Exosomes that deliver specific mirnas can regulate osteogenesis and promote angiogenesis北大核心

BACKGROUND: Exosomes are nanoscale paracrine vesicles containing a variety of bioactive factors, such as miRNAs. Exosome miRNAs play an important role in intercellular communication. In recent years, more and more studies have focused on whether miRNAs in exosomes promote bone regeneration. OBJECTIVE: To review research status of exosomal miRNAs promoting bone regeneration in the recent years so as to provide a theoretical basis for further research and application in the field of bone regeneration. METHODS: Using “bone regeneration, bone repair, exosomes, miRNA” in Chinese and English as search terms, biomedical literature database, CNKI, and PubMed were retrieved for articles on exosomal miRNA and bone regeneration published from 2010 to 2021. RESULTS AND CONCLUSION: Exosomes derived from different cells can effectively regulate osteogenesis and promote angiogenesis through the delivery of specific miRNAs, which has a broad prospect in bone tissue engineering. © 2022, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

Repair materials for bone defects: Present status,needs and future developments北大核心

BACKGROUND: Great development has been made in the research of various repair materials and tissue-engineered bone, and different materials exhibit a strong ability to repair bone defects. OBJECTIVE: To review the research status and progress of repair materials for bone defects. METHODS: PubMed, PMC, CBM, CNKI and WanFang databases were used online to retrieve the relative articles regarding repair materials for bone defects published from June 2007 to June 2017. The key words were “biomaterials, bone repair materials, bone substitute, bone tissue engineering, bone defect, bone repair” in English and Chinese, respectively. Finally, 66 eligible articles were included, while the unrelated and repeated ones were excluded. RESULTS AND CONCLUSION: The main repair materials for bone defects include autologous bone, allogeneic bone, xenogeneic bone, demineralized bone matrix, bioceramics, metal materials, polymer materials, tissue-engineered bone and relative derived composites. Different materials have shown certain advantages and disadvantages. Clinicians should make an optimal choice in view of the characteristics of materials. Although there is a great progress in the studies of repair materials for bone defects, further investigations are warranted on how to produce highly biomimetic materials, optimize cell adhesion and migration, precisely control the expression and release of related genes and growth factors, validate clinical safety, and provide medical evidence in clinical practice. © 2018, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.     

Biological characteristics and immunoregulation of exosomes derived from mesenchymal stem cells北大核心

BACKGROUND: Clarifying the synthesis and regulation of exosomes derived from mesenchymal stem cells is of great significance to the research and application of exosomes in the future. OBJECTIVE: To summarize the biological characteristics in exosomes derived from different mesenchymal stem cells and the role of these exosomes in the immune regulation, which hopes to find new breakthroughs in the study of exosomes in the future and provide ideas for cell-free therapy. METHODS: The articles were searched on PubMed, CNKI and Wanfang using the keywords of “stem cells, mesenchymal stem cells, exosomes, immunomodulation, inflammatory mediator, biological characteristics of exosomes, biological characteristics of mesenchymal stem cells, regeneration” in Chinese and English. Finally, 105 articles were included for review. RESULTS AND CONCLUSION: Mesenchymal stem cells are a type of pluripotent stem cells that exist widely in various tissues of the body. Mesenchymal stem cells not only have stem cell characteristics, but also play an important role in the immunosuppressive properties. Mesenchymal stem cells had been clinically applied for the treatment of many diseases. Therefore, mesenchymal stem cells were used to manage novel coronavirus pneumonia, and had ideal treatment effect. Exosomes are endosome-derived nanometer-scale vesicles (40–200 nm in diameter). Exosomes derived from mesenchymal stem cells have the same immune regulation function as its maternal cells, including that carrying immunosuppressive factors, promoting macrophages polarization into M2 type, preventing differentiation of pro-inflammatory T cell subsets and inhibiting antigen presentation. © 2022, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

