Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.08.12.244186v1?rss=1 Authors: Rajasekar, V., Darne, P., Prabhune, A., Kao, R. Y. T., Solomon, A. P., Ramage, G., Samaranayake, L., Neelakantan, P. Abstract: Candida albicans is an opportunistic fungal pathogen that is highly resistant to contemporary antifungals, and a major reason for this appears to be their predominant, filamentation-mediated, biofilm lifestyle. Hence, agents that inhibit biofilms and filamentation of the yeast offer promise as next- generation antifungals. Curcumin is a natural polyphenol with several beneficial pharmacological attributes, yet limitations such as poor solubility, acid, and enzyme tolerance have impeded its practical utility. Sophorolipids are biologically-derived surfactants that serve as efficient carriers and delivery agents of hydrophobic molecules, such as curcumin, into biofilms. The aim of this study was to investigate the effects of a novel, curcumin-sophorolipid (CU-ASL) nano-conjugate on Candida albicans biofilms and filamentation. The effects of CU and ASL, in combination, and alone, were investigated on planktonic cells of the yeast. The effects of sub-inhibitory concentrations of the compounds were investigated on biofilm biomass and biofilm architecture. Their effects on filamentation was compared by scanning electron microscopic imaging, and gene expression analysis by qRT-PCR. Our results demonstrated that sub-inhibitory concentration of CU-ASL (9.37 microgram/mL) significantly inhibited candidal adhesion to substrates, and subsequent biofilm development, maturation, and filamentation. This effect was associated with significant downregulation of a select group of biofilm, adhesins, and hyphal regulatory genes. In conclusion, the curcumin-sophorolipid nano-conjugate is a potent inhibitor of the two major virulence attributes of C. albicans, biofilm formation and filamentation, thus highlighting its promise as a putative anti-candidal agent with low toxicity and biofilm penetrative potential. Copy rights belong to original authors. Visit the link for more info