A phosphorylcholine-modified chitosan polymer as an endothelial progenitor cell supporting matrix

The aim of the present study was to develop a new biopolymer to increase endothelial progenitor cells (EPC) survival and amplification. As a cell culture platform, bone marrow-derived cells (BMDC) were used to investigate the biocompatibility of chitosan–phosphorylcholine (CH–PC). On CH–PC, BMDC were found in colonies with a mortality rate similar to that of fibronectin (FN), the control matrix. Adhesion/proliferation assays demonstrated a greater number of BMDC on CH–PC after 7 days with an amplification phase occurring during the second week. Difference in adhesion mechanisms between (CH–PC) and the control FN matrix suggest distinctive cell retention ability. Confocal microscopy analyses confirmed that (CH–PC) supported the survival/differentiation of endothelial cells. Moreover, flow cytometry analyses demonstrated that, (CH–PC) increased the percentage of progenitor cells (CD117+CD34+) (7.1 ± 0.8%, FN: 4.1 ± 0.8%) and EPC (CD117+CD34+VEGFR-2+CD31+) (2.33 ± 0.6%, FN: 0.25 ± 0.1%), while the mesenchymal stem cell fraction (CD44+CD106+CD90+) was decreased (0.07 ± 0.01%, FN: 0.55 ± 0.22%). Polymeric substrate CH–PC might provide a suitable surface to promote the amplification of EPC for future vascular therapeutic applications.