A self-assembling peptide inhibits the growth and function of fungi via a wrapping strategy.

Fungal infections contribute substantially to human morbidity and mortality. A particular concern is the high rate of mortality associated with invasive fungal infections, which often exceeds 50.0% despite the availability of several antifungal drugs. Herein, we show a self-assembling antifungal peptide (AFP), which is able to bind to chitin on the fungal cell wall and in situ form AFP nanofibers, wrapping fungi. As a result, AFP limits the proliferation of fungi, slows down the morphological transformation of biphasic fungi, and inhibits the adhesion of fungi to host cells and the formation of biofilms. Compared to the broad-spectrum antifungal fluconazole, AFP achieved a comparable inhibitory effect (MIC50 = 3.5 µM) on fungal proliferation. In addition, AFP significantly inhibited the formation of fungal biofilms with the inhibition rate of 69.6% at 1 µM, better than fluconazole (17.2% at 1 µM). In a skin infection model of mice, it was demonstrated that AFP showed significantly superior efficacy to fluconazole. In the systemic candidiasis mouse model, AFP showed similar efficacy to first-line antifungal amphotericin B (AmpB) and anidulafungin (AFG). This study provides a promising wrapping strategy for anti-fungal infection.

Genome-wide profiling of piggyBac transposon insertion mutants reveals loss of the F1F0 ATPase complex causes fluconazole resistance in Candida glabrata.

Invasive candidiasis caused by non-albicans species has been on the rise, with Candida glabrata emerging as the second most common etiological agent. Candida glabrata possesses an intrinsically lower susceptibility to azoles and an alarming propensity to rapidly develop high-level azole resistance during treatment. In this study, we have developed an efficient piggyBac (PB) transposon-mediated mutagenesis system in C. glabrata to conduct genome-wide genetic screens and applied it to profile genes that contribute to azole resistance. When challenged with the antifungal drug fluconazole, PB insertion into 270 genes led to significant resistance. A large subset of these genes has a role in the mitochondria, including almost all genes encoding the subunits of the F1F0 ATPase complex. We show that deleting ATP3 or ATP22 results in increased azole resistance but does not affect susceptibility to polyenes and echinocandins. The increased azole resistance is due to increased expression of PDR1 that encodes a transcription factor known to promote drug efflux pump expression. Deleting PDR1 in the atp3Δ or atp22Δ mutant resulted in hypersensitivity to fluconazole. Our results shed light on the mechanisms contributing to azole resistance in C. glabrata. This PB transposon-mediated mutagenesis system can significantly facilitate future genome-wide genetic screens.

Evolutionary diversity of the control of the azole response by Tra1 across yeast species.

Tra1 is an essential coactivator protein of the yeast SAGA and NuA4 acetyltransferase complexes that regulate gene expression through multiple mechanisms including the acetylation of histone proteins. Tra1 is a pseudokinase of the PIKK family characterized by a C-terminal PI3K domain with no known kinase activity. However, mutations of specific arginine residues to glutamine in the PI3K domains (an allele termed tra1Q3) result in reduced growth and increased sensitivity to multiple stresses. In the opportunistic fungal pathogen Candida albicans, the tra1Q3 allele reduces pathogenicity and increases sensitivity to the echinocandin antifungal drug caspofungin, which disrupts the fungal cell wall. Here, we found that compromised Tra1 function, in contrast to what is seen with caspofungin, increases tolerance to the azole class of antifungal drugs, which inhibits ergosterol synthesis. In C. albicans, tra1Q3 increases the expression of genes linked to azole resistance, such as ERG11 and CDR1. CDR1 encodes a multidrug ABC transporter associated with efflux of multiple xenobiotics, including azoles. Consequently, cells carrying tra1Q3 show reduced intracellular accumulation of fluconazole. In contrast, a tra1Q3 Saccharomyces cerevisiae strain displayed opposite phenotypes: decreased tolerance to azole, decreased expression of the efflux pump PDR5, and increased intracellular accumulation of fluconazole. Therefore, our data provide evidence that Tra1 differentially regulates the antifungal response across yeast species.

