# Impact of conduit-filling interactions on the efficacy of fiber and hydrogel fillers in nerve conduits

## TL;DR

This study explores how filling nerve conduits with materials like spider silk and hydrogel can improve cell behavior, which is crucial for nerve repair.

## Contribution

The study reveals how conduit-filling materials interact to enhance Schwann cell behavior, offering new insights for nerve conduit design.

## Key findings

- Empty nerve conduits hinder Schwann cell attachment, proliferation, and migration.
- Hydrogel and spider silk fillings significantly improve cell regenerative behaviors.
- Conduit morphology strongly affects the efficacy of filling materials.

## Abstract

Nerve conduits offer an alternative to autologous nerve grafts, yet their clinical application remains restricted to short injuries with unsatisfactory outcomes. This study aimed to elucidate the factors responsible for these poor results. We systematically compared three commercially available conduits, assessing their impact on Schwann cells and fibroblasts in vitro alongside their material properties. Additionally, we evaluated the impact of luminal fillings —spider silk, hydrogel, and their combination— on cell behavior. All three hollow nerve conduits inhibited cell attachment, proliferation, and migration. Fillings significantly improved cellular responses, with effects varying depending on conduit type and material. Notably, spider silk and hydrogel influenced each other’s efficacy. Our experiments highlight the limitations of empty nerve conduits and served as a mechanistic exploration to unravel the reasons behind the superior outcomes observed with filled nerve conduits, underscoring the imperative for advancements in conduit design.

•FDA-approved nerve conduits inhibit Schwann cell attachment, proliferation, and migration•Enhancements with hydrogel and spider silk fillings improved cell regenerative behaviors•Spider silk fibers enhanced directed cell migration within the hydrogel filling•Conduit morphology significantly influenced filling efficacy

FDA-approved nerve conduits inhibit Schwann cell attachment, proliferation, and migration

Enhancements with hydrogel and spider silk fillings improved cell regenerative behaviors

Spider silk fibers enhanced directed cell migration within the hydrogel filling

Conduit morphology significantly influenced filling efficacy

Neuroscience; Materials science; Biomaterials