Pectin/poly(vinylpyrrolidone) composite sponges as wound dressings for delivery of silver sulfadiazine

Wound dressings based on sponges with good antimicrobial performance could be suitable options to prevent wound infection and promote wound healing for exudative wounds. In the current study, silver sulfadiazine (AgSD) loaded ionically crosslinked pectin (PEC)/ polyvinylpyrrolidone (PVP) based composite sponges were fabricated by freeze-dried molding with tunable mechanical features for wound dressing application. The structure of composite sponges was confirmed by Fourier transform infrared spectroscopy (FT-IR) and they were characterized in terms of gel fraction, mechanical, swelling, degradation and drug release properties. In particular, the longer incubation of composite sponges in CaCl2 solution resulted in enhanced mechanical properties. For instance, compressive moduli of PEC sponges were improved from 23.30 kPa to 37.24 kPa after 30 minutes and 120 minutes incubation in CaCl2 solution, respectively. Moreover, the addition of PVP improved the mechanical property of pectin. All composite sponges exhibited higher gel fraction in distilled water compared to phosphate buffer saline (PBS, pH: 7.4). The composite sponges exhibited rapid and high swelling ability of 802.47±69.31% and 714.56±39.78% for PEC and PEC/PVP composite sponges, respectively. They degraded completely after 48 hours. AgSD entrapment efficiency was about 70% for all composite sponges. The AgSD release from PEC slightly reduced after blending PVP, and the cumulative release was 39.19% and 51.49% after 1 h, respectively. AgSD/PEC and AgSD/PEC/PVP composite sponges allowed AgSD release for six hours. In summary, AgSD/PEC/PVP composite sponges with antimicrobial activity have a favorable potential to accelerate wound healing by providing wound closure and effectively absorbing wound exudates.