title: Segmental bone regeneration using rhBMP-2-loaded collagen/chitosan microspheres composite scaffold in a rabbit model.
abstract: The reconstruction of segmental bone defects remains an urgent problem in the orthopaedic field, and bone morphogenetic protein-2 (BMP-2) is known for its potent osteoinductive properties in bone regeneration. In this study, chitosan microspheres (CMs) were prepared and combined with absorbable collagen sponge to maintain controlled-release recombinant human bone morphogenetic protein-2 (rhBMP-2). The rhBMP-2-loaded composite scaffolds were implanted into 15 mm radius defects of rabbits and the bone-repair ability was evaluated systematically. CMs were spherical in shape and had a polyporous surface, according to SEM images. The complex scaffold exhibited an ideal releasing profile in vitro. The micro-computed tomographic analysis revealed that the rhBMP-2-loaded composite scaffold not only bridged the defects as early as 4 weeks, but also healed the defects and presented recanalization of the bone-marrow cavity at 12 weeks. These results were confirmed by x-ray. When compared with other control groups, the composite scaffold group remarkably enhanced new bone formation and mechanical properties, as evidenced by bone mineral content evaluation, histological observations and biomechanical testing. Moreover, the biocompatibility and appropriate degradation of the composite scaffold could be obtained. All of these results clearly demonstrated that the composite scaffold is a promising carrier of BMP-2 for the treatment of segmental bone defects.
authors.affiliation: The State Key Laboratory of Bioreactor Engineering, Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Hou
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Lingyan
authors.initials: L
authors.lastname: Cao
authors.forename: Xiuzhen
authors.initials: X
authors.lastname: Qian
authors.forename: Wanli
authors.initials: W
authors.lastname: Xing
authors.forename: Jingxiong
authors.initials: J
authors.lastname: Lu
authors.forename: Changsheng
authors.initials: C
authors.lastname: Liu
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage* / Q000737:chemistry; D001861:Bone Regeneration / Q000187:drug effects*; D002214:Capsules / Q000138:chemical synthesis; D048271:Chitosan / Q000737:chemistry*; D003094:Collagen / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000008:administration & dosage* / Q000138:chemical synthesis; D017102:Fracture Healing / Q000187:drug effects / Q000502:physiology; D050723:Fractures, Bone / Q000628:therapy*; D008297:Male; D011817:Rabbits; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000737:chemistry; D054457:Tissue Scaffolds; D016212:Transforming Growth Factor beta / Q000008:administration & dosage* / Q000737:chemistry; D016896:Treatment Outcome
chemical_list: D055396:Bone Morphogenetic Protein 2; D002214:Capsules; D003692:Delayed-Action Preparations; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D003094:Collagen; D048271:Chitosan