Chitosan-based dressings containing eggshell calcium carbonate and collagen tripeptide emerge as promising platforms for skin regeneration.

Several strategies can be used to treat skin injuries, among which the use of hydrogel-based dressings stands out due to its wet wound healing process. In this class, chitosan-based hydrogels stand out due to the good characteristics of this matrix, which include its high biocompatibility, antimicrobial activity, and ability to act as a carrier for local delivery of actives. Therefore, the objective of this work was to obtain chitosan hydrogel (CS) crosslinked with tripolyphosphate (TPP), containing calcium carbonate (CaCO3) from chicken eggshell and/or collagen tripeptide (Tcol) for regeneration of skin. To obtain the systems, the CS concentration was fixed at 1% m/m in relation to the acetic acid solution, and 1 and 2% m/m of (CaCO3) and/or 5% m/m of Tcol were used, both in relation to CS mass. The obtained systems were characterized in terms of physicochemical properties of the systems, Tcol release and cytocompatibility and cellular adhesion of L929 fibroblasts. The results indicated that there is no formation of chemical bonds and/or strong chemical interactions between the actives and the CS matrix. Furthermore, it was observed that the systems do not generate cytotoxicity to the L929 fibroblast lineage and have an average porosity of around 70% with pore sizes between 200 and 500 μm. The Tcol release profile of the systems showed an initial burst effect in the first two hours followed by a Tcol release for up to 20 h. The addition of Tcol did not change the degree of porosity, swelling and cytocompatibility of the gels, but it increased the cell adhesion of fibroblasts to the scaffold. CaCO3, in turn, tended to slightly reduce the porosity and swelling of the gels and generated a reduction in the Tcol release rate, without altering the biological properties of the hydrogels. Regarding the compressive strength of the systems, the presence of the Tcol active ingredient did not significantly alter the strength of the systems; however, calcium carbonate tended to increase the compressive strength of the evaluated systems by 7–11%. Based on the results obtained, chitosan-based gels containing CaCO3, and Tcol shows promise for application in skin wound regeneration. [ABSTRACT FROM AUTHOR]