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18 October 2024, Volume 28 Issue 29 Previous Issue    Next Issue

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Effect of sagittal overcorrection design on displacement and stress of mandibular anterior teeth intrusion using clear aligners Huang Yangyang, Wang Shiyu, Liu Hao, Yang Li, Wang Penglai, Yuan Changyong 2024, 28 (29):  4593-4598.  doi: 10.12307/2024.565 Abstract ( 83 )   PDF (1340KB) ( 9 )   Save BACKGROUND: The thin alveolar bone in the lower anterior region increases the risk of labial bone resorption when intruding the teeth with clear aligners. The effect of sagittal overcorrection design on the labiolingual control of mandibular anterior teeth intrusion has not been fully investigated. OBJECTIVE: To explore the effect of overcorrection on the changes in the displacement and stress of the mandibular anterior teeth, especially the cervical and apical regions. METHODS: Through a male volunteer cone-beam CT data, the three-dimensional reconstruction of the mandible and teeth was conducted in the MIMICS and GEOMAGIC software. Moreover, the models of periodontal ligaments, attachments, and appliances were created in the SOLIDWORKS software. First, the study was divided into canine intrusion group and incisor intrusion group. Then, the overcorrection (0°, 1°, 2°) was designed on the bilateral mandibular central and lateral incisors. A total of six models were established. The models were assembled and imported into the ANSYS software to analyze and calculate the displacement and stress level. RESULTS AND CONCLUSION: (1) In the canine intrusion group, canines intruded and tipped lingually while incisors extruded and tipped lingually. In the incisor intrusion group, canines extruded and tipped lingually while incisors intruded and tipped lingually. (2) Without overcorrection, the incisors necks moved lingually while apexes moved labially. With overcorrection, the incisors tended to be upright, followed by labial tilt. The least cervical and apical displacements were detected under 1° overcorrection. (3) With overcorrection, the incisal cervical stress concentration area shifted from labial to lingual in the canine intrusion group, whereas the stress concentration area shifted from lingual to labial in the incisor intrusion group. (4) The incisors tended to tilt lingually when intruding the mandibular anterior teeth with clear aligners. The sagittal overcorrection design was conductive to maintain the stable position of incisors. However, the amount of overcorrection should be moderate. Excessive overcorrection might increase the labial inclination tendencies of incisors. Figures and Tables | References | Related Articles | Metrics

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Antibiotic-loaded bone cement enhances ability of tibial cortex transverse transport for treating infected wounds Liu Junpeng, Yao Xingchen, Zhao Hui, Xu Ziyu, Wu Yue, Pei Fuchun, Zhang Lin, Du Xinru 2024, 28 (29):  4599-4604.  doi: 10.12307/2024.570 Abstract ( 78 )   Save BACKGROUND: Diabetic foot patients with wound infections constitute a large patient population, and there is currently no satisfactory treatment approach.  OBJECTIVE: To investigate the clinical efficacy of a modified tibial cortex transverse transport combined with antibiotic-loaded bone cement for treating refractory diabetic foot ulcers. METHODS: A total of 46 diabetic foot ulcers patients, 27 males and 19 females, with an average age of 64.37 years, were selected from Beijing Chaoyang Hospital, Capital Medical University and Beijing Chaoyang Integrative Medicine Rescue and First Aid Hospital from January 2020 to January 2023. All of them underwent the modified tibial cortex transverse transport combined with antibiotic-loaded bone cement treatment. Ankle-brachial index, WIFi (Wound/Ischemia/Foot infection) classification, pain visual analog scale score, and ulcer area were recorded before and 3 months after surgery.  RESULTS AND CONCLUSION: (1) The mean ulcer healing time for the 46 patients was (58.07±24.82) days. At 3 months postoperatively, there were significant improvements in ankle-brachial index, pain visual analog scale score, ulcer area, and WIFi classification in 46 patients, as compared to the preoperative values, with statistically significant differences (P < 0.05). Two patients experienced pin-tract infections, without infection or ulcer recurrence during the follow-up period. (2) These findings indicate that the modified tibial cortex transverse transport combined with antibiotic-loaded bone cement effectively alleviates patients’ pain, improves lower limb circulation, controls infections, and promotes ulcer healing. Figures and Tables | References | Related Articles | Metrics

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Mechanism of local time-sensitive stimulation effect of catgut and polyglycolide-co-lactide thread embedding at “Zusanli” acupoint area of rats Ye Tingting, Liang Xin, Li Lihong, Nie Hongfang, Hou Xunrui, Zhou Mengdan, Zhong Yu 2024, 28 (29):  4605-4611.  doi: 10.12307/2024.585 Abstract ( 79 )   PDF (1927KB) ( 7 )   Save BACKGROUND: The researchers noted that upon embedding clinical-grade catgut and polyglycolide-co-lactide threads in the normal human “Zusanli” (ST 36) acupoint, the local area displayed temporal and inflammatory stimulatory effects, resulting in thread differentiation. However, the underlying mechanism behind thread involvement remains to be studied. OBJECTIVE: To investigate the expression levels of calcitonin gene-related peptide, 5-hydroxytryptamine, leukotriene B4, and bradykinin at point “Zusanli” (ST 36) in rats after embedding catgut and polyglycolide-co-lactide respectively at different time points.  METHODS: 110 male SD rats were divided into a blank group (10 rats), a catgut embedding group (50 rats), and a polyglycolide-co-lactide embedding group (50 rats) according to the random number table method. In the blank group, no thread was embedded. In catgut embedding group and the polyglycolide-co-lactide embedding group, the thread was embedded in the left side of the ST36 acupoint once. Tissue was collected from the left side of the ST36 acupoint area 8 hours, 3, 7, 14, and 21 days after embedding. The expression levels of calcitonin gene-related peptide and 5-hydroxytryptamine were detected by immunohistochemistry, and the contents of leukotriene B4 and bradykinin were detected by ELISA.  RESULTS AND CONCLUSION: (1) Compared with the blank group, the expression of calcitonin gene-related peptide, 5-hydroxytryptamine, bradykinin, and leukotriene B4 was significantly increased in the 8 hours, 3, 7, 14, and 21 days of the catgut embedding group (P < 0.05); calcitonin gene-related peptide expression was significantly increased in 8 hours, 3, 7, and 14 days in the polyglycolide-co-lactide embedding group (P < 0.05); the expression of bradykinin was significantly increased in 8 hours, 3, and 7 days (P < 0.05); the expression of leukotriene B4 was significantly increased at 8 hours, 3, 7, 14, and 21 days (P < 0.05). (2) Compared with the polyglycolide-co-lactide embedding group, the expression of calcitonin gene-related peptide was increased at 7, 14, 21 days after thread embedding (P < 0.05), and the expression of 5-hydroxytryptamine was increased at 8 hours, 3, 7, 14 and 21 days after thread embedding (P < 0.05); contents of leukotriene B4 and bradykinin in tissues were increased at 8 hours, 3, 14 and 21 days after embedding (P < 0.05) in the catgut embedding group. (3) The results show that calcitonin gene-related peptide, 5-hydroxytryptamine, leukotriene B4, and bradykinin in the acupoint region alter after catgut embedding in the ST36 of rats, as well as the alteration of calcitonin gene-related peptide, leukotriene B4, and bradykinin is found in the acupoint region after polyglycolide-co-lactide embedding in rats, which may be one of the mechanisms involved in the local time sensitive stimulus effects caused by embedding threads at acupoints. Moreover, there is a discernible difference between the two thread types. Figures and Tables | References | Related Articles | Metrics