Thyme Oil-Containing Fluconazole-Loaded Transferosomal Bigel for Transdermal Delivery.

The objective of the present research was to develop fluconazole-loaded transferosomal bigels for transdermal delivery by employing statistical optimization (23 factorial design-based). Thin-film hydration was employed to prepare fluconazole-loaded transferomal suspensions, which were then incorporated into bigel system. A 23 factorial design was employed where ratios of lipids to edge activators, lipids (soya lecithin to cholesterol), and edge activators (sodium deoxycholate to Tween 80) were factors. Ex vivo permeation flux (Jss) of transferosomal bigels across porcine skin was analyzed as response. The optimal setting for optimized formulation (FO) was A= 4.96, B= 3.82, and C= 2.16. The optimized transferosomes showed 52.38 ± 1.76% DEE, 76.37 nm vesicle size, 0.233 PDI, - 20.3 mV zeta potential, and desirable deformability. TEM of optimized transferosomes exhibited a multilamelar structure. FO bigel's FE-SEM revealed a globule-shaped vesicular structure. Further, the optimized transferosomal suspension was incorporated into thyme oil (0.1% w/w)-containing bigel (TO-FO). Ex vivo transdermal fluconazole permeation from different transferosomal bigels was sustained over 24 h. The highest permeation flux (4.101 µg/cm2/h) was estimated for TO-FO bigel. TO-FO bigel presented 1.67-fold more increments of antifungal activity against Candida albicans than FO bigel. The prepared thyme oil (0.1% w/w)-containing transfersomal bigel formulations can be used as topical delivery system to treat candida related fungal infections.

CWHM-974 is a fluphenazine derivative with improved antifungal activity against Candida albicans due to reduced susceptibility to multidrug transporter-mediated resistance mechanisms.

Multidrug resistance (MDR) transporters such as ATP-Binding Cassette (ABC) and Major Facilitator Superfamily proteins are important mediators of antifungal drug resistance, particularly with respect to azole class drugs. Consequently, identifying molecules that are not susceptible to this mechanism of resistance is an important goal for new antifungal drug discovery. As part of a project to optimize the antifungal activity of clinically used phenothiazines, we synthesized a fluphenazine derivative (CWHM-974) with 8-fold higher activity against Candida spp. compared to the fluphenazine and with activity against Candida spp. with reduced fluconazole susceptibility due to increased MDR transporters. Here, we show that the improved C. albicans activity is because fluphenazine induces its own resistance by triggering expression of Candida drug resistance (CDR) transporters while CWHM-974 induces expression but does not appear to be a substrate for the transporters or is insensitive to their effects through other mechanisms. We also found that fluphenazine and CWHM-974 are antagonistic with fluconazole in C. albicans but not in C. glabrata, despite inducing CDR1 expression to high levels. Overall, CWHM-974 is one of the few examples of a molecule in which relatively small structural modifications significantly reduced susceptibility to multidrug transporter-mediated resistance.

Mefentrifluconazole exposure disrupted hepatic lipid metabolism disorder tightly associated with gut barrier function abnormal in mice.

Mefentrifluconazole (MFZ) is an azole fungicide that is placed in agriculture for the control of fungal hazards. However, due to their non-biodegradability, azole fungicides can accumulate in plants, animals, and the environment, thus becoming a major health concern worldwide. In this study, we exposed 7-week-old C57BL/6 mice to 10, 30, and 100 mg/kg of MFZ for 28 d to assess the toxic effects of MFZ on the liver and gut tissues of the mice. Histopathological, biochemical indexes, and transcriptomic analyses revealed that MFZ exposure disrupted the liver structure and hepatic lipid metabolism as well as damaged gut barrier function and promoted inflammation in mice. Moreover, 16S rRNA sequencing demonstrated that MFZ exposure significantly increased the abundance of patescibacteria at the generic level. Also, MFZ exposure increased the abundance of bacterial genera associated with inhibition of glycolipid metabolism. These results suggested that the disruption of liver lipid metabolism caused by MFZ exposure may be caused by changes in gut microbiota function. This study provided a new disease occurrence study for risk assessment of MFZ and strengthened the focus on some novel fungicides.

