In vitro regenerative effects of a pooled pathogen-reduced lyophilized human cord blood platelet lysate for wound healing applications

Background - Cord blood platelets, easily obtained from blood units not suitable for hematopoietic stem cell transplantation, represent an abundant source of growth factors for use in wound healing. Although several protocols have been described for platelet lysate production, no standard manufacturing protocol is available. The use of pooled cord blood platelets could thus facilitate standardization. In this study, the effect of varying concentrations (up to 20%) of a pooled pathogen-reduced lyophilized cord blood platelet lysate (PRL-CBPL) was investigated in different cell types involved in the wound healing process. The effect of heparin addition was also evaluated. In parallel, a comparison was performed with a single donor cord blood platelet lysate (SD-CBPL). Materials and methods - The effect of PRL-CBPL on the viability and proliferation of different cell lines (L929 mouse fibroblasts and HaCaT keratinocytes) and human primary cells (fibroblasts-NHDF, coronary artery smooth muscle cells-HCASMC and coronary artery endothelial cells-HCAEC), on HaCaT migration and the chemotactic effect on human monocytes (THP-1) was evaluated. Results - PRL-CBPL showed a lower PDGF-AB amount compared to SD-CBPL. Differing concentrations of both CBPL were necessary to influence cell viability and proliferation. 3% was the optimal concentration for L929 and HaCaT as well as for NHDF and HCASMC, while HCAEC required 10%. The effect of added heparin was more evident on SD-CBPL and in particular on NHDF and HCASMC proliferation. Keratinocyte scratch closure was obtained with 3 and 5% PRL-CBPL and SD-CBPL respectively. Both CBPLs caused an increase in the number of migrated THP-1 monocytes in a concentration-dependent manner up to 20% with a higher monocyte migration for SD-CBPL with respect to PRL-CBPL and in cells treated with heparin. Discussion - The data obtained suggest that PRL-CBPL is an effective standardized alternative to SD-CBPL.