Improved cell adhesion of poly(amino acid) surface by cyclic phosphonate modification for bone tissue engineering

Abstract

ABSTRACTPoly(amino acid) (PAA) has been currently used as organic part of biocomposites for bone regeneration and reconstruction, but a poor cell adhesive surface becomes its major limitation. In this study, a novel strategy to improve cell adhesion of PAA by introducing a phosphonate (CP) unit into main chain of PAA was proposed. Copolymerizing with CP, the cell adhesion ability of the copolymers was effectively and efficiently improved, corresponding to an adjusted surface wettability. The structure and modification mechanism of copolymers were completely studied based on their surface cell adhesion ability, intrinsic viscosity, compressive strength, X‐ray photoelectron spectroscopy, Fourier transforms infrared spectra, X‐ray diffractometer, and water contact angle analyses. The surface wettability of PAA increased due to the formation of more hydrophilic groups (phosphoramide groups, carboxylic ester groups, and phosphomonoester groups) and stronger hydrogen bonds, which were induced by addition of CP. With a CP content of 1% and 2.5%, corresponding copolymers possessed sufficient compressive strength for bone repair and superior surface wettability 54.3° and 54.1° for mesenchymal stem cells adhesion. Since this valuable additional method improves cell adhesion ability of PAA surface, application of the PAA for bone tissue engineering would be broadened. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46226.