Quantitative proteomics revealed the transition of ergosterol biosynthesis and drug transporters processes during the development of fungal fluconazole resistance.

Fungal infections and antifungal resistance are the increasing global public health concerns. Mechanisms of fungal resistance include alterations in drug-target interactions, detoxification by high expression of drug efflux transporters, and permeability barriers associated with biofilms. However, the systematic panorama and dynamic changes of the relevant biological processes of fungal drug resistance acquisition remain limited. In this study, we developed a yeast model of resistance to prolonged fluconazole treatment and utilized the isobaric labels TMT (tandem mass tag)-based quantitative proteomics to analyze the proteome composition and changes in native, short-time fluconazole stimulated and drug-resistant strains. The proteome exhibited significant dynamic range at the beginning of treatment but returned to normal condition upon acquisition drug resistance. The sterol pathway responded strongly under a short time of fluconazole treatment, with increased transcript levels of most enzymes facilitating greater protein expression. With the drug resistance acquisition, the sterol pathway returned to normal state, while the expression of efflux pump proteins increased obviously on the transcription level. Finally, multiple efflux pump proteins showed high expression in drug-resistant strain. Thus, families of sterol pathway and efflux pump proteins, which are closely associated with drug resistance mechanisms, may play different roles at different nodes in the process of drug resistance acquisition. Our findings uncover the relatively important role of efflux pump proteins in the acquisition of fluconazole resistance and highlight its potential as the vital antifungal targets.

Fingerprint Stimulated Raman Scattering Imaging Unveils Ergosteryl Ester as a Metabolic Signature of Azole-Resistant Candida albicans.

Candida albicans (C. albicans), a major fungal pathogen, causes life-threatening infections in immunocompromised individuals. Fluconazole (FLC) is recommended as first-line therapy for treatment of invasive fungal infections. However, the widespread use of FLC has resulted in increased antifungal resistance among different strains of Candida, especially C. albicans, which is a leading source of hospital-acquired infections. Here, by hyperspectral stimulated Raman scattering imaging of single fungal cells in the fingerprint window and pixel-wise spectral unmixing, we report aberrant ergosteryl ester accumulation in azole-resistant C. albicans compared to azole-susceptible species. This accumulation was a consequence of de novo lipogenesis. Lipid profiling by mass spectroscopy identified ergosterol oleate to be the major species stored in azole-resistant C. albicans. Blocking ergosterol esterification by oleate and suppressing sterol synthesis by FLC synergistically suppressed the viability of C. albicans in vitro and limited the growth of biofilm on mouse skin in vivo. Our findings highlight a metabolic marker and a new therapeutic strategy for targeting azole-resistant C. albicans by interrupting the esterified ergosterol biosynthetic pathway.

Transport Across Membranes: Techniques for Measuring Drug Import in Fungal Cells.

The ability of many antifungal molecules to traverse the fungal cell wall and accumulate within the cell is crucial to its ability to have the desired biological activity. Altered accumulation of the drug is an important mechanism of antifungal drug resistance. The best characterized mechanism for altered accumulation is through the action of the drug efflux pump which actively transports the drugs out of the membrane, although this is not the only mechanism for this phenomenon. Here, we describe protocols for the measurement of uptake of tritiated fluconazole in both yeast and filamentous fungi.

Anticandidal Activity of Capsaicin and Its Effect on Ergosterol Biosynthesis and Membrane Integrity of Candida albicans.

