**13. miRNA as potential new generation drugs**

miRNAs are emerging as promising drugs in the pharmaceutical market. They are endogenous and hence associated with less harmful events for the body. Employing miRNAs as therapeutic targets have one key benefit that nucleotide content of the miRNAs can be easily modified by chemicals for the improved pharmacokinetics and pharmacodynamics of the potential miRNA-based drugs. Besides, miRNA has the capability of targeting multiple genes at a time. Moreover, nowadays chemical locked nucleic acid modifications are present for addressing the issues related to the susceptibility of miRNAs to the intracellular nucleases. Likewise, phosphorothioate alteration is another way of improving the efficacy of miRNAs in the in vivo systems [103]. Recently FDA approved drug, Onpattro against polyneuropathy marks the foundation of RNAi technology-based medicines in the commercial space. **Table 5** describes a few miRNA-based therapeutic compounds that are on the success path of drug development at the preclinical and clinical stages [104, 105].


**Table 5.**

*List of few miRNAs which are presently in the development.*

### **14. Conclusion**

In healthy body conditions, miRNAs are expected to assist in the maintenance of a regulated balance between the osteoblast-based bone-forming activity and osteoclast dependent bone-resorbing activity. This balance is dependent on the action of miRNAs on the biochemical signaling pathways operating inside the bone. While, during pathologies, the aberrant expression of the miRNAs due to misregulated

### *Clinical Implementation of Bone Regeneration and Maintenance*

bone signaling comes into existence. The upregulated or downregulated miRNAs during osteoporosis may serve as biomarkers or gene therapy targets respectively in the management of bone associated injuries including osteoporosis. As miRNAs are expressed in tissue specific manner, therefore miRNA-based biomarkers can differentiate between variable bone-related medical conditions, i.e. defects in bone fragility, reduction in bone mass density, osteoclast malfunctioning, etc. In addition, miRNA bears pleiotropic nature that favors controlling the diseases that have no efficient treatments as yet. Advances in the number of reports regarding miRNA therapeutics in osteoporosis display massive translational utility of miRNAs in the clinical practices. miRNAs are naturally occurring and expected to pose nil or few side effects to the body. The access of the first miRNA mediated therapy against hepatitis C virus infection (HCV) in the clinical phase has fulfilled the hopes for the success of miRNAs as potential therapeutic agents in the drug market. To conclude, miRNAs can undoubtedly be addressed as new generation drugs for the efficient and effective check of osteoporosis.
