Conductive Hydrogel Conduits with Growth Factor Gradients for Peripheral Nerve Repair in Diabetics with Non‐Suture Tape

Abstract

Diabetic patients suffer from peripheral nerve injury with slow and incomplete regeneration owing to hyperglycemia and microvascular complications. This study develops a graphene‐based nerve guidance conduit by incorporating natural double network hydrogel and a neurotrophic concentration gradient with non‐invasive treatment for diabetics. GelMA/silk fibroin double network hydrogel plays quadruple roles for rapid setting/curing, suitable mechanical supporting, good biocompatibility, and sustainable growth factor delivery. Meanwhile, graphene mesh can improve the toughness of conduit and enhance conductivity of conduit for regeneration. Here, novel silk tapes show quick and tough adhesion of wet tissue by dual mechanism to replace suture step. The in vivo results demonstrate that gradient concentration of netrin‐1 in conduit have better performance than uniform concentration caused by chemotaxis phenomenon for axon extension, remyelination, and angiogenesis. Altogether, GelMA/silk graphene conduit with gradient netrin‐1 and dry double‐sided adhesive tape can significantly promote repairing of peripheral nerve injury and inhibit the atrophy of muscles for diabetics.

Recent advances in GelMA hydrogel transplantation for musculoskeletal disorders and related disease treatment

“…Usually, the method has few kinds of raw materials, simple synthesis steps, and easy clinical transformation and application 9 , 131 , 143 , 144 . As an example, Cai et al 145 prepared a GelMA/SF/graphene nerve conduit and combined it with Netrin-1, a hydrogel with good mechanical properties, biocompatibility and sustainable nerve growth factor delivery for significant peripheral nerve repair and inhibition of muscle atrophy. Exosomes, cytokines, drugs, etc.…”

Silk‐based conductive materials for smart biointerfaces

“…The use of nerve conduits made of biopolymers is an alternative approach to nerve autograft 117,118 . SF nanofiber scaffolds have been proven to be a promising biopolymer with biocompatibility and biomimetic characteristics for the fabrication of nerve conduits 119 .…”

3D gradient printing based on digital light processing

“…32 Cai et al have fabricated conductive hydrogel conduits with growth factor gradients for peripheral nerve repair. 52 A netrin-1 gradient constructed using a controlled diffusion method proved able to significantly promote axon regeneration. Yu et al applied an orthogonal bioconjugation platform and produced a 3D chemotactic guidance model for programmable tissue vascularization.…”

“…Compared with traditional postprocessing methods, such as controlled diffusion and chemical vapor deposition (CVD), by adjusting light intensity and illumination time, the DLP method is capable of precisely tuning the subtle gradient change without complex remedial measures. 52,65 It is necessary to have a detailed discussion about the working principle, optical systems, and applications.…”