Effects Of Compessive Force On Espression Of COL-Ⅰ And MMP-1 Of Human Gingival Fibroblast Cells Cultured In PLGA Scaffold

Objective: ①The purpose of this study is to establish the model of three dimensional culture and mechanical loading of human gingival fibroblast (HGFs) cultured in a PLGA scaffold.②To investigate the effects of compression force on COL-I and MMP-I expression in HGFs, to investigate the mechanism of gingival tissue remodeling under compressive force.Methods: ①rimary culture of HGFs was performed using tissue-explant method. The fourth generation HGFs was identified.②The fourth generation of HGFs were plated on the PLGA scaffold at density of 1×105/ml. Fluorescence and scanning electron microscopy (SEM) observation were done after three days and cell proliferation activity of co-culture of HGFs were detected by CCK-8 assay.③After three days of co-cultured, the PLGA-HGFs complexs were subjected to 0,5,15,25,35g/cm of compression force for 6hrs,the Og/cm group was designated the control group. The CCK-8 assay was used to assess the changes in cell proliferative activity after application of compression force. ④ After three days of co-cultured, the PLGA-HGFs complexs were subjected to the optimal force that exertd above for 6,24,48,72h respectively, the same cultivation time with the compression of Og/cm2 group was designated the control group. The expression levels of COL-I, MMP-1 mRNA and protein were detected by RT-qPCR and ELIS A methods respectively.Results:①After10-14d primary culturing, fibroblast-like cells emigrated from the tissue block edge, and they were confirmed the mesenchymal origin. ②In Fluorescence microscopy results, there were a large number of HGFs growth in the PLGA scaffolds, and different resolution of cells were observed in the same vision. It could declare that cells were grown on different planes. According to the results of SEM, HGFs attached with the PLGA scaffold closely, and showed polygon, three dimensional full extension and visible matrix synthesis.③The result of CCK-8 assay showed that the growth of HGFs in the PLGA scaffolds met with the normal Growth Pattern. The OD value was highest at the compression of 25g/cm2 group, and light compression force could not stimulate the cells effectively, but over compression force could inhibition cell proliferation. ④omparing with control group, treatment of PLGA-HGFs complexs with application of compression force 25 g/cm after 6hrs, the mRNA and protein expression of COL-Ⅰ decreased, but then increased with time. But the expression of MMP-1 increased, and then decreased with time.Conclusion: ①PLGA scaffolds could achieve the three-dimensional culture of HGFs. ②We established the model of mechanical loading of HGFs cultured in a PLGA scaffold successfully. Suitable compression force could promote cell proliferation and the optimal compression force of our model was 25 g/cm2.③Compression force could elicit change the composition of ECM by down-regulating the expression of MMP-1 and up-regulating the expression of COL-I in HGFs.