Biological scaffold materials and printing technology for repairing bone defects / 中国组织工程研究

BACKGROUND:In recent years,with the development of biological scaffold materials and bioprinting technology,tissue-engineered bone has become a research hotspot in bone defect repair. OBJECTIVE:To summarize the current treatment methods for bone defects,summarize the biomaterials and bioprinting technology for preparing tissue-engineered bone scaffolds,and explore the application of biomaterials and printing technology in tissue engineering and the current challenges. METHODS:Search terms were"bone defect,tissue engineering,biomaterials,3D printing technology,4D printing technology,bioprinting,biological scaffold,bone repair"in Chinese and English.Relevant documents published from January 1,2009 to December 1,2022 were retrieved on CNKI,PubMed and Web of Science databases.After being screened by the first author,high-quality references were added.A total of 93 articles were included for review. RESULTS AND CONCLUSION:The main treatment methods for bone defects include bone transplantation,membrane-guided regeneration,gene therapy,bone tissue engineering,etc.The best treatment method is still uncertain.Bone tissue engineering technology is a new technology for the treatment of bone defects.It has become the focus of current research by constructing three-dimensional structures that can promote the proliferation and differentiation of osteoblasts and enhance the ability of bone formation.Biological scaffold materials are diverse,with their characteristics,advantages and disadvantages.A single biological material cannot meet the demand for tissue-engineered bone for the scaffold.Usually,multiple materials are combined to complement each other,which is to meet the demand for mechanical properties while taking into account the biological properties of the scaffold.Bioprinting technology can adjust the pore of the scaffold,build a complex spatial structure,and is more conducive to cell adhesion,proliferation and differentiation.The emerging 4D printing technology introduces"time"as the fourth dimension to make the prepared scaffold dynamic.With the synchronous development of smart materials,4D printing technology provides the possibility of efficient repair of bone defects in the future.

Application and prospect of tissue engineering in treatment of osteonecrosis of the femoral head / 中国组织工程研究

BACKGROUND:Osteonecrosis of the femoral head is a common orthopedic disease,and hip preservation surgery with bone grafting is commonly used in the early stage,in which autologous bone and allograft bone are commonly used as bone grafting materials.However,autologous bone transplantation is highly traumatic and bone supply is limited,and allograft bone is rich in sources,but there are serious risks of immune rejection and absorption.In recent years,the tissue engineering technique based on mesenchymal stem cells is a new method for the treatment of femoral head necrosis,which is gradually widely used after basic experiments and clinical application. OBJECTIVE:To review the application and prospect of tissue engineering in the treatment of osteonecrosis of the femoral head to provide a new choice for the clinical treatment of osteonecrosis of the femoral head. METHODS:The PubMed database and CNKI database from 2013 to 2023 were searched by the first author with Chinese and English search terms"tissue engineering,mesenchymal stem cells,biological scaffolds,cytokines,osteonecrosis of the femoral head,bone graft,hip preservation".The articles on the treatment of osteonecrosis of the femoral head with tissue engineering technology were selected,and 55 representative articles were included for review after the initial screening of all articles according to the inclusion and exclusion criteria. RESULTS AND CONCLUSION:(1)With the continuous development of biotechnology and materials science,great progress has been made in the treatment of osteonecrosis of the femoral head by bone tissue engineering,such as the application of gene-modified mesenchymal stem cells to repair osteonecrosis,the combination of gene recombination technology and surface modification technology with bone tissue engineering in the treatment of osteonecrosis of the femoral head.(2)When applied to the necrotic femoral head,tissue engineering technology can promote the regeneration of necrotic bone tissue and the repair of the vascular system,provide biomechanical stability for the necrotic area,and use bioactive factors to accelerate the repair of seed cells to complete the regeneration of new bone in necrotic area.(3)However,most of these studies are still in the animal experiment stage,and there are still many unsolved problems and challenges in bone tissue engineering research.With the rapid development of nanotechnology,tissue engineering and clinical medicine,biomimetic replacement bone grafting materials with perfect performance are expected to come into being.(4)In the future,bone tissue engineering for osteonecrosis of the femoral head is expected to be a satisfactory treatment for patients with hip preservation.

Advantages and features of nanocomposite hydrogel in treatment of osteoarthritis / 中国组织工程研究

BACKGROUND:Nanocomposite hydrogel has great research prospects and application potential in the treatment of osteoarthritis. OBJECTIVE:To review the research progress of nanocomposite hydrogel in osteoarthritis and cartilage repair. METHODS:Databases such as CNKI and PubMed were searched.The English key words were"nanocomposite hydrogel,nanogel,osteoarthritis,cartage,physical encapsulation,electrostatic interaction,covalent crosslinking",and the Chinese key words were"nanocomposite hydrogel,nanogel,osteoarthritis,cartage,physical encapsulation,physical encapsulation,electrostatic effect,covalent cross-linking".After an initial screening of all articles based on inclusion and exclusion criteria,71 articles with high correlation were retained for review. RESULTS AND CONCLUSION:In cell or animal experiments,nanocomposite hydrogel has the effect of improving osteoarthritis.Nanocomposite hydrogel can promote cartilage repair,improve the internal environment of osteoarthritis,and achieve the therapeutic purpose of osteoarthritis by improving the mechanical environment between joints,carrying targeted drugs,and promoting the chondrogenesis of seed cells.At present,the research of nanocomposite hydrogel in osteoarthritis disease still has a huge space to play.It is expected to open up a new way for the clinical treatment of osteoarthritis by continuing to deepen the research of material preparation and actively carrying out cell and animal experiments.

