An efficient technique for testing topical antifungal drugs for treating nail infections

Nail infection (onychomycosis) affects people worldwide, with estimated prevalence of about 14% in North America [1], 20% in East Asia [2], and 23% [3] in Europe. Among these, about 50% are caused by fungal pathogens [4]. Epidemiological surveys have identified several risk factors for onychomycosis, including old age; compromised immunity from HIV infection, organ transplantation, and cancer treatments; wearing non-breathable tight footwear for extended periods of time; working in certain occupations such as mining, lodging, and the military; extended use of damp spaces such as locker rooms and gymnasiums that are shared by large groups of people; and physical activities such as long-distance running and playing racket sports that cause trauma to nails [4-7]. With an increasing number of people exposed to these risk factors, the prevalence of onychomycosis is expected to rise, especially in developed countries with a looming aging population. While typically not life-threatening and often dismissed as merely an unsightly nuisance, onychomycosis can cause noticeable disfigurement of the nail, discomfort, and pain, and impact mobility and occupation choices [4,8]. In severe cases, onychomycosis can lead to systemic infection, limb amputation, and even death. However, none of the current treatments are ideal and often require extended long-term therapy and/or have significant side effects, especially for oral medications [5,8]. As a result, there is a pressing need to develop effective, topical treatment strategies.