Microsphere-based scaffolds encapsulating tricalcium phosphate and hydroxyapatite for bone regeneration.
Bioceramic mixtures of tricalcium phosphate (TCP) and hydroxyapatite (HAp) are widely used for bone regeneration because of their excellent cytocompatibility, osteoconduction, and osteoinduction. Therefore, we hypothesized that incorporation of a mixture of TCP and HAp in microsphere-based scaffolds would enhance osteogenesis of rat bone marrow stromal cells (rBMSCs) compared to a positive control of scaffolds with encapsulated bone-morphogenic protein-2 (BMP-2). Poly(D,L-lactic-co-glycolic acid) (PLGA) microsphere-based scaffolds encapsulating TCP and HAp mixtures in two different ratios (7:3 and 1:1) were fabricated with the same net ceramic content (30 wt%) to evaluate how incorporation of these ceramic mixtures would affect the osteogenesis in rBMSCs. Encapsulation of TCP/HAp mixtures impacted microsphere morphologies and the compressive moduli of the scaffolds. Additionally, TCP/HAp mixtures enhanced the end-point secretion of extracellular matrix components relevant to bone tissue compared to the "blank" (PLGA-only) microsphere-based scaffolds as evidenced by the biochemical, gene expression, histology, and immunohistochemical characterization. Moreover, the TCP/HAp mixture groups even surpassed the BMP-2 positive control group in some instances in terms of matrix synthesis and gene expression. Lastly, gene expression data suggested that the rBMSCs responded differently to different TCP/HAp ratios presented to them. Altogether, it can be concluded that TCP/HAp mixtures stimulated the differentiation of rBMSCs toward an osteoblastic phenotype, and therefore may be beneficial in gradient microsphere-based scaffolds for osteochondral regeneration.
Bioengineering Graduate Program, University of Kansas, Lawrence, KS, USA.
Vineet
V
Gupta
Department of Chemical and Petroleum Engineering, The University of Kansas, 4149 Learned Hall 1530 W. 15th Street, Lawrence, KS, 66045-7618, USA.
Dina V
DV
Lyne
Department of Molecular Biosciences, University of Kansas, Lawrence, KS, USA.
Marilyn
M
Barragan
Department of Chemical and Petroleum Engineering, The University of Kansas, 4149 Learned Hall 1530 W. 15th Street, Lawrence, KS, 66045-7618, USA.|Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, USA.
Cory J
CJ
Berkland
Bioengineering Graduate Program, University of Kansas, Lawrence, KS, USA. detamore@ku.edu.|Department of Chemical and Petroleum Engineering, The University of Kansas, 4149 Learned Hall 1530 W. 15th Street, Lawrence, KS, 66045-7618, USA. detamore@ku.edu.
Michael S
MS
Detamore
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001854:Bone Marrow Cells / Q000166:cytology; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism; D001861:Bone Regeneration; D002130:Calcium Phosphates / Q000737:chemistry*; D002454:Cell Differentiation; D017886:Durapatite / Q000737:chemistry*; D005109:Extracellular Matrix / Q000378:metabolism; D020869:Gene Expression Profiling; D019344:Lactic Acid / Q000737:chemistry; D008297:Male; D008863:Microspheres; D010006:Osteoblasts / Q000166:cytology; D010012:Osteogenesis; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration; D013314:Stress, Mechanical; D017154:Stromal Cells / Q000166:cytology; D054457:Tissue Scaffolds / Q000737:chemistry*
D001672:Biocompatible Materials; C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D017886:Durapatite; C018392:tricalcium phosphate