title: Degradation and osteogenic potential of a novel poly(lactic acid)/nano-sized β-tricalcium phosphate scaffold.
abstract: The purpose of this study was to investigate the influence of nano-sized β-tricalcium phosphate (β-TCP) on the biological performance of poly (lactic acid) (PLA) composite scaffolds by using in vitro degradation and an in vivo model of heterotopic bone formation. Nano-sized β-TCP (nβ-TCP) was prepared with a wet grinding method from micro-sized β-TCP (mβ-TCP), and composite scaffolds containing 0, 10, 30, or 50 wt% nβ-TCP or 30 wt% mβ-TCP were generated using a freeze-drying method. Degradation was assessed by monitoring changes in microstructure, pH, weight, and compressive strength over a 26-week period of hydrolysis. Composite scaffolds were processed into blocks, and implanted into muscular pockets of rabbits after loading with recombinant human bone morphogenetic protein-2 (rhBMP-2). New bone formation was evaluated based on histological and immunohistochemical analysis 2, 4, and 8 weeks after implantation. The in vitro results indicated that the buffering effect of nβ-TCP was stronger than mβ-TCP, which was positively correlated with the content of nβ-TCP. The in vivo findings demonstrated that nβ-TCP enhanced the osteoconductivity of the scaffolds. Although composite scaffolds containing 30% nβ-TCP exhibited similar osteoconductivity to 50% nβ-TCP, they had better mechanical properties than the 50% nβ-TCP scaffolds. This study supports the potential application of a composite scaffold containing 30% nβ-TCP as a promising scaffold for bone regeneration.
authors.affiliation: Department of Orthopedic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Cao
authors.forename: Ping-Guo
authors.initials: PG
authors.lastname: Duan
authors.forename: Hui-Ren
authors.initials: HR
authors.lastname: Wang
authors.forename: Xi-Lei
authors.initials: XL
authors.lastname: Li
authors.forename: Feng-Lai
authors.initials: FL
authors.lastname: Yuan
authors.forename: Zhong-Yong
authors.initials: ZY
authors.lastname: Fan
authors.forename: Su-Ming
authors.initials: SM
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Dong
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001846:Bone Development / Q000502:physiology*; D001861:Bone Regeneration / Q000502:physiology*; D018786:Bone Substitutes / Q000627:therapeutic use; D002130:Calcium Phosphates / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010012:Osteogenesis / Q000502:physiology; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D011817:Rabbits; D023822:Tissue Engineering / Q000295:instrumentation*
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; D011091:Polyesters; D011108:Polymers; C485817:beta-tricalcium phosphate; D019344:Lactic Acid; C033616:poly(lactide)