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Fe-Co/ZIF-8@SLC-0111-HA composite nanoplatform enhances feasibility of tumor chemodynamic therapy Wang Zhenxin, Zhou Peng, Chu Fuchao, Zhang Dazhen, Yuan Feng 2024, 28 (29):  4612-4619.  doi: 10.12307/2024.530 Abstract ( 75 )   PDF (2307KB) ( 4 )   Save BACKGROUND: The low catalytic activity and lack of targeting of commonly used metal ions have severely limited the clinical application of chemodynamic therapy in tumor treatment. On the other hand, although the composite nanoplatforms are endowed with tumor-targeting functions by surface functionalization, the lack of tumor microenvironment acidity also severely weakens the efficacy of chemodynamic therapy. OBJECTIVE: To prepare novel composite nanoplatforms and assess their feasibility to enhance the effects of chemodynamic therapy at the cellular level. METHODS: SLC-0111-loaded zeolite imidazole framework-8 doped with divalent iron ions (Fe2+) and divalent cobalt ions (Co2+) (Fe-Co/ZIF-8@SLC-0111) was synthesized by ion-exchange reaction and self-assembly, and loaded with hyaluronic acid (HA) by electrostatic adsorption, followed by obtaining the target nanoparticles Fe-Co/ZIF-8@SLC-0111-HA (abbreviated as FC-S). Meanwhile, nanoparticles Fe-Co/ZIF-8-HA (abbreviated as FC) without SLC-0111 were synthesized by the same method. The nanocomposite platform was tested for particle size, zeta potential, surface morphology, in vitro reactive oxygen species generation, and ability to consume glutathione. Human osteosarcoma cell MG-63 and mouse fibroblast cell L929 were used as experimental subjects. The cytotoxicity of FC-S was detected by CCK-8 assay. Human osteosarcoma cell MG-63 was used as the experimental object to detect the cell internalization of FC-S. In addition to H2O2, the effects of FC-S and FC on intracellular pH, carbonic anhydrase 9 protein expression, cell viability and apoptosis, intracellular reactive oxygen species and glutathione content, and mitochondrial membrane potential were investigated. RESULTS AND CONCLUSION: (1) The FC-S composite nanoplatform was successfully prepared with a well-defined rhombic dodecahedral structure, uniform size and good dispersion. Its particle size was about 323 nm; zeta potential was about -11.1 mV, and the nanoplatform had a certain reactive oxygen species generation capacity in vitro. (2) FC-S nanoplatforms accumulated intracellularly in a time-dependent manner and could successfully escape from lysosomes. When the mass concentration of FC-S was ≤ 20 µg/mL, there was no obvious cytotoxicity to MG-63 cells and L929 cells, and 20 µg/mL FC-S was selected to act on MG-63 cells in subsequent experiments. (3) Compared with FC group, the protein expression of carbonic anhydrase 9 in MG-63 cells in FC-S group was decreased (P < 0.01); the intracellular acidic environment was enhanced; the content of reactive oxygen species was increased (P < 0.001); the mitochondrial damage was aggravated; the number of dead cells was increased, and the apoptosis rate was increased (P < 0.001). (4) The results indicate that FC-S, as a novel composite nanoplatform, can effectively improve the weakly acidic microenvironment in tumor cells and enhance the level of intracellular reactive oxygen species production, thus enhancing the efficacy of chemodynamic therapy. Figures and Tables | References | Related Articles | Metrics

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Oxymatrine hydrogel promotes wound healing by activating Nrf2/HO-1 pathway in keratinocytes Liu Lu, Liu Shudan, Liu Xiaodan, Yang Li, Ling Chen, Hai Xiaoming, Ma Huiming, Chen Dongmei 2024, 28 (29):  4620-4627.  doi: 10.12307/2024.584 Abstract ( 75 )   PDF (3055KB) ( 6 )   Save BACKGROUND: Inflammation and oxidative stress contribute to the barriers of regeneration in chronic wound. Oxymatrine has various biological activities, such as anti-oxidation, anti-inflammation and so on, which may have the potential effect of promoting wound healing. OBJECTIVE: To investigate the effect of oxymatrine on wound healing and the protective effect on H2O2-induced oxidative stress injury in human keratinoid cell line HaCaT cells. METHODS: (1) In vivo experiment: Hyaluronic acid methacryloyl hydrogels containing 0, 0.05, 0.1, 0.2 g/L oxymatrine were prepared. A full-layer skin defect model with a diameter of 12 mm was made in the back of 75 diabetic mice and randomly divided into five groups for intervention, with 15 mice in each group. The wounds of the model group were bandaged and fixed. The wounds of the hydrogel group were covered with hyaluronic acid methacryloyl hydrogel. The wounds of the low-dose, moderate-dose and high-dose oxymatrine groups were covered with hyaluronic acid methacryloyl hydrogel containing 0.05, 0.1, and  0.2 g/L oxymatrine, respectively, and then bandaged and fixed after light curing. Relevant indicators were detected within 14 days. (2) In vitro experiment: Human keratinocyte line HaCaT was divided into five groups. The normal group was cultured conventionally. H2O2 group and low-, moderate- and high-concentration oxymatrine groups were treated with H2O2 for 4 hours, and then the medium was replaced with medium containing 0, 0.05, 0.1, and 0.2 g/L oxymatrine, respectively, and the relevant indexes were detected after 24 hours of culture. RESULTS AND CONCLUSION: (1) In vivo experiment: Compared with the model group, the wound healing rate of mice in the hydrogel group had no significant change. The wound healing rate of mice in the low-, moderate- and high-dose oxymatrine group was increased at 7 and 14 days after treatment (P < 0.05). Pathological observation of wound section 14 days after treatment showed that compared with the model group, the thickness of regenerated epidermal layer, the number of microvessels, and collagen deposition in the moderate- and high-dose oxymatrine groups were increased (P < 0.05). Western blot assay analysis of wound samples 7 days after surgery showed that compared with the model group, the protein expressions of tumor necrosis factor α and interleukin 6 in the moderate- and high-dose oxymatrine groups were decreased (P < 0.05). (2) In vitro experiment: CCK8 assay, EdU and Ki67 staining showed that compared with the H2O2 group, the cell proliferation ability of the moderate- and high-concentration oxymatrine groups was significantly increased (P < 0.05). Compared with the H2O2 group, mitochondrial membrane potential was increased (P < 0.05) and reactive oxygen species content was decreased (P < 0.05) in the moderate- and high-concentration oxymatrine groups. Western blot assay results showed that compared with the H2O2 group, the expression levels of Nrf2 nuclear protein, Nrf2 total protein, HO-1 protein, and superoxide dismutase 1 protein were increased in the high-concentration oxymatrine group (P < 0.05). (3) These findings confirm that oxymatrine can alleviate oxidative stress damage in HaCat cells and accelerate wound healing by upregulating the levels of Nrf2 and HO-1 protein.  Figures and Tables | References | Related Articles | Metrics

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Silk fibroin methacryloyl hydrogel loaded with Scriptaid regulates polarization of microglia cells Guo Qingxia, Wang Yue, Wu Tong 2024, 28 (29):  4628-4633.  doi: 10.12307/2024.583 Abstract ( 79 )   PDF (1539KB) ( 5 )   Save BACKGROUND: Microglia cells play a major role in maintaining the balance as well as the development and function reconstruction of the central nervous system. As a histone deacetylase inhibitor, Scriptaid can inhibit neuroinflammation and enhance neuroprotection. OBJECTIVE: To investigate the effect of silk fibroin methacryloyl hydrogel loaded with Scriptaid on the behaviors of microglia cells. METHODS: Microglia (BV2 cells) were cultured in medium containing different concentrations of Scriptaid (0, 0.1, 0.5, 1, 2, 5, 10 μmol/L). The optimal concentration of Scriptaid was screened by the CCK-8 assay and live/dead cell staining. Silk fibroin methacryloyl hydrogels loaded with or without Scriptaid were prepared using photocuring. The micromorphology, swelling properties, mechanical properties, slow release properties, and hydrophilicity of the hydrogels were characterized. Microglia (BV2 cells) were inoculated in the subventricular region of 24-well Transwell and cultured in five groups. In the control group, the cell culture medium was added to the lower chamber. In the lipopolysaccharide group, Scriptaid group, hydrogel group, and drug-loaded hydrogel group, cell culture media containing lipopolysaccharide were added into the lower chamber. After 24 hours of lipopolysaccharide intervention, in the Scriptaid group, hydrogel group and drug-loaded hydrogel group, Scriptaid, silk fibroin methacryloyl hydrogel, and silk fibroin methacryloyl hydrogel loaded with Scriptaid were added to the upper chamber, respectively. The culture medium was replaced with ordinary culture medium and continued to culture for 24 hours. The cell viability was detected by CCK-8 assay, and the cell phenotype was detected by immunofluorescence staining of induced nitric oxide synthase and arginase 1. RESULTS AND CONCLUSION: (1) Compared with the group without Scriptaid, the viability and number of BV2 cells were decreased after Scriptaid added. When Scriptaid 2 μmol/L or above was added, the cell viability was lower than the standardized cell viability (70%), and the number of BV2 cells was significantly reduced. Therefore, 1 μmol/L Scriptaid was selected to be loaded into the hydrogel. (2) Characterization experiments showed that the addition of Scriptaid did not affect the microscopic morphology, swelling rate of water absorption, compression modulus and hydrophilicity of silk fibroin methacryloyl hydrogel, and silk fibroin methacryloyl hydrogel had slow release performance. (3) The result of CCK-8 assay showed that compared with the control group, silk fibroin methacryloyl hydrogel significantly increased the viability of BV2 cells (P < 0.001). (4) Immunofluorescence staining showed that compared with the control group, the expression of inducible nitric oxide synthase was increased in the lipopolysaccharide group (P < 0.01); the expression of inducible nitric oxide synthase was decreased (P < 0.01) and the expression of arginase 1 was increased (P < 0.001) in the drug-loaded hydrogel group; the expression of arginase 1 was increased in the Scriptaid group (P < 0.01). (5) The results indicate that Scriptaid-loaded silk fibroin methacryloyl hydrogel is able to promote polarization of microglia to the M2 type after lipopolysaccharide induction.  Figures and Tables | References | Related Articles | Metrics

