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    28 January 2024, Volume 28 Issue 3 Previous Issue   
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    Effects of enamel adhesives with different components on Porphyromonas gingivalis and Streptococcus mutans
    Li Zhiyao, Hu Zheng, Li Xuan, Lu Peijun
    2024, 28 (3):  329-335.  doi: 10.12307/2023.985
    Abstract ( 245 )   PDF (893KB) ( 110 )   Save
    BACKGROUND: The light curing and fluoride light curing enamel adhesives have a certain sealing effect on the etched enamel surface. The fluoride light curing enamel adhesives can also achieve the anti-caries function by releasing fluoride ions. However, the existing researches lack the long-term tracing of fluoride release effect, especially the amount of local pathogenic bacteria after 1-3 months of local fluoride application.
    OBJECTIVE: To analyze the changes in the expression of Porphyromonas gingivalis and Streptococcus mutans in subgingival plaque of the upper anterior teeth adhered by different components of enamel adhesives in adolescent patients with fixed appliance.
    METHODS: Ninety adolescent patients who received orthodontic treatment in Shanghai Stomatological Hospital from January to December 2016 were enrolled, including 43 males and 47 females, with a mean age of (13.27±1.12) years. These patients were randomly divided into three groups (n=30 per group). In the chemical curing group, Unite™ bonding resin was used to bond fixed appliances. In the light curing group, Transbond XT light curing resin was used to bond the fixed appliance. In the fluoride light curing group, GC light curing orthodontic adhesive was used to bond the fixed appliance with cement. The subgingival plaque was collected on the day of bonding, 1st, 2nd, and 3rd month follow-up reviews. The expressions of Porphyromonas gingivalis and Streptococcus mutans in subgingival plaque were detected by PCR.
    RESULTS AND CONCLUSION: (1) Intragroup comparison: With the increase of bonding time, Porphyromonas gingivalis expression increased significantly in the 3rd month in the chemical curing group (P < 0.05). In the light curing group, Porphyromonas gingivalis showed a significant decrease in the 1st month (P < 0.05). Porphyromonas gingivalis expression decreased significantly in the 1st and 2nd months compared with initial data in the fluoride light curing group (P < 0.05). The expression of Streptococcus mutans was higher in the chemical curing group in the 1st, 2nd, and 3rd months compared with the initial data (P < 0.05). In the fluoride light curing group, the expression of Streptococcus mutans was lower in the 1st, 2nd, and 3rd months compared with the initial data (P < 0.05). There was no significant difference in the proliferation and expression of Streptococcus mutans during follow-up in the light curing group compared to the initial adhesion (P > 0.05). (2) Intergroup comparison: In the 1st month, the expression of Porphyromonas gingivalis was lower in the light curing group and fluoride light curing group than that in the chemical curing group (P < 0.05). In the 2nd and 3rd months, the expression of Porphyromonas gingivalis was lower in the fluoride light curing group than that in the light curing group and chemical curing group (P < 0.05). In the 1st, 2nd, and 3rd months, the expression of Streptococcus mutans was lower in the light curing group and fluoride light curing group than that in the chemical curing group (P < 0.05). The expression of Streptococcus mutans was lower in the fluoride light curing group than that in the light curing group (P < 0.05). (3) The results show that in the fixed orthodontic process, the use of different components of enamel adhesives has different effects on the proliferation and expression of oral Porphyromonas gingivalis and Streptococcus mutans in the short term. Fluoride light curing enamel adhesives at the initial stage can reduce the occurrence of enamel demineralization, caries, and periodontal inflammation. 
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    Finite element analysis of the effect of the distribution position and content of bone cement on the stress and displacement of reverse femoral intertrochanteric fracture
    Zhang Qianlong, Maihemuti•Yakufu, Song Chenhui, Liu Xiuxin, Ren Zheng, Liu Yuzhe, Muyashaer•Abudushalamu, Sajidan•Aikebaier, Ran Jian
    2024, 28 (3):  336-340.  doi: 10.12307/2023.978
    Abstract ( 200 )   PDF (1480KB) ( 22 )   Save
    BACKGROUND: The proximal femoral nail antirotation is the preferred treatment for reverse osteoporotic intertrochanteric fractures. Bone cement enhancement can reduce the probability of proximal femoral nail antirotation cut-out and cut-through, but there are no relevant biomechanical studies demonstrating the effect of bone cement content and location on the stress and displacement of the fracture end.
    OBJECTIVE: To investigate the effects of different contents and locations of bone cement in cement-reinforced proximal femoral nail antirotation on stress, strain, and displacement of reverse osteoporotic femoral intertrochanteric fractures in the elderly by finite element analysis.  
    METHODS: A healthy adult female right femur model was extracted by Mimics software and smoothed in Geometric software. Five types of internal fixation methods of proximal femoral nail antirotation (cementless, cephalic spherical 1 mL, cephalic spherical 2 mL, cephalic spherical 3.4 mL, and cylindrical 5 mL around spiral blade) and femoral intertrochanteric fracture (AO subtype 31-A3.1 type) model were established in Solidworks software. After assembly, the total stress distribution, peak stress and displacement of the five models of implants with the femur were compared in Ansys software.
    RESULTS AND CONCLUSION: (1) The peak stresses of proximal femoral nail antirotation with head-end spherical 1 mL, head-end spherical 2 mL, head-end spherical 3.4 mL, and cylindrical 5 mL enhanced proximal femoral nail antirotation around the spiral blade respectively were 571.07 MPa (located at the junction of the spiral blade and the main nail), 495.45 MPa (located at the junction of the spiral blade and the main nail), 467.20 MPa (located at the junction of the main nail and the distal screw connection), 642.70 MPa (located at the junction of the main nail and distal screw connection), and 458.58 MPa (located at the junction of the spiral blade and the main nail). (2) The maximum displacements of proximal femoral nail antirotation with head end sphere 1 mL, head end sphere 2 mL, head end sphere 3.4 mL, and with cylindrical 5 mL enhancement around the spiral blade were 9.260 5, 7.589 1, 7.316 8, 6.790 7, and 6.615 7 mm, respectively, all of which were located at the proximal end of the femoral head. (3) These findings revealed that for reverse femoral intertrochanteric fractures treated with proximal femoral nail antirotation, the bone cement enhancement had significant mechanical stability compared with no enhancement, and the enhancement of the spiral blade 5 mL around the perimeter was the best, which is more preferable for aged unstable intertrochanteric fractures.
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    Effect of nanobubbles carrying double antibodies on the proliferation of ovarian cancer cells
    Wu Tian, Zhao Yue, Hu Rong
    2024, 28 (3):  341-346.  doi: 10.12307/2023.974
    Abstract ( 235 )   PDF (1614KB) ( 57 )   Save
    BACKGROUND: Immunotherapy enhances the anti-cancer immune response in many ways, so combined immunotherapy is a better choice. Ultrasound-targeted microbubble destruction technique delivers drugs, genes, antibodies and cytokines directly to the cytoplasm of immune cells and enhances the immune response. However, the application of ultrasound-targeted microbubble destruction technique in the treatment of ovarian cancer with both CXC chemokine receptor 4 antibody and programmed death-ligand 1 antibody has not been reported.
    OBJECTIVE: To investigate the effect of ultrasound irradiation on the proliferation and migration of ovarian cancer cells with CXC chemokine receptor 4 antibody and programmed death-ligand 1 antibody double targeted nanobubbles.
    METHODS: IOSE-80 normal ovarian epithelial cells, SKOV3 and CAOV3 ovarian cancer cells were cultured and expanded. Double labeling fluorescence immunoassay was used to co-locate CXC chemokine receptor 4 and programmed death-ligand 1 protein. Western blot assay was used to detect the relative expression of CXC chemokine receptor 4 and programmed death-ligand 1 protein in three kinds of cells and screen out the experimental cells, i.e., pure nanobubbles, nanobubbles carrying CXC chemokine receptor 4 antibody, nanobubbles carrying CXC chemokine receptor 4 and programmed death-ligand 1 antibody. SKOV3 ovarian cancer cells in the logarithmic growth phase were taken and divided into six groups for treatment. Group A was added with McCoy's 5A medium. Group B was added with McCoy's 5A medium containing stromal cell-derived factor-1. Group C was added with pure nanobubble solution and McCoy's 5A medium containing stromal cell-derived factor-1. Group D was added with nanobubble solution containing CXC chemokine receptor 4 antibody and McCoy's 5A medium containing stromal cell-derived factor-1. Group E was added with nanobubble solution containing CXC chemokine receptor 4 and programmed death-ligand 1 antibody and McCoy's 5A medium containing stromal cell-derived factor-1. Pure nanobubble solution was added in group F. After ultrasonic irradiation for 120 seconds and incubation for 48 hours, the survival rate of cells was measured by CCK-8 assay, and the healing and migration ability of cells in groups B-E were measured by wound healing test.
