Enhanced osteoblast cells adhesion, spreading, and proliferation to surface-carboxylated poly(etheretherketone)

Poly(etheretherketone) is a rigid semicrystalline thermoplastic that combines excellent mechanical properties, broad chemical resistance, and bone-like stiffness, and is widely used in biomedical fields. However, the hydrophobic bio-inert surface of poly(etheretherketone) tends to hinder its biomedical applications when direct osteointegration between the implants and the host tissue is desired. In this investigation, poly(etheretherketone) surface was functionalized by a method with chemistry analogous to the formation of organosilane self-assembled monolayers on glass or silicon. First, poly(etheretherketone) surface activation with selective carbonyl reduction introduces surface hydroxylation. And then treatment of the hydroxylation-pretreated poly(etheretherketone) samples with a substituted organosilane solution forms the carboxyl (–COOH) functional surface layers. The modified surfaces were characterized using X-ray photoelectron spectroscopy, water contact angle measurements, differential scanning calorimetry, X-ray diffraction, and surface profiler. The effect of cell adhesion, spreading, and proliferation on each specimen was investigated. Pre-osteoblast cells (MC3T3-E1) adhesion, spreading, and proliferation were improved remarkably on surface-carboxylated poly(etheretherketone). Poly(etheretherketone) modified with –COOH on its surface has potential use in orthopedic or dental implants.