < 0.05). Cell proliferation of combined group was faster than that of polycaprolactone group and drug group at 4 and 7 days (P < 0.05), and cell proliferation of drug group was faster than that of polycaprolactone group at 4 and 7 days (P < 0.05). (2) The alkaline phosphatase activity of polycaprolactone group, drug group, and combined group was higher than that of blank control group at 4 and 7 days (P < 0.05). The alkaline phosphatase activity of combined group was higher than that of polycaprolactone group and drug group at 4 and 7 days (P < 0.05). The alkaline phosphatase activity of drug group was higher than that of polycaprolactone group at 7 days (P < 0.05). (3) The expression of osteocalcin mRNA in the four groups from high to low was the combined group, drug group, polycaprolactone group, and blank control group; there were significant differences between the two groups (P < 0.05). (4) Results suggest that polycaprolactone electrospinning membrane and cinnamaldehyde can promote the proliferation and differentiation of osteoblasts in high glucose environment.
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    Application of titanium ossicular prosthesis in one-stage open tympanoplasty for middle ear cholesteatoma
    Wang Shengjun, Yin Fei, Jiang Maoyu
    2021, 25 (22):  3505-3509.  doi: 10.3969/j.issn.2095-4344.3186
    Abstract ( 299 )   PDF (916KB) ( 35 )   Save
    BACKGROUND: With the development of modern otological microsurgery, for the lesions involving the ossicular chain, surgeons are required to select appropriate surgical methods to reconstruct the ossicular chain on the basis of thorough removal of the lesions. Titanium ossicular prosthesis becomes an appropriate material for reconstruction of the ossicular chain.
    OBJECTIVE: To analyze the clinical effect of titanium artificial ossicular prosthesis in one-stage open tympanoplasty for middle ear cholesteatoma.
    METHODS: This study enrolled 75 middle ear cholesteatoma patients admitted to the First Affiliated Hospital of University of Science and Technology of China (Anhui Provincial Hospital) from August 2015 to November 2018, including 40 males and 35 females, aged 4-76 years old. All patients underwent mastoidectomy and tympanoplasty. In the first stage of the operation, partial titanium artificial ossicles were implanted in 61 cases  and total titanium artificial ossicles were implanted in 14 cases. A thin cartilage perichondrium complex was placed between the tympanic membrane graft and the titanium artificial ossicle. The air, bone conduction threshold, and air bone conduction difference of 75 patients before and 6 months after the operation were compared to evaluate the hearing recovery after the operation. This study was approved by the First Affiliated Hospital of University of Science and Technology of China. 
    RESULTS AND CONCLUSION: (1) The follow-up time of all cases was ≥ 6 months. The outcome of dry ear was achieved about 4-6 weeks. At 6 and 12 months after the operation, the otoscope observation showed that the mastoid cavity was well epithelialized, the tympanic cavity was full of air, and the external auditory meatus was spacious and unobstructed. Totally 71 cases of tympanic membrane transplantation healed at the first stage, 3 cases of artificial ossicles were partially prolapsed, and 3 cases of ossicles were completely lost. (2) At 6 months after operation, the air conduction hearing threshold of 75 patients was lower than before operation (P < 0.05). There was no significant difference between bone conduction threshold and preoperative comparison (P > 0.05). (3) The results showed that the one-stage reconstruction of ossicular chain with titanium artificial ossicles on the basis of debridement of lesions in open tympanoplasty can achieve satisfactory hearing effect, with fewer postoperative complications and lower rejection reaction, which is a better optimal treatment option.
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    Poor efficacy after vertebral augmentation surgery of acute symptomatic thoracolumbar osteoporotic compression fracture: relationship with bone cement, bone mineral density, and adjacent fractures
    Liu Chang, Li Datong, Liu Yuan, Kong Lingbo, Guo Rui, Yang Lixue, Hao Dingjun, He Baorong
    2021, 25 (22):  3510-3516.  doi: 10.3969/j.issn.2095-4344.3241
    Abstract ( 290 )   PDF (1159KB) ( 31 )   Save
    BACKGROUND: In recent years, vertebral augmentation surgery has a good effect on osteoporotic vertebral fracture, but with the increasing number of cases, we have found that some patients still complain of obvious pain after receiving vertebral augmentation surgery.
    OBJECTIVE: To analyze the multiple factors that affect the poor efficacy after vertebral augmentation surgery of acute symptomatic thoracolumbar osteoporotic compression fracture, and to conduct a multivariate logistic regression analysis of related factors.
