Preparation and <i>in vitro</i> validation of ascorbyl palmitate-enriched marine collagen/alginate aldehyde hydrogels/cryogels for wound healing dressings

The present study involves the preparation of oxidized alginate/collagen (ADA/COL) hydrogels, their conversion into cryogels via a freeze-drying process, and the enrichment of these hydrogels with ascorbyl palmitate (AAP) to create a multifunctional material with enhanced properties for promoting wound healing. Both of ADA/COL and AAP-loaded cryogels were characterized in detail for their gel content, zeta potential, and morphology using scanning electron microscopy (SEM), while the chemical integrity was assessed by FTIR spectroscopy. Additionally, the in vitro study was performed in terms of water uptake, biodegradability, cytocompatibility on human skin fibroblasts (HSF), and the capability to inhibit microbial growth. The AAP-loaded samples showed a higher gel fraction, with the 20AAP-loaded cryogel formulation achieving the maximum value of 91.2 ± 7.1% and –7.36 ± 1.24 mV surface charge. The average pore diameter of the ADA/COL cryogels was 254 ± 65 µm, while the AAP loaded-cryogels showed irregular and small pores in the range of 25±7 μm. Besides their antimicrobial activities, the AAP-loaded cryogels demonstrated an impressive wound closure rate of 97.8 ± 2.8% over 48 h in a HSF migration assay. Overall, the study results highlight the significant advantages of using cryogels, especially those loaded with AAP, to address several critical requirements for effective wound healing, including superior water uptake, biocompatibility with human cells, and infection control.