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Effects of polystyrene microplastics on growth and development and hepatic lipid metabolism in mice Gao Xinxue, Gao Jiaxin, Zhu Jianyu, Shi Xinqi, Tao Bocheng, Li Ning, Chen Lijuan 2024, 28 (29):  4634-4638.  doi: 10.12307/2024.564 Abstract ( 88 )   PDF (1025KB) ( 3 )   Save BACKGROUND: Plastic as a durable, inexpensive, easy to manufacture organic synthetic polymer materials are widely used. At the same time, plastic resistance to high temperatures, acid and alkali resistance, corrosion-resistant properties make it difficult to degrade in nature, and ultimately forming a huge number of microplastic pollution threatening human health.  OBJECTIVE: To investigate the effects of microplastic exposure on growth and development and hepatic lipid metabolism in mice.  METHODS: Twenty C57BL/6J male mice were adaptively fed for one week, and then randomly divided into normal and microplastic groups (n=10 per group). Mice in the normal group were given a normal diet and water, for 4 weeks. Mice in the microplastic group were given a normal diet and free drinking of microplastic (polystyrene) water with a concentration of 1 000 μg/L, for 4 weeks. At 2 and 4 weeks of drinking, body mass and grip strength, blood lipids and liver and kidney function, ultrasonic morphology and pathological morphology of liver and lipid deposition were detected. RESULTS AND CONCLUSION: (1) With the extension of time, the body mass of mice in the two groups gradually increased, and the body mass of mice in the microplastic group was greater than that in the normal group after 2, 4 weeks of drinking water (P < 0.05). With the extension of time, the grip strength of mice in the normal group gradually increased, and the grip strength of mice in the microplastic group first decreased and then increased, and the grip strength of mice in the microplastic group was lower than that in the normal group after drinking water for 4 weeks (P < 0.05). (2) Liver ultrasound examination showed that compared with the normal group, the ultrasonic echo signal of the liver in the microplastic group was enhanced after 2 and 4 weeks of drinking water. (3) Hematoxylin-eosin staining showed that the morphology of liver cells in the microplastic group did not change significantly after 2 and 4 weeks of drinking water, but inflammatory cell infiltration could be seen. Oil red O staining showed that obvious lipid deposition was observed in the liver of microplastic group after 2 and 4 weeks of drinking water. (4) Compared with the normal group, the levels of serum high density lipoprotein cholesterol, triacylglycerol, and aspartate aminotransferase in the microplastic group were decreased after 2 weeks of drinking water (P < 0.05), and the serum triacylglycerol concentration was decreased after 4 weeks of drinking water (P < 0.05). (5) These findings confirm that microplastics may cause weight gain, loss of physical strength, and abnormal hepatic lipid metabolism in mice. Figures and Tables | References | Related Articles | Metrics

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3D printed personalized cervical orthopedic brace can alleviate and treat early cervical spondylosis Yang Yunxiao, Zhao Yu, Wang Minghai, Yang Zezheng, Wang Jinwu 2024, 28 (29):  4639-4644.  doi: 10.12307/2024.569 Abstract ( 74 )   PDF (1080KB) ( 6 )   Save BACKGROUND: Short-term wearing of cervical brace combined with shoulder and neck muscle exercise can significantly improve the symptoms of early cervical spondylosis. After stopping wearing cervical brace, patients’ symptoms are easy to recur, which may be due to the lack of cervical curvature correction function.  OBJECTIVE: To analyze the effect of 3D printed personalized cervical orthopedic brace for adjusting cervical curvature in the treatment of early cervical spondylosis. METHODS: From January 2021 to January 2023, 30 patients with early cervical spondylosis in the Shanghai Fifth People’s Hospital, Fudan University were studied, including 11 males and 19 females, with a mean age of (31.7±6.6) years old. All patients customized and wore 3D printed personalized cervical orthopedic braces for 3 hours a day for continuous 12 weeks. Borden value of cervical curvature, pain threshold of shoulder and neck muscles, cervical dysfunction index, and visual analog scale score in 30 patients were recorded before and 4 and 8 weeks after treatment.  RESULTS AND CONCLUSION: (1) Compared with before treatment, the difference of Borden value of cervical curvature, right trapezius tenderness threshold, and cervical dysfunction index was not significant in 30 patients after 4 weeks of treatment (P > 0.05). Visual analog scale score, left trapezius tenderness threshold, left and right C5C6 tenderness threshold were significantly improved (P < 0.05). (2) Compared with before treatment, the cervical curvature Borden value, left and right trapezius tenderness threshold, visual analog scale score, left and right C5C6 tenderness threshold, and cervical dysfunction index of 30 patients were significantly improved after 12 weeks of treatment (P < 0.05). (3) Compared with 4 weeks after treatment, the Borden value of cervical curvature, right trapezius tenderness threshold, visual analog scale score, left and right C5C6 tenderness threshold and cervical dysfunction index of 30 patients after 12 weeks of treatment were significantly improved (P < 0.05). (4) The results show that short-term wearing of 3D printed personalized cervical orthopedic brace can improve the pain of patients with early cervical spondylosis, while long-term application has certain effect on the recovery of cervical curvature. Figures and Tables | References | Related Articles | Metrics

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Preparation and characterization of 3D plant-based scaffold based on decellularization method in liver tissue engineering Hu Jingjing, He Songlin, Zhang Daxu, Zhao Shuo, Shi Xiaonan, Li Weilong, Ye Shujun, Wang Jingyi, Guo Quanyi, Yan Li 2024, 28 (29):  4645-4651.  doi: 10.12307/2024.588 Abstract ( 96 )   PDF (1601KB) ( 5 )   Save BACKGROUND: Tissue engineering has brought new hope to the clinical challenge of liver failure, and the preparation of plant-derived decellularized fiber scaffolds holds significant importance in liver tissue engineering. OBJECTIVE: To prepare apple tissue decellularized scaffold material by using fresh apple slices and a solution of sodium dodecyl sulfate, and assess its biocompatibility.  METHODS: Fresh apples were subjected to decellularization using phosphate buffer saline and sodium dodecyl sulfate solution, separately. Afterwards, the decellularized apple tissues and apple decellularized scaffold materials were decontaminated with phosphate buffer saline. Subsequently, scanning electron microscopy was used to assess the effectiveness of decellularization of the apple materials. Adipose-derived mesenchymal stem cells were extracted from the inguinal fat BALB/C of mice, and their expression of stem cell-related markers (CD45, CD34, CD73, CD90, and CD105) was identified through flow cytometry. The cells were then divided into a scaffold-free control group and a scaffold group. Equal amounts of adipose-derived mesenchymal stem cells were seeded onto both groups. The biocompatibility of the decellularized scaffold with adipose-derived mesenchymal stem cells was evaluated using CCK-8 assay, hematoxylin-eosin staining, and phalloidine staining. Cell adhesion and growth on the scaffold were observed under light microscopy and scanning electron microscopy. Furthermore, the scaffold was subdivided into the non-induced group and the hepatogenic-induced group. Adipose-derived mesenchymal stem cells were cultured on the decellularized apple scaffold, and they were cultured for 14 days in regular culture medium or hepatogenic induction medium for comparison. Immunofluorescent staining using liver cell markers, including albumin, cytokeratin 18, and CYP1A1, was performed. Enzyme-linked immunosorbent assay was used to detect the secretion of alpha fetoprotein and albumin. Additionally, scanning electron microscopy was employed to observe the morphology of the induced cells on the scaffold, verifying the expression of liver cell-related genes on the decellularized scaffold material. Finally, the cobalt-60 irradiated and sterilized decellularized apple scaffolds were transplanted onto the surface of mouse liver and the degradation of the scaffold was observed by gross observation and hematoxylin-eosin staining after 28 days. RESULTS AND CONCLUSION: (1) The scanning electron microscopy results revealed that the decellularized apple scaffold material retained a porous structure of approximately 100 μm in size, with no residual cells observed. (2) Through flow cytometry analysis, the cultured cells were identified as adipose-derived mesenchymal stem cells. (3) CCK-8 assay results demonstrated that the prepared decellularized apple tissue scaffold material exhibited no cytotoxicity. Hematoxylin-eosin staining and phalloidine staining showed that adipose-derived mesenchymal stem cells were capable of adhering and proliferating on the decellularized apple tissue scaffold. (4) The results obtained from immunofluorescence staining and enzyme-linked immunosorbent assay revealed that adipose-derived mesenchymal stem cells cultured on the decellularized apple scaffolds exhibited elevated expression of liver-specific proteins, including albumin, alpha-fetoprotein, cytokeratin 18, and CYP1A1. These results suggested that they were induced differentiation into hepatocyte-like cells possessing functional characteristics of liver cells. (5) The decellularized apple scaffold implanted at 7 days has integrated with the liver, with partial degradation of the scaffold observed. By 28 days, the decellularized apple scaffold has completely degraded and has been replaced by newly-formed tissue. (6) The results indicate that the decellularized scaffold material derived from apple tissue demonstrates favorable biocompatibility, promoting the proliferation, adhesion, and hepatic differentiation of adipose-derived mesenchymal stem cells. Figures and Tables | References | Related Articles | Metrics

