A Hydroxypropyl Chitosan (HPCH) Based Medical Device Prevents Fungal Infections: Evidences from an In Vitro Human Nail Model

A long lasting, protective and film forming HPCH-based medical device was developed and tested in a novel in vitro human nail infection model. HPCH-treated and untreated human distal fingernail fragments were disposed on the culture surface of Trychophyton rubrum, T. mentagrophytes, Scopulariopsis brevicaulis or Candida parapsilosis. After incubation for one or three weeks, the fragments were collected and histological analysis was performed. Results obtained in untreated nails evidenced, as expected, that the fungal invasion was different depending on the species: it was completed with Trichophyton spp., partial with Scopurlariopsis sp. and limited to the surface with Candida sp.. On the other hand, HPCH-treated nails were not invaded by fungal elements, neither dermatophytes nor moulds or yeasts. Besides showing the barrier effect of HPCH this paper describes a novel in vitro model of nail infection that is simple, reproducible and closely represents the in vivo human situation.