To summarize the medium-term cl inical result of bio-derived bone transplantation in orthopedics with tissue engineering technique. Methods From December 2000 to June 2001, 10 cases of various types of bone defect were treated with tissue engineered bone, which was constructed in vitro by allogenous osteoblasts from periosteum (1 × 106/ mL) with bio-derived bone scaffold following 3 to 7 days co-culture. Six men and 4 women were involved in this study, aged from 14 to 70 years with a median of 42 years. Among them, there were 2 cases of bone cyst, 1 case of non-union of old fracture, 6 cases of fresh comminuted fracture with bone defect, and 1 case of chronic suppurative ostemyel itis. The total weight of tissue engineered bone was 3-15 g in all the cases, averaged 7.3 g in each case. Results The wound in all the case healed by first intention. For 7 year follow up, bone union was completed within 3.0 to 4.5 months in 9 cases, but loosening occurred and the graft was taken out 1 year after operation in 1 case. The X-ray films showed that 9 cases achieved union except one who received resection of the head of humerus. No obvious abnormities were observed, and the function of affected l imbs met daily l ife and work. Conclusion Bio-derived tissue engineered bone has good osteogenesis. No obvious rejection and other compl ications are observed in the cl inical appl ication.
ObjectiveTo analyze the progress in biological tissue engineering scaffold materials and the clinical application, as well as product development status. MethodsBased on extensive investigation in the status of research and application of biological tissue engineering scaffold materials, a comprehensive analysis was made. Meanwhile, a detailed analysis of research and product development was presented. ResultsConsiderable progress has been achieved in research, products transformation, clinical application, and supervision of biological scaffold for tissue engineering. New directions, new technology, and new products are constantly emerging. With the continuous progress of science and technology and continuous improvement of life sciences theory, the new direction and new focus still need to be continuously adjusted in order to meet the clinical needs. ConclusionFrom the aspect of industrial transformation feasibility, acellular scaffolds and extracellular matrix are the most promising new growth of both research and product development in this field.
Objective To summarize and analyze the research progress of scaffold materials used in tissue engineered meniscus. Methods The classification and bionics design of scaffold materials were summarized by consulting domestic and foreign literature related to the research of tissue engineered meniscus in recent years. Results Tissue engineered meniscus scaffolds can be roughly classified into synthetic polymers, hydrogels, extracellular matrix components, and tissue derived materials. These different materials have different characteristics, so the use of a single material has its unique disadvantages, and the use of a variety of materials composite scaffolds can learn from each other, which is a hot research area at present. In addition to material selection, material processing methods are also the focus of research. At the same time, according to the morphological structure and mechanical characteristics of the meniscus, the bionic design of tissue engineered meniscus scaffolds has great potential. Conclusion At present, there are many kinds of scaffold materials for tissue engineered meniscus. However, there is no material that can completely simulate the natural meniscus, and further research of scaffold materials is still needed.
In sports system, the tendon-bone interface has the effect of tensile and bearing load, so the effect of healing plays a crucial role in restoring joint function. The process of repair is the formation of scar tissue, so it is difficult to achieve the ideal effect for morphology and biomechanical strength. The tissue engineering method can promote the tendon-bone interface healing from the seed cells, growth factors, and scaffolds, and is a new direction in the field of development of the tendon-bone interface healing.
Objective To review the current status and problems in the developing scaffolds for the myocardial tissue engineering appl ication. Methods The l iterature concerning the myocardial tissue engineering scaffold in recent years was reviewed extensively and summarized. Results As one of three elements for tissue engineering, a proper scafold is veryimportant for the prol iferation and differentiation of the seeding cells. The naturally derived and synthetic extracellular matrix (ECM) materials aim to closely resemble the in vivo microenvironment by acting as an active component of the developing tissue construct in myocardial tissue engineering. With the advent and continuous refinement of cell removal techniques, a new class of native ECM has emerged with some striking advantages. Conclusion Through using the principle of composite scaffold, computers and other high-technology nano-polymer technology, surface modification of traditional biological materials in myocardial tissue engineering are expected to provide ideal myocardial scaffolds.
Objective To investigate the biocompatibility of type I collagen scaffold with rat bone marrow mesenchymal stem cell (BMSCs) and its role on proliferation and differentiation of BMSCs so as to explore the feasibility of collagen scaffold as neural tissue engineering scaffold. Methods Type I collagen was used fabricate collagen scaffold. BMSCs were isolated by density gradient centrifugation. The 5th passage cells were used to prepare the collagen scaffold-BMSCs complex. The morphology of collagen scaffold and BMSCs was observed by scanning electron microscope (SEM) and HE staining. The cell proliferation was measured by MTT assay at 1, 3, 5, and 7 days after culturein vitro. After cultured on collagen scaffold for 24 hours, the growth and adhesion of green fluorescent protein positive (GFP+) BMSCs were observed by confocal microscopy and live cell imaging. Results The confocal microscopy and live cell imaging results showed that GFP+ BMSCs uniformly distributed in the collagen scaffold; cells were fusiform shaped, and cell process or junctions between the cells formed in some cells, indicating good cell growth in the collagen scaffold. Collagen scoffold had porous fiber structure under SEM; BMSCs could adhered to the scaffold, with good cell morphology. The absorbance (A) value of BMSCs on collagen scaffold at 5 and 7 days after culture was significantly higher than that of purely-cultured BMSCs (t=4.472,P=0.011;t=4.819,P=0.009). HE staining showed that collagen scaffold presented a homogeneous, light-pink filament like structure under light microscope. BMSCs on the collagen scaffold distributed uniformly at 24 hours; cell displayed various forms, and some cells extended multiple processes at 7 days, showing neuron-like cell morphology. Conclusion Gelatinous collagen scaffold is easy to prepare and has superior biocompatibility. It is a promising scaffold for neural tissue engineering.
