The ability of a collagen/calcium phosphate scaffold to act as its own vector for gene delivery and to promote bone formation via transfection with VEGF₁₆₅

Collagen/calcium phosphate scaffolds have been used for bone reconstruction due to their inherent similarities to the bone extracellular matrix. Calcium phosphate alone has also been used as a non-viral vector for gene delivery. The aim of this study was to determine the capability of a collagen/calcium phosphate scaffold to deliver naked plasmid DNA and mediate transfection in vivo. The second goal of the study was to deliver a plasmid encoding vascular endothelial growth factor₁₆₅ (pVEGF₁₆₅) to promote angiogenesis, and hence bone formation, in a mouse intra-femoral model. The delivery of naked plasmid DNA resulted in a 7.6-fold increase in mRNA levels of β-Galactosidase compared to the delivery of plasmid DNA complexed with a partially degraded PAMAM dendrimer (dPAMAM) in a subcutaneous murine model. When implanted in a muirne intra-femoral model, the delivery of pVEGF₁₆₅ resulted in a 2-fold increase in bone volume at the defect site relative to control scaffolds without pVEGF₁₆₅. It was concluded that a collagen/calcium phosphate scaffold can mediate transfection without the use of additional transfection vectors and can promote bone formation in a mouse model via the delivery of pVEGF₁₆₅.