    RESULTS AND CONCLUSION: (1) Immunofluorescence staining showed that CXC chemokine receptor 4 and programmed death-ligand 1 protein could be expressed in all three kinds of cells. Western blot assay showed that the expression levels of CXC chemokine receptor 4 and programmed death-ligand 1 in SKOV3 and CAOV3 ovarian cancer cells were significantly higher than those in IOSE-80 normal ovarian epithelial cells (P < 0.05). (2) CCK-8 assay results exhibited that the cell survival rate of group B was higher than that of group A (P < 0.05). The cell survival rate of group F was lower than that of group A (P < 0.05). The cell survival rate of groups B-E decreased gradually, and there were significant differences between the two groups (P < 0.05). (3) Wound healing test demonstrated that the cell healing rate of groups B-E decreased gradually, and there were significant differences between the two groups (P < 0.05). (4) The results show that the use of CXC chemokine receptor 4 antibody and programmed death-ligand 1 antibody double targeted nanobubbles under ultrasound-targeted microbubble destruction can significantly inhibit the proliferation and migration of ovarian cancer cells. 
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    Exosome-loaded injectable hydrogel for repairing bone defects around implants
    Dai Jing, Liu Shasha, Shen Mingjing
    2024, 28 (3):  347-354.  doi: 10.12307/2023.975
    Abstract ( 354 )   PDF (1631KB) ( 58 )   Save
    BACKGROUND: A large number of studies have confirmed that exosomes can promote osteogenesis and vascularization. However, simple exosome therapy has problems such as poor targeting, and the content of loaded molecules cannot reach the therapeutic concentration.
    OBJECTIVE: To load exosomes into injectable gluconolactone-sodium alginate β-tricalcium phosphate-polyethylene glycol hydrogel, and observe the effect of the hydrogel on peri-implant bone defect in vivo and in vitro. 
    METHODS: Exosomes were extracted from bone marrow mesenchymal stem cells and wrapped in injectable gluconolactone-sodium alginate β-tricalcium phosphate-polyethylene glycol hydrogel. (1) In vitro experiment: The hydrogel loaded with exosomes and the hydrogel without exosomes were cocultured with endothelial progenitor cells, and exosomes uptake experiment, tubule formation experiment, cell proliferation, migration ability, and angiogenic gene detection were carried out. (2) In vivo experiment: Twelve male New Zealand white rabbits were used to prepare two standard implant cavities and corresponding bone defects in the long axis of one femur. A hydrogel loaded with exosomes was implanted in the bone defect after an implant was implanted in a cavity at the proximal end of the implant (experimental group), and an unloaded exosome hydrogel was implanted in the bone defect after an implant was implanted in a cavity at the distal end of the implant (control group). At 3, 6 and 9 weeks after operation, bone defects with implants were removed and stained with hematoxylin-eosin staining and Masson staining. Simultaneously, osteogenic and angiogenic genes were detected at 9 weeks after operation.  
    RESULTS AND CONCLUSION: (1) In vitro experiment: Exosomes could enter endothelial progenitor cells. The proliferation, migration, angiogenesis and gene (CD31, vascular endothelial growth factor and basic fibroblast growth factor) expression of endothelial progenitor cells in the hydrogel-loaded group were higher than those in the hydrogel-unloaded group (P < 0.05). (2) In vivo experiment: Hematoxylin-eosin staining and Masson staining showed that at 3 weeks after operation, only a small amount of new bone was found in the two groups, and the material was partially degraded. At 6 weeks after operation, the amount of new bone in the two groups increased, and a large amount of new bone was found in the experimental group, with obvious calcium deposition. At 9 weeks after operation, compared with the control group, a large number of bone trabeculae thicker than mature were found in the experimental group, calcium salt deposition was more obvious, and a large number of osteoblasts were found around the bone trabeculae. The protein expressions of CD31, vascular endothelial growth factor, basic fibroblast growth factor, bone morphogenetic protein 2, type I collagen and osteocalcin in the experimental group were higher than those in the control group at 9 weeks after operation (P < 0.05). (3) The exosome-loaded gluconolactone-sodium alginate β-tricalcium phosphate-polyethylene glycol hydrogel could promote the proliferation, migration and angiogenic differentiation of endothelial progenitor cells and promote the repair and regeneration of bone defects around implants.
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    Hyaluronic acid hydrogel-encapsulated bone marrow mesenchymal stem cells promote cardiac function in myocardial infarction rats (III)
    Lin Feng, Cheng Ling, Gao Yong, Zhou Jianye, Shang Qingqing
    2024, 28 (3):  355-359.  doi: 10.12307/2023.837
    Abstract ( 343 )   PDF (1464KB) ( 35 )   Save
    BACKGROUND: Our previous experimental results have shown that hyaluronic acid hydrogel can act as a vehicle for bone marrow mesenchymal stem cell delivery to improve the cardiac function of rats with myocardial infarction. 
    OBJECTIVE: To explore the molecular mechanism of bone marrow mesenchymal stem cells and hyaluronic acid hydrogel in promoting damaged heart repair. 
    METHODS: Bone marrow mesenchymal stem cells from male Sprague-Dawley rats were isolated and cultured, and then hyaluronic acid-encapsulated bone marrow mesenchymal stem cells were cultured in vitro in a three-dimensional manner. A model of myocardial infarction was made by ligating the left anterior descending artery of female Sprague-Dawley rats. After 1 week, the model rats were screened by ultrasonic testing and then eligible ones were randomly divided into four groups: PBS group (n=12), hyaluronic acid group (n=12), bone marrow mesenchymal stem cell group (n=15), and hyaluronic acid-encapsulated bone marrow mesenchymal stem cell group (n=15). At 1 week after ligation, the model rats underwent the secondary thoracotomy followed by corresponding injections into the infarcted region and its marginal zone. The expression levels of matrix metalloproteinase-2, vascular endothelial growth factor, thymosin β4 and c-Kit were examined at post-injection day 1, week 1 and week 2 by western blot assay. At post-injection week 2, immunofluorescence staining was used to detect the differentiation of transplanted cells.
    RESULTS AND CONCLUSION: (1) The expression levels of matrix metalloproteinase-2 and vascular endothelial growth factor protein in the infarct zone in the bone marrow mesenchymal stem cell group were significantly up-regulated at week 1 compared with the other three groups (P < 0.05). At week 2, the hyaluronic acid group had a lower expression of matrix metalloproteinase-2 and vascular endothelial growth factor protein than the other three groups (P < 0.05). However, the expression of matrix metalloproteinase-2 and vascular endothelial growth factor protein in the hyaluronic acid+bone marrow mesenchymal stem cell group was not significantly different compared with the bone marrow mesenchymal stem cell group. This was primarily attributable to a prolonged paracrine effect via the controlled release of the hyaluronic acid hydrogel. This prolonged paracrine effect offsets the inhibitory effect induced by hyaluronic acid hydrogel at 2 weeks. (2) Compared with the PBS group, thymosin β4 and c-Kit expression levels in the hyaluronic acid group, bone marrow mesenchymal stem cell group and bone marrow mesenchymal stem cell+hyaluronic acid group were significantly increased (P < 0.05). (3) No differentiation of transplanted cells into cardiomyocytes or blood vessels was detected 2 weeks after transplantation. (4) It is indicated that transplanted bone marrow mesenchymal stem cells promote myocardial repair through the paracrine effect, and hyaluronic acid hydrogel prolongs the paracrine effect of transplanted bone marrow mesenchymal stem cells.
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    Effect of neodymium-doped:yttrium aluminum perovskite laser combined with two kinds of remineralizers on remineralization of early enamel caries
    Xu Yinghua, Liu Jing, You Quan, Wen Zhihao, Gao Lu
    2024, 28 (3):  360-365.  doi: 10.12307/2023.838
    Abstract ( 200 )   PDF (1378KB) ( 27 )   Save
    BACKGROUND: In recent years, a variety of lasers have been widely used in various diseases related to stomatology, including the prevention and treatment of dental caries. 