引导组织再生联合植骨修复根分叉病变的Meta分析

BACKGROUND: Numerous experimental and clinical observations have shown new attachment formation in the periodontium by guided tissue regeneration. OBJECTIVE: To evaluate the efficacy of guided tissue regeneration combined with bone grafting for the treatment of root furcation defects. METHODS: A computer-based online search combined with manual retrieval was conducted up to 2015 to screen the relevant English and Chinese literatures addressing guided tissue regeneration, bone grafting, and root furcation defects. Vertical and horizontal probing depth and attachment loss were analyzed. Meta-analysis was performed using Stata/SE version 12.0 software by extracting data from the relevant articles. Moreover, the publication bias was tested. RESULTS AND CONCLUSION: The meta-analysis results showed that at 6 months after treatment, the alterations in vertical probing depth and periodontal attachment were significantly increased after guided tissue regeneration compared with open-flap debridement (P < 0.000 01); the alterations and increment in the periodontal attachment were significantly increased after combined treatment of guided tissue regeneration and bone grafting compared with open-flap debridement (P < 0.000 01); the reduction in the vertical and horizontal probing depth and the increment in periodontal attachment were significantly increased after combined treatment of guided tissue regeneration and bone grafting compared with guided tissue regeneration (P < 0.000 01 or P = 0.01). At 12 months after treatment, the reduction in vertical probing depth and the increment in attachment loss were significantly increased after combined treatment of guided tissue regeneration and bone grafting compared with guided tissue regeneration (P < 0.000 01). These results indicate that the guided tissue regeneration combined with bone grafting in the treatment of root furcation defects is superior to guided tissue regeneration or open-flap debridement. In addition, in the latter two therapies, guided tissue regeneration shows a better therapeutic effect. However, the therapeutic effects of various types of regenerated membranes and bone grafts need further in-depth study to define the optimal treatment strategy. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

骨组织工程中的间质干细胞：成骨活性、免疫特性、促血管化及成骨效应

BACKGROUND: It is still a challenge to repair bone defects caused by trauma, infection, tumor and congenital diseases. Bone tissue engineering is a promising method for bone defect repair showing important guiding significance in the clinic. OBJECTIVE: To review the progress of proliferation, osteogenic activity, immunogenicity, proangiogensis and in vivo osteogenic effect of mesenchymal stem cells in bone tissue engineering. METHODS: The first author retrieved Wanfang and PubMed datebase for literatures published from 2008 to 2016, using the keywords of “mesenchymal stem cell, tissue engineering, osteogenesis, immune property, angiogenesis” in Chinese and English, respectively. Articles regarding mesenchymal stem cells, tissue engineering, osteogenesis, immune property and angiogenesis were included, and repetitive and dated studies were excluded. Totally 1 772 articles were retrieved initially, and in accordance with inclusion and exclusion criteria, 41 eligible articles were included for review analysis. RESULTS AND CONCLUSION: Bone marrow mesenchymal stem cells and adipose-derived mesenchymal stem cells are extensively applied in bone tissue engineering. Studies have shown that the osteogenic activity of bone marrow mesenchymal stem cells is higher than that of adipose-derived mesenchymal stem cells, but its immune regulation effect is weaker than that of adipose-derived mesenchymal stem cells. Mesenchymal stem cells hold remarkable immune regulation (immunosuppression and immune enhancement) and tissue repair capacity, which can eliminate inflammatory reactions at injured sites, promoting tissue repair. Adipose-derived mesenchymal stem cells cultured under hypoxia environment can secret more angiogenic cytokines generating more vascular structures. Furthermore, increasing proof have confirmed that porous nano-polylactic acid combined with nano-carbon biological material can significantly promote the proliferation and osteogenesis of bone marrow mesenchymal stem cells. Taking its tumorigenesis into consideration, mesenchymal stem cells should be prudently used in the clinic. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Application and progress of small extracellular vesicles in periodontal and pulp regeneration北大核心

