Acellular hydroxyapatite-collagen scaffolds support angiogenesis and osteogenic gene expression in an ectopic murine model: Effects of hydroxyapatite volume fraction.
Acellular hydroxyapatite (HA) reinforced collagen scaffolds were previously reported to induce angiogenesis and osteogenesis after ectopic implantation but the effect of the HA volume fraction was not investigated. Therefore, the objective of this study was to investigate the effect of HA volume fraction on in vivo angiogenesis and osteogenesis in acellular collagen scaffolds containing 0, 20, and 40 vol % HA after subcutaneous ectopic implantation for up to 12 weeks in mice. Endogenous cell populations were able to completely and uniformly infiltrate the entire scaffold within 6 weeks independent of the HA content, but the cell density was increased in scaffolds containing HA versus collagen alone. Angiogenesis, remodeling of the original scaffold matrix, mineralization, and osteogenic gene expression were evident in scaffolds containing HA, but were not observed in collagen scaffolds. Moreover, HA promoted a dose-dependent increase in measured vascular density, cell density, matrix deposition, and mineralization. Therefore, the results of this study suggest that HA promoted the recruitment and differentiation of endogenous cell populations to support angiogenic and osteogenic activity in collagen scaffolds after subcutaneous ectopic implantation. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2178-2188, 2016.
Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, Indiana, 46556.
Matthew J
MJ
Meagher
Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, Indiana, 46556.
Holly E
HE
Weiss-Bilka
Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, Indiana, 46556.
Margaret E
ME
Best
Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, Indiana, 46556.
Joel D
JD
Boerckel
Department of Mechanical Engineering, Indiana University Purdue University at Indianapolis, Indianapolis, Indiana, 46202.
Diane R
DR
Wagner
Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, Indiana, 46556.
Ryan K
RK
Roeder
D000818:Animals; D003094:Collagen / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D005260:Female; D005786:Gene Expression Regulation; D051379:Mice; D008819:Mice, Nude; D008954:Models, Biological; D018919:Neovascularization, Physiologic; D010012:Osteogenesis; D054457:Tissue Scaffolds / Q000737:chemistry*
D003094:Collagen; D017886:Durapatite
angiogenesis; collagen; hydroxyapatite; osteogenesis; osteoinduction; synthetic bone graft substitute; tissue engineering scaffold