    OBJECTIVE: To investigate the effect of neodymium-doped:yttrium aluminum perovskite (Nd:YAP) laser combined with two remineralizers on early enamel caries in vitro. 
    METHODS: Early enamel caries models in vitro were artificially established by 60 enamel blocks and randomly divided into 6 groups (n=10). Group A did not undergo any treatment but underwent extracorporeal pH circulation. Group B underwent remineralization of dentin (the main component of casein phosphopeptide-amorphous calcium phosphate composite) and extracorporeal pH circulation. Group C underwent remineralization treatment of Sensodyne toothpaste (the main component of bioactive glass) and then underwent extracorporeal pH circulation. Group D received Nd:YAP laser irradiation and extracorporeal pH circulation. Group E was treated with Nd:YAP laser irradiation, with remineralization of dentin, and then with extracorporeal pH circulation. In group F, Nd:YAP laser irradiation was performed, and then Sensodyne toothpaste was used for remineralization, and the extracorporeal pH circulation was performed; the remineralization treatment was conducted twice a day, and the experimental period was 20 days. Group G was a normal control group, without caries or remineralization, but only underwent extracorporeal pH circulation. After the experiment, the microhardness, morphology and Ca/P ratio of the dental enamel surface were measured in each group.
    RESULTS AND CONCLUSION: (1) The surface microhardness value of dental enamel in groups B, C and D was higher than that in group A (P < 0.000 1); the surface microhardness value of dental enamel in groups E and F was significantly higher than that in groups B, C and D (P < 0.000 1), and the surface microhardness value of dental enamel in group F was significantly higher than that in group E (P < 0.000 1). (2) Scanning electron microscopy showed that there were a lot of demineralized pores on the enamel surface of group A. There were mineral deposits on the enamel surface of group B, which were uneven and loose. In group C, there were a lot of mineral deposits on the enamel surface, and demineralized pores were found between the calcified masses. The enamel surface of group D was relatively flat; the demineralized pores were significantly smaller than that of group A, and the enamel column interstitium was damaged. In group E, the mineral deposits on the enamel surface were thicker and the demineralized pores were significantly reduced. The mineralized substances deposited on the enamel surface of group F were most dense and uniform and the demineralized pores were small. (3) The Ca/P ratio on the enamel surface of groups B and C was significantly higher than that of group A (P < 0.000 1); the Ca/P ratio on the enamel surface of group E was significantly higher than that of groups B, C and D (P < 0.000 1), and the Ca/P ratio on the enamel surface of group F was higher than that of group E (P < 0.001). (4) These findings indicate that bioactive glass, casein phosphopeptide-amorphous calcium phosphate composite, and Nd:YAP laser after enamel demineralization can promote the remineralization of early enamel caries. Nd:YAP laser combined with bioactive glass or casein phosphopeptide-amorphous calcium phosphate composite can further strengthen the remineralization of dental enamel caries, and the combination of Nd:YAP laser and bioactive glass has the best effect. 
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    Preparation and in vitro evaluation of a three-dimensional porous cartilage scaffold made of silk fibroin/gelatin/chitosan
    Gu Mingxi, Wang Changcheng, Tian Fengde, An Ning, Hao Ruihu, Guo Lin
    2024, 28 (3):  366-372.  doi: 10.12307/2023.881
    Abstract ( 318 )   PDF (1505KB) ( 50 )   Save
    BACKGROUND: Cartilage defects are one of the major clinical challenges faced by orthopedic surgeons. Tissue engineering is an interdisciplinary approach that combines knowledge of engineering and cell biology to provide new ideas and approaches for the repair of cartilage defects.
    OBJECTIVE: To prepare a multi-component composite scaffold based on silk fibroin, gelatin, and chitosan to screen for a three-dimensional porous scaffold suitable for cartilage regeneration by evaluating its physicochemical properties and biological performance.
    METHODS: Four groups of porous scaffolds were prepared by vacuum freeze-drying method using silk fibroin, gelatin and chitosan as the base materials, namely chitosan/gelatin scaffold, silk fibroin/chitosan scaffold, silk fibroin/gelatin scaffold and silk fibroin/chitosan/gelatin scaffold. The suitable cartilage scaffolds were screened by scanning electron microscopy, X-ray diffractometer, porosity, water absorption and swelling rate, biodegradation rate and mechanical property detection. Then cartilage scaffolds were co-cultured with chondrocytes isolated and extracted from patients with osteoarthritis. The feasibility of porous scaffolds for cartilage injury repair was evaluated in vitro by cell adhesion rate assay, cell live-dead staining and cell activity proliferation assay.
    RESULTS AND CONCLUSION: (1) All four groups of scaffolds had porous structures. The comprehensive physical performance test results showed that the silk fibroin/gelatin/chitosan scaffold was more in line with the requirements of cartilage defect repair. This scaffold had a pore size of (176.00±53.68) μm, the porosity of (80.15±2.57)%, and water absorption and swelling rate of (3 712±358)%. After immersion in PBS containing lysozyme for 28 days in vitro, the biodegradation rate was (46.87±3.25)%, and it had good mechanical properties. (2) Chondrocytes could adhere well on the silk fibroin/gelatin/chitosan scaffold, and the cell adhesion rate increased with time. CCK8 and live/dead cell double staining results showed that silk fibroin/gelatin/chitosan scaffold had good biocompatibility and low cytotoxicity. (3) The results showed that silk fibroin/gelatin/chitosan scaffold had a highly hydrated 3D structure, suitable pore size and porosity, good biodegradability and superior mechanical properties, which can provide a good reticular skeleton and microenvironment for nutrient transport and chondrocyte attachment and proliferation. 
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    Growth differentiation factor-5 modified by bisphosphonate promotes osteogenic differentiation of MC3T3-E1 cells
    Li Lisi, Zhang Chengdong, Li Xiaolong, Ye Ziyu, Pu Chao, Yang Zaijun, Shi Feng, Xiao Dongqin
    2024, 28 (3):  373-379.  doi: 10.12307/2023.981
    Abstract ( 207 )   PDF (1343KB) ( 19 )   Save
    BACKGROUND:  As a member of bone morphogenetic proteins, growth differentiation factor-5 shows promising potential in the application of cartilage and bone repair. The affinity of growth differentiation factor-5 onto bone tissue determines protein use efficiency, so it is of great significance to prepare growth differentiation factor-5 with bone targeting capability.
    OBJECTIVE: To modify growth differentiation factor-5 using bisphosphonates and investigate the effects of modified protein on the growth of preosteoblasts in mice.
    METHODS: Pamidronate disodium/growth differentiation factor-5 complex was prepared using chemical crosslinking to couple growth differentiation factor-5 with pamidronate disodium. The functional groups and structures of the complex were characterized using Fourier transform infrared spectroscopy and circular dichromatography. To determine the bone targeting in vitro, the binding of the modified growth differentiation factor-5 with calcium phosphate and in vitro release amount of growth differentiation factor-5 were measured with an ELISA kit. Growth differentiation factor-5 (control group) and the pamidronate disodium/growth differentiation factor-5 complex (experimental group) were co-cultured with preosteoblasts MC3T3-E1. Individually cultured cells were blank controls. The effect of the complex on cell proliferation and differentiation was evaluated.    
    RESULTS AND CONCLUSION: (1) The infrared spectroscopy and circular dichromatography results indicated that the bisphosphonate/growth differentiation factor-5 complex was successfully prepared without significant changes in the protein secondary structure. In vitro protein adsorption results showed that growth differentiation factor-5 adsorption on calcium phosphate was increased by about one time after coupling with a bisphosphonate. In the presence of cysteine, growth differentiation factor-5 could be released from the bisphosphonate/growth differentiation factor-5 complex. (2) CCK-8 assay results showed that the absorbance value of the experimental group cultured for 4 and 7 days was higher than that of the control group and blank control group (P < 0.000 1). 