BACKGROUND: Small extracellular vesicles are important components of paracrine pathways. In recent years, the application of small extracellular vesicles in oral tissue regeneration attracted wide attention. OBJECTIVE: To review the role and application of small extracellular vesicles in periodontal and pulp tissue regeneration. METHODS: PubMed, Web of Science, CNKI and Wanfang databases were searched for relevant articles published in the past ten years. The retrieval MeSH Terms or key words were “small extracellular vesicles, exosomes, pulp stem cells, periodontal regeneration, bone regeneration, pulp regeneration, regenerative endodontics, revascularization” in Chinese and English, respectively. After removal of poorly related, outdated, and duplicate studies by reading the title and abstract, 71 articles were finally included in result analysis. RESULTS AND CONCLUSION: (1) Small extracellular vesicles were secreted by many kinds of cells, participated in intercellular communication and mediated immune response. Small extracellular vesicles have a great application potential in tissue regeneration. (2) Small extracellular vesicles play an important role in periodontal tissue repair and regeneration. Small extracellular vesicles can regulate periodontal inflammation and promote periodontal ligament and surrounding bone tissue regeneration. (3) Small extracellular vesicles improve dental stem cells to regenerate functional pulp-dentin complexes. © 2023, Chinese Journal of Tissue Engineering Research. All rights reserved.     

中药诱导骨髓间充质干细胞的定向分化：研究与进展

BACKGROUND: In recent years, in-depth studies that single Chinese herbs or extracts, compound traditional Chinese medicine and medicated serum are used to regulate the directional differentiation of bone marrow mesenchymal stem cells into myofibroblasts, chondrocytes, osteoblasts, myocardial cells and nerve cells, which have become a highlight in the tissue engineering research.OBJECTIVE: To review the latest progress in the directional differentiation of bone marrow mesenchymal stem cells induced by Chinese herbs or their extracts.METHODS: The first author searched the CNKI, Wanfang and PubMed databases using the keywords of “Chinese herb, directional differentiation, mesenchymal stem cells” in Chinese and English, respectively, to retrieve relevant articles published from January 2010 to January 2016. Repetitive articles or those with no originality were eliminated. Totally 99 articles were searched initially, and then 43 articles were included in result analysis.RESULTS AND CONCLUSION: As the strongest seed cells in the bone differentiation system, bone marrow mesenchymal stem cells have a wide range of directional differentiation potential, and highlight the important value in combination with Chinese herbs for clinical treatment of various refractory diseases, especially for treatment of metabolic bone diseases, bone defects, nonunion and delayed union, which is not only conducive to in-depth, multi-angle studies on effects and mechanisms of Chinese herbs, but also to clinical treatment of various refractory diseases using bone marrow mesenchymal stem cells.   中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Preparation and application of acellular scaffold in tissue engineering and regenerative medicine北大核心

BACKGROUND: Biological scaffolds made from tissue or organ decellularization have been successfully applied to various tissue engineering and regenerative medicine. OBJECTIVE: To review the preparation methods of acellular scaffolds and their functions and applications in tissue engineering and regenerative medicine. METHODS: Databases of PubMed and CNKI were retrieved with the key words of “decellularization, scaffold, extracellular matrix, tissue regeneration and repair” in English and Chinese. Subjects and abstracts were initially screened to exclude documents that were not related to the subject of the article, and finally 66 articles were included for result analysis. RESULTS AND CONCLUSION: The decellularized scaffolds obtained by decellularizing tissues and organs through physical, chemical and biological methods can effectively retain the components of the extracellular matrix, are non-immunogenic, have good biocompatibility and mechanical properties, and can promote cell adhesion, proliferation, migration and differentiation, induce tissue repair, and reconstruct vascularized and functional tissues and organs. Acellular scaffolds have achieved ideal results in vitro and short-term in vivo experiments of many tissues and organs, such as heart, liver, kidney, lung, trachea, skin and bone, indicating that acellular scaffolds play an important role in tissue regeneration and repair, and have good application prospects. However, to be put into clinical use, more in-depth research and exploration are needed. © 2022, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

Research hotspot of biological scaffold materials promoting osteogenic differentiation of bone marrow mesenchymal stem cells北大核心

