title: Biocompatibility and degradation of poly(DL-lactic-co-glycolic acid)/calcium phosphate cement composites.
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 microm) 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 microm) 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.
authors.affiliation: Department of Biomaterials, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: P Quinten
authors.initials: PQ
authors.lastname: Ruhé
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Hedberg
authors.forename: Nestor Torio
authors.initials: NT
authors.lastname: Padron
authors.forename: Paul H M
authors.initials: PH
authors.lastname: Spauwen
authors.forename: John A
authors.initials: JA
authors.lastname: Jansen
authors.forename: Antonios G
authors.initials: AG
authors.lastname: Mikos
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D018786:Bone Substitutes / Q000378:metabolism*; D002130:Calcium Phosphates / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism*; D008297:Male; D008422:Materials Testing / Q000379:methods; D010012:Osteogenesis / Q000502:physiology*; D011100:Polyglycolic Acid / Q000378:metabolism*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D023822:Tissue Engineering / Q000379:methods
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C020243:calcium phosphate