    METHODS: The data of 850 patients who were treated with primary vertebral augmentation in the treatment of vertebral compression fractures in Honghui Hospital, Xi’an Jiaotong University from July 2016 to May 2019 were retrospectively analyzed. According to the visual analogue scale score of low back pain within one month after operation, the curative effect was judged by the score, in which ≥ 4 points were regarded as poor curative effect. A total of 61 patients had poor curative effect (poor curative effect group). The random number table method was used to select 61 patients from 789 patients with satisfactory curative effect as the satisfactory group. The gender, age, body mass index, preoperative bone mineral density T value, operative segment, operation time, surgical path, degree of fracture compression, bone cement injection volume, postoperative bone cement leakage, type of bone cement leakage, postoperative adjacent segment fracture, soft tissue injury, and postoperative bone cement distribution were investigated in both groups. Univariate and multivariate logistic regression analysis was used to explore the risk factors of poor efficacy. This study was approved by the Ethics Committee of Honghui Hospital, Xi’an Jiaotong University (approval No. 202005005). 
    RESULTS AND CONCLUSION: (1) There was no significant difference between the two groups of patients in terms of age, gender, operation time, surgical path, the degree of compression fracture, and injured vertebral segment (P > 0.05). There were statistically significant differences in bone cement leakage, adjacent segment fractures, soft tissue injury, bone cement distribution, bone mineral density T value, and bone cement injection volume (P < 0.05). (2) Binary Logistic regression analysis showed that the poor efficacy of vertebral body enhancement after surgery was significantly correlated with bone cement leakage, adjacent segment fractures, soft tissue injury, bone cement distribution, and bone mineral density T value (P < 0.05). (3) The results of ROC analysis showed that bone mineral density T predicted that the AUC of the poor efficacy after vertebral augmentation was 0.809 (β=0.040, 95%CI=0.729-0.888, P=0.000); the best cut-off value was -3.05; the sensitivity and specificity were 0.721 and 0.836, respectively. (4) These results indicate that bone cement distribution, bone cement leakage, adjacent segment fracture, soft tissue injury, and bone mineral density T value are the risk factors for the poor efficacy after vertebral augmentation in patients with acute symptomatic osteoporotic thoracolumbar vertebral compression fracture.
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    Feasibility of repairing the fixed end non-bolt abutment crown of MK1 precision attachment with porcelain-fused-to-metal crown
    Liu Ningning, Wang Bing
    2021, 25 (22):  3517-3521.  doi: 10.3969/j.issn.2095-4344.3227
    Abstract ( 460 )   PDF (788KB) ( 44 )   Save
    BACKGROUND: In clinical work, the main methods to repair the broken porcelain at the fixed end of the precise attachment are to dismantle and re-make, and the prosthodontics department adopts the method of porcelain crown to repair the broken porcelain patients, which has achieved good results.
    OBJECTIVE: To compare the repair effects of full crown type, buccal partial crown type and crown the resin after the MK1 precision attachment fixed end collapsed through the experiment in vitro. 
    METHODS: Forty-five specimens of MK1 gold porcelain crown fixed end non-bolting dental crown were prepared. Among them, 15 were fully crown reconstructed crown and 15 were buccal and facial reconstructed crown respectively. Conventional bonding of glass ion-cement was performed. The remaining 15 were repaired directly with resin. The maximum shear bonding strength of each sample was detected.
    RESULTS AND CONCLUSION: The shear bonding strength of the full-crown reconstructed crown, the buccal and facial reconstructed crown, and the resin directly repaired broken porcelain specimens were (9.95±0.97), (5.50±0.76), and (1.92±0.52) MPa, respectively, with significant differences among the groups (all P < 0.001). The results showed that it was feasible to repair the precise attachment of broken porcelain MK1 with the reconstructed gold porcelain crown, and the reconstructed crown and the reconstructed cheek and face crown were obviously superior to the resin direct repair. 
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    Restoration effect and stability of resin infiltration combined with bioactive glass on demineralized tooth enamel
    Cheng Yanan, Wu Yucong, Mao Qiuhua, Chen Ling, Lu Liying, Xu Pu
    2021, 25 (22):  3522-3526.  doi: 10.3969/j.issn.2095-4344.3097
    Abstract ( 297 )   PDF (781KB) ( 56 )   Save
    BACKGROUND: Resin infiltration is an effective way to repair the initial caries of enamel, but recent studies have found that it has defects such as insufficient anti-mineralization ability, aggregation shrinkage, easy aging and poor color stability. 
    OBJECTIVE: To observe the restoration effect and stability of resin infiltration combined with bioactive glass on demineralized tooth enamel. 
