Epsilon-poly-l-lysine decorated ordered mesoporous silica contributes to the synergistic antifungal effect and enhanced solubility of a lipophilic drug.

The emergence of drug-resistant fungal strains remains a severe threat for the public health, which prompts strict restrictions on the uses of antifungal drugs. However, the majority of lipophilic fungistatic agents are poorly water soluble with a low oral adsorption characteristic posing challenges for the precise prescriptions. In this study, a natural antimicrobial cationic peptide of epsilon-poly-l-lysine (EPL) decorated ordered mesoporous silica (SBA-15) was facilely prepared for the efficient loading of antifungal itraconazole (ITZ) drugs. The characterized mesoporous SBA-15/EPL/ITZ composite exhibited remarkable antifungal performance against Aspergillus fumigatus as a model mold, which was attributed to synergistic antifungal activities of ITZ and EPL in the mesopores. Moreover, the in vitro release behaviors of ITZ in the composite nanoexcipients both in simulated gastric fluid and fasted state simulated intestinal fluid were studied. The observed release kinetics of ITZ demonstrated a contributing role of SBA-15/EPL to enhance the solubility of ITZ and thereby may promote its flux across the gastrointestinal epithelium, which is beneficial for the absorption of drugs. Additionally, SBA-15/EPL/ITZ composites showed desirable biocompatibility toward mammalian red blood cells, human cervical cancer cells (Hela) and human embryonic kidney cells (HEK-293T). Furthermore, the pharmacokinetic profiles of obtained nano-formulations were assessed in rats, among which the improved adsorption of SBA-15/EPL/ITZ composites (AUC: 8381.7 nM·h) was identified compared with that of pure ITZ (525.1 nM·h) and the commercial drug of Sporanox (7516.6 nM·h). Collectively, the prepared SBA-15/EPL/ITZ provides an ecofriendly and integrated nanocomposite with enhanced solubility of lipophilic drugs to combat proliferations of infectious fungi.