Bone morphogenetic protein-2 plasmid DNA as a substitute for bone morphogenetic protein-2 protein in bone tissue engineering

Bone regeneration is one of the focus points in the field of regenerative medicine. A well-known stimulus of bone formation is bone morphogenetic protein-2 (BMP-2), which has already been extensively used in clinical applications. However, due to a short half-life, supraphysiological doses are applied resulting in severe side effects such as ectopic bone formation or even loss of bone. We compared the effectivity of transient BMP-2 gene delivery with the BMP-2 protein at clinical (high) and physiological (low) doses by subcutaneous implantation of alginate-based constructs in mice. After 6 weeks of implantation, both the protein laden constructs and BMP-2 plasmid DNA-based constructs showed similar early bone onset and elevated bone formation compared to controls without any BMP-2 added. We found no differences in efficiency by using BMP-2 plasmid DNA or any of the BMP-2 protein dosages. Therefore, we conclude that BMP-2 plasmid DNA-based gene therapy in alginate is a promising new strategy for BMP-2 administration for bone (re)generation.