Objective To review the recent advances in the application of graphene oxide (GO) for bone tissue engineering. Methods The latest literature at home and abroad on the GO used in the bone regeneration and repair was reviewed, including general properties of GO, degradation performance, biocompatibility, and application in bone tissue engineering. Results GO has an abundance of oxygen-containing functionalities, high surface area, and good biocompatibility. In addition, it can promote stem cell adhesion, proliferation, and differentiation. Moreover, GO has many advantages in the construction of new composite scaffolds and improvement of the performance of traditional scaffolds. Conclusion GO has been a hot topic in the field of bone tissue engineering due to its excellent physical and chemical properties. And many problems still need to be solved.
The establishing of myocardial tissue engineering techniques not only solve a series of issues that generate in cell and tissue transplantation after myocardial infarction, but also create a platform for selecting better materials and transplantation techniques. However, both experimental animal studies and recent clinical trials indicate that current transplantation techniques still have many defects, mainly including lack of suitable seed cells, low survival rate and low differentiation rate after transplantation. In this context, extracellular matrix （ECM）, as myocardial tissue engineering scaffold materials, has gained increasing attention and become a frontier and focus of medical research in recent years. ECM is no longer merely regarded as a scaffold or a tissue, but plays an important role in providing essential signals to influence major intracellular pathways such as cell proliferation, differentiation and metabolism. The involved models of ECM can be classified into following types：natural biological scaffold materials, synthetic polymer scaffold materials and composite scaffold materials with more balanced physical and biological properties. This review mainly introduces research progress of ECM in myocardial tissue engineering and ECM materials.
Objective To construct polyhydroxyalkanoate (PHA) microspheres loaded with bone morphogenetic protein 2 (BMP-2) and human β-defensin 3 (HBD3), and evaluate the antibacterial activity of microspheres and the effect of promoting osteogenic differentiation, aiming to provide a new option of material for bone tissue engineering. Methods The soybean lecithin (SL)-BMP-2 and SL-HBD3 were prepared by SL-mediated introduction of growth factors into polyesters technology, and the functional microsphere (f-PMS) containing BMP-2 and HBD3 were prepared by microfluidic technology, while pure microsphere (p-PMS) was prepared by the same method as the control. The morphology of microspheres was observed by scanning electron microscopy and the water absorption was detected; the release curves of BMP-2 and HBD3 in f-PMS were detected by ELISA kit. The antibacterial effect of microspheres in Staphylococcus aureus and Escherichia coli was tested with the LIVE/DEADTM BacLightTM bacterial staining kit; the biocompatibility of microspheres was tested using Transwell and cell counting kit 8 (CCK-8). The effect of microspheres on osteogenic differentiation was determined by collagen type Ⅰ (COL-1) immunofluorescence staining and alkaline phosphatase (ALP) concentration. Results In this experiment, the f-PMS and p-PMS were successfully constructed. Morphological characteristics showed that p-PMS surface was rough and distributed with micropores of 1-3 μm, while f-PMS surface was smooth and existed white granular material. There was no significant difference in water absorption between the two groups (P>0.05). The release curves of BMP-2 and HBD3 in the f-PMS and p-PMS were basically the same, showing both early sudden release and late slow release. The antibacterial activity of f-PMS was significantly higher than that of p-PMS in the test that against Staphylococcus aureus and Escherichia coli (P<0.05), but there was no significant difference in biocompatibility between the two groups (P>0.05). The results of osteogenic differentiation of human BMSCs showed that the fluorescence intensity of osteogenic specific protein COL-1 of f-PMS was significantly higher than that in p-PMS, and the activity of ALP in f-PMS was also significantly higher than that in p-PMS (P<0.05). Conclusion The p-PHA have good antibacterial activity and biocompatibility, and can effectively promote the osteogenic differentiation of human BMSCs, which is expected to be applied to bone tissue engineering in the future.
Objective To review the research progress of graphene and its derivatives in repair of peripheral nerve defect. Methods The related literature of graphene and its derivatives in repair of peripheral nerve defect in recent years was extensively reviewed. Results It is confirmed by in vitro and in vivo experiments that graphene and its derivatives can promote cell adhesion, proliferation, differentiation and neurite growth effectively. They have good electrical conductivity, excellent mechanical properties, larger specific surface area, and other advantages when compared with traditional materials. The three-dimensional scaffold can improve the effect of nerve repair. Conclusion The metabolic pathways and long-term reaction of graphene and its derivatives in the body are unclear. How to regulate their biodegradation and explain the electric coupling reaction mechanism between cells and materials also need to be further explored.