Biocompatibility and degradation of poly(DL-lactic-co-glycolic acid)/calcium phosphate cement composites.
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.
Ruhé
P Quinten
PQ
Department of Biomaterials, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
Hedberg
Elizabeth L
EL
Padron
Nestor Torio
NT
Spauwen
Paul H M
PH
Jansen
John A
JA
Mikos
Antonios G
AG
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
D018786:Bone Substitutes; D002130:Calcium Phosphates; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C020243:calcium phosphate