# In situ MgO nanoparticle-doped Janus electrospun dressing against bacterial invasion and immune imbalance for irregular wound healing

## TL;DR

A new wound dressing made with nanofibers and magnesium oxide nanoparticles helps fight infections and boost healing in irregular wounds.

## Contribution

A Janus electrospun scaffold with MgO nanoparticles is developed to address bacterial invasion and immune imbalance in wound healing.

## Key findings

- The PPGM scaffold effectively blocks bacterial colonization and maintains stability on wounds.
- The scaffold promotes anti-inflammatory effects and accelerates vascularization and epithelialization.
- The bilayer structure modulates collagen deposition and the inflammatory microenvironment.

## Abstract

Owing to the unpredictable size of wounds and irregular edges formed by trauma, nanofibers’ highly customizable and adherent in situ deposition can contribute to intervention in the healing process. However, electrospinning is limited by the constraints of conventional polymeric materials despite its potential for anti-inflammatory and antimicrobial properties. Here, inspired by the Janus structure and biochemistry of nanometal ions, we developed an in situ sprayed electrospinning method to overcome bacterial infections and immune imbalances during wound healing. The bilayer fiber scaffold has a hydrophobic outer layer composed of polycaprolactone (PCL) and a hydrophilic inner layer composed of gelatin, poly(L-lactic acid) (PLLA), and magnesium oxide nanoparticles, constituting the PCL/PLLA-gelatin-MgO (PPGM) electrospun scaffold. This electrospun scaffold blocked the colonization and growth of bacteria and remained stable on the wound for continuous anti-inflammatory properties to promote wound healing. Furthermore, PPGM electrospinning modulated collagen deposition and the inflammatory microenvironment in the full-thickness skin model, significantly accelerating vascularization and epithelialization progression. This personalized Janus electrospun scaffold has excellent potential as a new type of wound dressing for first aid and wound healthcare.