Quantitative Biofabrication Platform for Collagen-based Peripheral Nerve Grafts with Structural and Chemical Guidance.

Owing to its crucial role in the human body, collagen has immense potential as a material for the biofabrication of tissues and organs. However, highly refined fabrication using collagen remains difficult, primarily because of its notably soft properties. We introduced a quantitative biofabrication platform to construct collagen-based peripheral nerve grafts, incorporating bionic structural and chemical guidance cues. We established a viscoelastic model for collagen, which facilitated simulating material relaxation and fabricating collagen-based neural grafts, achieving a maximum channel density similar to that of the native nerve structure of longitudinal microchannel arrays. For axonal regeneration over considerable distances, a gradient printing control model and quantitative method were developed to realize the high-precision gradient distribution of nerve growth factor required to obtain nerve grafts through one-step bioprinting. Experiments verified that the bioprinted graft effectively guided linear axonal growth in vitro and in vivo. This study should advance biofabrication methods for a variety of human tissue-engineering applications requiring tailored cues. This article is protected by copyright. All rights reserved.