    After 7 days of culture, the expression of alkaline phosphatase in the experimental group was significantly higher than that in the control group and blank control group (P < 0.000 1). After 13 days of culture, the content of calcium nodules in the experimental group was significantly higher than that in the control group and the blank control group (P < 0.000 1). The results of qRT-PCR showed that the mRNA expression of alkaline phosphatase, osteocalcin and Runx2 in the experimental group was higher than that in the control group and the blank control group after 7 days of culture (P < 0.01, P < 0.001, P < 0.000 1). (3) These findings exhibit that bisphosphonate modification can enhance the binding capacity of growth differentiation factor-5 to calcium phosphate as well as improve its biological activity. 
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    Effect of gelatin methacryloyl hydrogel loaded with salvianolic acid B on intervertebral disc degeneration
    Cao Sheng, Kong Lingwei, Xu Kun, Sun Zhijie
    2024, 28 (3):  380-386.  doi: 10.12307/2023.883
    Abstract ( 267 )   PDF (1276KB) ( 85 )   Save
    BACKGROUND: Salvianolic acid B can inhibit cell damage induced by H2O2, effectively remove excess reactive oxygen species, and exert antioxidant properties. It has been used in the treatment of many diseases. However, there are relatively few studies on the role and mechanism of salvianolic acid B in intervertebral disc degeneration.
    OBJECTIVE: To observe the effect and mechanism of salvianolic acid B on oxidative stress-induced intervertebral disc degeneration by using gelatin methacryloyl hydrogel as a carrier through the in vitro cell experiment and the in vivo animal experiment.
    METHODS: The gelatin methacryloyl hydrogel (drug-loaded hydrogel) loaded with salvianolic acid B was prepared. (1) In vitro cell experiment: The lumbar nucleus pulposus cells of adult SD rats were isolated and extracted, and passage 3 nucleus pulposus cells were selected and divided into groups: Group A was added complete medium. In group B, a complete medium containing H2O2 was added. Group C was inoculated on methylacrylylated gelatin hydrogel and added with a complete medium containing H2O2. Group D was inoculated on methyl acrylyl gelatin hydrogel loaded with salvianolic acid B and added into a complete medium containing H2O2. The E group was inoculated on the methylacrylyl gelatin hydrogel loaded with salvianolic acid B, and the complete medium containing H2O2 and the complete medium containing TLR4 signaling pathway inhibitor were added. Cell proliferation, oxidative stress, inflammatory response, gene expression of cell matrix-associated proteins and the protein expression of TLR4/nuclear factor-kB signaling pathway were detected. (2) Animal in vivo experiment: Sixty adult SD rats were randomly divided into normal group, acupuncture group, acupuncture + salvianolic acid group, acupuncture + hydrogel group and acupuncture + loading potion gel group, with 12 rats in each group. The last four groups were treated with acupuncture to establish models of intervertebral disc degeneration and then injected with normal saline, salvianolic acid B solution, non-drug loaded gel and drug-loaded gel in turn. Imaging examination and pathological observation were performed 4 weeks after surgery.
    RESULTS AND CONCLUSION: (1) In vitro cell experiment: Compared with group A, the cell proliferation was decreased; the oxidative stress reaction and inflammation reaction were enhanced; the expression of extracellular matrix degrading enzymes (matrix metalloproteinase 3, matrix metalloproteinase 13, ADAMTS4, ADAMTS5) was increased in group B (P < 0.05), and the synthesis of extracellular matrix (type II collagen, proteoglycan) was decreased (P < 0.05). The protein expression of the TLR4/nuclear factor-kB signaling pathway was increased (P < 0.05). Compared with group B, the cell proliferation of groups D and E was increased, the oxidative stress response and inflammatory response were weakened, and the expression of extracellular matrix degrading enzymes (matrix metalloproteinase 3, matrix metalloproteinase 13, ADAMTS4, ADAMTS5) was decreased (P < 0.05), and the synthesis of extracellular matrix was increased (P < 0.05). The protein expression of TLR4/nuclear factor-kB signaling pathway was decreased (P < 0.05), and the effect was more significant in group E. (2) Animal in vivo experiment: 4 weeks after surgery, intervertebral disc height index, index of MRI and pathological and histological grading of the intervertebral disc had improved significantly in the acupuncture+drug-loaded hydrogel group, and simply injecting hydrogel or salvianolic acid B solution can to a certain extent improve the intervertebral disc degeneration, but they are not as good as the injection of the drug-loaded hydrogel. (3) It is concluded that gelatin methacryloyl hydrogel loaded with salvianolic acid B can inhibit oxidative stress and inflammation in the degenerated intervertebral disc tissue, inhibit the degradation of extracellular matrix, and alleviate the process of intervertebral disc degeneration, which may be accomplished by inhibiting the TLR4/nuclear factor-kB signaling pathway.
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    Influence of NIC X-FILE and DENCO Pre-Shaper nickel-titanium instruments on the shaping of simulated curved canals
    Shen Yurong, Nai Rentong, Zhao Ling, Liu Feigang, Yin Caoyang, Gu Yuanping, Chen Tieyi
    2024, 28 (3):  387-391.  doi: 10.12307/2023.886
    Abstract ( 181 )   PDF (923KB) ( 68 )   Save
    BACKGROUND: Root canal preparation is a key step in root canal therapy. In recent years, with the rapid development of new nickel-titanium instruments, the results of root canal shaping ability have been significantly improved. However, the shaping abilities of different nickel-titanium instruments are also different. At present, there are few reports about the influence of the shaping ability of R-phase heat treatment NIC X-FILE and DENCO Pre-Shaper in simulated curved canals. 
    OBJECTIVE: To compare the shaping effect of NIC X-FILE and DENCO Pre-Shaper nickel-titanium instruments in preparation for simulated curved canals. 
    METHODS: Fifty simulated resin-curved canals were selected and randomly divided into two groups (n=25). NIC X-FILE and DENCO Pre-Shaper nickel-titanium files were used for root canal preparation. The root canal preparation time was recorded. Images of pre-and post-root canal preparation were taken. Image processing and analysis software were used to measure the amount of resin removed from the inner and outer walls of the root canal at each observation point. Statistical software was used to compare the root canal preparation time and centering ability of two kinds of mechanical nickel-titanium files.
    RESULTS AND CONCLUSION: (1) The average root canal preparation time was (1.58±0.02) minutes in the DENCO Pre-Shaper group and (2.22±0.03) minutes in the NIC X-FILE group. There was a significant difference between the two groups (P < 0.05). (2) The amount of resin removed from the inner walls of the root canal of the DENCO Pre-Shaper group at 4, 5, 7, 8, 9, and 10 mm from the apical foramen was higher than that of the NIC X-FILE group (P < 0.05). The amount of resin removed from the outer walls of the root canal of the DENCO Pre-Shaper group at 3, 5, 6, 7, and 8 mm from the apical foramen was lower than that of the NIC X-FILE group (P < 0.05). (3) At 2, 4, 5, 6, 7, 8, and 9 mm away from apical foramen, the centering ability of the NIC X-FILE group was better than that of the DENCO Pre-Shaper group (P < 0.05), and the centering ability of the NIC X-FILE group was the best at 4 mm away from apical foramen. (4) The results show that DENCO Pre-Shaper has higher mechanical efficiency than NIC X-FILE nickel-titanium root canal files. However, the centering ability of DENCO Pre-Shaper is inferior to NIC X-FILE nickel-titanium root canal files. 
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    Mechanism underlying the effect of Liuwei Dihuang Pill on osteolysis and osteogenesis induced by titanium particles
    Zhu Zhiqi, Yuan Sijie, Zhang Zilin, Ji Shijie, Meng Mingsong, Yan Anming, Han Jing
    2024, 28 (3):  392-397.  doi: 10.12307/2023.880
    Abstract ( 227 )   PDF (1413KB) ( 27 )   Save
    BACKGROUND: At present, a large number of studies have found that Liuwei Dihuang Pill can be used to treat osteoporosis, but there are few related studies on the differentiation and mineralization of osteoblasts induced by wear particles using Liuwei Dihuang Pill.
    OBJECTIVE: To investigate the positive effect of different concentrations of Liuwei Dihuang Pill-containing serum on titanium particle-induced mouse MC3T3-E1 osteoblast in vitro osteolysis model.  
