Objective To review new progress of related research of peri pheral nerve defect treatment with tissue engineering in recent years. Methods Domestic and internationl l iterature concerning peri pheral nerve defect treatment with tissue engineering was reviewed and analyzed. Results Releasing neurotrophic factors with sustained release technology included molecular biology techniques, poly (lactic-co-glycol ic acid) microspheres, and polyphosphate microspheres. The mixture of neurotrophic factors and ductus was implanted to the neural tube wall which could be degraded then releasing factors slowly. Seed cells which were the major source of active ingredients played an important role in the repair and reconstruction of tissue engineering products. The neural tube of Schwann cells made long nerve repair and the quality of nerve regeneration was improved. Nerve scaffold materials included natural and synthetic biodegradable materials. Tube structure usually was adopted for nerve scaffold, which performance would affect the nerve repair effects directly. Conclusion With the further research of tissue engineering, the treatment of peripheral nerve defects with tissue engineering has made significant progress.
Objective To introduce the cells and cell-transplantation methods for periodontal tissue engineering. Methods Recent l iterature about appl ication of cell-based therapy in periodontal tissue engineering was extensively reviewed, the cells and cell-transplantation methods were investigated. Results Mesenchymal stem cells were important cell resourcesfor periodontal tissue engineering, among which peridontal l igament stem cells were preferred. Bone marrow mesenchymal stem cells had several disadvantages in cl inical appl ication, and adipose-derived stem cells might be a promising alternative; different transplantation methods could all promote periodontal regeneration to some extent. Single-cell suspension injection could only promote a l ittle gingival regeneration, and tissue engineered scaffolds still needed some improvement to be used in periodontal regeneration, while cell sheet technique, with great cell loading abil ity and no need of scaffolds, could promote regeneration of cementum, periodontal l igament, and alveolar bone under different conditions. Conclusion Multipotent stem cells are fit to be used in periodontal tissue engineering; improvement of cell-transplantation methods will further promote periodontal regeneration.
The engineered heart tissues (EHTs) present a promising alternative to current materials for native myocardial tissue due to the unique characteristics. However, until now, the clinical application of EHTs is limited by a serial of practical problems yet. Generally, the challenges need to further optimize include biomaterials, cell sources, and strategies of revascularization or establishment of EHTs. This review focuses on the newly progress on these aspects to encourage the emergence of novel EHTs that can meet clinic requirement properly.
Objective To observe the biological characters of chondrocytes in articular loose body and to find out seeding cells for cartilage tissue engineering. Methods Samples from 5 loose body cartilages, 2 normal articular cartilages and 6 osteoarthritis articular cartilages were collected. Part of each sample’s cartilage was histologically studied to observe the chondrocytes distribution the morphologic changes by toluidine-blue staining, chondrocytes’ apoptosis by terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL). The rest of each cartilage was digested and isolated by 0.25% trypsin and 0.2% collagenase Ⅱ, and then were cultivated in 10%DMEM. Their morphologic changes were observed 24h later.Comparison was made btween three cartilages. Results Compared with normal cartilage and osteoarthritis articular cartilage, the cells density was higher, their lacunars were larger, cells distribution was irregular, and apoptosis was more apparent in loose body cartilage. Conclusion The characters of chondrocytes from loose body is more like fibroblasts so they can not serve as seeding cells directly for cartilage tissue engineering.
