Fungal infections have become a major health concern, given that invasive infections by Candida, Cryptococcus, and Aspergillus species have led to millions of mortalities. Conventional antifungal drugs including polyenes, echinocandins, azoles, allylamins, and antimetabolites have been used for decades, but their limitations include off-target toxicity, drug-resistance, poor water solubility, low bioavailability, and weak tissue penetration, which cannot be ignored. These drawbacks have led to the emergence of novel antifungal therapies. In this review, we discuss the nanosystems that are currently utilized for drug delivery and the application of antifungal therapies.

Candida commonly adheres to implanted medical devices and forms biofilms. Due to the minimal activity of current antifungals against biofilms, new drugs or drug-delivery systems to treat these persistent infections are urgently needed. In the present investigation, voriconazole-loaded nanostructured lipid carriers (Vrc-NLCs) were formulated for enhanced drug-delivery efficiency to C. albicans to increase the antifungal activity of Vrc and to improve the treatment of infectious Candida diseases. Vrc-NLCs were prepared by a hot-melt, high-pressure homogenization method, and size distribution, ζ-potential, morphology, drug-encapsulation efficiency, drug loading, and physical stability were characterized. The antifungal activity of Vrc-NLCs in vitro was tested during planktonic and biofilm growth in C. albicans. The mean particle size of the Vrc-NLCs was 45.62±0.53 nm, and they exhibited spheroid-like morphology, smooth surfaces, and ζ-potential of -0.69±0.03 mV. Encapsulation efficiency and drug loading of Vrc-NLCs were 75.37%±2.65% and 3.77%±0.13%, respectively. Physical stability results revealed that despite the low measured ζ-potential, the dispersion of the Vrc-NLCs was stable during their 3-week storage at 4°C. The minimum inhibitory concentration of Vrc-NLCs was identical to that of Vrc. However, the inhibition rate of Vrc-NLCs at lower concentrations was significantly higher than that of Vrc during planktonic growth in C. albicans in yeast-extract peptone dextrose medium. Surprisingly, Vrc-NLCs treatment reduced cell density in biofilm growth in C. albicans and induced more switches form hyphal cells to yeast cells compared with Vrc treatment. In conclusion, Vrc-NLCs maintain antifungal activity of Vrc and increase antifungal drug-delivery efficiency to C. albicans. Therefore, Vrc-NLCs will greatly contribute to the treatment of infectious diseases caused by C. albicans.

Cutaneous candidiasis, caused by Candida albicans , is a severe and frustrating condition, and finding effective treatments can be challenging. Therefore, the development of farnesol-loaded nanoparticles is an exciting breakthrough. Ethosomes are a novel transdermal drug delivery carrier that incorporates a certain concentration (10–45%) of alcohols into lipid vesicles, resulting in improved permeability and encapsulation rates compared to conventional liposomes. Farnesol is a quorum-sensing molecule involved in morphogenesis regulation in C. albicans , and these ethosomes offer a promising new approach to treating this common fungal infection. This study develops the formulation of farnesol-loaded ethosomes (farnesol-ethosomes) and assesses applications in treating cutaneous candidiasis induced by C. albicans in vitro and in vivo . Farnesol-ethosomes were successfully developed by ethanol injection method. Therapeutic properties of farnesol-ethosomes, such as particle size, zeta potential, and morphology, were well characterized. According to the results, farnesol-ethosomes demonstrated an increased inhibition effect on cells’ growth and biofilm formation in C. albicans . In Animal infection models, treating farnesol-ethosomes by transdermal administration effectively relieved symptoms caused by cutaneous candidiasis and reduced fungal burdens in quantity. We also observed that ethosomes significantly enhanced drug delivery efficacy in vitro and in vivo . These results indicate that farnesol-ethosomes can provide future promising roles in curing cutaneous candidiasis. IMPORTANCE: Cutaneous candidiasis attributed to Candida infection is a prevalent condition that impacts individuals of all age groups. As a type of microbial community, biofilms confer benefits to host infections and mitigate the clinical effects of antifungal treatments. In C. albicans , the yeast-to-hypha transition and biofilm formation are effectively suppressed by farnesol through its modulation of multiple signaling pathway. However, the characteristics of farnesol such as hydrophobicity, volatility, degradability, and instability in various conditions can impose limitations on its effectiveness. Nanotechnology holds the potential to enhance the efficiency and utilization of this molecule. Treatment of farnesol-ethosomes by transdermal administration demonstrated a very remarkable therapeutic effect against C. albicans in infection model of cutaneous candidiasis in mice. Many patients suffering fungal skin infection will benefit from this study.

