Biocompatibility and degradation of poly(DL-lactic-co-glycolic acid)/calcium phosphate cement composites

✍ Scribed by P. Quinten Ruhé; Elizabeth L. Hedberg; Nestor Torio Padron; Paul H. M. Spauwen; John A. Jansen; Antonios G. Mikos

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 824 KB
• Volume: 74A
• Category: Article
• ISSN: 1549-3296
• DOI: 10.1002/jbm.a.30341

✦ Synopsis

Abstract

Injectable calcium phosphate (Ca‐P) cement materials exhibit favorable osteocompatible behavior but are resorbed slowly because of a lack of a bone ingrowth–enabling macroporosity. In this study, poly(DL‐lactic‐co‐glycolic acid) (PLGA) microparticles (average size 66 ± 25 μm) were incorporated into Ca‐P cement to obtain a macroporous Ca‐P cement scaffold after PLGA hydrolysis in vivo. Preset PLGA/Ca‐P cement composite discs of various weight ratios (0/100, 15/85, 30/70, and 50/50) were implanted subcutaneously and in cranial defects in rats for 12 weeks. Histological analysis revealed that all macropores in the PLGA‐containing composites (average pore size 73 ± 27 μm) were filled with fibrous tissue and blood vessels (subcutaneous implants) and/or bone (cranial implants). Histologically, bone formation appeared most abundant and most consistent in the 30/70 PLGA/Ca‐P cement composites. Histomorphometrical evaluation revealed a significant increase in defect fill in the 15/85 and 30/70 PLGA/Ca‐P cement composites. Finally, subcutaneous and cranial 50/50 PLGA/Ca‐P cement composites had degraded to a large extent, without adequate replacement by bone in the cranial implants. Therefore, we conclude that PLGA/Ca‐P cement composites enable tissue ingrowth and show excellent osteocompatibility in weight ratios of 15/85 and 30/70 PLGA/Ca‐P cement. In this model, 30/70 PLGA/Ca‐P cement composites showed the most favorable biological response. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005