Oral candidiasis is an infection of the oral cavity commonly caused by Candida albicans. Endodontic treatment failure has also been found to be persistent from C. albicans in the root canal system. Despite the availability of antifungal drugs, the management of Candida oral infection is difficult as it exhibits resistance to a different class of antifungal drugs. Therefore, it is necessary to discover new antifungal compounds to cure fungal infections. This study aimed to examine the antifungal susceptibility of Capsaicin, an active compound of chili pepper. The susceptibility of Capsaicin and Fluconazole was tested against the Candida species by the CLSI (M27-A3) method. The effect of Capsaicin on the fungal cell wall was examined by the ergosterol inhibitory assay and observed by the scanning electron micrograph. The MIC range of Capsaicin against Candida isolates from oral (n = 30), endodontic (n = 8), and ATCC strains (n = 2) was 12.5−50 µg/mL. The MIC range of Fluconazole (128- 4 µg/mL) significantly decreased (2- to 4-fold) after the combination with Capsaicin (MIC/4) (p < 0.05). Capsaicin (at MIC) significantly reduced the mature biofilm of C. albicans by 70 to 89% (p < 0.01). The ergosterol content of the cell wall decreased significantly with the increase in the Capsaicin dose (p < 0.01). Capsaicin showed high sensitivity against the hyphae formation and demonstrated a more than 71% reduction in mature biofilm. A fluorescence microscopy revealed the membrane disruption of Capsaicin-treated C. albicans cells, whereas a micrograph of electron microscopy showed the distorted cells' shape, ruptured cell walls, and shrinkage of cells after the release of intracellular content. The results conclude that Capsaicin had a potential antifungal activity that inhibits the ergosterol biosynthesis in the cell wall, and therefore, the cells' structure and integrity were disrupted. More importantly, Capsaicin synergistically enhanced the Fluconazole antifungal activity, and the synergistic effect might be helpful in the prevention of Fluconazole resistance development and reduced drug-dosing.

[Mechanism of human airway epithelial cell injury induced by Candida albicans infection].

Objective: To investigate the immune mechanism of human airway epithelial cell injury induced by invasion of Candida albicans with different biofilm formation abilities. Methods: Twenty-five strains of Candida albicans isolated and cultured in General Hospital of Ningxia Medical University from June to December 2019 were selected, and quality control strain SC5314 was used as the standard strain. An in vitro model of Candida albicans biofilm was established, and the biofilm formation ability of different Candida albicans was detected by crystal violet staining and enzyme plate method. The absorbance value at 570 nm (A570) was determined by enzyme plate method. A570≥0.5, 0.250.05). Conclusion: Strong biofilm Candida albican can inhibit cell proliferation, disrupt the integrity of epithelial cells and induce cell damage by down-regulating the expression of cell proliferation-related protein.

Antifungal Activity of Fibrate-Based Compounds and Substituted Pyrroles That Inhibit the Enzyme 3-Hydroxy-methyl-glutaryl-CoA Reductase of Candida glabrata (CgHMGR), Thus Decreasing Yeast Viability and Ergosterol Synthesis.

Due to the emergence of multidrug-resistant strains of yeasts belonging to the Candida genus, there is an urgent need to discover antifungal agents directed at alternative molecular targets. The aim of the current study was to evaluate the capacity of three different series of synthetic compounds to inhibit the Candida glabrata enzyme denominated 3-hydroxy-methyl-glutaryl-CoA reductase and thus affect ergosterol synthesis and yeast viability. Compounds 1c (α-asarone-related) and 5b (with a pyrrolic core) were selected as the best antifungal candidates among over 20 synthetic compounds studied. Both inhibited the growth of fluconazole-resistant and fluconazole-susceptible C. glabrata strains. A yeast growth rescue experiment based on the addition of exogenous ergosterol showed that the compounds act by inhibiting the mevalonate synthesis pathway. A greater recovery of yeast growth occurred for the C. glabrata 43 fluconazole-resistant (versus fluconazole-susceptible) strain and after treatment with 1c (versus 5b). Given that the compounds decreased the concentration of ergosterol in the yeast strains, they probably target ergosterol synthesis. According to the docking analysis, the inhibitory effect of 1c and 5b could possibly be mediated by their interaction with the amino acid residues of the catalytic site of the enzyme. Since 1c displayed higher binding energy than α-asarone and 5b, it is the best candidate for further research, which should include structural modifications to increase its specificity and potency. The derivatives could then be examined with in vivo animal models using a therapeutic dose. IMPORTANCE Within the context of the COVID-19 pandemic, there is currently an epidemiological alert in health care services due to outbreaks of Candida auris, Candida glabrata, and other fungal species multiresistant to conventional antifungals. Therefore, it is important to propose alternative molecular targets, as well as new antifungals. The three series of synthetic compounds herein designed and synthesized are inhibitors of ergosterol synthesis in yeasts. Of the more than 20 compounds studied, two were selected as the best antifungal candidates. These compounds were able to inhibit the growth and synthesis of ergosterol in C. glabrata strains, whether susceptible or resistant to fluconazole. The rational design of antifungal compounds derived from clinical drugs (statins, fibrates, etc.) has many advantages. Future studies are needed to modify the structure of the two present test compounds to obtain safer and less toxic antifungals. Moreover, it is important to carry out a more in-depth mechanistic approach.

