This Small Business Innovation Research (SBIR) Phase I project will perform proof-of-concept development and testing of a novel, safe, and effective treatment option for onychomycosis (nail fungal infection). The device would offer patients and doctors a reliable method to treat nail fungal infections without toxic side effects. Over 35 million Americans suffer from onychomycosis, which carries a direct cost of over $4 billion in the US healthcare system. Current treatment options include surgical removal of the nail, oral medications that may cause liver damage, or topical creams and lasers that have low or unproven efficacy.
The broader impact/commercial potential of this project beyond providing a safe, effective cure for 35 million Americans suffering from nail fungal infections, will be to enhance the treatment of other fungal and bacterial infections of the body and material surfaces. This would include healthcare uses such as skin and wound disinfection, decontamination of teeth and gums (oral hygiene), and the sterilization of medical instruments and implanted devices. Outside the healthcare field, the knowledge acquired in this fungal nail system development would have sterilization and decontamination uses such as in commercial equipment, food, and water sterilization.
This Small Business Innovation Research Phase I project performed proof-of-concept prototype development and experimental feasibility studies around a novel medical device to cure fungal nail infection. Onychomycosis or fungal nail affects over 38 million Americans and carries a direct cost of more than $4 billion in the US healthcare system. Current treatment options include surgical removal of the nail, oral medications that can cause liver damage or topical medicine with low efficacy. The development of an innovative topical technology that is lower in off-target effects and systemic toxicity than current treatments and is not susceptible to resistance mechanisms that are problematic for antibiotics would be beneficial to this patient community. Also, current treatments require protracted periods of application and this technology could reduce treatment time and so increase compliance. There is significant public health relevance in addressing the need for therapies that eradicate fungal nail infections, which are typically well-entrenched. Nail fungal infections can become a persistent reservoir for more significant infectious disease problems. Diabetic patients with foot ulcers are four times more likely to have their foot amputated if they have onychomycosis. The successful implementation of our strategy could alter the way fungal nail infections are treated and significantly lower the morbidity caused by these infections as well as improve the quality of life for millions of Americans. The project's objectives were to design and develop a functioning instrument prototype that can show proof of concept and then validate its performance using a bovine hoof model (a commonly used in vitro human nail model) and the fungal strain T. rubrum, the primary fungus that causes over 80% of onychomycosis cases. The bench top experiments combined ultrasound stimulation of the hoof with nonthermal plasma gas treatment. This combination was chosen because nonthermal plasma gas is a proven antifungal and gas is the optimal material to penetrate into a porous, infected nail. An ultrasound stimulation pre-treatment was used to both create pores that would increase the permeation of the nail and break up biofilms that may form within the structure. Our experimental studies demonstrated proof-of-concept by showing that a nonthermal plasma can penetrate through a bovine hoof and eliminate fungal infection. Multiple plasma gas treatments through a bovine hoof achieved complete mycological cure (100% elimination of T. rubrum fungus), which indicates the treatment could be a very promising commercial product. However, experiments using ultrasound pre-treatment showed no statistical improvement in increasing permeability of the plasma through the hoof and showed no ability to decrease plasma treatment times or increased elimination of the fungus at a set treatment time.
