Electrospun polyvinyl alcohol fibres incorporating an antimicrobial gel for enzymatically controlled reactive oxygen species release

Wounds pose a risk to the skin, our body’s primary defence against infections. The rise of antibiotic resistance has prompted the development of novel therapies. RO-101 ® is an antimicrobial gel that delivers therapeutic levels of hydrogen peroxide (H 2 O 2 ), a reactive oxygen species, directly to the wound bed. In this study, electrospinning was used to incorporate RO-101 ® into a polyvinyl alcohol (PVA) sub-micron fibrous mesh that can act as a delivery agent, achieve a sustained release profile, and provide a barrier against infection. Adequate incorporation of this gel into sub-micron fibres was confirmed via nuclear magnetic resonance spectroscopy. Furthermore, scanning electron microscopy exhibited smooth and uniform meshes with diameters in the 200–500 nm range. PVA/RO-101 electrospun meshes generated H 2 O 2 in concentrations exceeding 1 mM/(g·mL) (1 mM = 1 mmol/L) after 24 h, and the role of sterilisation on H 2 O 2 release was evaluated. PVA/RO-101 meshes exhibited antimicrobial activity against both Gram-positive Staphylococcus aureus ( S. aureus ) and Gram-negative Pseudomonas aeruginosa ( P. aeruginosa ) bacteria, achieving viable count reductions of up to 1 log unit CFU/mm 2 (CFU: colony-forming units). Moreover, these meshes were capable of disrupting biofilm formation, even against multidrug-resistant organisms such as methicillin-resistant S. aureus (MRSA). Furthermore, increasing the RO-101 ® concentration resulted in higher H 2 O 2 production and an enhanced antimicrobial effect, while fibroblast cell viability and proliferation tests showed a concentration-dependent response with high cytocompatibility at low RO-101 ® concentrations. This study therefore demonstrates the potential of highly absorbent PVA/RO-101 meshes as potential antimicrobial wound dressings. Graphic abstract