A COMPARISON OF THE INFLAMMATORY POTENTIAL OF PARTICULATES DERIVED FROM 2 COMPOSITE-MATERIALS

In order to develop total joint prostheses with moduli of elasticity c lose to bone while retaining excellent strength characteristics, compo site materials are being developed. Composites consist of graphite fib ers embedded in a polymer matrix. We studied the inflammatory potentia l of particulates derived from two composites with different matrix co mponents, polysulfone (PFS) and polyetherketoneketone (PEKK), in the r at subcutaneous air pouch model. Neat components of the composites wer e studied separately in the air pouch. Particulates also were studied in culture using the macrophage cell line RAW 264.7, adherent synovial cells (ASC), and human polymorphonuclear neutrophils (PMNs). Particle s derived from the PEKK-containing composite material consistently wer e less inflammatory than the PFS composite-derived particles, as measu red by PMN infiltration, neutral metalloprotease activity, tumor necro sis factor (TNF) activity, and prostaglandin E(2) (PGE(2)) accumulatio n. Results from the neat materials confirmed the findings in the compo site-derived material. PEKK composite-derived material produced less T NF from macrophage cultures, but there were no significant differences noted in PGE(2) production from ASC or in superoxide anion generation from PMNs. Particles from both PSF and PEKK produced minimal inflamma tory responses in the rat subcutaneous air pouch. PEKK elicited a resp onse virtually the same as the saline control and significantly less t han that produced by particles of PSF. (C) 1997 John Wiley & Sons, Inc .