    METHODS: 100 isolated human tooth specimens were selected to establish an artificial enamel demineralization model, which were randomly divided into four groups and received remineralization treatment. In the group A, models were immersed in artificial saliva. In the group B, the models were immersed in artificial saliva after resin infiltration treatment. In the group C, the models were treated with resin infiltration and then treated with sodium fluoride (twice a day), and finally immersed in artificial saliva. In the group D, the models were treated with resin infiltration and treated with bioactive glass (twice a day), and finally immersed in artificial saliva. The remineralization time of the four groups was 4 weeks. After remineralization, the four groups were re-demineralized and removed after 72 hours. Optical coherence tomography, enamel surface roughness and enamel microhardness were measured before treatment, after demineralization, after remineralization and after re-demineralization. 
    RESULTS AND CONCLUSION: (1) Optical coherence tomography scan showed that the enamel surface of each group was smooth before treatment; the signal was strongest; and there was no difference between the groups. After the initial demineralization, the surface of each group was slightly uneven; the signal enhancement region extended below the surface; and there was no difference between the groups. After remineralization and re-demineralization, the signal enhancement region extended more obviously below the surface, and the signal enhancement region of group D enamel surface was weakened more significantly than other groups. (2) Before treatment and after initial demineralization, there was no significant difference in enamel surface roughness between four groups (P > 0.05). After remineralization, the roughness values were: group A > group B > group C > group D, and the difference was significant among groups (P < 0.01). After re-demineralization, the roughness value of group A was higher than that after the initial demineralization (P < 0.01); the roughness values of groups B, C, and D were lower than those after the initial demineralization (P < 0.01). (3) Compared with the initial demineralization, there was no significant difference in microhardness between the four groups (P ﹥ 0.05). After remineralization, the microhardness values were: group A < group B < group C < group D, and the difference was significant among groups (P < 0.01). After re-demineralization, the microhardness value of group A was lower than that after the initial demineralization (P < 0.01); the microhardness values of groups B, C, and D were higher than those after the initial demineralization (P < 0.01). (4) The results showed that the effect and anti-demineralization stability of porous resin combined with bioactive glass were better than that of using only permeable resin combined with fluoride.
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    Research and development status and development trend of hydrogel in tissue engineering based on patent information
    Liu Liyong, Zhou Lei
    2021, 25 (22):  3527-3533.  doi: 10.3969/j.issn.2095-4344.3152
    Abstract ( 287 )   PDF (1069KB) ( 48 )   Save
    BACKGROUND: Hydrogels play an important role in tissue engineering due to their unique flexibility and biocompatibility. Patent is the most important carrier of technical information. Therefore, it has important reference value for research to use patent information metrology to count, extract and compare the information contained in it.
    OBJECTIVE: To identify and discover hydrogel in tissue engineering technology distribution, research & development focus, trend development, and national competition situation using patent information.
    METHODS: The Derwent Patent Database as a data source was used to search all patent applications in related fields in the past 30 years. Statistical analysis, community clustering analysis and development path analysis were utilized to conduct research and analysis on the main technology distribution, country advantages, scope of protection, technology path, core patent, and main patentees in the field.
    RESULTS AND CONCLUSION: The patent analysis of hydrogels in tissue engineering objectively reflects the scale, layout and trend of the patent technology of hydrogels in tissue engineering: (1) Technically, the main research & development fields of hydrogels in tissue engineering are mainly fillers, drug carriers, bio-polymer hydrogels and preparation technologies. Among them, bio-polymer hydrogel technology is the main part. (2) In the focus of research and development, good biocompatibility and degradability are the main goals of the design, and technically using protein/peptide and plant polysaccharides as the main material, metal coordination bond cross-linking and radiation method are the main synthetic process. (3) In the development trend, stem cells and nanotechnology are deeply involved, and nanocellulose and pluripotent stem cells have generally appeared in the core patents in the past 5 years. (4) In terms of country, the number of patents in China is leading, but mainly based on preparation technology patent. The structure is relatively simple. There is still a gap in core patents and core research & development institutions. The original preparation of hydrogel is relatively low. It is necessary to concentrate on developing original research & development in institutions with fundamental advantages.
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    Structure analysis of platelet-rich fibrin derived from two centrifugation procedures
    Bi Qingwei, Liu Chengpu, Li Yan, Zhao Wenwen, Han Mei
    2021, 25 (22):  3534-3539.  doi: 10.3969/j.issn.2095-4344.3189
    Abstract ( 336 )   PDF (1174KB) ( 51 )   Save
    BACKGROUND: Platelet-rich fibrin has been widely used in clinic because of its characteristics, but the structure and composition of fibrin produced by different centrifugation procedures will be different, which will affect the clinical effect.
    OBJECTIVE: To compare the histological characteristics of platelet-rich fibrin prepared by the different centrifugation procedures.