BACKGROUND: At present, a single biological scaffold material is difficult to meet the osteogenic needs of bone tissue engineering, and bone marrow mesenchymal stem cells have excellent osteogenic characteristics. Composite scaffolds and scaffolds combined with growth factors have better osteogenic ability. It is a research hotspot at present. OBJECTIVE: To review different biological scaffolds and their modified scaffolds to promote the osteogenic differentiation of bone marrow mesenchymal stem cells. METHODS: The related articles published in CNKI, Wanfang, VIP, PubMed and Embase databases from January 2014 to July 2020 were searched by the first author with the keywords of “bone marrow mesenchymal stem cells, scaffolds, osteogenic differentiation, hydroxyapatite, collagen, chitosan” in English and Chinese. Finally, 69 articles were selected. RESULTS AND CONCLUSION: The rapid development of bone tissue engineering can effectively solve the problem of bone defect repair. Seed cells and biological scaffold materials are the core of bone tissue engineering. Bone marrow mesenchymal stem cells have excellent osteogenic differentiation ability and are widely used in bone tissue engineering. The combination of different scaffold materials, the use of advanced preparation technology, or the surface modification of scaffolds and the addition of growth factors can fully combine the advantages of various biological scaffold materials, induce the osteogenic differentiation of bone marrow mesenchymal stem cells and the formation of scaffold blood vessels, and achieve the purpose of repairing bone defects, and is the research focus of bone tissue engineering. © 2022, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

Application of concentrated growth factor and epidermal growth factor in the field of oral and maxillofacial soft and hard tissue injury repair北大核心

BACKGROUND: Oral and maxillofacial region is a sensitive part of beauty in appearance, and its damage often involves both soft and hard tissues. Concentrated growth factor and recombinant human epidermal growth factor can promote the repair and regeneration of local soft and hard tissue injury, which has become a new research hotspot in recent years. OBJECTIVE: To review the research progress and application of concentrated growth factor and recombinant human epidermal growth factor in the repair of soft and hard tissue injury in oral and maxillofacial region, and discuss the limitations of current research and the possibility of their combined application in the future. METHODS: The English search terms were “CGF, concentrated growth factor, rhEGF, recombinant human epidermal growth factor, tissue regeneration” and the Chinese search terms were “concentrated growth factor, epidermal growth factor, tissue engineering, tissue regeneration, oral and maxillofacial region”. Relevant articles about concentrated growth factor and recombinant human epidermal growth factor were searched in CNKI and PubMed databases. The retrieval time was from 2011 to 2021. Finally, 63 articles were selected. RESULTS AND CONCLUSION: (1) In this paper, the biological characteristics and sources of concentrated growth factor and recombinant human epidermal growth factor were briefly introduced. The research progress and clinical application status of concentrated growth factor and recombinant human epidermal growth factor in promoting the proliferation and differentiation of stem cells related to the regeneration of soft and hard tissues in oral and maxillofacial regions were emphatically summarized. The limitations of current research and possible application directions in the future were discussed. (2) Concentrated growth factor contains a variety of growth factors and CD34+ cells, which can promote the growth, proliferation, migration and differentiation of a variety of tissue cells, especially stem cells, and play an important role in tissue injury repair. (3) Concentrated growth factor is widely used in implant surgery, autologous tooth transplantation, jaw cyst resection, gingival surgery, debridement and suture, which can relieve pain, reduce inflammation, and improve postoperative bone regeneration effect and aesthetic effect. (4) Recombinant human epidermal growth factor has a great development space in soft tissue and nerve regeneration. It has been proven that recombinant human epidermal growth factor can promote a variety of stem cells to differentiate into neuron-like cells, and also induce adipocytes to differentiate into epidermal cells. Most clinical studies suggest that recombinant human epidermal growth factor can promote healing of oral ulcers and reduce scar formation. (5) “Concentrated growth factor + recombinant human epidermal growth factor” combined with adipose-derived stem cells and other stem cells that can be easily obtained have the possibility of directional formation of oral and maxillofacial soft and hard tissue. In the future, it may fill the deep oral and maxillofacial tissue defects caused by trauma, tumor resection, and promote the repair and regeneration of damaged nerves. (6) Trying to use “concentrated growth factor + recombinant human epidermal growth factor” for refractory oral ulcers, periodontal surgery, dental implants, oral and maxillofacial trauma surgery is also a new way to improve oral and maxillofacial function and appearance. Collagen sponge and chitosan membrane may be used as carriers of “concentrated growth factor + recombinant human epidermal growth factor” to facilitate shaping and prolong the action time of the composite. © 2023, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

