Mechanical properties and stem cell adhesion of injection-molded poly(ether ether ketone) and hydroxyapatite nanocomposites

A nanocomposite of poly(ether ether ketone) (PEEK) with 10 wt % hydroxyapatite (HA) was produced by extrusion and injection molding. Afterward, the samples were thermally treated. Thermal and short- and long-term mechanical characterizations of the samples were made. The adhesion of human adipose stem cells (h-ASCs) on the samples was also monitored. The ultimate tensile strength (UTS) and elastic modulus values of the nanocomposite were found to be much higher than those of trabecular bone. The impact strength of PEEK was not modified by HA; this suggested that there was no formation of large agglomerates of nanoparticles that could concentrate the stresses. With regard to fatigue life, both the thermally and nonthermally treated nanocomposites did not fail after 10(6) cycles when maximum stresses of 30 and 50% of the UTS were applied, but they failed when the maximum applied stress was 75% of the UTS and behaved as cortical bone. After 5 days of culturing, the h-ASCs had a higher proliferation in the nanocomposite than in pure PEEK because of the presence of HA. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41748.