Graphene nanoribbons: A promising nanomaterial for biomedical applications.

Graphene nanoribbons (GNRs) are narrow lengthened strips of single-layer graphene. Among the graphene family of nanomaterials, GNRs are remarkable materials due to their attractive physical, chemical, electrical, mechanical, thermal, and optical properties. They have an ultra-high surface area. Graphene-oxide nanoribbons (GONRs), the oxygenated derivative of GNRs, offer more possibilities in the biomedicine due to their amphiphilic nature. Noncovalent and covalent modifications of these are possible for advanced biomedical applications. This review describes the properties, synthesis, surface modifications, and toxicities of GNRs, along with their biomedical applications. Their applications in drug delivery, anticancer therapy, sensing, antimicrobial therapy, imaging, gene therapy, photothermal therapy, management of spinal cord injury, bone regeneration, etc. are reviewed.