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Relationship between bone cement-vertebral volume ratio and therapeutic effect of osteoporotic vertebral compression fractures Ma Chao, Ding Jiangping, Wang Bin, Niu Ben, Muhetaer•Wumaier, Tang Guozhu, Yang Hongtao, Feng Xinwen 2024, 28 (29):  4652-4656.  doi: 10.12307/2024.533 Abstract ( 79 )   PDF (1099KB) ( 3 )   Save BACKGROUND: Percutaneous vertebroplasty has become the main treatment method for osteoporotic vertebral compression fractures due to its advantages of convenient operation and low trauma. However, the optimal bone cement-vertebral volume ratio has not been determined. OBJECTIVE: To investigate the effect of bone cement-vertebral volume ratio on percutaneous vertebroplasty for osteoporotic vertebral compression fractures.  METHODS: The clinical data of 100 patients with single-stage osteoporotic vertebral compression fractures admitted to Xinjiang Bazhou People’s Hospital from July 2019 to July 2022 were retrospectively analyzed. All patients received percutaneous vertebroplasty. According to the bone cement-vertebral volume ratio, they were divided into the low volume group (15% ≤ ratio ≤ 20%) and the high volume group (20% < ratio ≤ 25%) with 50 cases in each group. The visual analog scale score, Oswestry disability index, vertebral anterior margin height, Cobb angle of injured vertebra, bone cement distribution pattern, and bone cement leakage rate were analyzed before surgery, 3 days and 1 year after surgery.  RESULTS AND CONCLUSION: (1) Compared with the preoperative results, the visual analog scale scores, vertebral anterior margin height, Cobb angle of injured vertebra at 3 days and 1 year after surgery, and Oswestry disability index at 1 year after surgery were significantly improved in 100 patients (P < 0.05). There were no significant differences in visual analog scale scores at 3 days and 1 year after surgery and Oswestry disability index at 1 year after surgery between the low volume group and the high volume group (P > 0.05). The vertebral anterior margin height in the low volume group was lower than that in the high volume group at 3 days and 1 year after surgery (P < 0.05). The Cobb angle of the injured vertebrae in the low volume group was higher than that in the high volume group at 3 days and 1 year after surgery (P < 0.05). (2) There were 10 H-type and 40 O-type bone cement distributions in the low volume group. There were 36 H-type and 14 O-type bone cement distributions in the high volume group, and there was no significant difference in bone cement distributions between the two groups (P < 0.05). The bone cement leakage rate in the high volume group and low volume group was 10% and 6%, respectively. (3) It is indicated that both low and high bone cement-vertebral volume ratios can improve postoperative pain and functional dysfunction, but high bone cement-vertebral volume ratio can improve the morphological recovery of injured vertebral, which may be related to the fact that the distribution of bone cement in this group is more H-type. Figures and Tables | References | Related Articles | Metrics

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Influence of bone cement distribution on surgical and adjacent vertebral refractures in percutaneous vertebroplasty Abuduwupuer·Haibier, Alimujiang·Yusufu, Lin Hang, Tuerhongjiang·Abudurexiti 2024, 28 (29):  4657-4662.  doi: 10.12307/2024.813 Abstract ( 78 )   PDF (1099KB) ( 4 )   Save BACKGROUND: Studies have shown that good bone cement distribution during percutaneous vertebroplasty reduces postoperative secondary vertebral fractures and helps improve prognosis. However, how to get a good distribution of bone cement is a problem for spine surgeons.  OBJECTIVE: To analyze the correlation of bone cement distribution with surgical and adjacent vertebral refractures after percutaneous vertebroplasty.  METHODS: A total of 193 patients with thoracolumbar compression fracture (≤ 2 fractured vertebrae) admitted to Xinjiang Uygur Autonomous Region Orthopedic Hospital from January 2018 to December 2022 were selected. They underwent percutaneous vertebroplasty via unilateral approach and were followed up after surgery. They were divided into fracture group (n=30) and non-fracture group (n=163) based on whether the surgical and adjacent vertebral fractures were observed during the follow-up period (more than 6 months). The basic data of the two groups were analyzed by univariate analysis. Statistically significant factors were replaced with binary logistic regression model to explore the correlation with recompression fracture of surgical and adjacent vertebrae after percutaneous vertebroplasty.  RESULTS AND CONCLUSION: (1) Univariate analysis showed that there was no significant difference between the two groups in gender, body mass index, menopause age of female patients, bone cement dose, previous history, smoking history, drinking history, operation segment, operation time, and hospital stay (P > 0.05). There were significant differences in age, bone mineral density T value, bone cement leakage, and bone cement distribution between the two groups (P < 0.05). (2) Binary logistic regression analysis showed that age (95%CI: 1.016-1.167, P=0.016), bone cement leakage (95%CI: 0.080-0.582, P=0.002), bone mineral density T value (95%CI: 1.214-22.602, P=0.026), and bone cement distribution (P=0.007) were risk factors for recurrent fractures after percutaneous vertebroplasty and adjacent vertebroplasty. Patients with type I bone cement distribution (which did not touch the upper and lower endplates of the vertebral body) had a higher risk of recurrent fractures of surgical and adjacent vertebrae after percutaneous vertebroplasty. (3) The results of this study show that refracture of surgical and adjacent vertebrae is caused by the interaction of various risk factors. Age, bone cement leakage, T value of bone mineral density and bone cement distribution are independent risk factors for surgical and adjacent vertebral refracture. Refracture of surgical and adjacent vertebrae can easily occur when bone cement is distributed type I.  Figures and Tables | References | Related Articles | Metrics

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Antibacterial magnesium oxide-calcium phosphate composite coating prepared by combining electrodeposition and sol-gel impregnation Tan Junjie, Du Jiaheng, Wen Zhenyu, Yan Jiyuan, He Kui, Duan Ke, Yin Yiran, Li Zhong 2024, 28 (29):  4663-4670.  doi: 10.12307/2024.523 Abstract ( 71 )   PDF (2115KB) ( 7 )   Save BACKGROUND: Calcium phosphate (CaP) coatings are widely used to improve the integration of titanium implants into bone but these coatings are associated with risks of infection. It is thus desirable to confer antibacterial properties to CaP coatings. OBJECTIVE: To prepare CaP-MgO composite coatings by impregnating magnesium oxide (MgO) sol into CaP coatings and assess the in vitro antibacterial activities and cytocompatibility. METHODS: An electrolyte was determined by titration and used for CaP coating electrodeposition on titanium (referred to as Ti-CaP). MgO was impregnated into the coating by immersing in an MgO sol with different mass fractions (15%, 30%, 50%) and subsequently calcined to form MgO-CaP composite coatings, which were recorded as Ti-CaP-15Mg, Ti-CaP-30Mg and Ti-CaP-50Mg, respectively. Microstructure, tensile properties, critical load, and Mg2+ release of coatings in vitro were characterized. Antibacterial activity was assayed using spread plate method by culturing S. aureus on the pure titanium sheet surface and Ti-CaP, Ti-Cap-15mg, Ti-Cap-30mg and Ti-Cap-50mg surfaces for 24 and 48 hours. Mouse osteoblast suspension was inoculated on pure titanium sheets and Ti-CaP, Ti-CaP-15Mg, Ti-CaP-30Mg and Ti-CaP-50Mg coated titanium sheets, respectively. Cell proliferation was detected by CCK-8 assay, and cell survival rate was calculated. The morphology of composite coating soaked in DMEM was also observed. RESULTS AND CONCLUSION: (1) Homogeneous, microporous CaP coatings consisting of octacaclium phosphate crystal flakes were prepared on titanium by electrodeposition. After sol impregnation-calcination, MgO aggregates were filled into the inter-flake voids. The extent of MgO filling and Mg concentration in the coating increased with the number of sol impregnation procedures. When immersed in phosphate buffered saline, all composite coatings actively released Mg2+ within 1 day; subsequently, the Mg2+ release slowed down on day 3. A small amount of Mg2+ release was still detected on day 7. The yield strength, tensile strength and fracture growth rate of Ti-CaP-30Mg coated titanium were not significantly different from those of pure titanium (P > 0.05). There was no significant difference in the critical load of Ti-CaP, Ti-CaP-15Mg, Ti-CaP-30Mg and Ti-CaP-50Mg groups (P > 0.05). (2) Except that pure titanium sheet and Ti-CaP had no antibacterial properties, the other samples had good antibacterial properties, and the antibacterial rate increased with the increase of MgO content in the coating. (3) After 1 and 3 days of co-culture, the cell survival rate of Ti-CaP-15Mg, Ti-CaP-30Mg and Ti-CaP-50Mg groups was lower than that of pure titanium group and Ti-CaP group (P < 0.05). After 5 and 7 days of culture, there was no significant difference in cell survival rate among five groups (P > 0.05). The content of MgO in the coating decreased gradually with the time of immersion in the medium. (4) The MgO sol impregnation added antibacterial properties to the CaP coatings while retained their biocompatibility.  Figures and Tables | References | Related Articles | Metrics

