Crosslinking optimization of sericin-based hydrogel membranes: A statistical approach to achieving stability and flexibility

The development of flexible membranes from biodegradable polymers for wound healing has gained attention due to their biocompatibility, ability to control humidity, and capacity to absorb exudate. However, polymer selection and crosslinking challenges must be addressed to ensure stability without compromising elasticity or fluid absorption. This study focuses on developing a physical crosslinking strategy for membranes composed of sericin, gelatin, and polyvinyl alcohol to achieve the desired properties for bioactive dressings. An experimental design was employed to evaluate the effects of polymer mixture concentration, glycerol content, and post-treatment time with water vapor to optimize the absorption capacity (ABS), degradation, and elastic modulus (EM). The optimal membrane (Opt-M) consisted of a 6 % (w/v) polymeric mixture with 1.5 % (v/v) glycerol; no water vapor post-treatment was required. Opt-M demonstrated a phosphate-buffered saline (PBS) ABS of 497 %, minimizing PBS degradation (8 %) and EM (121 MPa). These results were attributed to the fabrication method, hydrogen bonding interactions between the polymers and glycerol, and balanced distribution of hydrophobic-hydrophilic regions within the polymer chains, as confirmed by FTIR and SEM analyses. Opt-M exhibited a water vapor transmission rate (WVTR) of 901 g/m²/24 h, ensuring moisture management in wounds with low to medium exudate levels. The inclusion of sericin and glycerol was essential for modulating the polymer network, facilitating WVT, while enhancing the stability and flexibility of the membrane. This combination of properties contributes to its functionality and suitability for applications requiring flexibility, stability, and moisture control.