Mechanism and application of stem cell-derived exosomes in promoting diabetic wound healing北大核心

BACKGROUND: The exosomes are one of important active components of adult stem cells paracrine, providing the basis for stem cell “non-cellular” treatment. Exosomes from stem cells can play different roles in the wound through different mechanisms to promote the healing of diabetic wounds. OBJECTIVE: To summarize the main mechanism and application of stem cell derived exosomes in the treatment of diabetic wounds. METHODS: Computers were used to retrieve English databases such as PubMed database, Web of Science database, FMRS foreign language medical information resource retrieval platform, and Chinese databases such as CNKI and Wanfang Data Knowledge Service Platform. The retrieval scope was from the inception of the database to September 2020. The English and Chinese search terms were “stem cells, exosomes, wound healing, cell proliferation, neovascularization, inflammation, extracellular matrix, therapeutic use”. According to the inclusion and exclusion criteria, 66 articles were included and the results were analyzed. RESULTS AND CONCLUSION: (1) It is summarized that stem cell-derived exosomes can promote diabetic wound healing by regulating inflammation, promoting neovascularization, re-epithelialization and remodeling of extracellular matrix. (2) The application of stem cell-derived exosomes in diabetic wounds was listed. (3) The exosomes from stem cells can avoid the immune response of stem cells in the treatment of diabetic wounds, and the genetic material of stem cells carried by them is more widely regulated and more effective than that from ordinary cells in the treatment of diabetic wounds. (4) At present, the application of stem cell derived exosomes in diabetes wounds still has some problems, such as low purity, high cost of separation, low production efficiency, and the way to reach the target area, loss rate and diffusion efficiency. © 2022, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

Extracellular vesicles in chronic periodontitis北大核心

BACKGROUND: Extracellular vesicles can control the inflammatory response by participating in immunomodulation of intercellular signaling, while also repairing periodontal tissue and promoting periodontal tissue regeneration. The application of this technology to the preventive diagnosis and tissue regeneration of chronic periodontitis is expected to become a method of cell-free tissue regeneration. OBJECTIVE: To review the synthesis and secretion of extracellular vesicles, biological function, relationship with chronic periodontitis, and recent advances in the diagnosis, prevention and treatment of chronic periodontitis. METHODS: The first author applied the computer to search for relevant studies involving extracellular vesicles in the prevention and treatment of chronic periodontitis in databases such as PubMed, Web of Science and CNKI. The search keywords were “extracellular vesicle, exosome, periodontal disease, immunomodulatory, outermembrane vesicles, bone regeneration” in Chinese and English. The retrieval time was from April 2014 to October 2021. RESULTS AND CONCLUSION: Extracellular vesicles are balloon-like bodies that can be produced by almost all cells, which are widely present in various body fluids, and are rich in proteins, lipids and genetic material on the surface, which affect the biological behavior of target cells by mediating information transfer between cells. On the one hand, the inflammatory response of chronic periodontitis is inseparable from the mediation of extracellular vesicles secreted by bacteria, which can be used as a biomarker to diagnose and evaluate chronic periodontitis; on the other hand, the new chronic periodontitis vaccine made by extracellular vesicles has initially been effective, and the extracellular vesicles containing information molecules can also participate in regulating the immune response and promoting the repair and regeneration of periodontal tissue. Therefore, in the field of tissue damage repair and regeneration of chronic periodontitis, extracellular vesicles are a new and potential cell-free therapy, but their extraction, purification and safety are still challenges to be overcome before clinical translation. © 2023, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

