Surface modification of polycaprolactone membrane via aminolysis and protein-immobilization for promoting bone cell growth

Abstract

In order to make polycaprolactone (PCL) more preferable for tissue engineering, the study aims to improve the cytocompatibility, hydrophilicity as well as cellular responsibility of PCL membrane by surface modification. PCL films were firstly aminolyzed by reacting with 1,6-hexamethylene diamine (HMD) and followed by immobilizing with crude bone protein (CBP) and bovine serum albumin (BSA) by using N’N disuccinimidyl (DSC) as a coupling agent. Several techniques; UV-VIS Spectroscopy, water contact angle ATR-FTIR, and XPS, were used to confirm the existence of functional group on the surface of PCL after modification occurred. The potential use of the modified materials as bone tissue engineering was evaluated by mouse-calvaria derived pre-osteoblastic cells (MC3T3-E1). In vitro indirect cytotoxicity evaluation performed revealed that both the neat and the modified PCL film mats released no substances at levels that were harmful to these cells. Scanning electron microscopy observation showed an evidence of the extension of cell cytoplasm on protein-immobilized PCL films surface even at 6 h after cell seeding. The culture MC3T3-E1 proved that the cell proliferation was improved remarkably on the protein-immobilization, especially the BSA-immobilized PCL film mats which showed the greatest proliferation after cell culture as well as the highest ALP activity. In mineralization, the deposition of minerals was highest on the BSA-immobilized PCL film. All the obtained results suggested that the improvements of bone cell growth can be achieved by immobilization of CBP and BSA on the surface of PCL, which is an attractive method for bone tissue engineering.