Effects Of IGF-Ⅰ And TGF-β1 On Extracellular Matrix Synthesis Of Self-assembled Constructs Of Goat Temporalmandibular Joint Disc Cells

Objective:The purpose was to examine the effects of high and low concentrations of growth factors (GF) IGF-Ⅰand TGF-β1 respectively on the extracelluar matrix synthesis of the self-assembled constructs of temporomandibular joint (TMJ) disc.Methods:1. Using digestiong method.That is,using 0.2%Ⅰcollagenase to digest articular disc tissue overnight,then the separated cells were collected and seeded onto the cultural bottle. Cells' shape were observed by inverted phase contrast microscope and passaged to passage 2 when they adhered to 85-90% of the bottom of bottle.2.We mixed the passage 1-2 cells and primary cells together,and seeded them in the argrose mould that prefabricated.After 4 hours of the cells self-assembling in the argrose well,the experimental groups of self-assembled constructs were exposed to IGF-Ⅰ(lOng/ml,100ng/ml) and TGF-β1(5ng/ml,50ng/ml), the control groups were not added any growth factors. All groups were examined at 3 and 6 weeks for gross morphological, histological, and biochemical changes. Safranin-O/fast green staining was examined for GAG distribution, picrosirius red and immunohistochemical staining were observed for type I collagen distribution. Type I collagen contents were tested by ELISA assay kit, GAG contents were measured by Blyscan GAG assay kit, and the cell numbers were quantified with a Picogreen reagent kit.Results:The growth factor groups all upregulated the matrix synthesis of the self-assembled constructs compared with control groups. TGF-β1 (5ng/ml) and IGF-Ⅰ(10ng/ml) were the two most potent concentration in increasing type I collagen and GAG synthesis and cells proliferation. IGF-Ⅰ(10ng/ ml) produced about 3 times type I collagen than the control group. Expressions of the matrix contents of control group and all GF groups at 6 weeks were more than that of 3 weeks.Conclusion:IGF-Ⅰ(lOng/ml) is the most beneficial growth factor and can be applied in tissue-engineering stratigies of the temporomandibular joint disc. At the same time, exposure time of GFs is another key factor that affects matrix synthesis of TMJ disc constructs.