# Freeze-Dried Chitosan Scaffolds Containing Grape Seed Oil for Wound Healing Applications

## TL;DR

This study creates chitosan scaffolds with grape seed oil to improve wound healing by controlling inflammation and exudate.

## Contribution

A novel freeze-drying method incorporating grape seed oil into chitosan scaffolds for enhanced wound healing properties.

## Key findings

- Scaffolds with 0.6% grape seed oil showed 17% higher porosity, aiding cell proliferation and nutrient transport.
- Scaffolds exhibited up to 800% swelling, indicating potential for exudate control in chronic wounds.
- Higher grape seed oil concentration reduced in vitro degradation rates, aligning with chronic wound healing timelines.

## Abstract

Wound healing is the ultimate goal in skin repair and
tissue engineering.
Skin is highly susceptible to injuries, with a mortality rate in chronic
wounds comparable to cancers, thus imposing a high cost ($126.8bi/USA)
to health care systems. Chronic wound regeneration stagnates in the
inflammatory phase, progressing after its control. Porous biomaterials
with a tunable degradation that control bleeding and exudate and maintain
a moist environment could improve skin repair. Chitosan is biocompatible,
biodegradable, antimicrobial, and hemostatic. Vitis
vinifera (grape) seed oil (grape seed oil (GSO)) has
a high content of unsaturated fatty acids with antioxidant and anti-inflammatory
activity. In this study, 0.3% and 0.6% (v/v) GSO were incorporated
into chitosan without cross-linker via freeze-drying process aiming
scaffolds with enhanced properties for wound healing applications.
The porous scaffolds maintained their shape throughout the 28 days
in phosphate buffer solution. The overall physical and chemical characterizations
showed that GSO was fully incorporated into the chitosan scaffolds
(CSs), even after neutralization in NaOH, demonstrating a durable
incorporation. Scanning electron microscopy images revealed superficial
and interconnected pores in a stratified structure, possibly favorable
to cell proliferation and nutrient transport The addition of 0.6%
GSO increased porosity by 17%, without altering freeze-drying parameters,
possibly by the coalescence of oil droplets during freezing. Moreover,
the scaffolds showed high swelling, up to 800%, indicating the potential
for exudate control. Higher GSO concentration leads to lower degradation
rates in vitro, which is compatible with the wound closure time in
chronic wounds. The biological in vitro results showed the high biocompatibility
of GSO and the scaffolds in epithelial Vero cells. Altogether, our
results show that incorporating GSO in CS using a freeze-drying process
allows scaffolds with modulated morphological and physicochemical
features, maintaining the biocompatibility of these natural products,
making them a promising biomaterial for wound healing.