# Pinecone-Inspired Water-Responsive Curling Adhesive Conduit for Peripheral Nerve Repair

## TL;DR

A self-curling adhesive conduit inspired by pinecones is developed for easier and effective repair of peripheral nerve injuries.

## Contribution

A water-responsive, suture-free conduit that autonomously curls and adheres to nerves for regeneration.

## Key findings

- The PU/PGAX film autonomously curls into a tubular structure upon water exposure.
- The conduit shows excellent biocompatibility and promotes peripheral nerve regeneration.
- The adhesive conduit provides a biomimetic scaffold with straightforward operability and repair efficacy.

## Abstract

Neural guidance conduits represent a promising approach for treating peripheral nerve injuries. However, challenges remain, including the complexity of microsuturing, potential iatrogenic damage, and variations in nerve dimensions. Inspired by the deformation of pinecone scales upon water absorption, this study developed a water-responsive self-curling adhesive conduit to achieve adaptive wrapping and suture-free repair for peripheral nerve injury. The self-curling film (PU/PGAX) was composed of hydrophilic γ-polyglutamic acid (PGA) and hydrophobic polyurethane (PU). Differential swelling of these components in water drives the autonomous curling of the membrane into a tubular structure. Coating the self-curling film with a PU adhesive emulsion endows the material with adhesion functionality. The resulting self-curling adhesive conduit can adaptively wrap around nerve tissue and achieve adhesion fixation, providing a biomimetic scaffold for nerve regeneration. Furthermore, the PGA-loaded conduit exhibits excellent biocompatibility and effectively promotes peripheral nerve regeneration. This self-curling adhesive conduit offers straightforward operability and demonstrates marked repair efficacy, indicating substantial potential for applications in nerve repair.