# Octopus minor Antimicrobial Peptide-Loaded Chitosan Nanoparticles Accelerate Dermal Wound Healing

## TL;DR

This study shows that chitosan nanoparticles loaded with an antimicrobial peptide from an octopus can enhance wound healing in zebrafish.

## Contribution

The study introduces a novel nanoencapsulation method for delivering an octopus-derived antimicrobial peptide to improve wound healing.

## Key findings

- Octominin-loaded chitosan nanoparticles showed no significant toxicity in human fibroblasts and zebrafish larvae.
- Octominin-CNPs demonstrated higher wound healing activity than Octominin alone, especially at 21 days post-wounding.
- Nanoencapsulation reduced pro-inflammatory gene expression and improved tissue repair compared to free peptide.

## Abstract

Octominin is a peptide derived from the Octopus minor defense protein, which has shown antimicrobial and immunomodulatory properties. The present study describes the efficacy of Octominin-encapsulated chitosan (CN) nanoparticles (Octominin-CNPs) on in vitro and dermal wound healing in zebrafish. Initial viability analysis revealed there was no significant toxicity of Octominin-CNPs up to 200 μg/mL in human dermal fibroblast (HDF) cells and in zebrafish larvae (up to 50 μg/mL). Moreover, the potential wound healing activity of Octominin-CNPs was observed using the cell-scratch assay. In the in vivo study, wounded adult zebrafish were applied with the appropriate treatment (PBS, CNPs, Octominin, and Octominin-CNPs) 20 μg/wound/fish as a topical application at 0, 2, and 4 days post-wounding (dpw) while photographs of each wound site were taken at 2, 4, 7, 10, 14, and 21 dpw, and surface area was measured using ImageJ software (Ver. 1.8.0, NIH, Bethesda, MD, USA) to calculate the wound healing percentage (WHP) and wound healing rate (WHR). From the observed results, at 4 dpw, all treatments showed a negative impact on wound healing, where the lowest WHR and the WHP were given by the negative control (NC) until the 14th day. After 7 dpw, all fish except the NC showed increased wound healing activity. Compared to the Octominin, the Octominin-CNPs showed higher activity, which was at its peak on 21 dpw. Furthermore, Octominin-CNPs suppressed the expression of pro-inflammatory cytokine and chemokine mRNA expression with increased wound healing efficacy, and tissue repair compared to the Octominin-alone-treated fish at 7 dpw. Together, the observed results give insights into the use of nanoencapsulation as a means of drug delivery, especially for small peptides.