Chronic wounds are injuries that persist beyond expected healing timeframes. Although they have varying aetiologies abnormal development, prolonged inflammation and evident hypoxia are common features in all chronic wounds. Innovative treatments are sought and gas-based therapies in particular have shown promise in supporting conventional treatment strategies. This scoping review aims to identify and compare the range of formulations that are used for gas-based therapy and evaluate their effectiveness in treating chronic wounds.

A scoping review was conducted with articles identified from the Medline, Embase and Scopus databases. Articles exploring gas-based therapies in chronic wound healing were identified after screening all the search results against inclusion and exclusion criteria.

There were 54 clinical studies and 45 preclinical studies eligible for analysis. Gas-based therapies were delivered by various modalities. Hyperbaric oxygen therapy and topical gas therapies demonstrated some clinical utilisation, though adoption into standard care protocols was limited by costs and variable treatment outcomes. Novel formulations were of significant interest within the preclinical space, with micro- and nanoparticle systems and hydrogel scaffolds demonstrating an ability to effectively deliver various therapeutic gases and improve chronic injury outcomes in cell and animal-based models. However, the wound healing capacities of established and exploratory approaches have rarely been compared to each other.

Hyperbaric oxygen therapy and topical gas therapy are clinically used in chronic wound management, although they have not been adopted as part of standard wound care. A variety of recently developed gas-loaded formulations have demonstrated preclinical potential and are poised to soon migrate into the clinical trial domain.