血管化鹿茸软骨组织与骨组织修复

BACKGROUND:Deer antlers are the only known mammalian organ that can regenerate periodically, and its cartilage is rich in blood vessels. Study on deer antler vascularized cartilage can uncover the antler biological characteristics and is of vital significance for bone repair and regenerative medicine. OBJECTIVE:To review the distribution of blood vessels in antler cartilage tissue, the generating process and mechanism of blood vessels, cytokines influncing angiogenesis, and to analyze the features of deer antler models in bone tissue engineering, providing medical reference for bone repair. METHODS: A computer-based online search of PubMed and CNKI databases was performed using the keywords of “deer antler, bone tissue engineering, vascularized cartilage” in English and Chinese, respectively. Articles concerning antler histology, morphology, antler cartilage and vascularized cartilage and bone tissue engineering were enrolled and repetitive studies and irrelevant articles were excluded. RESULTS AND CONCLUSION: Fifty-one eligible articles were selected finally. Deer antler is a kind of periodic regenerative bone, and antler cartilage is different from normal cartilage that is rich in blood vessels with the growth speed of 2.7 cm/day. Scholars have studied the vascularization of antler cartilage tissue, and obtained some achievements. Exploring the distribution of antler blood vessels in cartilage tissue, the generating process and mechanism of antler blood vessels, the cytokines acting on antler angiogenesis, as well as analyzing the advantages of deer antler model for bone tissue engineering provide a reference for tissue-engineered cartilage vascularization. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Stem cells combined with three-dimensional scaffolds for the treatment of osteoporotic bone defects北大核心

BACKGROUND: Stem cells combined with a three-dimensional scaffold have great potential for the treatment of osteoporotic bone defects. OBJECTIVE: To introduce the application of stem cells combined with the three-dimensional scaffold in repairing osteoporotic bone defects. METHODS: A computer-based search of PubMed, Web of Science, Springerlink, Medline, WanFang and CNKI databases was performed for relevant articles published from 2007 to 2017 with “stem cells, scaffold, osteoporosis, bone defects” as key words in English and Chinese, repsectively. Initially, 142 articles were retrieved, and finally 45 articles were included in result analysis. RESULTS AND CONCLUSION: Due to the potential of self-renewal and multilineage differentiation, stem cells can be used to repair or regenerate damaged tissues, which are considered as an ideal cell source for the treatment of diseases in orthopedics. The suitable scaffold can provide a favorable microenvironment for repairing the attachment and growth of the cells related to the bone defect, which can promote the healing without additional side effects. Furthermore, stem cells combined with three-dimensional scaffolds provide a promising clinical application for the treatment of osteoporotic bone defects by regulation of bone metabolism. In addition, gene-modified stem cells with three-dimensional scaffolds bring a huge potential in the treatment of osteoporotic bone defects. In conclusion, the combination of stem cells and three-dimensional scaffolds provides a new approach for the treatment of osteoporotic bone defects, which may be one of the future therapeutic strategies. © 2018, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.     

生物材料在牙再生领域中的应用与未来

BACKGROUND: The emergence of tissue engineering technology has provided a new possibility for the study of tooth regeneration. The biomaterials used in the research of tooth regeneration have a good implementation prospect, and have achieved some research results, which have become a study hotspot. OBJECTIVE: To review the research history, types, characteristics of biomaterials and the research evelopments in the field of tooth regeneration. METHODS: The articles about biomaterials and their applications in the tooth regeneration published during 2000 to 2015 were retrieved from CNKI, PubMed and Google Scholar by computer. Typical and creative research achievements were enrolled in result analysis. RESULTS AND CONCLUSION: Many research results demonstrate that biomaterials play an irreplaceable role in tooth regeneration, among which the soft biomaterials can be used for wrapping cytoskeleton, whereas the mechanical rigid biomaterials act as the structural substitutes. Therefore, we can use these two kinds of biomaterials together and complementarily. Biomaterials and a variety of dental stem cells all have a good biocompatibility, low cytotoxicity and immunogenicity, which may induce some cells to differentiate toward a particular direction. As more and more research achievements of biomaterials in the field of tissue regeneration have been discovered, how to reduce the costs and realize the clinical applications still need further research. 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

Inhalation of bone marrow mesenchymal stem cells-derived exosomes alleviates inflammatory injury in chronic obstructive pulmonary disease北大核心

