Authors: Mela R Johnson Joel D Boerckel Kenneth M Dupont Robert E Guldberg
Publish Date: 2011/08/24
Volume: 469, Issue: 11, Pages: 3111-
Abstract
Bone defects and fracture nonunions remain a substantial challenge for clinicians Grafting procedures are limited by insufficient volume and donor site morbidity As an alternative biomaterial scaffolds functionalized through incorporation of growth factors such as bone morphogenetic proteins BMPs have been developed and appear to regenerate the structure and function of damaged or degenerated skeletal tissueOur objectives were therefore to determine whether 1 the addition of heparin alone to collagen scaffolds sufficed to promote bone formation in vivo 2 collagenheparin scaffold improved BMPmediated bone regeneration and 3 precomplexed heparin and BMP2 delivered on collagen scaffold could restore long bone biomechanical strengthWe created bilateral surgical defects in the femora of 20 rats and filled the defects with PCL scaffolds with one of five treatments collagen matrix n = 5 collagen/heparin matrix n = 7 collagen matrix + BMP2 n = 9 collagen/heparin matrix + BMP2 n = 9 or collagen matrix + BMP2/heparin complex n = 9 Bone formation was observed with radiographs and microCT analysis and biomechanical testing was used to assess strengthThe addition of heparin alone to collagen did not promote bone ingrowth and the addition of heparin to collagen did not improve BMPmediated bone regeneration Delivery of precomplexed BMP2 and heparin in a collagen matrix resulted in new bone formation with mechanical properties similar to those of intact bone
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