    METHODS: Venous blood samples from 40 voluntary patients were divided into two groups (n=20). In group A, modified platelet-rich fibrin was obtained by low-speed centrifugation (1 500 r/min centrifugation for 14 minutes). In group B, traditional platelet-rich fibrin was obtained by medium-speed centrifugation 
    (3 000 r/min for 10 minutes). Hematoxylin-eosin staining, immunohistochemistry, scanning electron microscopy, and transmission electron microscope were used to analyze the difference of leukocytes and fibrin matrix in two groups of platelet-rich fibrin.
    RESULTS AND CONCLUSION: (1) Hematoxylin-eosin staining: Both groups contained more leucocytes, mostly concentrated in the middle layer and biased towards the end layer of erythrocytes. Gel layer was mainly composed of fibrin matrix, and the leucocytes were coagulated in the advanced platelet-rich fibrin. The glue layer was scattered and evenly distributed. (2) Immunohistochemistry: The two groups contained a large number of leucocytes in the middle layer, including monocytes and neutrophils. The proportion of neutrophils in the modified platelet-rich fibrin was greater than that of the leukocyte-rich platelet fibers (P < 0.05). There was no significant difference in the ratio of monocytes between the two groups (P > 0.05). (3) Scanning electron microscopy: The leucocytes of the two groups were distributed slightly widely. The numbers of leucocytes and platelet in the advanced platelet-rich fibrin were slightly higher than those in leucocyte- and platelet-rich fibrin. The fiber matrix cords were slightly tightly arranged in the modified platelet-rich fibrin. (4) Transmission electron microscopy: The two groups of intermediate layers gathered a large number of platelets and many neutrophils and monocytes. The protein matrix was densely arranged, among which the fiber matrix in the modified platelet-rich fibrin was slightly denser than that in leucocyte- and platelet-rich fibrin. (5) The results showed that the modified platelet-rich fibrin may be better than leucocyte- and platelet-rich fibrin due to the difference in the number of leucocytes. The advanced platelet-rich fibrin may play a more active role in promoting tissue healing.
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    Hydrophilicity and cell adhesion of hydroxyapatite bioceramics after the coating of polydopamine
    He Lin, Wu Xi, He Song, Yang Sen
    2021, 25 (22):  3540-3544.  doi: 10.3969/j.issn.2095-4344.3234
    Abstract ( 284 )   PDF (1976KB) ( 43 )   Save
    BACKGROUND: Bone graft materials are the key points and difficulties in current research. Hydroxyapatite has good biocompatibility and degradation. However, the mechanical properties of synthetic hydroxyapatite are poor and lack of osteoinductive properties. It is more close to clinical application to combine the more easily obtained apical papilla stem cells with hydroxyapatite bioceramics, which is widely used in clinical bone repair.           
    OBJECTIVE: To observe the physicochemical properties and cytotoxicity of hydroxyapatite bioceramics coated with polydopamine.           
    METHODS: Polydopamine-hydroxyapatite bioceramics were prepared by placing hydroxyapatite bioceramics in dopamine Tris buffer solution. Uncoated hydroxyapatite bioceramics were used as control. The average pore diameter, porosity and contact angle of water droplets of polydopamine coated hydroxyapatite bioceramics and uncoated hydroxyapatite bioceramics were measured. The third generation of human apical papilla stem cells was inoculated on the two kinds of ceramic surfaces respectively. After 15 minutes of culture, the cell adhesion was observed under inverted microscope and laser confocal microscope. After 1, 3, 5 and 7 days of culture, the cytotoxicity was detected by CCK-8 assay.
    RESULTS AND CONCLUSION: (1) There was no significant difference in the average pore size and porosity of hydroxyapatite bioceramics before and after coating (P > 0.05). The particles on the surface of polydopamine coated hydroxyapatite bioceramics were larger and the surface of polydopamine coated hydroxyapatite bioceramics was more flat. (2) The contact angle of polydopamine coated hydroxyapatite bioceramics was lower than that of uncoated hydroxyapatite bioceramics (P < 0.001). (3) Inverted microscope showed that human apical papilla stem cells were scattered around the uncoated cell slides, but not around the coated cell slides; and uniformly adhered human root tip papilla stem cells were observed on the surface of polydopamine coated cell slides. Laser confocal microscopy showed that compared with uncoated cell slides, the volume of human apical papilla stem cells on the surface of polydopamine coated cell climbing tablets was larger, more fully extended, and cell antennae were more obvious. (4) The relative proliferation rates of human apical papilla stem cells cultured at different time points on the two scaffolds were above 75%, and the cytotoxicities were 0-1 grade. (5) The results showed that compared with uncoated hydroxyapatite bioceramics, polydopamine coated hydroxyapatite bioceramics had better hydrophilicity and cell adhesion.