Tissue engineering scaffolds in repairing oral and maxillofacial soft tissue defects / 中国组织工程研究

BACKGROUND: In recent years, more and more scaffold materials have been used to repair soft tissue defects, and the clinical repair effect of soft tissue defects is strongly associated with the source and performance of materials. OBJECTIVE: To summarize the research progress of preparation and application of different biological scaffolds in the field of oral and maxillofacial soft tissue defect repair. METHODS: PubMed and Medline were searched for articles published from 1966 to 2019 with the English key words of “materials, scaffold, biological scaffold, soft tissue, coloboma, tissue engineering, review”. Chinese journal full-text database and Chinese science citation database were retrieved for articles published from 2003 to 2019 with key words of “material, scaffold, biological scaffold, soft tissue, defect, tissue engineering, review”. RESULTS AND CONCLUSION: Natural bio-scaffold materials are directly derived from organisms with pretty biocompatibility. Natural bio-scaffold materials can release cytoactive factors, promote cell adhesion, proliferation and differentiation, and can be combined with synthetic polymer materials with controllable properties to form composite scaffolds, which is an ideal scaffold material for repairing soft tissue defects of oral and maxillofacial regions. Nanomaterials have higher biological activity than other scaffold materials and can promote the adhesion and proliferation of seed cells, providing ideal three-dimensional space for cell growth, but their applications are currently mainly reflected in bone tissue repair, and the applications in soft tissue repair are very few. At present, there are many researches on natural biological scaffold materials in oral and maxillofacial soft tissue repair, mainly including small intestinal submucosa, acellular dermal matrix and acellular vascular scaffolds. The combination of natural biological scaffold materials and synthetic polymer materials will be a major research trend in materials for repairing oral and maxillofacial soft tissue defects.

Evaluation of a canine small intestinal submucosal xenograft and polypropylene mesh as bioscaffolds in an abdominal full-thickness resection model of growing rats

We evaluated the biological scaffold properties of canine small intestinal submucosa (SIS) compared to a those of polypropylene mesh in growing rats with full-thickness abdominal defects. SIS is used to repair musculoskeletal tissue while promoting cell migration and supporting tissue regeneration. Polypropylene mesh is a non-resorbable synthetic material that can endure mechanical tension. Canine SIS was obtained from donor German shepherds, and its porous collagen fiber structure was identified using scanning electron microscopy (SEM). A 2.50-cm2 section of canine SIS (SIS group) or mesh (mesh group) was implanted in Sprague-Dawley rats. At 1, 2, 4, 12, and 24 weeks after surgery, the implants were histopathologically examined and tensile load was tested. One month after surgery, CD68+ macrophage numbers in the SIS group were increased, but the number of CD8+ T cells in this group declined more rapidly than that in rats treated with the mesh. In the SIS group, few adhesions and well-developed autologous abdominal muscle infiltration into the SIS collagen fibers were observed. No significant differences in the tensile load test results were found between the SIS and mesh groups at 24 weeks. Canine SIS may therefore be a suitable replacement for artificial biological scaffolds in small animals.

Constructing a Completely Biological Hybrid Scaffold for Small-Diameter Vascular Tissue Engineering Using Fibrin and Decellularized Artery / 中国康复理论与实践

@#Objective To prepare a completely biological hybrid scaffold for small-diameter vascular tissue engineering using porcine fibrin and decellularized canine carotid artery.MethodsPorcine fibrin was sprayed coating on the external surface of decellularized canine carotid artery to construct completely biological hybrid scaffold for small-diameter vascular tissue engineering. The completely biological hybrid scaffold was evaluated with Hematoxylin and Eosin (H&E) staining, scanning electron microscopy and biomechanics test.ResultsHistology examination revealed that the porcine fibrin was sprayed coating uniformly on the external surface of decellularized canine carotid artery. Scanning electron microscopy examination confirmed that the external surface of completely biological hybrid scaffold was smooth and uniformly. Compared with fresh canine carotid artery and decellularized artery, the biological hybrid scaffold had similar burst and breaking strength. Furthermore, compared with decellularized artery, the biological hybrid scaffold had higher compliance.ConclusionThe porcine fibrin was sprayed coating uniformly on the external surface of decellularized canine carotid artery to prepare a completely biological hybrid scaffold for small-diameter vascular tissue engineering. The biological hybrid scaffold had appropriate biomechanical properties and had potential to serve as scaffolds for small-diameter vascular tissue engineering.

Construction of Completely Biological Tissue-Engineered Small-Diameter Blood Vessel Based on a Biological Hybrid Scaffold / 中国康复理论与实践

@#Objective To prepare completely biological tissue-engineered small-diameter blood vessel based on a biological hybrid scaffold.MethodsEndothelial cells and smooth muscle cells were isolated from the porcine aorta and expanded in vitro. Mixture of smooth muscle cells and porcine fibrin was prayed coating on the decellularized canine carotid artery. Then, the inner surface of the decellularized artery was seeded with the endothelial cells to construction of completely biological tissue-engineered small-diameter blood vessel. The tissue-engineered blood vessel was evaluated with Hematoxylin and Eosin (H&E) staining and scanning electron microscopy.ResultsHistology examination revealed that the completely biological tissue-engineered small-diameter had intact media and intima. Scanning electron microscopy examination confirmed that the inner surface of tissue-engineered blood vessel was covered with intact monolayer endothelial cells and the external surface was covered with multilayer smooth muscle cells.ConclusionThe completely biological tissue-engineered small-diameter with intact media and intima was prepared using mixture of blood vessel cells and porcine fibrin on the decellularized canine carotid artery.