miR-148b-nanoparticle conjugates for light mediated osteogenesis of human adipose stromal/stem cells

Delivery systems providing spatial and temporal control have the potential to improve outcomes in surgical reconstruction and regenerative medicine by precise modulation of wound healing and tissue repair processes. In this study we describe a synthesis and oligonucleotide functionalization process of silver nanoparticle complexes for photoactivated microRNA (miRNA) delivery. The activity of the PC-miR-148b-SNP construct is demonstrated by light mediated delivery of miR-148b mimic resulting in differentiation of human autologous adipose derived mesenchymal stromal/stem cells (hASCs) into an osteogenic linage. The conjugate, upon photoactivation, increases alkaline phosphatase (ALP) activity in the cell membrane and calcification (mineralization) of hASCs on days 7 and 14 respectively. Additionally, the expression of mRNA for the early, middle and late stage osteogenic markers; ALP, RunX2 and osteocalcin (OCN) respectively, was also significantly upregulated at days 7 and 28, respectively after photoactivation of PC-miR-148b-SNP and release of miR-148b mimics. Additionally, PC-miR-148b-SNP conjugate is readily delivered to the intracellular compartment without the use of transfection vectors commonly required for free oligonucleotides. This technology demonstrates photo-controlled, spatial and temporal modulation of osteogenesis in hASCs.