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    Regulatory effect of decellularized cartilage matrix on macrophage polarization
    Tian Guangzhao, Yang Zhen, Zha Kangkang, Sun Zhiqiang, Li Xu, Sui Xiang, Huang Jingxiang, Guo Quanyi, Liu Shuyun
    2021, 25 (22):  3545-3550.  doi: 10.3969/j.issn.2095-4344.3185
    Abstract ( 269 )   PDF (999KB) ( 60 )   Save
    BACKGROUND: Biomaterials derived from extracellular matrix have been successfully applied in the field of tissue engineering regeneration. In recent years, great attention has been paid to the effect of biomaterials on the phenotypic polarization of macrophages.
    OBJECTIVE: To investigate the regulatory effects of decellularized cartilage extracellular matrix (DCM) and pepsin-treated decellularized cartilage extracellular matrix (PDCM) on phenotypic polarization of macrophages. 
    METHODS: The DCM of the pig was prepared by physical comminution, repeated freeze-thaw and differential centrifugation. The biodegradation product (PDCM) was obtained by dissolving it in pepsin solution. Mouse macrophage cell line RAW264.7 was divided into five groups. In the control group, complete macrophage culture medium was added. In the M1 positive control group, lipopolysaccharide + interferon γ solution was added. In the M2 positive control group, interleukin 4 solution was added. In the PDCM group, PDCM solution was added. In the pepsin group, pepsin solution was added. After 18 hours of culture, immunofluorescence staining for CD86 (M1 type macrophages) and CD206 (M2 type macrophages) was performed. In addition, mouse macrophage cell line RAW264.7 was divided into six groups: control group, M1 positive control group, M2 positive control group, pepsin group, DCM coating group and PDCM coating group. After 24 hours of culture, CD86 and CD206 were detected by flow cytometry. 
    RESULTS AND CONCLUSION: (1) Immunofluorescence results showed that in the PDCM group, induced CD86 expression ratio was approximately 0.13; induced CD206 expression ratio was approximately 0.5. (2) Flow cytometry results showed that DCM induced CD86 (20.1%) and CD206 (28.8%) expression in macrophages; PDCM only induced CD206 expression (23.2%). (3) The results showed that DCM and its biodegradation products could promote M2 polarization of macrophages. 
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    Designing of periosteum tissue engineering: combination of generality and individuality
    Zhou Anqi, Tang Yufei, Wu Bingfeng, Xiang Lin
    2021, 25 (22):  3551-3557.  doi: 10.3969/j.issn.2095-4344.3158
    Abstract ( 293 )   PDF (938KB) ( 45 )   Save
    BACKGROUND: Tissue engineered periosteum has broad application prospect in bone repair for its promising osteogenic potential. However, we are facing the dilemma of taking advantage of periosteum to develop an optimal strategy for bone regeneration.
    OBJECTIVE: In this review, we summary the histological structure and osteogenic potential of periosteum as well as its application in tissue engineering from the point of view of generality and individuality, discuss some undefined issues of periosteum tissue engineering and explore perspective strategies for bone repair.
    METHODS: We searched in PubMed, Embase, Web of Science, CNKI and Wanfang databases with the main keywords of “periosteal osteogenesis; periosteum tissue engineering; PDC; PEM; periosteal structure; scaffold of periosteal tissue engineering; vascularized periosteum” and 69 articles were included for the review.
    RESULTS AND CONCLUSION: The designing of tissue engineered periosteum is based on the structure of natural periosteum. The components of natural periosteum are widely used in periosteum tissue engineering. However, limited researches on osteogenic potential of various components and their combinations hinder our understanding and how to design the optimal tissue engineered periosteum remains to be further clarified. Here, we propose a new strategy called “Generality and Individuality”, which customizes tissue engineered periosteum on the basis of commonality to meet the clinical needs of bone repair better. We believe it is of great significance to reach the practically sound combination of generality and individuality and achieve the optimal curative effect of bone repair in the future researches.
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    Effects of drug coating on implant surface on the osseointegration
    Huo Hua, Cheng Yuting, Zhou Qian, Qi Yuhan, Wu Chao, Shi Qianhui, Yang Tongjing, Liao Jian, Hong Wei
    2021, 25 (22):  3558-3564.  doi: 10.3969/j.issn.2095-4344.3183
    Abstract ( 289 )   PDF (649KB) ( 37 )   Save
    BACKGROUND: Drug coating on implant surface can effectively enhance dental implant osseointegration and reduce the difficulty of implant restoration.
    OBJECTIVE: To review the effects of different drug coating on implant surface on osseointegration.  