    METHODS: Drug-containing serum was extracted after oral administration of Liuwei Dihuang Pill. The best concentration of Liuwei Dihuang Pill-containing serum and titanium particles on the viability of MC3T3-E1 cells was screened. MC3T3-E1 cells were divided into three groups. The blank group was given osteoblastic differentiation culture. The model group was given titanium particles (5 μg/mL) ossification culture. The drug-containing serum group was given titanium particles (5 μg/mL) + Liuwei Dihuang Pill-containing serum (10%, 15% and 20% doses). Osteoblast viability was detected by CCK-8 assay. Cell alkaline phosphatase activity was detected by alkaline phosphatase staining. Cell mineralization was detected by silver nitrate (Von Kossa) and alizarin red staining. Expression levels of bone differentiation-related genes Runx-2, Osterix, Ocn, Axin, Alp, and Opn were detected by qRT-PCR. Wnt/β-catenin signaling pathways β-catenin, p-GSK-3β, GSK-3β, Runx2 and Osterix protein expression levels were detected by western blot assay.  
    RESULTS AND CONCLUSION: (1) Liuwei Dihuang Pill-containing serum culture reversed the decrease in alkaline phosphatase activity of MC3T3E-1 cells induced by titanium particles, increased the alizarin red staining and calcification of MC3T3E-1 cells, increased the expression of osteogenesis-related genes in MC3T3E-1 cells, and increased the expression of proteins related to the Wnt/β-catenin signaling pathway. (2) These findings indicate that Liuwei Dihuang Pill-containing serum can reverse the inhibitory effect of titanium particles on the differentiation and mineralization of osteoblasts, upregulate the expression of osteogenesis-related genes, and its mechanism is related to the regulation of Wnt/β-catenin signaling pathway, suggesting that Liuwei Dihuang Pill is expected to become an effective drug for preventing aseptic loosening of artificial joints.
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    3D printing process of gelatin/oxidized nanocellulose skin scaffold with high elastic modulus and high porosity 
    Xu Xiaodong, Zhou Jiping, Zhang Qi, Feng Chen, Zhu Mianshun, Shi Hongcan
    2024, 28 (3):  398-403.  doi: 10.12307/2023.977
    Abstract ( 213 )   PDF (1521KB) ( 85 )   Save
    BACKGROUND: In the treatment of skin trauma with active repair, tissue engineering techniques are needed to generate new tissue to replace necrotic tissue. Skin scaffolds have a good application prospect in the field of wound repair. Skin scaffolds need to present three-dimensional porous structures with certain mechanical strength to meet the needs of cell proliferation and division. However, the mechanical strength of the currently used gelatin-based biomaterials is weak and cannot meet the requirements of the use of skin scaffolds.
    OBJECTIVE: To study the 3D printing process used in the preparation of tissue engineering skin scaffolds by gelatin/oxidized nanocellulose composites, and focus on the relationship between the porosity and mechanical strength of the scaffolds prepared under different process parameters.
    METHODS: Oxidized nanocellulose whiskers at 10% concentration were extracted from Humulus scandens and then compounded with 5% gelatin to obtain gelatin/oxidized nanocellulose composites. The elastic modulus of gelatin and gelatin/oxidized nanocellulose composite was determined. Skin scaffolds were prepared by 3D printing extrusion molding using gelatin/oxidized nanocellulose composite as the base material. Mechanical and rheological properties of the composite were tested to determine extrusion molding parameters (filling gap 1.5-2.5 mm, uniform distribution of 0.1 mm; air pressure of 160-200 kPa), and the skin scaffold with a three-dimensional porous structure was prepared. The compressive performance of the skin scaffold was tested and compared with the finite element analysis results. The relationship between the filling gap and the porosity and mechanical strength of the scaffold was demonstrated. 
    RESULTS AND CONCLUSION: (1) The elastic modulus of 5% gelatin was increased by 8.84 times by adding 10% oxidized nanocellulose whisker. A gel filament with a diameter of 1 mm was obtained by extrusion at the air pressure of 160 kPa. When the filling gap increased from 1.5 mm to 2.5 mm, the theoretical porosity of the scaffold increased from 33% to 60%, but the compressive strength decreased from 230 000 Pa to 95 000 Pa. (2) These findings showed that the skin scaffold with theoretical porosity of 50% and elastic modulus of 160 000 Pa was prepared by using 2 mm filling gap. The scaffold had a clear three-dimensional porous structure.
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    Leukocyte- and platelet-rich fibrin with autologous hamstring tendon for traumatic patella dislocation
    Wang Xinmin, Yan Wenkai, Song Yahui, Liu Fei
    2024, 28 (3):  404-410.  doi: 10.12307/2023.888
    Abstract ( 337 )   PDF (1507KB) ( 87 )   Save
    BACKGROUND: Traumatic patellar dislocation with medial patellofemoral ligament tearing at femoral attachment or body is usually performed by medial patellofemoral ligament reconstruction surgery. To promote tendon bone healing after medial patellofemoral ligament reconstruction, the researchers used a variety of biological treatment technologies including growth factors, stem cells and platelet-rich plasma.
    OBJECTIVE: To investigate the clinical effect of medial patellofemoral ligament reconstruction by leukocyte- and platelet-rich fibrin with autologous hamstring tendon for traumatic patellar dislocation. 
    METHODS: Thirty-seven patients with traumatic patellar dislocation in First Hospital of Qinhuangdao from February 2019 to February 2021 were randomly divided into a trial group (n=18) and a control group (n=19). The trial group received medial patellofemoral ligament reconstruction by leukocyte- and platelet-rich fibrin with an autologous hamstring tendon. The control group received medial patellofemoral ligament reconstruction by a simple autologous hamstring tendon. Patients in the two groups were followed up for 12 months. Knee pain and functional status were evaluated by visual analog scale score, Lysholm score, Kujala patellofemoral joint score and knee range of motion. The patellar tilt angle, patellar congruence angle and patellar lateral shift rate of the patellofemoral joint were measured by MRI and CT films to evaluate the stability and improvement of the patellofemoral joint. 
    RESULTS AND CONCLUSION: (1) The visual analog scale scores of the two groups at 6 and 12 months after operation were lower than those before operation (P < 0.05). The Lysholm score and Kujala patellofemoral joint score at 6 and 12 months after operation were higher than those before operation (P < 0.05). The Lysholm score and Kujala patellofemoral joint score in the trial group were higher than those in the control group 6 months after operation (P < 0.05). There was no significant difference between the two groups in the visual analog scale score, Lysholm score and Kujala patellofemoral joint score 12 months after operation (P > 0.05). (2) The patellar tilt angle, patellar congruence angle, patellar lateral shift rate and range of motion of the patellofemoral joint were significantly improved in both groups 12 months after operation (P < 0.05). The patellar tilt angle was smaller in the trial group than that in the control group 12 months after operation (P < 0.05). Patellar congruence angle, patellar lateral shift rate, range of motion and MRI score were not statistically significant between the two groups 12 months after operation (P > 0.05). (3) These results confirm that medial patellofemoral ligament reconstruction by leukocyte- and platelet-rich fibrin with autologous hamstring tendon can treat traumatic dislocation effectively, improve the function of the knee joint, and restore the movement track of the patella. 
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    Finite element analysis of the influence of scaffold materials on the fixed restoration of edentulous maxillary implants under two designs
    Chen Yuanyuan, Wang Wei, Zhao Lu, Annikaer·Aniwaer, Nijati·Turson
    2024, 28 (3):  411-418.  doi: 10.12307/2023.877
    Abstract ( 237 )   PDF (2169KB) ( 49 )   Save
    BACKGROUND: In the treatment of edentulous maxillary implants supported fixed repair, the selection of upper scaffold structure materials and the design of different distal implant implantation methods have a close influence on the long-term stability of the whole mouth implant repair.
    OBJECTIVE: To comprehensively explore the influence of three different materials of upper scaffold and two implant fixation designs on the biomechanics of the fixed maxillary implant repair based on the three-dimensional finite element method. 
    METHODS: Based on the conical beam CT data of a healthy adult with normal jaws, the Mimics software was used to separate the maxillary and maxillary dentin three-dimensional solid models, and the Geomagic Studio software was used to construct the three-dimensional finite element model of denture with denture implant and fixed maxillary arch combined with specific model parameters. According to the different designs of distal implants in the maxillary posterior region, two scheme models were established. Scheme 1 (Design 1) was designed in accordance with the “All-on-4” design used in clinical practice. Two implants were vertically implanted in the bilateral incisor region of the maxilla, and the other two implants were implanted in the bilateral second premolar region at a 30° angle. In scheme 2 (Design 2), two implants were vertically implanted in the lateral incisor region of the maxilla, and two short implants were vertically implanted in the posterior region of the maxilla in the bilateral second premolar region. Three materials (titanium, zirconia and polyether ether ketone) were used to assign values to the upper scaffold structure in the two designs, and six different models were obtained. The biomechanical effects of the implant, surrounding bone tissue and the upper scaffold structure were compared and analyzed in the oblique loading direction.
