Regulation of collagenolytic activity using platelet preparations <i>in vitro</i>

Purpose: to study different platelet preparations' impact on collagenase activity in vitro. Materials and methods. Human amnion transplants and collagen covers, based on human type 1 collagen, were used as collagen matrices. The drug Fermencol was used as a source of collagen-lytic peptidases. We used platelet-rich plasma (PRP); concentrated suspension of platelets washed from plasma (WP); platelet-poor plasma (PPP); lysates of PRP, PPP and WP. To assess the collagen-lytic activity we studied the level of collagen autofluorescence in tissue grafts, collagen concentration in solution, proliferation intensity of mesenchymal multipotent stromal cells (MMSC) on the surface of the grafts. Results. Preparations based on PRP and WP stimulated significant inhibition of collagen-lytic activity, which was absent in PPP. The inhibition of collagen-lytic effect in PRP and WP depended on the initial content of platelets with granules. Platelet preparations significantly enhanced the adhesion and growth of MMSC on the surface of the amnion and collagen cover. Conclusion. The use of platelet lysates combined high inhibition of collagen-lytic peptidases and growth-stimulating effect, which persists even with dilution of PRP lysate in ratio 1:200. For effective inhibition of collagen-lytic peptidases is recommended to use PRP with initial concentration of platelets with granules at least 350 thousand/ml.