    METHODS: The first author searched PubMed, VIP, Wanfang and CNKI databases for relevant articles published from January 1986 to July 2020. The search terms were “implant, osseointegration, surface coatings, systemic drugs, carrier” in English and Chinese, respectively. Finally, 67 articles were included in result analysis after screening and summarizing.
    RESULTS AND CONCLUSION: Drug coating on the surface of dental implants can promote the local release of bone binding of dental implants through the carrier, and significantly enhance osseointegration intensity and success rate and maximum load of implant, especially reducing the risk of implantation failures rates by osteoporosis. However, we need to solve some problems before this new coating technical is applied to the clinic: the reliability of the combination of carrier materials and drugs, drug release rate and release amount difficult to control, high initial sustained release concentration of local target tissue and difficult to maintain long-term stability and biocompatibility after implantation. Therefore, in the face of the complex oral microenvironment, as well as the influence of many factors of the patient’s physical condition, it needs to be further verified in clinical trials in the later stage, so as to play a positive role of drug coating technology in the field of oral implantation.
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    Advantages of calcium phosphate nanoparticles for drug delivery in bone tissue engineering research and application
    Chen Song, He Yuanli, Xie Wenjia, Zhong Linna, Wang Jian
    2021, 25 (22):  3565-3570.  doi: 10.3969/j.issn.2095-4344.3184
    Abstract ( 278 )   PDF (771KB) ( 44 )   Save
    BACKGROUND: Local drug delivery system has several advantages, and as an excellent carrier, calcium phosphate nanoparticles have been widely researched and applied in bone tissue engineering. 
    OBJECTIVE: To review the development and applications of calcium phosphate nanoparticles for drug delivery in bone tissue engineering field, looking forward to its future development direction. 
    METHODS: The literature search was performed in CNKI, Wanfang, Web of Science, and PubMed databases. The keywords were “calcium phosphate particles, bone, drug delivery, drug loading” in Chinese and “calcium phosphate particle, calcium phosphate granule, bone, drug delivery” in English. According to the inclusion and exclusion criteria, 60 articles were finally reviewed. 
    RESULTS AND CONCLUSION: Hydroxyapatite, β-tricalcium phosphate, amorphous calcium phosphate and biphasic calcium phosphate were the most commonly used calcium phosphate nanoparticles for drug delivery. They showed some special properties: excellent biocompatibility and biodegradability, controlled particle size, high specific surface area, mild preparation conditions and pH responsiveness. Most drugs were adsorbed on calcium phosphate nanoparticles by charge and hydrogen bonding. Some drugs can form strong ionic bond or chelate with calcium ion. Loaded with growth factors, bisphosphonates, antibiotics, anti-inflammatory molecules and nucleic acids, calcium phosphate nanoparticles have shown effective protection, release drugs under control, and mediated their entry into cells, which have achieved good osteogenic effects both in vitro and in vivo.
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    Status and problems of polycaprolactone and its composite materials in bone tissue engineering
    Zhang Zhenhua, Liu Zichen, Yu Baoqing
    2021, 25 (22):  3571-3577.  doi: 10.3969/j.issn.2095-4344.3176
    Abstract ( 372 )   PDF (730KB) ( 59 )   Save
    BACKGROUND: With the development of bone tissue engineering, the role of scaffold materials has become more and more important. Polycaprolactone and its composite materials have also increasingly attracted researchers to become one of the research highlights in this field.
    OBJECTIVE: To introduce the basic properties and synthesis methods of polycaprolactone, to summarize the research status of polycaprolactone and its composite materials in the field of bone tissue engineering, and to prospect the future development and research direction.
    METHODS: These articles published from 1950 to 2020 in Web of Science database were retrieved by using the search terms “PCL, PCL composites, bone tissue engineering, scaffold, bone, PCL synthesis”, taking “and” as the logical combination relationship. Totally 253 articles were initially obtained, and finally 52 articles were reviewed and analyzed after careful reading and selection.
    RESULTS AND CONCLUSION: (1) Pure polycaprolactone materials have certain shortcomings in bone tissue engineering. Due to their easy chemical modification and physical modification, polycaprolactone composite undoubtedly has become one of the candidate materials for bone tissue engineering scaffolds. (2) Due to the excellent solubility and thermal properties of polycaprolactone, it can be applied to a variety of scaffold preparation technologies. The appropriate scaffold preparation technology can be selected according to the application site. A variety of scaffold preparation technologies also broaden the application field of polycaprolactone, and there are also developed some novel technologies, so scaffold preparation technology should also attract the attention researchers. (3) For the modification direction of polycaprolactone, the modification of inorganic substances and natural or synthetic polymers has received extensive attention. (4) In terms of experimental research methods, researchers should pay attention to introducing more kinds of experimental cells and experimental models in accordance with clinical needs. 
