# Lyophilized Catechol–Chitosan Mucoadhesive Hydrogels Loaded with Dental Follicle-Derived Mesenchymal Stem Cells Enhance Regenerative Healing of Palatal Donor Wounds

## TL;DR

A new hydrogel containing dental follicle stem cells improves healing of palatal wounds in rats.

## Contribution

A ready-to-use lyophilized hydrogel loaded with dental follicle-derived mesenchymal stem cells is developed for palatal wound healing.

## Key findings

- DFMSC-loaded hydrogels showed over 80% cell viability after rehydration.
- Palatal wounds healed faster with reduced inflammation and increased epithelial regeneration.
- Cell viability remained above 70% even after five months of storage.

## Abstract

Mesenchymal stem cells (MSCs) are candidates for the treatment of palatal wounds in combination with biomaterials. In this study, we developed a method for the production of a ready-to-use mucoadhesive hydrogel containing MSCs for palatal wounds and evaluated its healing effects. Dental follicle MSCs (DFMSCs) were isolated from the dental follicle tissue of a healthy twenty-year-old donor. DFMSCs were suspended in a cell-preserving solution containing platelet-rich plasma, trehalose, and DMSO, and loaded into a catechol–chitosan hydrogel solution at a ratio of 1:400 (v/v) with 5 × 105 or 6 × 106 cells per hydrogel to create a novel lyophilization method for cell integration into the biomaterial. Hydrogels were fabricated as scaffolds with a diameter of 5 mm and a depth of 4 mm. After lyophilization of the hydrogels with cells, a viability test was performed after the production of hydrogels on the seventh day and the fifth month. Palatal wounds were created as full-thickness wounds in rats using a 5 mm diameter punch. The hydrogels were applied to the palatal wounds of rats, and histochemical and immunohistochemical analyses were performed. The results showed that, after rehydration of the hydrogels, DFMSCs had over 80% viability and were homogeneously distributed in the hydrogels. After the application of DFMSC-loaded hydrogels, palatal wounds healed within 7 days, and inflammatory cell infiltration, fibroblastic proliferation, and ulceration were significantly reduced, while epithelial regeneration was significantly increased compared to the control group. The viability ratio of DFMSCs was 83.7% on the seventh day and 71.3% in the fifth month. Hydrogels loaded with DFMSCs represent a promising, ready-to-use biomaterial approach for supporting palatal wound healing.