Peripheral sensory nerve regeneration: Novel target in bone tissue engineering

Synthetic biomaterials are emerging candidate solutions for treating large bone defects. However, the clinical performances of most synthetic materials are not satisfactory, with the need for improvement in design and synthesis. Although bone is highly innervated, the central role during healing of the peripheral nervous system, and in particular sensory nerves (SNs), has only recently been acknowledged. SNs can improve osteogenic differentiation of bone marrow stem/stromal cells through neurotransmitters and peptides; the interplay between SNs and the vascular system also facilitates vascular network reconstruction, indirectly facilitating bone healing. These factors suggest the importance of SNs in bone healing, a vital point that has been overlooked in bone biomaterial design until very recently. SN regeneration represents a novel direction in the development of biomaterials for bone regeneration. The current perspective paper summarizes the cellular and molecular mechanisms under the regulatory influence of SNs in the bone healing process and outlines the recent advances in biomaterials for innervated bone tissue regeneration. This establishes potential future directions for bone engineering biomaterial design.