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    Hydrogel as drug scaffold in skin wound repair: challenges of clinical application possibilities
    Gan Lili, Xiong Na, Liu Yanfei
    2021, 25 (22):  3578-3583.  doi: 10.3969/j.issn.2095-4344.3153
    Abstract ( 466 )   PDF (931KB) ( 86 )   Save
    BACKGROUND:  Hydrogels play an important role in the field of wound repair because of its three-dimensional network structure, excellent moisture absorption and retention properties and biocompatibility.
    OBJECTIVE: To review the application of hydrogel dressings as scaffold materials in sustained drug release, debridement and hemostasis for skin traumas.
    METHODS: We took “hydrogels, wound healing, diabetic foot, skin ulcer, burns, radiodermatitis, chronic wounds, drug Carriers” as the key words in Chinese and English, respectively, to retrieve the related literature published from 2000 to 2019 in PubMed, CNKI, and Wanfang databases based on internet search. 
    RESULTS AND CONCLUSION: Hydrogels have a three-dimensional structure similar to extracellular matrix and possess good plasticity, moisture retention, self-healing and long-lasting sustained release properties. As scaffold materials, hydrogels loaded with one or more drugs on skin wounds can enhance the anti-infection, hemostatic and debridement ability of drugs, promote cell adhesion and growth factor expression, induce angiogenesis, collagen deposition, macrophage polarization and granulation tissue formation, and finally, lead to the sweat glands and hair follicles formation, epithelialization acceleration, and shorten the healing process. However, the development and application of multi-functional hydrogels are mostly in the basic research stage of animal experiments, and there is still a lack of large-scale clinical studies to prove their efficacy and safety.
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    Application progress of conductive composite materials in the field of tissue engineering treatment of myocardial infarction
    Lang Limin, He Sheng, Jiang Zengyu, Hu Yiyi, Zhang Zhixing, Liang Minqian
    2021, 25 (22):  3584-3590.  doi: 10.3969/j.issn.2095-4344.3120
    Abstract ( 293 )   PDF (678KB) ( 53 )   Save
    BACKGROUND: In recent years, many new conductive materials have provided a new direction for translational medicine treatment of myocardial infarction.
    OBJECTIVE: To classify and summarize conductive materials mentioned in the current literature, and review their research progress. 
    METHODS: The key words were “biomaterial, nanomaterial, myocardial infarction, polypyrrole, polyaniline” in English and “biomaterials, myocardial infarction, heart tissue engineering” in Chinese. PubMed, Web of Science, Embase, CNKI, Wanfang, Vip and Chinese biomedical literature databases were retrieved for relevant literature published from 2015 to 2020. 
    RESULTS AND CONCLUSION: Currently, in the field of myocardial infarction treatment, conductive biomaterials were divided into three categories: electroactive polymers (polypyrrole, polyaniline, polythiophene), carbon nanomaterials (grapheme and carbon nanotubes), and gold nanomaterials. These materials could be used in animal experiments to repair infarcted areas in the form of hydrogel or heart film patch. These materials, compared with traditional materials, had also shown better conductivity in vivo and in vitro experiments. The process of making materials, however, involved more multi-step synthesis reaction. Whether these materials could ensure low cytotoxicity and stability, there was no method or standard that could be accurately evaluated. At present, the conductive composites have only obtained promising effects in small animal myocardial infarction models. The safety and effectiveness of large animal models are still to be verified.
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    Application of tissue engineering urethral stent and its preparation technology in urethral reconstruction
    Chen Jie, Liao Chengcheng, Zhao Hongbo, Zhao Wei, Chen Zhiwei, Wang Yan
    2021, 25 (22):  3591-3596.  doi: 10.3969/j.issn.2095-4344.3179
    Abstract ( 279 )   PDF (662KB) ( 57 )   Save
    BACKGROUND: Complicated urethral stricture is a difficult problem faced by urological surgeons, and urethral reconstruction based on tissue engineering technology is expected to be an effective method to cure the disease. 
    OBJECTIVE: To review recent research progress of tissue engineering urethral stent and its preparation technology in urethral reconstruction. 
    METHODS: With the keywords of “urethral reconstruction; urethral scaffold” in Chinese and in English, respectively, a computer-based search for articles published from 2005 to 2020 was performed in CNKI and PubMed databases. Articles addressing application of urethral scaffolds and its preparation technology in urethral reconstruction were selected, and the applications of various types of urethral scaffolds materials and manufacturing techniques in urethral reconstruction were summarized, organized and discussed.