Palmarumycin P3 Reverses Mrr1-Mediated Azole Resistance by Blocking the Efflux Pump Mdr1.

Palmarumycin P3 (PP3) reduces fluconazole-induced MDR1 transcription to reverse azole resistance in clinical Candida strains. Here, we demonstrated that PP3 restores the susceptibility to several antifungal drugs for Candida albicans strains with gain-of-function mutations in the transcription factor Mrr1. In addition, PP3 inhibits the efflux of Mdr1 substrates by C. albicans strains harboring hyperactive MRR1 alleles. Molecular docking revealed that PP3 is a potential Mdr1 blocker that binds to the substrate binding pocket of Mdr1.

Inhibitor-Resistant Mutants Give Important Insights into Candida albicans ABC Transporter Cdr1 Substrate Specificity and Help Elucidate Efflux Pump Inhibition.

Overexpression of ATP-binding cassette (ABC) transporters is a major cause of drug resistance in fungal pathogens. Milbemycins, enniatin B, beauvericin, and FK506 are promising leads for broad-spectrum fungal multidrug efflux pump inhibitors. The characterization of naturally generated inhibitor-resistant mutants is a powerful tool to elucidate structure-activity relationships in ABC transporters. We isolated 20 Saccharomyces cerevisiae mutants overexpressing Candida albicans ABC pump Cdr1 variants resistant to fluconazole efflux inhibition by milbemycin α25 (8 mutants), enniatin B (8), or beauvericin (4). The 20 mutations were in just 9 residues at the centers of transmembrane segment 1 (TMS1) (6 mutations), TMS4 (4), TMS5 (4), TMS8 (1), and TMS11 (2) and in A713P (3), a previously reported FK506-resistant "hot spot 1" mutation in extracellular loop 3. Six Cdr1-G521S/C/V/R (TMS1) variants were resistant to all four inhibitors, four Cdr1-M639I (TMS4) variants were resistant to milbemycin α25 and enniatin B, and two Cdr1-V668I/D (TMS5) variants were resistant to enniatin B and beauvericin. The eight milbemycin α25-resistant mutants were altered in four amino acids as follows: G521R, M639I, A713P, and T1355N (TMS11). These four Cdr1 variants responded differently to various types of inhibitors, and each exhibited altered substrate specificity and kinetic properties. The data infer an entry gate function for Cdr1-G521 and a role for Cdr1-A713 in the constitutively high Cdr1 ATPase activity. Cdr1-M639I and -T1355N possibly cause inhibitor resistance by altering TMS contacts near the substrate/inhibitor-binding pocket. Models for the interactions of substrates and different types of inhibitors with Cdr1 at various stages of the transport cycle are presented.

In Silico Structural Modeling and Analysis of Interactions of Tremellomycetes Cytochrome P450 Monooxygenases CYP51s with Substrates and Azoles.