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Applications of 3D printing in periodontal tissue engineering Nie Wen, Huang Hongli, Mo Wenwen, Long Guiyue, Liao Hongbing 2024, 28 (29):  4671-4676.  doi: 10.12307/2024.589 Abstract ( 85 )   PDF (844KB) ( 24 )   Save BACKGROUND: Three-dimensional (3D) printing is an emerging technology in the field of dentistry. It utilizes a layer-by-layer manufacturing technique to create scaffolds suitable for periodontal tissue engineering applications. Tissue scaffolds produced through 3D printing can possess controlled characteristics, including internal structure, porosity, and interconnectivity, making it an ideal strategy for periodontal tissue engineering. OBJECTIVE: To review the applications of 3D printed scaffolds in periodontal regeneration.  METHODS: English search terms were “3D printing, periodontal tissue engineering, additive manufacturing, regenerative medicine, bioengineering, scaffold, bioprinting, periodontitis”. Chinese search terms were “3D printing, additive manufacturing, periodontal tissue engineering, scaffolds, bio-inks, bioprinting, tissue engineering”. Relevant literature published from 2000 to 2023 in PubMed and CNKI databases was retrieved and included in the review. RESULTS AND CONCLUSION: Over the past few decades, 3D printing technology has made significant progress and breakthroughs in tissue engineering and biomedical fields. 3D printing technology can provide highly personalized treatment programs, improve the suitability and therapeutic effect of therapeutic stents, and has broad application prospects in periodontal tissue engineering. In periodontal tissue engineering, 3D printing applications can better mimic the complex structures of biological tissues and manufacture biocompatible scaffold materials with suitable mechanical and rheological properties. The layer-by-layer construction of tissue engineering scaffolds through 3D printing not only enables the creation of precise and intricate scaffold models for personalized treatment of periodontal disease but also facilitates the incorporation of complex microstructures and channels within the scaffolds to promote cell growth and tissue regeneration. Figures and Tables | References | Related Articles | Metrics

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Research progress on effects of wearable resistance training on lower limb movement ability Dong Zhaojing, Jiang Dongting, Luo Xinjian, Yan Bing, Wang Yang, Ling Xiaoyu 2024, 28 (29):  4677-4684.  doi: 10.12307/2024.586 Abstract ( 72 )   PDF (1047KB) ( 8 )   Save BACKGROUND: Superior lower limb mobility is regarded as one of the prerequisites for winning competitions. Wearable resistance training can effectively overcome the deficiency in the transfer efficiency of traditional strength training in enhancing lower limb mobility. Considering that the impact of wearable resistance training based on different body parts on lower limb mobility may have significant differentiated characteristics, it is particularly important to review and summarize the specific application strategies and acute and chronic intervention effects. OBJECTIVE: To comb and analyze acute and chronic intervention effects of wearable resistance training based on different body parts on lower limb mobility, in order to provide insightful and methodological references for optimizing application strategies for lower limb movement ability. METHODS: A literature search was conducted in CNKI, Wanfang, VIP, Web of Science, Medline, SPORTDiscus, and PubMed databases for publications up to October 2023. Chinese and English search terms were “arm, forearm, limb, leg, lower extremity, vest, trunk, resist, weight, load, sprint, agility, change of direction”. A total of 60 articles were ultimately included for review after screening the retrieval results. RESULTS AND CONCLUSION: (1) Trunk loading of 6-20% of body mass is suitable for optimizing acceleration in sprinting, while trunk loading of ≤6% body mass is suitable for optimizing high-speed running. A trunk load of 5% body mass is applicable for optimizing change-of-direction movement; forearm, calf, or thigh loading often uses 1% or 2% body mass. (2) Trunk loading optimizes the functional performance of the lower limb stretch-shortening cycle by increasing vertical load. This enhances the efficiency of ground reaction force utilization and strengthens the coordinated stability control of the whole body musculature. Forearm loading effectively enhances the driving force of the upper limb swing, improves the propulsive force of the lower limb sprint, and optimizes the efficiency of inter-limb coordination. Calf loading can impose restrictions on the function of the hip joint, thereby leading to localized load stimulation and compensatory functional enhancement in the knee or ankle joint. Thigh loading partially restricts the peak extension angle and speed of the knee joint, creates specific load stimulation at the hip joint, and significantly improves its rotational kinetic energy output. (3) During larger-angle change-of-direction movements, the impact of calf loading is more significant than thigh loading. Thigh loading stimulation helps to enhance power output, while calf loading stimulation aids in improving stability control and directional change. (4) Currently, wearable resistance training has been proven to be an effective way to improve sprint and change-of-direction performance. The methodological strategies to improve sprint performance are relatively mature, but the optimal application scheme to improve change-of-direction performance needs to be further refined and optimized. Further research is recommended to supplement this area. Figures and Tables | References | Related Articles | Metrics

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3D-printed scaffolds repair infected bone defects Dong Bo, Li Xiaoyu, Li Birong, Li Zhen, Wang Zixuan, Yin Zhaoyi, Meng Weiyan 2024, 28 (29):  4685-4690.  doi: 10.12307/2024.581 Abstract ( 69 )   PDF (902KB) ( 15 )   Save BACKGROUND: At present, the treatment of infected bone defects has the problems of long course of disease, poor treatment effect and high cost. The osteogenic effect of personalized bone replacement materials in clinical treatment is limited. Therefore, a 3D-printed bone graft material with both good osteogenic effect and antibacterial effect is urgently needed for clinical treatment. OBJECTIVE: To summarize the research status of 3D-printed scaffolds loaded with antimicrobial agents for the treatment of infected bone defects. METHODS: PubMed, Web of Science, Elsevier, and CNKI databases from January 2010 to June 2022 were searched for related articles. The Chinese search terms were “bone defect, 3D printing, scaffold material, antibacterial, animal experiments, in vitro experiments”. English search terms were “bone defect, 3D printing, scaffold, antibiosis, animal experiment, in vitro”. Finally, 60 articles were included for review and analysis. RESULTS AND CONCLUSION: The 3D scaffolds made of titanium, magnesium, tantalum and other metals and their alloys have certain osteogenic properties, but do not have antibacterial function. Hydroxyapatite and other bioceramic materials have good biocompatibility and are prone to be degraded, whereas due to the lack of strength, they are usually combined with artificial polymer materials to form composite materials, which respectively mimic the inorganic and organic components in natural bone, and play their respective excellent functions. Antibiotics, silver/copper nanoparticles, antimicrobial peptides, gallium and other antibacterial agents play an antibacterial role by destroying bacterial cell membrane, producing reactive oxygen species to interfere with bacterial DNA replication, inhibiting iron absorption and other mechanisms. As a result, the 3D-printed scaffold has both antibacterial and osteogenic effects. However, there are still some problems such as drug resistance and difficult to control effective concentrations. 3D-printed scaffolds are often loaded with antibacterial agents by loading drug-loaded microspheres on scaffolds, preparing antibacterial coating on the scaffold surface, and participating in joint 3D printing with drugs. The loading mode of antibacterial coating prepared on the scaffold surface is the most widely used, and its antibacterial effect is more stable. Nonetheless, the selection of the most suitable loading mode for antibacterial agents needs to be further discussed and summarized. It is a future research prospect to optimize the mechanical properties of composite scaffolds and prepare biomimetic bone scaffolds so that the degradation rate is consistent with the bone reconstruction rate in infected bone defects. The ideal antibacterial agents may play a role through a variety of antibacterial mechanisms, thus being expected to play a good antibacterial effect through low antibacterial concentration, which should be a hot spot of anti-bone infection research. After loading antibacterial agents on the surface of the scaffold, antibacterial agents can “intelligently” react to the local microenvironment, achieving controlled release, and regulating the osteogenesis, vascularization and immune response of the microenvironment, which is the focus of current research. Figures and Tables | References | Related Articles | Metrics

