Improved cell adhesion and osteogenesis using a PLTGA (poly l-lactide, 1,3-trimethylene carbonate, and glycolide) terpolymer by gelatin-assisted hydroxyapatite immobilization for bone regeneration

Abstract

A PLTGA (poly L-lactide, trimethylene carbonate, glycolide) terpolymer possesses great potential for orthopedic applications due to its excellent biocompatibility and controllable biodegradability. However, the unfavorable surface conditions of bare PLTGA such as its poor hydrophilicity and smooth morphology impede its clinical applications, highlighting the need for tailored surface modifications to improve its cytological behavior and osteogenic capacity. We herein develop a facile and effective strategy to deposit a gelatin/hydroxyapatite (GEL/HAP) hybrid coating onto the surface of PLTGA that involves consecutive chemical grafting and in situ reaction steps. Following the surface modification treatment, the resultant PLTGA scaffold with the GEL/HAP coating exhibited drastically improved hydrophilicity (79.1° vs. 48.2° in water contact angle) and increased surface roughness (18.4 vs. 267.9 nm, more than 14-fold, in root-mean-square roughness), respectively. In addition, preosteoblast (MC3T3-E1) cells were seeded onto the bare/modified PLTGA scaffold to evaluate biological performance, including cell adhesion, proliferation, mineralization and osteogenic differentiation. Based on these results, the GEL/HAP hybrid coating can endow the PLTGA terpolymer substrate with enhanced cell adhesion, proliferation and osteogenic functionality. Overall, post-treatment of PLTGA with the GEL/HAP hybrid coating may be a promising methodology in bone regeneration applications.