O-carboxymethyl chitosan/gelatin/silver-copper hydroxyapatite composite films with enhanced antibacterial and wound healing properties

Abstract

Wound dressing composite films of O-carboxymethyl chitosan (OCMC) and gelatin were prepared and mixed with hydroxyapatite (HA) composited with Silver (Ag) and Copper (Cu) at different concentrations. The chemical, thermal, morphological, and biological properties of the composite films were studied. The analysis by FTIR confirmed the presence of interactions between gelatin and OCMC, and at the same time, the polymer matrix interactions with Ag-Cu/HA complex. The inclusion of nanoparticle to the composite was associated with an improvement of the thermal stability, morphological roughness, a 9–12% more hydrophobic behavior (composite C1, C5, and C8), increase in antibacterial activity from 23.2 to 33.1% for gram negative bacteria and from 37.28 to 40.59% for gram positive bacteria, and with a cell viability greater than 100% for 24 and 72 h. The films obtained can serve as a wound healing dressing and regenerating biomaterial.

Comparative Study of the Antibacterial, Biodegradable, and Biocompatibility Properties of Composite and Bi-Layer Films of Chitosan/Gelatin Coated with Silver Particles

“…Additionally, fibroblasts in the proliferation phase were observed to a greater extent in the bilayer films, in addition to their morphological difference, being more elongated and with greater cellular interconnection than in the composite films, which, although they present cell adhesion, do not show a high interconnection and cell proliferation as in the case of bilayers. This may be because chitosan presents cell adhesion characteristics; however, gelatin has been reported in several investigations as a material that promotes cell proliferation and invasion, providing a greater hydrophilic character that allows cells to adhere and grow [5,[28][29][30]. This confirms the results obtained from the hydrophilic characterization analysis, showing that the bilayer films show a greater hydrophilic character.…”

“…The degradation of films composed of different polymers has been studied in several investigations, such as films with O-carboxymethyl chitosan and gelatin with copper and silver-doped hydroxyapatite [5]. Where a similar degradation is observed at the end of the study, between 65 to 78% degradation of exposed films with the same enzyme, lysozyme [23].…”

“…The composite films were prepared using a modified methodology reported by Valencia-Gomez, in 2022 [5]. Three different gelatin solutions were prepared with different concentrations, 2%, 2.5%, and 3%, dissolving the gelatin in distilled water, for 20 min in constant agitation and at room temperature.…”

“…Several investigations have used chitosan and gelatin to elaborate composite films to improve polymer complexes' mechanical, physical, and biological properties [1,5]. These composite films can be created of polyelectrolyte complexes through electrostatic interactions between the ammonium groups of the chitosan chain and the negatively charged side-chain groups of the gelatin [1].…”