Multifunctional Nanomachinery for Enhancement of Bone Healing.

The visionary idea that RNA adopts non-biological roles in today's nanomaterial world has been nothing short of phenomenal. These RNA molecules have ample chemical functionality and self-assemble to form distinct nanostructures in response to external stimuli. They may be combined with inorganic materials to produce nanomachines that carry cargo to the target sites in a controlled manner and respond dynamically to environmental changes. Comparable to biological cells, programmed RNA nanomachines have the potential to replicate bone healing in vitro. Here, an RNA-biomineral nanomachine has been developed that accomplishes intrafibrillar and extrafibrillar mineralization of collagen scaffolds to mimic bone formation in vitro. Molecular dynamics simulation indicates that noncovalent hydrogen bonding provides the energy source that initiates self-assembly of these RNA-biomineral nanomachines. Incorporation of RNA-biomineral nanomachines into collagen scaffolds in vivo creates an osteoinductive microenvironment within a bone defect that is conducive to rapid biomineralization and osteogenesis. Addition of RNA degrading enzymes into the RNA-biomineral nanomachines further creates a stop signal that inhibits unwarranted bone formation in tissues other than bone and teeth. The potential of RNA in building functional nanostructures has been underestimated in the past. The concept of RNA-biomineral nanomachines participating in physiological processes may transform the nanoscopic world of life science. This article is protected by copyright. All rights reserved.