Introduction: The increasing prevalence of systemic fungal infections, especially among immunocompromised individuals, highlights the need for advancements in targeted and effective antifungal treatments. This study presents a novel nanomaterial, CFW-phosphatidylethanolamine conjugate (CFW-PEc), designed to enhance the delivery and efficacy of antifungal agents by targeting fungal cell walls through specific chitin binding. Ethosomes, lipid-based nanocarriers known for their ability to improve drug delivery across skin and cell membranes, were utilized in this study. Methods: The physicochemical characteristics of voriconazole-loaded CFW-PEc ethosomes (CFW-PEc-VRC-ethosomes) were examined, including particle size, zeta potential, and entrapment efficiency. Antifungal efficacy of CFW-PEc-VRC-ethosomes was evaluated, including antifungal activity in vitro, CFW-PEc-ethosomes cellular uptake, and models of animal infection and imaging analyses. Results: In vitro experiments demonstrated a concentration-dependent inhibition of C. albicans growth by CFW-PEc, with cell inhibition rates reaching nearly 100% at 256 μM. In vivo investigations confirmed a 5-fold reduction in fungal burden in the liver and a 7.8-fold reduction in the kidney compared to the control group following treatment with CFW-PEc (0.1 μM)-VRC-ethosomes. Imaging analyses also confirmed the extended tissue retention of fluorescent dye-loaded CFW-PEc-ethosomes in mice, further underscoring their potential for clinical use. Discussion: The targeted delivery of antifungal medications via ethosomes coated with CFW-PEc presents a promising strategy to improve antifungal effectiveness while reducing adverse effects, marking a significant advancement in fungal infection therapy.

Fungal infections gradually lead to a high mortality rate due to difficulties in diagnosis, the limited number of antifungal drugs available, and the appearance of resistant isolates. Here, we developed a calcofluor white-cholesteryl hydrogen succinate conjugate (CFW–CHSc) as a novel nanomaterial that specifically binds to chitin chains in the cell wall. We showed that fluorescent-dye loaded CFW–CHSc-liposomes entered the cytoplasm of Candida albicans cells with increased efficacy. Voriconazole-loaded CFW–CHSc-liposomes displayed an increased antifungal activity against C. albicans yeast cells in an in vitro assay. Animal infection models and animal imaging analysis showed that fluorescent-dye loaded CFW–CHSc-liposomes maintained prolonged residence in rodent tissues. In mouse liver and kidney tissue, voriconazole-loaded CFW–CHSc-liposomes showed significantly enhanced antifungal activity when administered intravenously. Taken together, our studies confirm that CFW–CHSc increases the drug delivery efficacy of nanoparticles in vitro by interacting with chitin chains in the C. albicans cell wall. The fungi-targeting nanoparticles improve the drug delivery efficacy in vivo by enriching the nanoparticles at the site of fungal infection via the blood circulation system. Fungi-targeting nanomaterials have a promising future in the treatment of nosomycosis.

Cryptococcus neoformans is a significant and pathogenic encapsulated basidiomycete fungus responsible for cryptococcosis, particularly in immunocompromised individuals. With increasing incidence rates globally, there is an urgent need for improved therapeutic strategies. This study presents the development of a fungal-targeted nanodrug delivery system utilizing a calcofluor white-phosphatidylethanolamine conjugate (CFW-PEc) to enhance the delivery and efficacy of amphotericin B against C. neoformans . We successfully formulated AmB-loaded CFW-PEc-ethosomes, which demonstrated favorable physicochemical properties, including suitable particle size, zeta potential, and high drug entrapment efficiency. In vitro antifungal assessments revealed that CFW-PEc-AmB-ethosomes exhibited superior antifungal activity compared to conventional AmB formulations, maintaining high inhibition rates at lower concentrations, while also demonstrating a favorable safety profile with reduced cytotoxicity. Additionally, in vivo studies in a mouse model of cryptococcal pneumonia illustrated remarkable reductions in fungal burdens and improved histopathological outcomes, attributing these effects to effective targeting of C. neoformans via CFW-PEc. Our findings underscore the potential of CFW-PEc in enhancing the therapeutic efficacy and safety profile of antifungal treatments, paving the way for advanced treatment strategies against cryptococcal pneumonia. IMPORTANCE: Cryptococcal pneumonia presents a significant global health burden with limited therapeutic options due to inherent toxicity and suboptimal bioavailability of conventional antifungal agents. This investigation demonstrates the innovative application of calcofluor white-phosphatidylethanolamine conjugate (CFW-PEc) to enhance amphotericin B (AmB) delivery via ethosomes for cryptococcal infection treatment. Our findings elucidate that CFW-PEc significantly potentiates the antifungal efficacy of AmB-loaded ethosomes against Cryptococcus neoformans while concomitantly mitigating associated cytotoxicity at optimal concentrations. In murine models of pulmonary cryptococcosis, this novel formulation achieved a remarkable 10-fold reduction in fungal burden compared to controls, while preserving pulmonary histoarchitecture and attenuating inflammatory responses. This delivery system’s integrated strategy of increasing antifungal effectiveness while reducing adverse effects marks a significant leap forward in developing safer and more targeted nanomaterial-mediated antifungal treatments. These results have profound implications for developing more efficacious and less toxic treatment modalities for cryptococcal pneumonia and potentially other invasive fungal infections.