Polyelectrolyte complexes hydrogels based on chitosan/pectin/NaCl for potentially wound dressing: development, characterization, and evaluation

Abstract

In this research, hydrogels based on chitosan, pectin, and salt (NaCl) were synthesized through the formation of polyelectrolyte complexes (PECs). The synthesis parameters, including pH, salinity, and polymer concentration, were varied to explore their influence. Weight and texture analysis revealed differences in hydrogel morphology. Swelling behavior studies showed hydrogels synthesized at pH 4 exhibiting higher swelling capacities. Additionally, the presence of salt affected the formation process. Thermal characterization showed a first decomposition step occurring around 180–224 °C. Morphological testing using SEM highlighted differences in pore size and distribution, notably when salt was included in the formulation (pore wall diameter without NaCl, 2.2 ± 1.1 um, with NaCl, 4.7 ± 1.2 um). Physico-chemical tests, including Zeta potential, FTIR, and XRD, provided insights into interactions within the hydrogels: hydrogen bonds and electrostatic interactions. Moreover, antibacterial tests demonstrated efficacy against Escherichia coli and Staphylococcus aureus, with varying inhibition degrees correlated with NaCl content (halo for E. coli without NaCl, 8 and 10 mm; with NaCl, 10 and 15 mm). Further assessments, including water vapor transmission rate (WVTR) and lidocaine release assays, highlighted hydrogel potential for wound dressing applications, with suitable moisture retention properties and controlled drug release capabilities. The release percentage achieved by the hydrogel with 0.15 M NaCl was higher than without salt (111.1% ± 9.5% and 31.16% ± 15.13%, respectively). Preliminary in vivo wound healing studies showed promising results. Overall, our findings emphasize the tunable properties of these hydrogels and their potential for wound dressings.