Surface Modification of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Membrane by Combining Surface Aminolysis Treatment with Collagen Immobilization

Abstract

Amino groups were introduced onto a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) surface by applying 1,6-hexanediamine treatment. The effects of aminolysis time and 1,6-hexanediamine concentration on hydrophilicity of the treated PHBV were investigated using contact angle measurement. The occurrence of the aminolysis and the introduction of NH2 groups were verified by X-ray photoelectron spectroscopy (XPS) and ninhydrin method. By use of the NH2 groups as active sites, collagen was further immobilized on the aminolyzed PHBV (NH2-PHBV) membrane via a cross-linking agent, glutaraldehyde. The increase of nitrogen content and further decrease of water contact angle after immobilization of collagen suggested that the surfaces became more hydrophilic. Mouse bone marrow stromal cells (BMSc) cultured on untreated PHBV and treated PHBV films were evaluated by cell attachment, cell proliferation, and morphological observation under scanning electron microscope (SEM). The order of cytocompatibility is Coll-PHBV > NH2-PHBV > PHBV, indicating coll-PHBV was a promising material in future tissue-engineering application.