    RESULTS AND CONCLUSION: The acellular matrix usually contains growth factors necessary for cell adhesion and differentiation. They can effectively mimic the extracellular matrix of the urothelium during urethral reconstruction, thereby benefiting the regeneration of urethral tissue. The natural-derived material scaffold was used to repair the urethra after cell inoculation, and the result showed a good effect. The biodegradable synthetic scaffold has sufficient porosity and can support cell adhesion, growth and proliferation, and signal molecules such as extracellular matrix components and growth factors can be incorporated into the scaffold structure, so the scaffold is likely to be the first choice for clinical application in the future. Advanced manufacturing technology combines these scaffold materials with cells or signal molecules to prepare a urethral scaffold with excellent performance, thereby promoting the recovery of urethral structure and function. It is hoped that more experimental studies on urethral stents can be transformed into clinical applications, and these urethral stents can be used for the complete repair of urethral strictures.
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    Research status and prospect of zirconia ceramics in dental prosthesis
    Ma Qing, Shi Liyan, Huang Sixue, Zheng Zhangbowen, Zhang Aihua, Zhan Desong, Fu Jiale
    2021, 25 (22):  3597-3602.  doi: 10.3969/j.issn.2095-4344.3095
    Abstract ( 351 )   PDF (641KB) ( 135 )   Save
    BACKGROUND: Zirconia ceramics, as one of crown and bridge restoration materials, has been widely used in dental clinical treatment for its excellent physical and chemical properties, satisfied aesthetic effects, stability of biocompatibility and many other advantages.
    OBJECTIVE: To analyze the physical and chemical properties and the clinical usage, service life and key points of cementation operation of zirconia ceramics by consulting the literature, and summarize its research status and look forward to its development trend. 
    METHODS: We searched the articles about zirconia ceramic in PubMed database, CNKI database, SCIE database and Wanfang database with the key words of “zirconia and physical property, zirconia and chemical property, zirconia ceramics and clinical applications, zirconia ceramics and service life, zirconia ceramics and surface treatment, zirconia ceramics and adhesives, self-glazed zirconia” in English and Chinese, respectively.
    RESULTS AND CONCLUSION: Zirconia ceramics has excellent physical and chemical properties, biocompatibility and aesthetic characteristics. Clinical bonding performance and durability of zirconia ceramics could be significantly improved by physical sandblasting and chemical bonding with functional monomer 10-MDP contained adhesive/primer treatment. Different from the traditional zirconia ceramics, the new zirconia ceramic production so-called “self-glazed zirconia” is produced by additive manufacturing technology, which can save the cost of consumables and be used in the processing and manufacture of various restorations; however, its actual bonding performance needs to be confirmed by scientific experiments and long-term follow-up visit of clinical cases.
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    Development of high molecular polymer polyetherketoneketone and its prospects in medical applications
    Wen Zhijing, Gu Pengzhen, He Xijing, Li Jialiang, Wang Yibin, Wang Yiqun
    2021, 25 (22):  3603-3608.  doi: 10.3969/j.issn.2095-4344.3175
    Abstract ( 282 )   PDF (728KB) ( 64 )   Save
    BACKGROUND: Polyetherketoneketone has excellent biocompatibility and is widely used in biomedical fields such as spine, joint and oral and maxillofacial surgery.
    OBJECTIVE: To summarize the synthesis of polyetherketoneketone and its research progress in medical applications.
    METHODS: PubMed, Web of Science and CNKI databases were searched for the articles concerning about the synthesis and development of polyetherketoneketone and their applications in the field of biomedicine with the search terms of “polyetherketoneketone, synthesis, scaffold material, implant, tissue engineering, biocompatibility” in English and Chinese, respectively. After initial screening of all articles according to inclusion and exclusion criteria, articles with higher relevance were included for review.
    RESULTS AND CONCLUSION: In recent years, with the rise of the combination of medical and engineering, polyetherketoneketone and its composites have been gradually applied to the fields of orthopedics, oral and maxillofacial surgery. In orthopedics, polyetherketoneketone and its compounds modified with different physical and chemical properties can not only maintain the elastic modulus similar to human bones, increase the hardness, but also improve its biocompatibility, increase its antibacterial properties, and promote osseointegration. In oral and maxillofacial surgery, it can be used as a dental implant matrix, frame, and snap ring for removable partial dentures. Polyetherketoneketone can not only maintain good aesthetic advantages, but also has good fatigue resistance and retention, which is comparable to the oral cavity. The bonding system can ensure sufficient bonding ability, so polyetherketoneketone has great potential as a dental restoration material. In-depth research on the modification of polyetherketoneketone and its compound is still a hot topic. Through continuous improvement of the performance of the material, more in vivo and in vitro experiments have been carried out to confirm the superiority of polyetherketoneketone as an implant material for orthopedics and oral and maxillofacial surgery to make clinical transformation and it will have very good application prospects.
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