Proliferation, morphology, and protein expression by osteoblasts cultured on poly(anhydride-co-imides)

In vitro cell biocompatibility models are crucial in the study of any newly synthesized material. Our focus has been on the development of a new class of biocompatible, degradable, high-strength polymeric materials, the poly( anhydride-co-imides), for use in bone regeneration. This study examined ost eoblast cell adherence, proliferation, viability, and phenotypic preservati on on the surface of the poly(anhydride-co-imide) poly[pyromellitylim-idoal anine (PMA-ala):1,6-bis(carboxyphenoxy) hexane (CPH)] over a period of time . Cell proliferation on PMA-ala:CPH degradable matrices over 21 days was ex amined. Throughout the 21-day period of study, osteoblast proliferation was similar on PMA-ala:CPH and on tissue culture polystyrene controls. Osteobl asts maintained their characteristic morphology as demonstrated by both sca nning electron microscopy and immunofluorescence studies. Alkaline phosphat ase activity for cells grown on PMA-ala:CPH was confirmed. Retention of the osteoblastic phenotype was demonstrated using immunofluorescence technique s and staining with antibodies against osteocalcin (an extracellular matrix protein of bone) and osteopontin (a marker of cell adhesion). Radioimmunoa ssay results provided evidence that levels of osteocalcin production by ost eoblasts were similar when cells were cultured on PMA-ala:CPH and on tissue culture polystyrene controls. The present study provided evidence of norma l osteoblast function on PMA-ala:CPA surfaces. PMA-ala:CPH may therefore be useful as a synthetic material for orthopedic applications. (C) 1999 John Wiley & Sons, Inc.