| Articular cartilage injury is very common, which can be caused by various factors such as trauma, osteoarthritis et al. It was generally thought that there was no effective clinical treatment to restore a damaged cartilage and prevent the normal sequelae of degenerative joint disease. However, from 70s, people found gradually that various homones and growth factors could influence the biobehavior of chondrocytes , such as insulin - like growth factor ( IGF) , transforming growth factor (TGF) , basic fibroblast growth factor (bFGF) , platelet derived growth factor ( PDGF) , interleukin ( IL ) and tumor necrosis factor(TNF) , et al. Among these growth factors, the effects of bFGF were most extensive. It can not only accelerate the mitosis of cells coming from mesoblast and neural ectoblast, but also advance the mitosis of cells coming from the other ectoblasts and endoblast. But it was not reported that if bFGF influence the chondrocytes in tissue engineering. In this study we cultured the rabbit chondrocyte - PLA complexes in vitro with bFGF to understand how the bFGF modulates articular chondrocytes in tissue engineering to explore a suitable method for repairing articular defect.Materials and methods1. Establishing the cell suspensionThe rabbit articular chondrocytes were isolated enzymatically from cartilage chips scraped from the tibial plateaus and femoral condyles of 4 - week - old New Zealand White rabbits. The chondrocytes were released by continuous digestion 4 hours at 371 homoiothermy agitation with 2mg/ml collagenase II and cultured in DMEM culture medium with 15% FBS. 3 days later the culture medium was exchanged first time,and then exchanged every two days. When the chondrocytes was nearly 90% fusion, we transfer the chondrocytes at 1 to 2. The third passage of chondrocytes was collected and concentrated to the cell suspension at 1.5 104/ul and reserved for seeding.2. Embedding the scaffoldsThe poly - aparture PLA scaffolds were embedded by 1 % lecithin and 10% poly - 1 - lysine, and then were sterilized by 75% alcohol and ultraviolet rays. The sterile scaffolds were tailored as round texture with 4.5mm diameter and were weighed by electronic balance.3. Seeding chondrocytes and culturing the complexesPLA scaffolds embedded with PLYS and LEG were random divided into the test group(T) and control group( C). Each group 20 examples. The cell suspention wad even added into the scaffolds and then put at 37℃ ,5%CO2 culture box for 4 hours followed with moving to the 96 pore plate. Adding culture medium 200ulto each example, culturing for 48 hours and then moving the examples to 24 pore plates culturing at the same situation. BFGF was added to T group, but C group did not. The other culturing situations were same.4. Observing index(1) Macroscope and invert microscope ( 2 ) Histological light microscope ( 3 ) Scanning electron microscope ( 4) Immunohistochemistry (5) Weight of chondrocyte-scaffold complexes ( 6 ) Statistics analysisResultAfter culturing one week, there were collagen matrices generating like spider in the T group followed by decreasing transmittance. Two week later, we can see cell structure at the edge of complexes and dar-ity matrice lacuna formation. At the same time, the complexes were gradually decreasing the consistency, however,increasing the ductility with elasticity and lubrication surface. HE staining indicated that the cells were round and rich plasm with collagen bubbles.With scanning electron microscope, many grooves were found on the PLA scaffold. Two weeks later,the round chondrocytes were seen in these grooves or at the surface. The two groups differed in the density of chondrocytes and secretions. Chondrocytes and the scaffolds bonded as a whole.When culturing the complexes for two weeks, the collagen n im-munohistochemistry was proceed. The results indicated that T groups were stained obviously powerlier than C groups. Moreover,the staining increased progressively.Culturing four weeks later, each example in the two groups w...
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