    RESULTS AND CONCLUSION: (1) The maximum stress peaks of all models were distributed in the neck region around the posterior implant and the cortical bone under the two edentulous implant fixed restoration schemes, regardless of the material of the upper scaffold. (2) Compared with the alternative design of Design 2, which adopted vertical implantation of short implants, Design 1 showed a more ideal stress distribution on the maxilla. (3) The scaffold model constructed by polyether ether ketone material transferred higher stress to the implant and surrounding bone tissue close to the loading zone of the upper jaw bone, followed by titanium and zirconia. As for the support itself, the peak stress of the upper scaffold of polyether ether ketone was significantly lower than that of the zirconia and titanium scaffolds. Zirconia scaffolds were used among the three upper scaffolds to disperse the stress distribution of implant and bone tissue. (4) The results suggest that both designs can be applied to clinical practice. However, from the perspective of biomechanics, the stress distribution of the implant, surrounding bone tissue and upper scaffold in Design 1 is more rational, which is more conducive to the long-term prognosis of fixed implant repair in patients with edentulous jaws. The upper scaffold material has a certain influence on the stress distribution of the implant-bone interface. 
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    Strategy and significance of Chinese medicine combined with medical hydrogel for disease treatment
    Bi Yujie, Ma Dujun, Peng Liping, Zhou Ziqiong, Zhao Jing, Zhu Houjun, Zhong Qiuhui, Yang Yuxin
    2024, 28 (3):  419-425.  doi: 10.12307/2023.971
    Abstract ( 424 )   PDF (1701KB) ( 126 )   Save
    BACKGROUND: Medical hydrogels are new functional polymer materials with three-dimensional structural networks and excellent biocompatibility, which have been widely studied in the field of tissue engineering and drug carriers, but the research on the combination of medical hydrogels and Chinese medicine for the treatment of diseases based on tissue engineering is still in the early exploration stage. Therefore, through the analysis of the mechanism of the role of medical hydrogels, the integration of medical hydrogels and Chinese medicine in the research of the joint application of the article, can better provide ideas for scientific researchers, and the joint application of Chinese medicine and medical hydrogels is of great significance.
    OBJECTIVE: To explore the strategy and significance of Chinese medicine combined with medical hydrogel for disease treatment based on tissue engineering research. 
    METHODS: PubMed and CNKI were used to retrieve articles about the application of Chinese medicine combined with medical hydrogel in tissue engineering from January 2010 to November 2022, with the Chinese and English search terms “hydrogel, traditional Chinese medicine, drug carrier, tissue engineering”. After the initial screening of all articles according to the inclusion and exclusion criteria, the 61 articles with high relevance were retained for review. 
    RESULTS AND CONCLUSION: (1) Although the application of Chinese medicine combined with medical hydrogel is involved in intra-articular, intra-tissue organ, soft tissue wounds, tissue engineering, etc., except for the clinical application of Chinese medicine combined with hydrogel dressing for soft tissue injury, other aspects are still in the experimental stage. (2) The development of Chinese medicine combined with medical hydrogel has great potential and development prospects, but there is a certain difficulty in the manufacture of the gel with high-performance requirements, and it is difficult to master the physical and chemical properties precisely. (3) At present, the comprehensive view of injectable hydrogel with the characteristics of easy to use, its joint use of Chinese medicine can be extended to a wider range, can be used for joint, organ, tissue engineering-related disease treatment. Smart hydrogel has high sensitivity and reversible transformation can also meet the use of the special environment. During the combined use of Chinese medicine, it also needs to understand the mechanism of action of Chinese medicine components. (4) The strategy of combining Chinese medicine with medical hydrogels for disease treatment should start with matching the therapeutic effects of Chinese medicine on organs, tissues and cells combined with appropriate types of medical hydrogels to make up for the shortcomings of traditional Chinese medicine delivery methods and frequent drug delivery. In tissue engineering, hydrogels can be loaded with stem cells after Chinese medicine intervention, or with both Chinese medicine and stem cells for disease treatment. (5) In future research of combined Chinese medicine and medical hydrogel application, we also need to consider: we should ensure that the biological properties of medical hydrogel can be quantified, and grasp the characteristics of hydrogel with different manufacturing processes of different materials to produce the required medical hydrogel that meets the application conditions. In Chinese medicine, we need to comprehensively understand and analyze the therapeutic effects and application mechanisms of known Chinese medicine monomer and Chinese medicine compound extracts, so as to achieve a more perfect combination between Chinese medicine and medical hydrogel under a more clear mechanism. With the continuous improvement of medical science and technology innovation, the medical hydrogel can be innovatively combined with other traditional treatment methods of Chinese medicine, such as acupuncture, massage, cupping and so on, to be used from multiple angles. 
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    Electrospun nanofiber scaffolds for soft and hard tissue regeneration
    Wang Xinyi, Xie Xianrui, Chen Yujie, Wang Xiaoyu, Xu Xiaoqing, Shen Yihong, Mo Xiumei
    2024, 28 (3):  426-432.  doi: 10.12307/2023.982
    Abstract ( 283 )   PDF (1016KB) ( 68 )   Save
    BACKGROUND: Currently, electrospun nanofibers, which are biomimetic materials of natural extracellular matrix and contain a three-dimensional network of interconnected pores, have been successfully used as scaffolds for various tissue regeneration, but are still faced with the challenge of extending the biomaterials into three-dimensional structures to reproduce the physiological, chemical as well as mechanical properties of the tissue microenvironment.
    OBJECTIVE: To summarize the process and principles of electrostatic spinning and to explore the applications of the resulting electrospun nanofibers in tissue regeneration of skin, blood vessels, nerves, bone, cartilage and tendons/ligaments. 
    METHODS: With “electrospinning, electrospun nanofibers, electrospun nanofiber scaffolds, tissue regeneration” as the Chinese and English search terms, Google Academic Database, PubMed, and CNKI were searched, and finally 88 articles were included for review.
    RESULTS AND CONCLUSION: (1) The electrospun nanofibers are a natural fibrous extracellular matrix mimetic material and contain a three-dimensional network of interconnected pores that have been successfully used as scaffolds for a variety of tissue regeneration applications. (2) Several papers have described the great potential of electrospun nanofiber scaffolds applied to the regeneration of skin, blood vessels, nerves, bones, cartilage and tendons/ligaments, providing a solid theoretical basis for its final application in clinical disease treatment, or for its transformation into practical products to enter the market. (3) However, the current research results are mostly based on cell experimental research results in vitro, and whether it can be finally applied to human body still needs clinical verification. (4) At present, many kinds of electrospun products for various clinical needs have been commercialized in and outside China, indicating that the research field of electrospun nanofiber scaffolds for soft and hard tissue regeneration has great research value and application potential.
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    Effects of different freezing techniques on the rejection of allogeneic vascular transplantation
    Long Jundong, Shi Yehong, Wang Cheng, Chen Shijiu
    2024, 28 (3):  433-438.  doi: 10.12307/2024.241
    Abstract ( 259 )   PDF (980KB) ( 48 )   Save
    BACKGROUND: Cryopreservation can better ensure the integrity of the vascular structure. How to reduce its immunogenicity to improve rejection after transplantation has attracted more and more attention.
    OBJECTIVE: To review the research progress of freezing treatment to reduce vascular immunogenicity after allogeneic vascular transplantation in order to provide a reference for clinical research.
    METHODS: A systematic search of Chinese and English databases CNKI, WanFang and PubMed, as well as online websites Baidu and Google Scholar since the establishment of the database has published literature on reducing vascular immunogenicity after allogeneic vascular transplantation. Keywords were “cardiovascular disease, endothelial cells, cryopreservation, blood vessel transplantation or vascular graft, immunogenicity, immune rejection, allograft or allogeneic transplantation or allograft transplantation and cryoprotectant”. A total of 68 articles were included according to the inclusion and exclusion criteria. 