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Polyetheretherketone and its composite materials in post core crown restoration: problems and clinical application value Liu Yang, Cao Youhui, Bao Xuemei 2024, 28 (29):  4691-4696.  doi: 10.12307/2024.582 Abstract ( 87 )   PDF (910KB) ( 12 )   Save BACKGROUND: Polyetheretherketone is a special plastic polymer with good mechanical properties, biocompatibility, and chemical stability, which can be added with different fillers to form new composite materials and has potential clinical application value in post core repair.  OBJECTIVE: To review the properties of polyetheretherketone and its composite materials, as well as the clinical application progress in post core repair. METHODS: CNKI database was searched using the Chinese search terms “polyetheretherketone, post core repair, metal post, fiber post, zirconia post”. PubMed database was searched using English search terms “PEEK, polyetheretherketone post, post core repair, dental dowels”. Search time ranged from January 2019 to October 2023. By reading literature titles, abstracts, and selecting the entire text, the inclusion and exclusion criteria were used to screen and finally include 71 articles for review.  RESULTS AND CONCLUSION: Polyetheretherketone is a high-performance thermoplastic polymer. Experimental studies have proven that polyetheretherketone and its composites have advantages in mechanical properties, biocompatibility, aging resistance, chemical stability, adhesive properties, etc., and have promising application prospects in the field of post core repair. The clinical application of polyetheretherketone and its composite materials as post core restorations is limited to anterior teeth and premolars, but they have achieved satisfactory restoration results. Polyetheretherketone and its composite materials are new materials in post core repair, and there are still many problems to be solved, such as whether the 3D printing equipment and printing process will affect the mechanical properties of the materials; short observation time for clinical repair effects, lack of long-term research validation. There is a lack of case reports on the use of polyetheretherketone and its composite materials as post and core materials for repairing molars, and further research is needed to continuously improve related studies.  Figures and Tables | References | Related Articles | Metrics

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Minipigs used in hydrogel wound repair research Mei Rigeng, Geng Shaohui, Lin Zhimin, Wu Jiapeng, Liu Xin, Lan Xinyi, Gao Yuruo, Huang Guangrui 2024, 28 (29):  4697-4702.  doi: 10.12307/2024.568 Abstract ( 74 )   PDF (1000KB) ( 14 )   Save BACKGROUND: Minipigs are often used in research fields such as skin injury, vascular trauma and cosmetic medicine because they are highly similar to human beings in terms of skin tissue structure and cardiovascular system. Hydrogel as a wound repair drug possesses a variety of excellent physicochemical properties such as strong water retention and adhesion, which can provide isolation moisturization and drug release for wounds.  OBJECTIVE: To summarize and conclude the progress of the application of trauma models for different experimental purposes of hydrogel therapy for minipigs, to reveal the development status of various types of minipig trauma models, to analyze the deficiencies of minipig trauma models at the present stage. METHODS: The relevant articles published in Web of Science database and CNKI database from the establishment of each database to 2023 were checked, using “piglet, miniature pig, minipig, miniature pig; gel, hydrogel; trauma, injury, wound, lesion, incision” as Chinese search terms and “Miniature Swine, Miniature pig, minipig; gel, hydrogel; injury, wound, lesion, incision” as English search terms. A total of 438 Chinese and English documents were retrieved, and 59 documents were included in the study through the inclusion and exclusion criteria.  RESULTS AND CONCLUSION: (1) At present, the main models used clinically for trauma repair are large animal species (dogs and pigs), rabbits, and rodents (rats and mice). Because the skin structure of the minipig is more like that of humans, the minipig is the most ideal animal model for trauma repair. (2) In the in-vitro skin injury model, skin defect model is the basic wound model, which can be divided into full skin defect model and medium-thickness skin defect model according to the depth of the wound defect. Burn wound model and infected wound model are multidimensional models with hot metal scald and bacterial culture imposed on the basis of the skin defect model, which have the advantages of high safety coefficient and low operation difficulty. (3) In the in-vivo trauma repair model, mini-pigs are used as esophageal cricothyrotomy model which is more in line with the pathological state of clinical diseases. Mini-pigs are used in the gastric perforation and vascular hemostasis model, which can visually demonstrate the stronger organ adhesion, hemostatic properties and tissue regeneration-promoting effects of the hydrogel. (4) The specific parts of the pig also has the corresponding mode of use: pig ear is usually used to evaluate the hydrogel drug delayed-release effect. Porcine cellular proteins and pig skin collagen are mostly used to prepare composite hydrogels of tissue origin. Figures and Tables | References | Related Articles | Metrics

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3D-printed biomimetic hydrogel for repairing tissue damage in motor systems Wu Jicenyuan, Zhu Zhou, Pei Xibo 2024, 28 (29):  4703-4709.  doi: 10.12307/2024.535 Abstract ( 80 )   PDF (1090KB) ( 13 )   Save BACKGROUND: Trauma, inflammation, tumors, and other factors commonly result in tissue defects, including damage to bones, joints, skeletal muscles, and associated blood vessels and nerves. Clinically, it is often challenging to repair all the functional injuries involving these tissues, posing great challenges for clinical treatment. OBJECTIVE: To elucidate the application of 3D-printed hydrogel biomimetic structures in motor system tissue injuries. METHODS: Relevant literature published from 2003 to 2023 was retrieved from the CNKI, Wanfang Data, and PubMed databases. The Chinese and English search terms were “3D printing, hydrogel, bone, cartilage, muscle, nerve, vasculature, tissue engineering, biomimetics”. After screening, induction and summary, 63 relevant articles were finally included for review. RESULTS AND CONCLUSION: (1) 3D-printed hydrogels can be achieved in several different ways, such as direct 3D printing, hybrid mode 3D printing, or manufacturing 3D bio-inspired structures in hydrogels by printing intermediate molds. Among these manufacturing processes, extrusion-based printing is currently the most widely used for 3D printing hydrogels with bio-inspired structures. (2) Bioprinting hydrogels enables the production of biovascular structures with complex perfusion patterns, and it can induce the formation of biologically relevant, highly organized, and intact blood vessels. (3) By utilizing bioprinting technology, it is possible to mimic the hierarchical structure and function of natural bone, combining hydrogels with different types of cells and growth factors to create tissue engineering scaffolds that closely resemble the composition and structure of natural bone, thereby facilitating better bone regeneration. (4) Neural fiber structure can be bio-inspired by incorporating different fiber materials into the 3D-printed hydrogel conduit structure. (5) Utilizing specific hydrogel formulations, it is possible to simulate muscle bundle structures or engineer muscle tissues integrating blood vessels and nerves, which can enhance the repair of volumetric muscle injuries in vivo. (6) Based on current related research, methacrylated gelatin, which closely resembles the characteristics of the extracellular matrix, is often considered as a raw material for 3D printing various tissue bio-inspired structures. Researchers also incorporate different growth factors or cells into the hydrogels for bioprinting to achieve the desired tissue repair outcomes. (7) Although there is a lack of clinical trial reports on 3D-printed hydrogel bio-inspired structures, this indicates that the clinical translation of such materials still requires a long-term process. Further improvements are needed in terms of clinical applications, as well as comprehensive in vivo safety assessments. Figures and Tables | References | Related Articles | Metrics

