# Gelatin/Ascorbic Acid Scaffolds for Controlled Release of Allantoin: A Fully Natural Approach for Skin Tissue Regeneration Through Pro-Regenerative, Antimicrobial, and Keratinocyte-Supportive Properties

## TL;DR

This paper introduces a fully natural scaffold made of gelatin, ascorbic acid, and allantoin that supports skin tissue regeneration by promoting healing, fighting bacteria, and supporting skin cells.

## Contribution

The study introduces a fully natural scaffold combining gelatin, ascorbic acid, and allantoin for skin tissue regeneration with pro-regenerative, antimicrobial, and keratinocyte-supportive properties.

## Key findings

- The scaffolds have a highly porous structure with tunable porosity (87.37–92.39%) and soft-tissue-like mechanical properties.
- Incorporation of allantoin improved mechanical performance and swelling capacity while enabling sustained release for up to 76 hours.
- The scaffolds showed antibacterial activity against Escherichia coli and Staphylococcus epidermidis and supported keratinocyte viability.

## Abstract

Background/Objectives: Nature-inspired therapeutic strategies that promote biological regenerative mechanisms and replicate the native structural microenvironment conductive to formation of healthy tissue are increasingly recognized as a promising platform for skin tissue regeneration and wound healing. This study proposes an innovative design of novel multifunctional scaffolds composed entirely of natural components—gelatin, L-ascorbic (ASA) acid and allantoin—as a bioinspired approach for skin tissue regeneration through pro-regenerative, antimicrobial, and keratinocyte-supportive properties. Methods: The biocompatible, skin-adhesive scaffolds were prepared via a simple and environmentally friendly heat-induced crosslinking of gelatin with varying ASA contents, and by enriching the system with allantoin. The influence of ASA content on scaffold properties was investigated through characterization of their morphology, porosity, swelling behavior, skin tissue adhesion, and allantoin release potential. Biocompatibility was evaluated in vitro using human keratinocyte (HaCaT) cells, while antibacterial activity was assessed against Escherichia coli and Staphylococcus epidermidis. Results: The scaffolds revealed a highly porous, interconnected structure with tunable porosity (87.37–92.39%) and soft-tissue-matched mechanical properties (0.81–1.47 MPa). Incorporation of allantoin into the scaffolds enhanced their mechanical performance and swelling capacity. All scaffolds demonstrated antibacterial activity against both tested bacteria, supported keratinocyte viability and provided sustained release of allantoin for up to 76 h, confirming their multifunctional pro-regenerative potential. Conclusions: The novel gelatin/ascorbic acid scaffolds enriched with allantoin combine a porous replicated structure of native extracellular matrix, fluid absorption capacity, soft-tissue-like mechanical properties, stable skin tissue adhesion, cytocompatibility and antibacterial functionality with the pro-regenerative properties of allantoin, thereby representing a multifunctional and biologically inspired platform for advanced skin tissue regeneration and wound-healing applications.