Engineering Personalised Cutaneous Hypobaric Microchambers to Facilitate the Treatment of Local Infectious Diseases with Gaseous Signalling Molecules

Plants release several volatile sulphur-containing compounds as a stress response. When scientists mimicked this plant response using sulphur-containing gases they inhibited fungal and bacterial growth on the surface of fruit. These results have important implications on food preservation, but in addition preliminary experiments by the King's College London and the University of Bath have shown that these gases can inhibit organisms that cause human skin and nail infections.

Despite the potential of gases to be used as anti-infective agents, it is difficult to use them with patients because gases do not readily pass into the body other than via the airways. However, reports have suggested that certain natural chemicals, e.g., allicin extract from garlic, can react once in the body to release a gas can be used to administer gases to the skin and nail. A medical device is now required that can control the deliver of these gases released by chemical donors such that they can effectively treat human infections.
Applying positive and negative pressure gradients to tissues can control the delivery of gases. For example, Continuous Positive Airway Pressure (CPAP) machines used with COVID-19 patients, increased the amount of oxygen in the blood by pushing the gas into the body under positive presure. If a device can be made that exerts negative pressure on the skin, then the gas delivered by a donor chemical will be released and held at the site of application to target its deliver and enhance its efficacy.

In this project, a customized 3D printed silicone sheath containing a microchamber that holds a gas donor chemical impregnated gauze on the nail surface, already designed by researchers at King's College London, will be refined and used to administer hydrogen sulphide to the nail for the treatment of nail infections. The microchamber and gauze will be customized to the exact region of the nail to be treated. This new device has the potential to treat over 100 million people who are thought to suffer from nail disease.

This research project will develop a new treatment paradigm for cutaneous infections. It will use personalised fabrication techniques, via commercially available benchtop 3D printers and digital 3D scanners, to provide patients with the flexibility to have effective treatments provided in the most user-friendly manner possible. The product will be a cost-effective solution to overcome a significant health problem as it facilitates the fabrication of a bespoke medical device from medical grade silicone materials using 3D printing (total cost of goods <50p). This approach could be developed to treat other skin infections including those arising as a consequence of chronic wounds and burns.