Evaluation of Semi-Interpenetrating Polymeric Networks Based on PDMS/CS/PVA/GEN as a Skin Wound Dressing

We demonstrate the feasibility of semi-interpenetrating polymeric networks (SIPNs) based on poly(dimethylsiloxane) (PDMS), chitosan (CS), poly(vinyl alcohol) (PVA), and genipin (GEN). Three different weight ratios of PDMS and CS/PVA/GEN -SIPNs 7:3, 5:5, and 3:7, respectively, were prepared via solvent-casting for skin wound dressings. These SIPNs exhibited thicknesses of 300-550 μm, which varied with PDMS content; higher PDMS fractions reduced CS/PVA/GEN solvent evaporation rates, resulting in greater thickness. SIPNs maintained chemical stability under in vitro and in vivo conditions for up to 2 weeks, which is suitable for wound-dressing treatment duration. Beyond this, SEM revealed microcracks, and FT-IR showed increased -OH intensity, indicating 3.7-15.1% (in vitro) and 9.7-25.5% (in vivo) of weight loss associated with hydrolysis of CS/PVA. No cytotoxic effects were observed in human dermal fibroblasts (HDFs) from primary culture stained with calcein and ethidium homodimer, confirming cell viability of more than 95% and indicating cell attachment which did not require additional coatings or interfaces between SIPNs and seeded cells. HDFs were also able to spread, showing fusiform morphologies and cell confluence. Proliferation, via DNA quantification, increased with PDMS ratio: 247 ± 11 ng/mL (SIPN 7:3), 197 ± 5 ng/mL (5:5), and 142 ± 8 ng/mL (3:7). Subdermal implants formed connective tissue pseudo-capsules over four weeks, absent multinucleated giant cells indicative of foreign body reactions. SIPN 7:3 matched commercial dressings in wound closure, wound length, collagen synthesis, and neo-vascularization, outperforming in blood vessel count at day 7 -statistically significant- and equaling at day 14 versus control. SIPN 7:3 offers commercial-level efficacy, hyperelasticity, adaptability to irregular sites, and transparency for monitoring, positioning it as a promising alternative for chronic wound treatment.