ObjectiveTo explore the morphological and functional features of tissue engineered composite constructed with bone mesenchymal stem cells (BMSCs) as seeding cells, thermosensitive collagen hydrogel (TCH) and poly-L-lactic acid (PLLA) as the extracellular matrix (ECM) scaffolds in the dynamic culture system. MethodsBMSCs were separated from long bones of Fischer344 rat, and cultured; and BMSCs at the 3rd generation were seeded on the ECM scaffold constructed with braided PLLA fiber and TCH. The BMSCs-ECM scaffold composite was cultured in the dynamic culture system which was designed by using an oscillating device at a frequency of 0.5 Hz and at swing angle of 70° (experimental group), and in the static culture system (control group) for 7 days. The general observation and scanning electron microscopy (SEM) observation were performed; total DNA content was measured at 0, 1, 3, and 7 days. ResultsPLLA was surrounded by collagen to form translucent gelatiniform in 2 groups; and compact membrane developed on the surface of PLLA. SEM observation showed that BMSCs had high viability and were fusiform in shape with microvilli on the surface of cells, and arranged in line; collagen and cells filled in the pores of PLLA fiber in the experimental group. The cells displayed a flat shape on the surface; there were less cells filling in the pores of PLLA fiber in the control group. At 1, 3, and 7 days, total DNA content in the experimental group was significantly higher than that in control group (P < 0.05). The total DNA content were increased gradually with time in 2 groups, showing significant difference between at 0 day and at 7 days (P < 0.05). ConclusionThe ECM constructed with TCH and PLLA has good biocompatibility. The dynamic cultivation system can promote the cell proliferation, distribution, and alignment on the surface of the composite, so it can be used for tissue engineered composite in vitro.
Osteochondral defects is a common clinical joint disease. The complexity of cartilage-bone interface and the poor self-repair capacity of cartilage are both reasons for current relatively limited clinical treatments. The introduction of tissue engineering provides a new treatment method for osteochondral repair. This paper reviews three main elements of cartilage-bone tissue engineering: seed cell source and culture method, cytokines regulation and synergistic effect, and scaffold components and type. We mainly focused on current status quo and future progress of cartilage-bone repair scaffolds. This paper provides some reference for the further development of osteochondral tissue engineering.
Objective To sum up the research advances of the seed cell and the culture system using in tissue engineering cartilage. Methods The recent original articles about the seed cell and the culture system in tissue engineering cartilage were extensively reviewed. Results At present, autologous or homologous cells is still major seed cell and the three dimensional culture system is also major system for tissue engineering cartilage. Conclusion The source of seed cell for tissue engineering cartilage. Conclusion The source of seed cell for tissue engineering cartilage should be further explored, and the culture system need to be improved and developed.
Objective To establ ish an efficient and stable culture method of human umbil ical vein endothel ial cells (HUVECs) in vitro so as to provide good source of seed cells for tissue engineered vascular grafts and for precl inical research. Methods The umbil ical cords were harvested from full-term normal delivered neonates, which were perfused with0.1% collagenase II by self-made needle and were digested at 37 and 5% CO2 humidified incubator. The HUVECs were cultured in endothel ial culture medium (ECM) containing 5% fetal bovine serum (FBS) and 1% endothel ial cell growth factor (ECGS). HE staining of the umbil ical cords before and after digestion was used to observe the detachment of HUVECs, flow cytometry to detect the purity of primary HUVECs, and inverted phase contrast microscope to observe the morphology of the cultured HUVECs. The growth of the 3rd passage cells was measured by MTT assay; immunocytochemical technique and matrigelbased capillary-l ike tube formation assay were carried out to identify the function of HUVECs. Results After digestion of 0.1% collagenase II, marked HUVECs detachment was observed with complete digestion. The purity of the HUVECs was 99.56% by digestion of 0.1% collagenase II at 37 and 5% CO2 humidified incubator for 15 minutes. Primary HUVECs showed a cobblestone or pitching stone-l ike appearance in vitro, forming a confluent monolayer cells after 2-3 days of culture. MTT assay demonstrated that HUVECs showed the fastest growth speed at 3 to 4 days, and showed growth of cell fusion at about 5 days. Immunocytochemistry showed that HUVECs highly expressed endothel ial marker factor VIII. Matrigel based capillary-l ike tube formation assay showed that it could form endothel ial-l ike tube structures after 24 hours of culture. Conclusion Using improved method and ECM could obtain high quantity and high qual ity primary HUVECs, which might be a kind of promising seed cells for tissue engineering and precl inical research.