Incorporation of shRNA in bioactive glass coated SS316L implant material and its role in inhibition of the osteoclast activity for better post implantation fixation

Abstract

The possibility of the use of small non-coding RNAs as therapeutics in targeted treatment of damaged hard tissue are presently being explored largely and for the same, a good understanding of the underlying molecular mechanisms of osteoblast and osteoblast differentiation is necessary, which would lead to better fixation of the implant. In the present communication, we made an attempt to incorporate a model non coding RNA viz. short hairpin RNA (shRNA), in the form of shRNA-plasmid, in a porous bioactive coating of phosphate free bioactive glass (PFBG) on surgical grade SS316L implant material, used as reservoir/carrier of the biomolecule and evaluated its time dependent inhibitory action on the osteoclastogenic cytokine, tumor necrosis factor alpha (TNFα), that in turn aids in growth and differentiation of osteoblast cells, for faster remodelling, repair and healing of the damaged hard tissue at the implanted site. Upon treatment with the shRNA-plasmid, results exhibited significant downregulation (approximately 12-fold) of the TNFα, as evidenced from the sandwich ELISA assay and confirmed by quantitative reverse transcription–polymerase chain reaction (qRT–PCR) analysis, followed by upregulation of alkaline phosphatase (approximately 4-fold), corresponding to osteoblast formation, on the contrary, confirming a pivotal role of the same in osteoblast formation. The flow cytometry data showed significant cellular uptake (16.04%) of the shRNA-plasmid into osteoclast cells at a time period of 24h, that was in turn corroborated by confocal imaging.