BACKGROUND: Many studies have demonstrated that exosomes derived from bone marrow mesenchymal stem cells show strong repair and regeneration ability in various models of respiratory inflammation and disease injury, but there are few studies on chronic obstructive pulmonary disease, and no studies have applied aerosolized inhalation of exosomes in model experiments of chronic obstructive pulmonary disease. OBJECTIVE: To investigate the therapeutic effects of exosomes derived from rat bone marrow mesenchymal stem cells on inflammation and lung injury in rats with chronic obstructive pulmonary disease by aerosol inhalation, and to determine the optimal therapeutic dose. METHODS: Rat bone marrow mesenchymal stem cells were isolated and cultured in vitro, and exosomes were extracted and identified. The rat model of chronic obstructive pulmonary disease was established by lipopolysaccharide combined with smoking for 28 days. Then low dose (0.5×108 particles/kg), medium dose (1.0×108 particles/kg), and high dose (1.5×108 particles/kg) exosome aerosol treatment and exosome (1.5×108 particles/kg) were given by tail vein injection. The model group was atomized with 1 mL PBS, while the control group was not molded with 1 mL PBS. Continuous atomization or injection was conducted for 5 days, and the test was started on the second day after the last atomization or injection treatment. The lung function indexes were tested by small animal pulmonary function instrument. The levels of interleukin-1β and tumor necrosis factor-α in bronchoalveolar lavage fluid and serum were detected by ELISA. The changes of lung tissues were assessed histologically by hematoxylin-eosin staining and Masson staining. RESULTS AND CONCLUSION: (1) The exosomes of bone marrow mesenchymal stem cells showed elliptic double-membrane vesicles under transmission electron microscopy, which were typical cup-shaped. Particle size analysis indicated that the peak diameter of exosomes was 91.7 nm, accounting for 97.3%, and the particle concentration was 3.3×109 L-1. In addition, surface proteins CD9 and CD63 were highly expressed. (2) Compared with caudal vein injection of exosome, aerosol inhalation of exosome significantly improved lung function, collagen deposition and pathological changes of lung tissue in rats with chronic obstructive pulmonary disease, and significantly decreased the levels of interleukin-1β and tumor necrosis factor-α in bronchoalveolar lavage fluid and serum. The low exosome dose had the most significant therapeutic effect. (3) These results suggest that inhalation of exosomes from bone marrow mesenchymal stem cells can reduce inflammatory injury in chronic obstructive pulmonary disease and the optimal dose may be 0.5×108 particles/kg. © 2023, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

Application of biomaterial scaffolds in the treatment of spinal cord injury北大核心

BACKGROUND: Due to the weak regeneration ability after spinal cord injury, it is still a difficult medical problem to repair the damaged spinal cord tissue and normalize its function. The rapid development of biological tissue materials and its wide application in medicine provide new therapeutic ideas and methods for spinal cord injury repair. OBJECTIVE: To summarize the research situation of biomaterial scaffolds on nerve tissue regeneration and repair after spinal cord injury, and forecast its development trend, so as to explore the methods of spinal cord injury repair and summarize experience. METHODS: The articles published from January 2011 to January 2021 were retrieved using the advanced retrieval function of PubMed database. The search terms were “spinal cord injury, biomaterials, nerve regeneration, material”. By using the advanced retrieval functions of CNKI, Wanfang, VIP and other databases, relevant articles published from January 2011 to January 2021 were searched, and the search terms were “spinal cord injury, biomaterials, scaffolds”. RESULTS AND CONCLUSION: With further development of the combination of bioengineering research and medicine, biomaterial scaffolds have been widely used in the study of spinal cord injury repair, and the histocompatibility and degradation of biomaterials have been improved. There are many kinds of biomaterials, each of which has its own advantages and disadvantages. It is better to prepare composite scaffolds loaded with seed cells, cytokines or drugs for nerve regeneration. However, how to select the composite scaffold material combination, how to select the seed cells, cytokines or drugs, so as to make the biomaterial scaffold combined with seed cells, cytokines or drugs become the best combination value of in-depth research. In conclusion, biomaterial repair of spinal cord injury is a new idea and may become a breakthrough point to promote the repair of spinal cord injury. © 2022, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