Cytochrome P450 monooxygenase CYP51 (sterol 14α-demethylase) is a well-known target of the azole drug fluconazole for treating cryptococcosis, a life-threatening fungal infection in immune-compromised patients in poor countries. Studies indicate that mutations in CYP51 confer fluconazole resistance on cryptococcal species. Despite the importance of CYP51 in these species, few studies on the structural analysis of CYP51 and its interactions with different azole drugs have been reported. We therefore performed in silico structural analysis of 11 CYP51s from cryptococcal species and other Tremellomycetes. Interactions of 11 CYP51s with nine ligands (three substrates and six azoles) performed by Rosetta docking using 10,000 combinations for each of the CYP51-ligand complex (11 CYP51s × 9 ligands = 99 complexes) and hierarchical agglomerative clustering were used for selecting the complexes. A web application for visualization of CYP51s' interactions with ligands was developed (http://bioshell.pl/azoledocking/). The study results indicated that Tremellomycetes CYP51s have a high preference for itraconazole, corroborating the in vitro effectiveness of itraconazole compared to fluconazole. Amino acids interacting with different ligands were found to be conserved across CYP51s, indicating that the procedure employed in this study is accurate and can be automated for studying P450-ligand interactions to cater for the growing number of P450s.

Effects of nanoplastic on toxicity of azole fungicides (ketoconazole and fluconazole) in zebrafish embryos.

The ubiquity of nanoplastics (NPs) raises concerns about their interactions and combined toxicity with other common contaminants. Although azoles are present throughout the natural environment, their interactions with NP are not well known. We investigated the effects of polystyrene (PS) NP on the toxicity of ketoconazole (KCZ) and fluconazole (FCZ) in zebrafish embryos using the developmental toxicity, oxidative-stress-related biochemical parameters, and expression of genes related to neurotoxicity (ache), cardiotoxicity (gata4, bmp4), inflammation (il1b), oxidative stress (sod1, sod2, cyp1a), and apoptosis (bax, bcl2). Co-exposure to NP (1 mg/L) and KCZ/FCZ (1 mg/L) for 96 h reduced the hatching rate, survival rate, and heart rate and increased the malformation rate and catalase activity. The bax/bcl2 ratio, an apoptosis indicator, was higher after NP, KCZ, or FCZ treatment. However, the bax/bcl2 ratio after exposure to NP + KCZ or NP + FCZ was much higher than that after single exposure. Overall, the results indicated that NP aggravated the toxicity of azole by significantly increasing the reactive oxygen species, lipid peroxidation and altering the expression of oxidative-stress- and apoptosis-related genes. The interactive toxicity of PS NP with KCZ/FCZ reported in this study emphasises the need for caution in the release of azole fungicides in the environment.

Nanostructured lipid carrier-incorporated gel for efficient topical delivery of fluconazole.

Background: Nanostructured lipid carriers (NLCs) of fluconazole were prepared to improve permeability and thereby effective topical drug delivery. Materials and methods: NLCs were prepared and evaluated, and then the optimized NLC suspension was incorporated into a gel that was further evaluated for topical drug delivery. Results and discussion: F-2 NLC formulation was optimized based on results of particle size (161.3 ± 1.385 nm), polydispersity index (0.401), zeta potential (-33 ± 0.46), entrapment efficiency (82.26 ± 0.91%) and in vitro drug release (76.40 ± 0.21%). Ex vivo skin permeation studies showed flux of F-2 gel and the comparison marketed gel as 0.21 and 0.18 mg/cm2/h, respectively. The in vitro antifungal study revealed significantly better activity compared with the marketed gel. Conclusion: Fluconazole NLCs increase drug permeability and proved to be effective in topical drug delivery.

Transcriptome Analysis Unveils Gln3 Role in Amino Acids Assimilation and Fluconazole Resistance in Candida glabrata.

