Objective To review the research progress of the current methods of inducing bone marrow mesenchymal stem cells (BMSCs) to chondrogenic differentiation in vitro so as to provide references for researches in cartilage tissue engineering. Methods Various methods of inducing BMSCs differentiation into the chondrogenic l ineage in vitro inrecent years were extensively reviewed and analyzed. Results Adding exogenous growth factors is still the mainly methodof inducing BMSCs differentiation into the chondrogenic l ineage; among the members, transforming growth factor β (TGF-β) family is recognized as the most important chondrogenic induction factor. Other important inducing factors include various chemical factors, physical factors, transgenic methods, and the microenvironmental induction. But the problems of low inducing efficiency and unstable inducing effects still exist. Conclusion The progress of chondrogenic induction of BMSCs promotes its util ization in cartilage tissue engineering. Further researches are needed for establ ishing more efficient, simpler, and safer inducing methods.
The rectus femoris muscles of rabbits were used as muscle model. The electrical stimulation which resembled the normal motor-unit activity was used to observe its effects on free transferred muscle. After three months, the moist muscle weight (MW), its maximum cross-section area, its contractility and its histochemical characteristics were examined. The results showed that the function and morphology of the muscles were well preserved. These findings might encourage its clinical application.
The repair of defects of articular cartilage has continued to be a difficult problem. This article provided a collective review from literature pertaining to the advances gained in the repair of cartilaginous defects. In the spontaneous repair, if the defect of the cartilage was less than 3 mm, might result in complete or partial repair, but in those the diameter was more than 3 mm, the defect could not be repaired by normal cartilage. Although the cartilaginous autograft could give good result, but it could not be widely applied because short of supply of the autogenous cartilage. Cartilagious allograft could not be taken to repair cartilaginous defect because of reaction from tissue rejection. The transplantation of periosteal or perichondral graft had been tried but was eventually abandoned because of poor long-term result. The transplantation of free chondrocytes might be a method of hope. In general, transplantation of free chondrocytes into the cartilaginous defect will be lost. The supply of autogenous chondrocytes was very limited, and the heterogenous chondrocytes would inflict immunoreaction after being transplanted. In late of 1980, a new concept of tissue engineering was proposed. The problem that a scaffold of appropriate material which could hold the free chondrocytes in place from being lost might undergo proliferation and differentiation into new cartilage was far from being solved. Although tissue engineering still had various problems needed further investigation, but it will probably be the main direction of development in this field.
Objective To review the application and research progress of transcutaneous oxygen pressure (TcPO2) in scar assessment. Methods The original articles about scar and TcPO2 were reviewed and analyzed. Results Hypoxia environment plays an important role in the progression of scar tissue. TcPO2 can accurately reflect the oxygen tension of scar tissue, which is of great significance in the assessment of scar maturity, the guidance of scar treatment, and the study of correlations between hypoxia and the progression of scar. Conclusion TcPO2 measurement is important in the study of scar evaluation, treatment, and correlation between hypoxia and scar formation.
To study the feasibil ity of human adipose derived stem cells (ADSCs) in monolayer culture induced into smooth muscle cells in vitro as seeding cells in vascular tissue engineering. Methods The mononuclear cells in human adipose were separated by collagenase treatment and seeded on culture dishes with the density of 5 × 105/cm2. Cellswere cultured in M-199 plus 10% FBS. When reaching confluence, the cells were subcultured by 0.1% trypsin and 0.02%EDTA treatment, PDGF-BB (50 ng/mL) and TGF-β1 (5 ng/mL) were added at the passage 1 to enhance the smooth muscle cells’ phenotype. Cells were cultured under the inducing medium for 14 days. The morphology of induced cells was observed under the microscope. Cellular immunofluorescence and RT-PCR were used to determine the expression of smooth muscle cell markers of the post-induced cells. Flow cytometry (FACs) was used to examine the positive rate of induced team. Results Cocultured in M-199 media including TGF-β1 and PDGF-BB, the prol iferating capabil ity of the induced cells was significantly downregulated compared with the uninduced cells(P lt; 0.01). The induced cells exhibited “Hill and Valley” morphology, while the uninduced cells were similar to ADSCs of P0 which had the fibroblast-l ike morphology. The results of immunofluorescence indicated that the induced cells expressed smooth muscle (SM) cell- specific markers including α-smooth muscle actin (α-SMA), SM-myosin heavy chain (SM-MHC) and Calponin. The results of RT-PCR revealed that the induced cells also expressed α-SMA, SM-MHC, Calponin and SM-22α.The positive rates of α-SMA, SM-MHC and Calponin in FACs were 3.26% ± 1.31%, 3.55% ± 1.6% and 4.02% ± 1.81%, respectively, before the cells were induced. However, 14 days after the cell induction, the positive rates were 48.13% ± 8.31%, 45.33% ± 10.68% and 39.13% ± 9.42%, respectively. The positive rates in induced cells were remarkably higher than those in uninduced cells(P lt; 0.01). Conclusion The human ADSCs can be induced to express vascular smooth muscle markers, and they are a new potential source of vascular tissue engineering.