An investigation into uptake and delivery of oligonucleotides in Candida.

Candida represent a leading cause of morbidity and mortality worldwide resulting from opportunistic fungal infections. Increasing antifungal resistance calls for new ways of treating multidrug resistant fungal infections. Antisense oligonucleotides that target essential genes can offer a new treatment option; however, uptake of oligonucleotides presents the problem of passage across cell membrane and/or cell wall layers. Liposomes have been used to deliver pharmaceutical drugs, proteins, and nucleic acids to a variety of bacterial and eukaryotic cells. Here we investigated the utilization of commercially available liposomes to facilitate uptake of antisense oligonucleotides in Candida. Dynamic light scattering analysis determined the method which produced the most uniform commercially available liposome. Flow cytometry revealed which liposome composition facilitated the best delivery of fluorescein-labeled oligonucleotides in planktonic cells of Candida albicans, Candida auris and Candida glabrata. A time dependent uptake of liposomes within Candida biofilms demonstrated delivery of fluorescein-tagged DNA in Candida glabrata by 24 h. Efficient delivery of antisense-EFG1 was further indicated by a corresponding reduction in C. albicans hyphae length and number as well as a reduction in the levels of EFG1 gene expression.