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Advance in preparation methods of bone tissue engineering scaffolds Huang Lei, Wang Xiaoli, Wang Siming, Bao Xin, Zhou Xin, Wang Bendi 2024, 28 (29):  4710-4716.  doi: 10.12307/2024.539 Abstract ( 74 )   PDF (1056KB) ( 24 )   Save BACKGROUND: Due to the small number of autologous bone sources and the risk of immune rejection and disease spread caused by the use of allogeneic bone, artificial bone materials have played an irreplaceable role in bone transplantation today. Along with functional customization, biocompatibility requirements, and the emergence of biodegradable materials, a variety of biomaterials and a variety of preparation methods have emerged. OBJECTIVE: To summarize the preparation methods of scaffolds used in bone tissue engineering, and the advantages and disadvantages, research status and progress of various preparation methods. METHODS: A computer search was conducted on CNKI, WanFang Data, PubMed, and ScienceDirect databases for literature related to bone tissue engineering scaffold from January 2008 to August 2023. Chinese and English search terms were “tissue engineering, bone scaffold, gas foaming, cryotropic gelation, additive manufacturing”. After excluding irrelevant and repetitive studies, a total of 80 articles were retained for summary. RESULTS AND CONCLUSION: (1) Compared with the traditional preparation process of scaffolds, the emerging additive manufacturing and electrospinning technologies have shown great potential in the production of complex structures such as bone and cartilage for tissue engineering in recent years, demonstrating enormous potential. (2) In addition to the advantages of speed, precision and the range of materials used, additive manufacturing methods also provide the feasibility of manufacturing highly complex geometry and topologically optimized structures, achieving precise adjustment and high repeatability of the structure. (3) Electrospinning is one of the most adaptable and promising technologies for the production of a series of fiber mats. The nanofiber scaffolds produced by electrospinning are biomaterials with surprisingly similar microstructures to the cytoplasmic matrix. (4) At present, hydroxyapatite and tricalcium phosphate are the best in ceramic materials, and there are a variety of materials in polymer materials, with excellent biocompatibility. (5) Therefore, the selection of materials should be based on a better understanding of their properties, avoiding complexity, and producing more enhanced scaffolds. However, most of the literature reports so far are exploratory in terms of clinical applicability, and the specific diseases for which they are suitable for treatment remain to be tested. The future development of bone scaffolds is reflected in the following aspects: mechanical properties matching the missing bone, controllable degradation rate, strong ability to promote bone regeneration, and specific functions. Figures and Tables | References | Related Articles | Metrics

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Review of PGC-1α role in exercise anti-aging in different tissues and organs Li Zhaojin, Zheng Pengcheng, Kong Jianda, Zhu Tengqi, Jiang Fugao 2024, 28 (29):  4717-4725.  doi: 10.12307/2024.540 Abstract ( 64 )   PDF (1360KB) ( 8 )   Save BACKGROUND: Peroxisome proliferators-activated receptor gamma co-activator 1α (PGC-1α) is closely related to aging and plays an important regulatory role in exercise anti-aging. However, there is a lack of comprehensive reviews on the role of PGC-1α in exercise anti-aging from the perspective of different tissues and organs. OBJECTIVE: To provide a detailed overview of the role of PGC-1α in exercise anti-aging and discuss its regulation from the perspective of different tissues and organs. METHODS: A literature search was conducted from May 1, 2023 to July 1, 2023. The search covered self-built databases up to July 2023, as well as databases such as Web of Science, PubMed, China National Knowledge Infrastructure (CNKI), WanFang, and VIP. The Chinese search terms included “PGC-1α, peroxisome proliferators-activated receptor gamma co-activator 1α, PPARGC1A, aging, exercise, older adults”. The English search terms were “PGC-1α, aging, exercise, exercise training, older adults”. Boolean logical operators were used to connect the search terms, and corresponding search strategies were developed. Based on inclusion and exclusion criteria, 83 articles were included in the review. RESULTS AND CONCLUSION: (1) PGC-1α is an important transcriptional coactivator that plays a key regulatory role in maintaining mitochondrial function, regulating energy metabolism, and adapting to different metabolic demands. (2) PGC-1α has a significant regulatory role in mitochondrial aging and various functions in multiple cell types, and is associated with inflammatory pathways, redox control, protein modifications, and epigenetic changes. (3) The expression level of PGC-1α can be increased by exercise training, and it exerts positive effects through regulating mitochondrial biogenesis, energy metabolism, and anti-oxidative stress pathways. It plays an important role in exercise-induced improvement of adipose tissue aging, cardiovascular aging, neurosystem aging, renal aging, skeletal muscle aging, and liver aging. (4) The expert group recommends future research directions including exploring the regulatory effects of different types, intensities, and durations of exercise on PGC-1α expression, studying the regulatory mechanisms of protein modifications and epigenetic changes in PGC-1α, and strengthening the research on the mechanisms of PGC-1α in different aging-related diseases. Figures and Tables | References | Related Articles | Metrics

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Bioactive glass: different application forms and functions by adjusting preparation process and doping elements Gao Hua, Che Hui, Hu Dan, Hao Yuefeng 2024, 28 (29):  4726-4733.  doi: 10.12307/2024.561 Abstract ( 72 )   PDF (1128KB) ( 68 )   Save BACKGROUND: Bioactive glass is a multifunctional synthetic composite material that releases active ions slowly and exhibits certain biological activities after affinity with tissues. Their versatility stems from the versatility of their preparation processes and components, allowing them to be applied in different clinical scenarios.  OBJECTIVE: To review the main application forms, application fields of bioactive glass, as well as the influence of doping different elements on its function. METHODS: A literature search was conducted across WanFang Medical Database, CNKI Database, PubMed Database, and Web of Science Database, using the search terms “bioactive glass, slow-release ions, bone tissue engineering, composite scaffold, tissue regeneration and repair, biomedical engineering” in Chinese and English. The timeframe was limited from 2000 to 2023. Finally, 88 articles were included for review. RESULTS AND CONCLUSION: (1) In terms of application forms, bioactive glass can be fabricated as coatings, particles, bone cements, and scaffolds according to needs. Coatings have the potential to enhance the biological activity of implants, yet they are susceptible to instability as a result of degradation. Particles offer a viable solution for the repair of irregular bone defects; however, particles produced through traditional methods often possess limited functionality. Bone cement provides the benefits of minimal invasiveness and injectability, yet its application is restricted to smaller bone defects. Scaffolds exhibit excellent mechanical properties and are commonly used for larger-sized bone defects, yet they have limited toughness. (2) In terms of applications, bioactive glass can be used in a variety of tissue regeneration and repair and disease treatment fields, including dentistry, orthopedics, soft tissue engineering, and cancer. (3) In terms of element doping, the addition of specific elements to bioactive glass not only improves its mechanical properties but also endows it with special biological functions such as bioactivity, degradability, and antibacterial properties. (4) Biologically active glass is a versatile material that can be used in different forms and functions by adjusting the preparation process and element doping to meet various clinical needs in bone tissue engineering and is widely used in the field of biomedical engineering. Figures and Tables | References | Related Articles | Metrics

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Application and development of bone tissue engineering scaffolds with bone immune regulatory properties in repairing bone defects Zhou Yuxiang, Shen Liejun, Wan Shiyu, Chai Luyu, Pang Renqi, Li Dengshun, Wang Xin, Li Zhanzhen 2024, 28 (29):  4734-4740.  doi: 10.12307/2024.566 Abstract ( 82 )   PDF (1530KB) ( 15 )   Save BACKGROUND: Careful regulation of bone immune response during repair of bone scaffold is important for bone regeneration. OBJECTIVE: To review the influence of bone immune response on bone repair and the design of bone tissue engineering scaffold with regulating bone immune function and its application in bone repair. METHODS: Relevant articles published from 1973 to 2023 were retrieved from Science Direct, PubMed, Web of Science, and CNKI databases. English search terms were “osteoimmunology, macrophages, bone repair materials, bone scaffold, bone defects, bone regeneration”. Chinese search terms were “bone immunity, macrophages, bone repair material, bone stent, bone defect, bone regeneration”. Totally 80 articles of the latest research progress in this field were summarized and analyzed.  RESULTS AND CONCLUSION: (1) A detailed review was conducted on the important time points in the origin and development process of bone immunity, and it was explained that macrophages, as important members of the bone immune regulatory system, can be divided into two phenotypes: M1 (pro-inflammatory) and M2 (anti-inflammatory), and play a key role in different stages of bone regeneration. During the inflammatory phase, M1 type macrophages can activate osteoclasts, initiate tissue repair processes, and participate in the reconstruction of bone microvascular networks. On the other hand, during the bone tissue regeneration process in the later stages of inflammation, sustained high expression of M1 type macrophages can hinder the formation of new bones. During the repair phase, M2 macrophages can secrete osteogenic cytokines, stimulate osteogenic differentiation and mineralization of bone marrow mesenchymal stem cells, and promote bone formation. On the other hand, long-term activation of M2 macrophages can increase the secretion of fibrogenic molecules, leading to excessive formation of scar tissue and delaying the healing process. Therefore, regulating macrophages to undergo phenotype transformation at appropriate stages and constructing an immune microenvironment beneficial for osteogenesis has great significance for bone regeneration. (2) In the process of designing bone scaffolds with bone immune regulation characteristics, the physical and chemical properties such as scaffold roughness, pore structure, stiffness, hydrophilicity, surface charge, and surface functional groups can be changed to affect non-specific protein and cell adhesion, thereby affecting the interaction between bone scaffolds and the immune system. By designing surface functional coatings of bioactive substances such as hydroxyapatite, bioactive glass, metal ions, extracellular matrix, drugs, cytokines, and exosomes, the immune microenvironment can be actively regulated by releasing bioactive substances after implantation into the body, affecting macrophage polarization and crosstalk between macrophages and bone cells, and promoting more M2 polarization of macrophages, so as to build a bone immune microenvironment that is conducive to bone regeneration. (3) Based on the research and development of bone tissue engineering scaffolds, in addition to focusing on the direct regulatory factors of stem cell osteogenic differentiation, this article also proposes that attention should be paid to the management of the immune microenvironment of stem cell differentiation. By regulating the appropriate bone immune microenvironment, more stem cell osteogenic differentiation can be induced; the osteogenic efficiency of the scaffold can be enhanced, and the concept of “bone immune regulatory characteristics” can be condensed; deeply elucidated the multi-directional regulatory role of the bone immune microenvironment and introduced the existing strategies for changing the physicochemical properties and surface functional coating of scaffolds to endow them with bone immune regulatory potential, providing new ideas for guiding the development of a new generation of bone tissue engineering scaffolds with bone immune regulatory characteristics. However, the bone immune microenvironment is a dynamic equilibrium state, and most of the existing regulatory strategies do not consider the dynamic matching of regulation. Therefore, the research and development of intelligent bone immune regulatory scaffolds with efficient and targeted regulation of the immune microenvironment will be a key focus of attention for scholars in future. Figures and Tables | References | Related Articles | Metrics

