title: Repair of rat calvarial bone defects by controlled release of rhBMP-2 from an injectable bone regeneration composite.
abstract: The objective of the present study was to enhance the regeneration ability of an injectable bone regeneration composite (IBRC) by the controlled release of recombinant human bone morphogenetic protein-2 (rhBMP-2). The IBRC comprised nano-hydroxyapatite/collagen (nHAC) particles in an alginate hydrogel carrier. First, bovine serum albumin (BSA) as a model protein was released from IBRC to evaluate its release rules. The results suggested that IBRC is a good controlled release carrier for BSA in the range 5-75 µg/ml. In the in vitro study the rhBMP-2 released from IBRC was determined by an enzyme-linked immunosorbent assay specific for rhBMP-2. The bioactivity of the released rhBMP-2 was evaluated through differentiated function of marrow mesenchymal stem cells (MSCs), as measured by alkaline phosphatase activity. The results of an in vitro study confirmed that rhBMP-2 released continuously for 21 days, and its bioactivity was well preserved during this period. The bone formation ability was assessed using a rat calvarial defect model of critical size. Micro-computed tomography (micro-CT) and histological analysis demonstrated that the IBRC had good bone formation ability, which was promoted through rhBMP-2 released from IBRC/rhBMP-2. In vitro and in vivo studies suggested that the present system is a potential bone critical defect repair material for clinical applications.
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing, People's Republic of China.
authors.forename: Rongwei
authors.initials: R
authors.lastname: Tan
authors.forename: Zhending
authors.initials: Z
authors.lastname: She
authors.forename: Mingbo
authors.initials: M
authors.lastname: Wang
authors.forename: Xing
authors.initials: X
authors.lastname: Yu
authors.forename: He
authors.initials: H
authors.lastname: Jin
authors.forename: Qingling
authors.initials: Q
authors.lastname: Feng
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage* / Q000494:pharmacology*; D001861:Bone Regeneration / Q000187:drug effects*; D002417:Cattle; D003094:Collagen / Q000737:chemistry*; D003692:Delayed-Action Preparations; D017886:Durapatite / Q000737:chemistry*; D006801:Humans; D007267:Injections; D008297:Male; D010865:Pilot Projects; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000378:metabolism; D012886:Skull / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology*; D016212:Transforming Growth Factor beta / Q000008:administration & dosage* / Q000494:pharmacology*; D014945:Wound Healing / Q000187:drug effects*; D055114:X-Ray Microtomography
chemical_list: D055396:Bone Morphogenetic Protein 2; D003692:Delayed-Action Preparations; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C509317:nano-hydroxyapatite-collagen; C499469:recombinant human bone morphogenetic protein-2; D012710:Serum Albumin, Bovine; D003094:Collagen; D017886:Durapatite