After Candida albicans, Candida glabrata is one of the most common fungal species associated with candidemia in nosocomial infections. Rapid acquisition of nutrients from the host is important for the survival of pathogens which possess the metabolic flexibility to assimilate different carbon and nitrogen compounds. In Saccharomyces cerevisiae, nitrogen assimilation is controlled through a mechanism known as Nitrogen Catabolite Repression (NCR). NCR is coordinated by the action of four GATA factors; two positive regulators, Gat1 and Gln3, and two negative regulators, Gzf3 and Dal80. A mechanism in C. glabrata similar to NCR in S. cerevisiae has not been broadly studied. We previously showed that in C. glabrata, Gln3, and not Gat1, has a major role in nitrogen assimilation as opposed to what has been observed in S. cerevisiae in which both factors regulate NCR-sensitive genes. Here, we expand the knowledge about the role of Gln3 from C. glabrata through the transcriptional analysis of BG14 and gln3Δ strains. Approximately, 53.5% of the detected genes were differentially expressed (DEG). From these DEG, amino acid metabolism and ABC transporters were two of the most enriched KEGG categories in our analysis (Up-DEG and Down-DEG, respectively). Furthermore, a positive role of Gln3 in AAA assimilation was described, as was its role in the transcriptional regulation of ARO8. Finally, an unexpected negative role of Gln3 in the gene regulation of ABC transporters CDR1 and CDR2 and its associated transcriptional regulator PDR1 was found. This observation was confirmed by a decreased susceptibility of the gln3Δ strain to fluconazole.

Combatting fungal biofilm formation by diffusive release of fluconazole from heptylamine plasma polymer coating.

A drug-eluting coating applied onto biomedical devices and implants is an appropriate way to ensure that an inhibitory concentration of antimicrobial drugs is present at the device surface, thus preventing surface colonization and subsequent biofilm formation. In this study, a thin polymer coating was applied to materials, and it acted as a drug-delivery reservoir capable of surface delivery of the antifungal drug fluconazole to amounts up to 21 µg/cm2. The release kinetics into aqueous solution were quantified by UV spectroscopy and conformed to the Ritger-Peppas and Korsmeyer-Peppas model. Complementary microbiological assays were used to determine effectiveness against Candida albicans attachment and biofilm formation, and against the control heptylamine plasma polymer coating without drug loading, on which substantial fungal growth occurred. Fluconazole release led to marked antifungal activity in all assays, with log 1.6 reduction in CFUs/cm2. Cell viability assays and microscopy revealed that fungal cells attached to the fluconazole-loaded coating remained rounded and did not form hyphae and biofilm. Thus, in vitro screening results for fluconazole-releasing surface coatings showed efficacy in the prevention of the formation of Candida albicans biofilm.

Hair removal and bioavailability of chemicals: Effect of physicochemical properties of drugs and surfactants on skin permeation ex vivo.

Cosmetic hair removal procedures are everyday routines in our society. However, it is unclear if such routines lead to increased uptake of applied substances such as drugs or formulation compounds, potentially resulting in skin irritation or sensitization. The aim of this study was to elucidate the effect of common depilation and epilation methods on skin penetration of two surfactants and four model drugs of different physicochemical properties using the porcine ear model. It should be elucidated whether the substances' skin penetration behavior would be affected by hair removal procedures and if potential effects would be related to their polarity. Confocal Raman spectroscopy revealed no effect of hair removal on total penetration depths of SDS and sulfathiazole. Significantly higher relative penetrated amounts within 0-6 µm of stratum corneum depth were found for SDS after dry shaving, depilatory cream and waxing and for sulfathiazole after all depilation methods and partly after epilation. ATR-FTIR spectroscopy revealed no effect of hair removal on the penetration depth of lecithin LPC80, but higher relative amounts at the skin surface after wet shaving and electric epilation. Diffusion cell experiments using a lecithin-based microemulsion as carrier system for fluconazole, fludrocortisone acetate and flufenamic acid showed higher cumulative amounts, higher drug fluxes and shorter lag times for the more lipophilic drugs for some of the methods, but only shorter lag times in some cases for fluconazole. In summary, the observed effects appeared to depend on drug polarity and experimental setup.