Modification of polyvinyl alcohol-based electrospun mats with naturally-derived halochromic molecules for potential applications in wound healing monitoring

Chronic wounds represent a major problem for healthcare worldwide. Currently, the treatments used (conventional dressings) do not provide the necessary response, and new wound management approaches and innovations in dressings are needed. One of the biggest challenges in the healing of chronic wounds is the control and inhibition of microbial proliferation, keeping the wound site as sterile as possible, and hence facilitate tissue renewal. Natural extracts such as geraniol, cinnamaldehyde and citral were tested as antifungal allies, targeting Candida spp. fungi, which are often neglected in chronic wound healing. They were loaded onto polyvinyl alcohol (PVA) electrospun mats, which were also modified with halochromic molecules, namely anthocyanins. These specialized molecules can assist with the monitoring of the healing progression through pH-sensitivity, without requiring frequent dressing removal, thus preventing the destruction of newly formed tissue. Anthocyanins were obtained through in house extraction and commercially and their halochromic response verified. Antifungal natural extracts were combined with the PVA via blending (prior to electrospinning). On its turn, immobilization of anthocyanins was done also via blending or via absorption (after electrospinning and crosslinking process). The first option was found the most impactful, evidencing immediate and lasting effects of the halochromic properties, which mapped the antifungal extracts activity against the Candida spp.