    RESULTS AND CONCLUSION: (1) The review found that the rejection of allogeneic vascular transplantation can be reduced by improving the existing freezing technology, which mainly involves the selection of freezing and thawing methods and cryoprotectants. (2) The existing research suggests that the freeze-drying method is superior to the low-temperature cryopreservation, but due to the limited conditions, it is still dominated by low-temperature cryopreservation. Among them, vitrification cryopreservation, slow rewarming and the use of stainless steel and even silver-containing materials are better than programmed cryopreservation and rapid rewarming. (3) The combined selection of permeable and non-permeable cryoprotectants can further reduce the occurrence of rejection while reducing their toxicity. 
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    Application of metal ions in bone tissue engineering
    Gao Xueyu, Zhang Wentao, Sun Tianze, Zhang Jing, Li Zhonghai
    2024, 28 (3):  439-444.  doi: 10.12307/2023.972
    Abstract ( 314 )   PDF (1029KB) ( 103 )   Save
    BACKGROUND: Metal ions play an important role in the human body. With the progress of material synthesis and processing technology, a variety of metal ions that can be used in bone tissue engineering have been developed, such as magnesium (Mg2+), zinc (Zn2+), manganese (Mn2+), strontium (Sr2+), and copper (Cu2+).
    OBJECTIVE: To summarize the research progress and development direction of metal ions in bone tissue engineering. 
    METHODS: The literature collected by CNKI, PubMed and WanFang databases from 2014 to 2022 was retrieved. The Chinese and English key words were “metal ions, bone tissue engineering, osteogenic activity, magnesium ions, zinc ions, manganese ions, strontium ions, copper ions, calcium ions, lithium ions, cobalt ions”.
    RESULTS AND CONCLUSION: Different metal ions will be released to varying degrees after the materials are implanted into the body, which can change the tissue microenvironment, thus improving the ability of materials to form blood vessels and bones. Compared with growth factors, metal ions are easier to control the release rate, have lower cost, and can also improve the mechanical properties of implant materials. The application of metal ions in bone tissue engineering is full of prospects. Although some metal ions can already be used to treat bone defects, the mechanism of action of many metal ions in the human body is not completely clear, and the application effect is a lack of clinical experiment verification. Further exploration is needed before clinical application.
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    Application of bio-inks for 3D printing in tissue repair and regenerative medicine
    Yang Jie, Hu Haolei, Li Shuo, Yue Wei, Xu Tao, Li Yi
    2024, 28 (3):  445-451.  doi: 10.12307/2023.876
    Abstract ( 440 )   PDF (951KB) ( 246 )   Save
    BACKGROUND: With the right bio-inks, 3D printing can be used to create replacements for human tissues and organs that work inside the body. In recent years, 3D printing technology has developed rapidly and has great application potential in regenerative medicine.
    OBJECTIVE: To introduce the types of bio-inks for 3D printing, and review the classification, application, advantages and disadvantages of bio-inks, as well as the future vision.
    METHODS: With “3D printing, biological ink, tissue engineering, hydrogel, synthetic material, cytoactive factor” as search terms, relevant articles published on PubMed and CNKI databases from 2000 to 2022 were searched by computer and finally 83 articles were included for review. 
    RESULTS AND CONCLUSION: 3D bioprinting technology has developed rapidly over the past few decades and has received great attention in various fields, including tissue engineering and biomedicine. Compared with the limitations of traditional biological scaffold manufacturing methods in terms of function and structure, 3D printing can better simulate the complex structure of biological tissues and has appropriate mechanical, rheological and biological characteristics. Bio-ink is an essential part of 3D printing. Bioscaffolds produced by printing bio-ink prepared by biological materials have great scientific potential and clinical significance in tissue repair and regenerative medicine. The research of the materials itself is also getting more and more attention from experts. Bio-inks for 3D printing come in a variety of materials, from natural to synthetic, to aggregations of cells that do not require any additional biomaterials, and their usefulness in practical use varies. In the future, more and more bio-inks will be developed for tissue engineering. It is necessary to analyze the printability of bio-inks through sufficient experimental simulation and equipment testing to meet the actual medical needs.
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    Function and advantages of magnetically responsive hydrogel in bone tissue engineering
    Chen Pinrui, Pei Xibo, Xue Yiyuan
    2024, 28 (3):  452-457.  doi: 10.12307/2023.884
    Abstract ( 301 )   PDF (978KB) ( 48 )   Save
    BACKGROUND: Magnetically responsive hydrogels have great advantages in bone tissue engineering, which is more conducive to the minimally invasive and efficient promotion of osteogenesis.
    OBJECTIVE: To review the application advances of magnetically responsive hydrogels in bone tissue engineering. 
    METHODS: PubMed, Web of Science, WanFang and CNKI databases were used to search relevant literature. The English search terms were “Magnetic Hydrogels, Magnetic Nanoparticles, Superparamagnetic Nanoparticles, Fe3O4, SPIONs, Magnetic Fields, Bone Regeneration, Bone Repair, Bone Tissue Engineering”. The Chinese search terms were “Magnetic Hydrogel, Magnetic Nanoparticles, Superparamagnetic Iron Oxide Nanoparticles, Magnetic Field, Iron Oxide Nanoparticles, Bone Regeneration, Bone Reconstruction, Bone Repair, Bone Tissue Engineering”. After preliminary screening of all articles according to the inclusion and exclusion criteria, 60 articles were finally retained for review.
    RESULTS AND CONCLUSION: (1) In recent years, due to the emergence of magnetic nanoparticles, more and more magnetic responsive scaffold materials have been developed. Among them, magnetic responsive hydrogels containing iron oxide nanoparticles and superparamagnetic iron oxide nanoparticles have outstanding mechanical properties and good biocompatibility. It can quickly respond to the external magnetic field and provide the magnetic-mechanical signals needed for seed cells to form bone. (2) Magnetic-responsive hydrogel can be used as a carrier to accurately regulate the release time of growth factors. (3) Under the three-dimensional microenvironment culture platform based on magnetically responsive hydrogel, the magnetic force at the interface between the magnetic response hydrogel and cells can activate cell surface sensitive receptors, enhance cell activity, and promote the integration of new bone and host bone. (4) The injectable magnetically responsive hydrogel can be used in the field of magnetic hyperthermia and biological imaging of bone tumors. (5) At present, magnetically responsive hydrogels are expected to mimic the anisotropic layered structure observed in natural bone tissue. However, most of the studies on magnetically responsive hydrogels focus on in vitro studies, and the mechanism of interaction between magnetically responsive hydrogels and the local microenvironment in vivo is still insufficient. (6) Therefore, based on the successful application of magnetic nanoparticles in magnetic resonance imaging, it is expected to optimize the properties of magnetic nanoparticles in the future to construct magnetic responsive hydrogels with suitable degradation properties, mechanical properties, and vascular functionalization, which can monitor changes in vivo in real time.
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    Cartilage targeting function in the drug delivery system by intra-articular injection for the treatment of osteoarthritis
    Chen Junyan, Meng Qingqi, Li Siming
    2024, 28 (3):  458-463.  doi: 10.12307/2023.879
    Abstract ( 307 )   PDF (1006KB) ( 34 )   Save
    BACKGROUND: Intra-articular injection played an important role in the treatment of osteoarthritis and has more options with the development of novel drug delivery systems. The cartilage targeting function is aimed at the adhesion or retention of drugs in the cartilage layer to form a drug bank to achieve slow release and precise drug delivery. 
    OBJECTIVE: To review various cartilage targeting biomaterials and their characteristics in the treatment of osteoarthritis by articular injection. 
    METHODS: Using the term “osteoarthritis, drug carrier, drug delivery, cartilage targeting, penetrate” as key words, relevant articles were searched in CNKI, WanFang and PubMed databases. According to inclusion and exclusion criteria, 67 articles were finally selected for further review. 
    RESULTS AND CONCLUSION: The research on cartilage-targeting biomaterials is mainly divided into two directions. One is the combination of electrostatic interaction, such as the combination of positively charged biomaterials and negatively charged polysaccharides in cartilage. This kind of scheme is operable and easy to modify, but limited by the shortcomings of electrostatic interaction itself, it performs badly in advanced osteoarthritis. Another one is the specific binding of various components in cartilage which is strong and reliable, and related biomaterials have excellent performance in advanced osteoarthritis, which is an important direction for future cartilage-targeted therapy.
