title: MicroCT evaluation of three-dimensional mineralization in response to BMP-2 doses in vitro and in critical sized rat calvarial defects.
abstract: Numerous growth factors, peptides, and small molecules are being developed for bone tissue engineering. The optimal dosing, stability, and bioactivity of these biological molecules are likely influenced by the carrier biomaterial. Efficient evaluation of various formulations will require objective evaluation of in vitro culture systems and in vivo regeneration models. The objective of this paper is to examine the utility of microcomputed tomography (microCT) over conventional techniques in the evaluation of the bone morphogenetic protein-2 (BMP-2) dose response effect in a three-dimensional (3D) in vitro culture system and in an established calvarial defect model. Cultured MC3T3-E1 osteoblasts displayed increased cellular density, extracellular matrix (ECM) production, and mineralization on 3D poly(lactic-co-glycolic acid) (PLGA) scaffolds in a BMP-2 dose dependent manner. MicroCT revealed differences in shape and spatial organization of mineralized areas, which would not have been possible through conventional alizarin red staining alone. Additionally, BMP-2 (doses of 30 to 240 ng/mm(3)) was grafted into 5 mm critical sized rat calvarial defects, where increased bone regeneration was observed in a dose dependent manner, with higher doses of BMP-2 inducing greater bone area, volume, and density. The data revealed the utility of microCT analysis as a beneficial addition to existing techniques for objective evaluation of bone tissue engineering and regeneration.
authors.affiliation: Department of Bioengineering, University of California, Los Angeles, California 90095, USA.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Cowan
authors.forename: Tara
authors.initials: T
authors.lastname: Aghaloo
authors.forename: Yu-Fen
authors.initials: YF
authors.lastname: Chou
authors.forename: Benjamin
authors.initials: B
authors.lastname: Walder
authors.forename: Xinli
authors.initials: X
authors.lastname: Zhang
authors.forename: Chia
authors.initials: C
authors.lastname: Soo
authors.forename: Kang
authors.initials: K
authors.lastname: Ting
authors.forename: Benjamin
authors.initials: B
authors.lastname: Wu
mesh_terms: D016475:3T3 Cells; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage* / Q000502:physiology; D001861:Bone Regeneration / Q000502:physiology; D018786:Bone Substitutes; D002113:Calcification, Physiologic / Q000502:physiology*; D002478:Cells, Cultured; D051379:Mice; D051381:Rats; D017207:Rats, Sprague-Dawley; D012886:Skull / Q000293:injuries* / Q000378:metabolism*; D014057:Tomography, X-Ray Computed / Q000379:methods; D016212:Transforming Growth Factor beta / Q000008:administration & dosage* / Q000502:physiology
chemical_list: C525719:Bmp2 protein, mouse; C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D018786:Bone Substitutes; D016212:Transforming Growth Factor beta