title: In vivo evaluation of composites of PLGA and apatite with two different levels of crystallinity.
abstract: The cortical bone response towards poly(lactide-co-glycolide) (70/30) (PLGA) (70/30)/apatite complex scaffolds with different levels of crystallinity was investigated. Apatite with different levels of crystallinity, Ca-deficient hydroxyapatite (CDHA), which has a low crystallinity, and a mixture of carbonated hydroxyapatite (CHA) and CDHA, which has a higher crystallinity, were prepared from an aqueous mixture of Ca-EDTA complex, H(2)O(2), H(3)PO(4), and NH(4)OH. Two porous PLGA(70/30)/apatite composite scaffolds, composite scaffold A (containing low crystallinity CDHA) and composite scaffold B (containing the higher crystallinity CHA/CDHA mixture), were prepared. Afterwards, pure porous PLGA and the two composite scaffolds were implanted into the cortical bone of rabbit tibiae for 12 weeks. High-resolution microfocus X-ray computed tomography and histological examinations revealed a better bone response for composite scaffold A compared with PLGA and composite scaffold B. For composite scaffold A, the original bone defect was almost filled with new bone. Quantitative analysis revealed that composite scaffold A produced a significantly greater amount of new bone. The present study demonstrated that the level of apatite crystallinity influences bone response. A PLGA/apatite porous composite with a low level of apatite crystallinity shows promise as a bone substitute or scaffold material for bone tissue engineering.
authors.affiliation: Department of Dental Biomaterials, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan. hayakawa.tohru@nihon-u.ac.jp
authors.forename: Tohru
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Chihiro
authors.initials: C
authors.lastname: Mochizuki
authors.forename: Hiroki
authors.initials: H
authors.lastname: Hara
authors.forename: Fei
authors.initials: F
authors.lastname: Yang
authors.forename: Hong
authors.initials: H
authors.lastname: Shen
authors.forename: Shenguo
authors.initials: S
authors.lastname: Wang
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Sato
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry; D003460:Crystallization; D017886:Durapatite / Q000737:chemistry*; D005260:Female; D017102:Fracture Healing / Q000502:physiology; D050723:Fractures, Bone / Q000628:therapy; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D016348:Osseointegration / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D011817:Rabbits; D054457:Tissue Scaffolds / Q000737:chemistry*; D055114:X-Ray Microtomography
chemical_list: D018786:Bone Substitutes; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D017886:Durapatite