Photoinactivation of Yeast and Biofilm Communities of Candida albicans Mediated by ZnTnHex-2-PyP4+ Porphyrin

Abstract

Candida albicans is the main cause of superficial candidiasis. While the antifungals available are defied by biofilm formation and resistance emergence, antimicrobial photodynamic inactivation (aPDI) arises as an alternative antifungal therapy. The tetracationic metalloporphyrin Zn(II) meso-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin (ZnTnHex-2-PyP4+) has high photoefficiency and improved cellular interactions. We investigated the ZnTnHex-2-PyP4+ as a photosensitizer (PS) to photoinactivate yeasts and biofilms of C. albicans strains (ATCC 10231 and ATCC 90028) using a blue light-emitting diode. The photoinactivation of yeasts was evaluated by quantifying the colony forming units. The aPDI of ATCC 90028 biofilms was assessed by the MTT assay, propidium iodide (PI) labeling, and scanning electron microscopy. Mammalian cytotoxicity was investigated in Vero cells using MTT assay. The aPDI (4.3 J/cm2) promoted eradication of yeasts at 0.8 and 1.5 µM of PS for ATCC 10231 and ATCC 90028, respectively. At 0.8 µM and same light dose, aPDI-treated biofilms showed intense PI labeling, about 89% decrease in the cell viability, and structural alterations with reduced hyphae. No considerable toxicity was observed in mammalian cells. Our results introduce the ZnTnHex-2-PyP4+ as a promising PS to photoinactivate both yeasts and biofilms of C. albicans, stimulating studies with other Candida species and resistant isolates.

Multifaceted Applications of Luminescent Metalloporphyrin Derivatives: Fluorescence Turn-On Sensing of Nicotine and Antimicrobial Activity

“…Further, we have evaluated the antifungal activity of porphyrin derivatives P , Ni–P , and Zn–P . To observe the effect of porphyrin compounds on Candida albicans survival, optical density and disk diffusion assay was performed (Figure a,b) . It was observed that P exhibited an antifungal activity against C.…”

“…To observe the effect of porphyrin compounds on Candida albicans survival, optical density and disk diffusion assay was performed (Figure 8a,b). 41 It was observed that P exhibited an antifungal activity against C. albicans with MICs of 1 mg/mL, while Ni−P and Zn−P exhibited an antifungal activity at 4 mg/mL. Thus, for disk diffusion study of C. albicans, 1 mg/mL concentration was used for P and 4 mg/mL for Ni−P and Zn−P, and a similar expansion of disk diffusion was observed on given concentrations of porphyrin compounds as compared to control.…”

A Novel Strategy Based on Zn(II) Porphyrins and Silver Nanoparticles to Photoinactivate Candida albicans

“…The PIT and IR conditions applied in this work were based on a previous study carried out by us. 3 To simultaneously photoexcite the ZnPs and induce the LSPR phenomenon in AgNPs, a blue LED (410 ± 20 nm, LEDbox, BioLambda) was used, as this wavelength range overlaps with the absorption of ZnPs and the plasmon band of AgNPs. Yeast suspensions were pre-incubated with the ZnPs, AgNPs or AgNPs-ZnPs systems for 10 min, and then immediately irradiated for 3 min (irradiance of 24.1 mW/cm 2 and a light dose of 4.3 J/cm 2 ).…”

“… 1 , 5–7 Notwithstanding the similarities of these ZnPs, ZnP-ethyl differs from ZnP-hexyl in its shorter aliphatic chain, with greater hydrophilicity, and usually requires higher molar concentrations for PDI applications. 2 , 3 …”

Inhibitory Effects and Mechanism of Action of Elsinochrome A on Candida albicans and Its Biofilm

“…It can even lead to life-threatening systemic candidiasis in severe cases [ 2 ]. Candida albicans can form a protective dense biofilm [ 3 ], which acts as a barrier to prevent drug entry, as a mechanism of resistance against antifungal drugs [ 4 ]. With the growing problem of drug resistance in C. albicans , there is an urgent need to find new antifungal therapies and drugs that inhibit the formation and proliferation of biofilms caused by C. albicans .…”