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    Application and mechanism of tissue flossing in sports and rehabilitation
    Yan Hailong, Huo Jiangtao, Zhou Wucheng, Bai Xuehua, Liang Yuanyuan
    2024, 28 (3):  464-471.  doi: 10.12307/2023.878
    Abstract ( 506 )   PDF (1333KB) ( 290 )   Save
    BACKGROUND: Tissue flossing is a new injury prevention tool and auxiliary exercise training strategy. Tissue flossing can increase joint range of motion, improve athletic performance, and relieve pain, and is increasingly widely used in the field of sports and rehabilitation.  
    OBJECTIVE: To review the mechanism of tissue flossing and its application in sports and rehabilitation to provide a reference for follow-up research.
    METHODS: “Tissue flossing; compression tissue flossing; floss band; voodoo flossband; blood flow restriction; shearing of fascia; musculoskeletal rehabilitation; sport injury” were used as Chinese and English search terms to search on the databases of CNKI, WanFang, VIP, PubMed and EBSCO databases. Relevant articles from January 2000 to October 2022 were retrieved, and 86 articles were finally included according to inclusion and exclusion criteria.
    RESULTS AND CONCLUSION: Tissue flossing intervention can improve lower limb joint motion, improve sprint and jump performance, promote joint injury rehabilitation, and relieve pain subjectively. However, tissue flossing intervention did not improve the range of motion of the upper limb. There is still controversy on the acute enhancement of lower limb muscle strength. It has a good tendency to improve lower limb balance and stability and improve mental state, but more studies are needed to confirm. The possible mechanisms of tissue flossing intervention are mainly fascia shear, pain gating, blood flow restriction and reperfusion, and compression. Tissue flossing is a useful treatment option that can provide important contributions in the future in the areas of sports training, sports injury prevention and rehabilitation, but more long-term in-depth studies are needed. 
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    Characteristics of hydrogel microspheres in bone tissue engineering
    Long Zhirui, Huang Lei, Xiao Fang, Wang Lin, Wang Xiaobei
    2024, 28 (3):  472-478.  doi: 10.12307/2023.973
    Abstract ( 258 )   PDF (871KB) ( 120 )   Save
    BACKGROUND: Hydrogel microparticles, due to their porous and injectable properties, have demonstrated unique advantages in biomedical fields, such as the delivery of cells and bioactive factors/drugs, the construction of tissue repair scaffolds. They have broad application prospects.
    OBJECTIVE: To review the latest research progress and discuss the key problems and challenges in the research of bone tissue engineering based on hydrogel microparticles. 
    METHODS: The relevant articles in PubMed and CNKI were searched by computer. The English key words were “hydrogels, microparticles, microspheres, microcarriers, bone, bone defect, bone repair, bone healing, bone tissue engineering” while the Chinese key words were “hydrogels, microparticles, microspheres, bone tissue engineering, bone defect, bone repair, bone regeneration”. The retrieval period was from 2002 to 2022, and 127 articles were finally included for review. 
    RESULTS AND CONCLUSION: (1) At present, various hydrogel microparticles have been developed for use in bone tissue engineering strategies, for example, hydrogel microparticles carrying cells or bioactive factors/drugs, hydrogel microparticles as biological scaffolds, stimulus-responsive hydrogel microparticles, biomineralized hydrogel microparticles, hydrogel microparticles combined with other biological materials. (2) Bone tissue engineering repair strategies based on hydrogel microparticles mainly regulate bone repair by promoting stem cell recruitment and osteogenic differentiation, regulating the local inflammatory microenvironment and promoting angiogenesis at the site of injury. However, the present studies did not deeply explore the effect of bone tissue engineering based on hydrogel microparticles on the recruitment and differentiation of endogenous stem cells and the regulation of the inflammatory microenvironment by the physical and chemical properties of hydrogel microparticles. The long-term in vivo adverse reactions of hydrogel microparticles have not been explored yet, and it is difficult to mass-produce them, thus future research needs to strengthen the mechanism exploration and technical route, so as to provide a reasonable reference for the development of hydrogel microparticles that can be used for clinical transformation.
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    Biological scaffold materials and printing technology for repairing bone defects
    Kong Xiangyu, Wang Xing, Pei Zhiwei, Chang Jiale, Li Siqin, Hao Ting, He Wanxiong, Zhang Baoxin, Jia Yanfei
    2024, 28 (3):  479-485.  doi: 10.12307/2024.244
    Abstract ( 336 )   PDF (978KB) ( 167 )   Save
    BACKGROUND: In recent years, with the development of biological scaffold materials and bioprinting technology, tissue-engineered bone has become a research hotspot in bone defect repair. 
    OBJECTIVE: To summarize the current treatment methods for bone defects, summarize the biomaterials and bioprinting technology for preparing tissue-engineered bone scaffolds, and explore the application of biomaterials and printing technology in tissue engineering and the current challenges.
    METHODS: Search terms were “bone defect, tissue engineering, biomaterials, 3D printing technology, 4D printing technology, bioprinting, biological scaffold, bone repair” in Chinese and English. Relevant documents published from January 1, 2009 to December 1, 2022 were retrieved on CNKI, PubMed and Web of Science databases. After being screened by the first author, high-quality references were added. A total of 93 articles were included for review. 
    RESULTS AND CONCLUSION: The main treatment methods for bone defects include bone transplantation, membrane-guided regeneration, gene therapy, bone tissue engineering, etc. The best treatment method is still uncertain. Bone tissue engineering technology is a new technology for the treatment of bone defects. It has become the focus of current research by constructing three-dimensional structures that can promote the proliferation and differentiation of osteoblasts and enhance the ability of bone formation. Biological scaffold materials are diverse, with their characteristics, advantages and disadvantages. A single biological material cannot meet the demand for tissue-engineered bone for the scaffold. Usually, multiple materials are combined to complement each other, which is to meet the demand for mechanical properties while taking into account the biological properties of the scaffold. Bioprinting technology can adjust the pore of the scaffold, build a complex spatial structure, and is more conducive to cell adhesion, proliferation and differentiation. The emerging 4D printing technology introduces “time” as the fourth dimension to make the prepared scaffold dynamic. With the synchronous development of smart materials, 4D printing technology provides the possibility of efficient repair of bone defects in the future.
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    Application of near infrared responsive hydrogels in tissue engineering
    Xu Jing, Lyu Huixin, Bao Xin, Zhang Yi, Wang Yihan, Zhou Yanmin
    2024, 28 (3):  486-492.  doi: 10.12307/2023.836
    Abstract ( 264 )   PDF (1115KB) ( 244 )   Save
    BACKGROUND: Near infrared responsive hydrogels, have a variety of excellent properties such as high spatial and temporal precision, remote tunability, and safety and non-invasiveness, providing a new direction of exploration for the development of tissue engineering.
    OBJECTIVE: To summarize the application progress of near infrared responsive hydrogels in the field of tissue engineering in recent years.
    METHODS: The literature search was performed on PubMed and CNKI databases. The keywords were “near infrared responsive hydrogels, tissue engineering, bone defect, bone repair, bone regeneration, wound healing, wound dressing, angiogenesis” in Chinese and English. The search time limit was from May 2006 to October 2022 and extended for some classical literature. The abstracts and contents of the retrieved literature were analyzed, and the relevant literature was obtained according to inclusion and exclusion criteria. Finally, 97 articles were included for review.
    RESULTS AND CONCLUSION: (1) Near infrared responsive materials are involved in tissue repair by controlling infection and reducing inflammation, promoting angiogenesis, osteoblast differentiation and new bone formation. (2) Near infrared responsive hydrogel can be prepared by constructing a thermosensitive hydrogel with a photothermal effect or by using a photochemical reaction. (3) Near infrared responsive hydrogels as wound dressings perform various functions such as rapid hemostasis, tissue adhesion through polymerization of polymer monomers, antibacterial and anti-inflammatory effects, and promotion of angiopoiesis and epithelial regeneration through the local photothermal effect of photothermal nanomaterials during soft tissue healing and regeneration. (4) Near infrared responsive hydrogels function during bone reconstruction and repair by promoting osteogenic differentiation of mesenchymal stem cells, stimulating the expression of heat shock proteins, and increasing angiogenesis. (5) Near infrared responsive hydrogels present a combination of multiple therapeutic strategies with significant synergistic therapeutic functions and are also being progressively developed for application in other tissue reconstruction and disease treatment scenarios. 
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