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Influence of heat treatment technology on mechanical properties of 3D printed titanium alloy specimens Yu Luxiang, Zhang Ruojin, Tan Fabing 2024, 28 (29):  4741-4747.  doi: 10.12307/2024.567 Abstract ( 75 )   PDF (1078KB) ( 12 )   Save BACKGROUND: In recent years, additive manufacturing (also known as 3D printing) has gradually become the mainstream method for producing titanium alloy brackets for removable partial dentures. Heat treatment, as an important method to improve the mechanical properties of 3D printed titanium alloys, has become a current hot topic of attention.  OBJECTIVE: To summarize the main heat treatment technologies currently applied to 3D printed titanium alloy specimens (including annealing, solution aging, hot isostatic pressing, and other heat treatments) and their effects on the mechanical properties and microstructure of 3D printed titanium alloy specimens, providing a theoretical basis for improving the heat treatment technology of removable partial denture titanium alloy supports. METHODS: A computer search was conducted on research materials related to 3D printed titanium alloy heat treatment in databases such as CNKI, PubMed, and ScienceDirect. The search period was from 2012 to 2023. A total of 61 articles were selected based on inclusion and exclusion criteria.  RESULTS AND CONCLUSION: (1) Using conventional annealing techniques to treat 3D printed titanium alloy specimens, keeping them at 500-900 °C for 2-4 hours, can effectively increase the elongation of 3D printed titanium alloy specimens. (2) Compared to conventional annealing techniques, solid solution aging treatment is more complex, and the titanium alloy specimens after solid solution aging treatment exhibit outstanding yield strength and better corrosion resistance. However, the 3D printed titanium alloy specimens after solid solution aging treatment have no advantage in terms of ductility. (3) Hot isostatic pressing treatment can reduce the internal defects of 3D printed titanium alloy specimens, significantly increase the elongation of 3D printed titanium alloy specimens, and increase their fatigue life. (4) Rapid heat treatment can significantly improve the elongation of 3D printed titanium alloy specimens, and the speed is faster. In terms of elongation improvement and heat treatment efficiency, it has more advantages than conventional annealing in the past. (5) The improvement of elongation of 3D printed titanium alloy specimens by cyclic heat treatment exceeds that of conventional annealing. Cyclic heat treatment can significantly improve the grain structure of 3D printed titanium alloy specimens, but the heat treatment time is too long and the efficiency is low. Figures and Tables | References | Related Articles | Metrics

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Network meta-analysis on efficacy and safety of different biological agents in treatment of rheumatoid arthritis Jia Hongsheng, Wang Fan, Chen Chun, Sun Bo, Fang Shengqi 2024, 28 (29):  4748-4756.  doi: 10.12307/2024.587 Abstract ( 100 )   PDF (2929KB) ( 7 )   Save OBJECTIVE: There are many kinds of biological agents for the treatment of rheumatoid arthritis in clinic, but the differences in therapeutic efficacy and safety are still unclear. The purpose of this study is to compare the differences in effectiveness and safety of different biological agents for the treatment of rheumatoid arthritis. METHODS: CNKI, VIP, WanFang, China Biomedical Literature System, PubMed, Cochrane Library, Web of Science, and Embase databases were searched to collect the randomized controlled trials on biological agents for rheumatoid arthritis that meet the requirements from inception to October 1, 2022. The literature was selected by EndNote software, and the quality of the included literature was evaluated by RevMan 5.3 software. The software Stata 14.2 was used for direct meta-analysis and network meta-analysis of ACR20 (American College of Rheumatology 20% response), ACR50 (American College of Rheumatology 50% response), ACR70 (American College of Rheumatology 70% response), erythrocyte sedimentation rate, and adverse reactions. RESULTS: Totally 39 articles were included, including 5 low-risk articles, 4 high-risk articles, and the remaining 30 articles contained unknown risk bias, with a total of 13 treatment measures. The results of network meta-analysis: (1) In ACR20, infliximab combined with methotrexate (OR=5.54, 95%CI: 1.33-23.01, P < 0.05), abatacept+methotrexate tablets (OR=3.21, 95%CI: 1.13-9.10, P < 0.05), and tocilizumab (OR=2.95, 95%CI: 1.61-5.44, P < 0.05) were better than methotrexate tablets. The probabilistic ranking of ACR20 was: infliximab+methotrexate tablets > abatacept+methotrexate tablets > tocilizumab > certlizumab > etanercept+methotrexate tablets. (2) In the aspect of ACR50, etanercept combined with methotrexate tablets (OR=4.04, 95%CI: 2.13-7.66, P < 0.05), infliximab combined with methotrexate tablets (OR=4.79, 95%CI: 1.19-19.26, P < 0.05), and tocilizumab combined with methotrexate tablets (OR=3.54, 95%CI: 1.36-9.22, P < 0.05) had better therapeutic effects than methotrexate tablets. The probabilistic ranking of ACR50 was: etanercept+methotrexate tablets > infliximab+methotrexate tablets > tocilizumab+methotrexate tablets > tocilizumab > certlizumab+methotrexate tablets. (3) In terms of ACR70, the therapeutic effects of infliximab combined with methotrexate tablets (OR=8.00, 95%CI: 2.31-27.69, P < 0.05), etanercept combined with methotrexate tablets (OR=4.26, 95%CI: 2.51-7.21, P < 0.05), and tocilizumab combined with methotrexate tablets (OR=3.51, 95%CI:1.82-6.80, P < 0.05) were better than methotrexate tablets. The probabilistic ranking of ACR70 was infliximab+methotrexate tablets > etanercept+methotrexate tablets > tocilizumab+methotrexate tablets > certlizumab > adalimumab+methotrexate tablets. (4) In erythrocyte sedimentation rate, etanercept combined with methotrexate tablets (SMD=-9.23, 95%CI: -16.55 to -1.92, P < 0.05) was better than etanercept and methotrexate tablets (SMD=14.59, 95%CI: 7.28-21.91, P < 0.05). The probabilistic ranking of erythrocyte sedimentation rate was etanercept+methotrexate tablets > infliximab+methotrexate tablets > etanercept > adalimumab+methotrexate tablets > methotrexate tablets. (5) In terms of adverse reactions, placebo (OR=0.62, 95%CI: 0.39-0.99, P < 0.05) was better than infliximab and certlizumab (OR=0.44, 95%CI: 0.25-0.78, P < 0.05). The probabilistic ranking of adverse reactions was placebo > infliximab > etanercept+methotrexate tablets > certlizumab > etanercept. CONCLUSION: Based on evidence from 39 randomized controlled trials, infliximab combined with methotrexate tablets (highly recommended) can be the first choice in clinic, and etanercept combined with methotrexate tablets (highly recommended) can be the second choice in terms of good effectiveness and safety. Figures and Tables | References | Related Articles | Metrics