Complications associated with bone transport: A literature review of nonunion at the docking site北大核心

BACKGROUND: Bone transport is a powerful tool described by Ilizarov, which is an excellent biological method for the correction of large bone defects. But complications specifically associated with bone transport including delayed union or nonunion at the docking site occur frequently. OBJECTIVE: To analyze the research status and clinical treatments of the delayed union or nonunion at the docking site in bone transport using Ilizarov method. METHODS: A computer-based search of CNKI and PubMed databases was performed for the articles related to the docking site, osteotomy, bone defects and bone transport with the keywords of “docking site, bone transport, bone defects, Ilizarov” in English and Chinese, respectively. Finally, 44 eligible articles were included to review. RESULTS AND CONCLUSION: Docking sites are the result of a classic bone transport technique for dealing with bone loss. Union may prove to be the rate-limiting step of this surgical procedure. About the delayed union or nonunion at the docking site, different clinicians have different foci, some clinicians focus on prevention, some focus on the biological treatment, and some focus on surgical intervention. The emergence of decortications and debridement under arthroscopy provides a new treatment strategy for the delayed union or nonunion at the docking site. How to promote the healing at the docking site and shorten treatment course still needs a further investigation. © 2018, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.     

Application and value of polymer materials in three-dimensional printing biological bones and scaffolds北大核心

BACKGROUND: At present, the main factors restricting the development of three-dimensional (3D) technology are the limited types of printable materials, and polymer materials have made great progress in the field of 3D printing biological bones and scaffolds due to their excellent physical and chemical properties and variety. OBJECTIVE: To review application status of polymer materials in the biological field and the advantages and disadvantages of 3D printing technology. METHODS: CNKI, Wanfang, VIP, and PubMed databases were searched for articles published from 2000 to 2020. The Chinese key words were “3D printing, fused deposition molding, UV curing molding technology, selective laser sintering technology, natural polymer, synthetic polymer, biomedical, artificial bone, artificial bone scaffold”. The English key words were “3D printing; FDM; SLA; SLS; natural polymer; synthetic polymer; biomedical; artificial bone; artificial bone scaffold”. Finally, 56 articles were selected to summarize. RESULTS AND CONCLUSION: Polymer materials play a more and more important role in the biological field because of their wide variety, excellent physical and chemical properties, high dimensional accuracy, good processability and other characteristics. Not only that, the composite of polymer materials with metal and inorganic can improve their biocompatibility, controllable degradation and other characteristics, which further expands the application space of polymer materials in the biological field. 3D printing technology is mainly through the combination of information technology and manufacturing technology to achieve 3D solid printing, which is with the characteristics of rapid, accurate, personalized customization. 3D printing is widely used in biomedical, casting, aerospace and other fields. The combination of polymer materials and 3D printing technology can realize the personalized customization of human bones, organs and tissues, which is expected to solve the problem of insufficient donors in clinic. Therefore, the research and development of biomedical materials more suitable for 3D printing process and how to better combine polymer materials with 3D printing technology become the current research hotspot. © 2022, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.     

Isolation and Culture of Rabbit Marrow-derived Mesenchymal Stem Cells

1 Introduction Repair of tissues like bone, cartilage, muscle,etc., is a tough problem in clinical treatment. The recent research show that there are plenty of mesenchymal stem cells (MSCs) in myeloid tissue besides hemopoietic stem cells(HSCs). Just as the pluripotential hemopoietic stem cell can give bone marrow tissue excellent hemopoietic ability and maintain the metabolism of, MSCs can give potential repair ability to bone, cartilage tissue injury[1] . But compared with the HSCs, the content of MSCs in myeloid tissue are not abundant. We separated and purified the MSCs from myeloid tissue through in vitro cell culture,and studied the proliferation and growth characteristics under in vitro culture conditions, providing experimental foundations for further research on repair epiphyseal plate cartilage defect through MSCs tissue engineering.