Evaluation of BMP-2 Minicircle DNA for Enhanced Bone Engineering and Regeneration

Abstract

ABSTRACT To date, the significant osteoinductive potential of bone morphogenetic protein 2 (BMP-2) non-viral gene therapy cannot be fully exploited therapeutically. This is mainly due to weak gene delivery and brief expression peaks restricting the therapeutic effect. The use of minicircle DNA allows prolonged expression potential. It offers notable advantages over conventional plasmid DNA. The lack of bacterial sequences and the resulting reduction in size, enable safe usage and improved performance for tissue regeneration. In this study, we report the combination of an optimized BMP-2 cassette (in the following referred to as conventional BMP-2-Advanced plasmid) with minicircle plasmid technology, thereby attaining an improved therapeutic plasmid for osteogenic gene therapy. C2C12 cell line transfected with BMP-2-Advanced minicircle showed significantly elevated expression of osteocalcin, alkaline phosphatase (ALP) activity and BMP-2 protein amount when compared to cells transfected with conventional BMP-2-Advanced plasmid. Furthermore, the plasmids show suitability for stem cell approaches by showing significantly higher levels of ALP activity and mineralization when introduced into human bone marrow stem cells (BMSCs). Here in, we present a highly bioactive BMP-2 minicircle plasmid with the potential to fulfill requirements for clinical translation in the field of bone regeneration.