OBJECTIVE To study the biocompatibility on bioactive glass ceramics (BGC) and polylactic acid (PLA) combined with cultured bone marrow stromal cells (BMSCs) in bone tissue engineering. METHODS BMSCs were cultured combined with BGC and PLA in vitro, and the morphological characters, cell proliferation, protein content, and alkaline phosphatase activity were detected. RESULTS: BMSCs could be attached to and extended on both BGC and PLA, and normally grown, proliferated, had active function. BGC could promote cell proliferation. CONCLUSION The results show that both BGC and PLA have good biocompatibility with BMSCs, they can be used as biomaterials for cell transplantation in tissue engineering.
OBJECTIVE: From the point of view of material science, the methods of tissue repair and defect reconstruct were discussed, including mesenchymal stem cells (MSCs), growth factors, gene therapy and tissue engineered tissue. METHODS: The advances in tissue engineering technologies were introduced based on the recent literature. RESULTS: Tissue engineering should solve the design and preparation of molecular scaffold, tissue vascularization and dynamic culture of cell on the scaffolds in vitro. CONCLUSION: Biomaterials play an important role in the tissue engineering. They can be used as the matrices of MSCs, the delivery carrier of growth factor, the culture scaffold of cell in bioreactors and delivery carrier of gene encoding growth factors.
OBJECTIVE: To discuss the approaches of tissue engineered blood vessels (TEBV) reconstruction. METHODS: The recent literatures about TEBV were widely reviewed. We summarized various types of biomaterials served as scaffold for TEBV and evaluated the construction model of TEBV. And the biological properties of some TEBV were compared. RESULTS: Although the final model of construction of TEBV was not clear, reports in the last two years had shown several important advances in this exciting field. CONCLUSION: Mimicry of some or all of the properties of three layers of natural healthy blood vessels has been the strategy of all TEBV approaches.
Compared with traditional orthopedic metal implants, magnesium alloys demonstrate superior mechanical strength and biocompatibility, while also exhibiting biodegradability, bone-inducing properties, and antibacterial activity. However, currently developed medical magnesium alloys suffer from insufficient corrosion resistance, failing to meet clinical requirements. Rare earth elements, which can effectively enhance critical properties like corrosion resistance in magnesium alloys, have become the core additive elements for developing new medical magnesium alloys. Consequently, the design, preparation, and clinical translation of rare earth magnesium alloys have garnered significant attention in recent years. This study aims to briefly explore the feasibility, challenges, and future prospects of biodegradable rare earth magnesium alloys as orthopedic internal fixation implants.
Objective To introduce the development of dextran-based hydrogel and its drug delivery system in drug sustained and/or controlled release, and to investigate their application in tissue engineering.Methods Related literature was extensively reviewed and comprehensively analyzed. Results In recent years, great progress was made in the studies of dextran-based hydrogels and study on dextran-based intelligent materials became an investigative hotspot especially in tissue engineering. Conclusion Dextran based hydrogel is considered to be a good potential material in field of drug delivery and tissue engineering. Endowed with new characteristics, a series of intelligent biomaterials can be derived from dextran-based hydrogels, which can be widely used in biomedicine. Further study should be done on the industrialization of its interrelated production.
Objective To investigate the currently-used biomaterials in reparative and reconstructive surgery and to clarify the relationship between the development of biomaterials and the progress of reparative and reconstructive surgery. Methods Based on the author’s many years’ scientific researches and combined with the literature available at home and abroad, the biomaterials used in the clinical practice, and their kinds and application fields were summarized. Results Based on the sufficient knowledge of the component structure of biomaterials and the patient’s pathological status, the matching biomaterials could be designed and developed. According to the analysis on some common defects occurring in the skin, bone, cartilage, vocalcord, nerve, and drum membrane, the methods of repairing the defects with biomaterials that we had developed, such as collagen, chitosan, and hyaluronate, achieved good results. Conclusion The rapid development of biomaterials can greatly promote progress of reparative and reconstructive surgery andthere exists a dependence relationship between the two. The related histological responses and the importance of biological estimation after implantation of biomaterials should be emphasized.
Objective To investigate bone regeneration of the cell-biomaterial complex using strategies of tissue engineering based on cells.Methods Hydroxyapatite/collagen (HAC) sandwich composite was produced to mimic the natural extracellular matrix of bone, with type Ⅰ collagen servingas a template for apatite formation. A three-dimensional ploy-porous scaffoldwas developed by mixing HAC with poly(L-lactic acid) (PLA) using a thermally induced phase separation technique (TIPS). The rabbit periosteal cells were treated with 500 ng/ml of recombinant human bone morphogenetic protein 2(rhBMP-2), followed by seeded into pre-wet HAC-PLA scaffolds. Eighteen 3-month nude mice were implanted subcutaneously cell suspension (groupA, n=6), simple HAC-PLA scaffold (group B, n=6) and cell-biomaterial complex(group C, n=6) respectively.Results Using type Icollagen to template mineralization of calcium and phosphate in solution, we get HAC sandwich composite, mimicking the natural bone both in compositionand microstructure. The three dimensional HAC-PLA scaffold synthesized by TIPShad high porosity up to 90%, with pore size ranging from 50 μm to 300 μm. SEMexamination proved that the scaffold supported the adhesion and proliferation of the periosteal cells. Histology results showed new bone formation 8 weeks after implantation in group C. The surface of group A was smooth without neoplasma. Fibrous tissueinvasion occured in group B and no bone and cartilage formations were observed.Conclusion The constructed tissue engineering bone has emerged as another promising alternative for bone repair.
Objective To introduce the development of the collagen materials in drug release and tissue engineering. Methods Literature review and complex analysis were adopted. Results In recent years, some good progress hasbeen made in the studies of collagen, and study on collagen-based materials has become an investigative hotspot especially in tissue engineering. Some new collagen-based drug delivery andengineered materials have come into clinically-demonstrated moment, which willpromote their clinical applications in tissue repairs.ConclusionCollagen has been considered a good potential material in drug release, especially in the tissue-engineering field. To give collagen new characters we should pay more attention to grafting with different function branches through chemistry technique in the future work, except- moderate cross-linking treatment or commingling withother nature or synthesized macromolecules.
Objective To investigate cell cycle as a new tool to evaluate the biocompatibility of biomaterials.Methods The cell cycle and the expression of related genes were analyzed by the methods of immunocytochemistry, protein blotting, RT PCR and flow cytometry. Results The physical properteis, chemical properties and topological properities of biomaterials could not only influence cell cycle of the cells attached onto biomaterials but also affect the expression of related genes of target cells. Conclusion As an important extension of routine proliferation epxeriments, the study of cell cycle control will be great help for us to to study the cell group as an organic society. It revealed the balance between cell proliferation, cell differentiation and apotosis. It is suggested that the study of cell cycle control will play a key role in the research of tissue engineering.
For the damage and loss of tissues and organs caused by urinary system diseases, the current clinical treatment methods have limitations. Tissue engineering provides a therapeutic method that can replace or regenerate damaged tissues and organs through the research of cells, biological scaffolds and biologically related molecules. As an emerging manufacturing technology, three-dimensional (3D) bioprinting technology can accurately control the biological materials carrying cells, which further promotes the development of tissue engineering. This article reviews the research progress and application of 3D bioprinting technology in tissue engineering of kidney, ureter, bladder, and urethra. Finally, the main current challenges and future prospects are discussed.