Chitinase-functionalized UiO-66 framework nanoparticles active against multidrug-resistant Candida Auris

Comparative evaluation of biologically and chemically synthesized zinc oxide nanoparticles for preventing Candida auris biofilm

Candidozyma auris (formerly Candida auris) is a multidrug-resistant yeast that poses a significant global health threat due to its ability to form biofilms and resist various antifungal treatments. This study evaluates and compares the antifungal efficacy of biologically synthesized zinc oxide nanoparticles (ZnO-NP-B) and chemically synthesized ZnO nanoparticles (ZnO-NP-C1 and ZnO-NP-C2), developed using the dry-wet chemical method and sol-gel method, respectively. ZnO-NP-B was synthesized using Lactobacillus gasseri. The nanoparticles were characterized for size, charge, and morphology using Particle Size Analyzer, photon correlation spectroscopy with a 90 Plus Zetasizer, and scanning electron microscopy (SEM), respectively. The antifungal activity was assessed through minimum inhibitory concentration (MIC50) determination, biofilm inhibition assays by XTT assay, and gene expression analysis. ZnO-NP-C1 exhibited the highest antifungal activity against C. auris planktonic cells, with a MIC50 value of 61.9 ± 3.3 µg/ml, followed by ZnO-NP-C2 (151 ± 7.83 µg/ml), whereas ZnO-NP-B showed limited efficacy (MIC50 = 1 mg/ml). Chemically synthesized ZnO-NPs, particularly ZnO-NP-C2, did not induce overexpression of resistance genes (CDR1, MDR1, ERG2, ERG11, FKS1, CHS1), whereas ZnO-NP-B triggered their upregulation, potentially promoting resistance. ZnO-NP-C1 was the most effective in preventing biofilm formation, reducing C. auris adhesion by 67.9 ± 2.35% at 150 µg/ml, while ZnO-NP-B exhibited negligible inhibition. Gene expression analysis further confirmed that ZnO-NP-C1 significantly downregulated adhesive genes (ALS5, IFF4, CSA1) by up to 0.37 ± 0.006, 0.043 ± 0.002, and 0.06 ± 0.0004, respectively. These findings highlight the potential of ZnO-NP-C1 as a promising antifungal agent for preventing C. auris biofilms, emphasizing the critical role of synthesis methods in optimizing nanoparticle properties for antifungal applications.

Enhanced biological activity of chitinase immobilized on cobalt metal-organic framework: Isolation, characterization, and potential applications

Chitinase, an enzyme that hydrolyzes glycosidic bonds in chitin, holds significant potential for industrial applications, including biological control, antifungal treatments, and antibiofilm strategies. In this study, chitinase derived from Planomicrobium sp. (PP133202) was immobilized onto a cobalt metal-organic framework (Co-MOF), and its properties were extensively analyzed using various biological, chemical, and physical characterization techniques. The microbial source was identified via 16S rRNA sequencing, and enzyme activity was optimized under submerged conditions using Response Surface Methodology (RSM). Structural and morphological characterization of the chitinase/Co-MOF complex was conducted through FTIR, SEM, TEM, XPS, XRD, EDX, and surface area analyses. The encapsulation efficiency and loading capacity were determined to be 42 % and 20 %, respectively. Notably, the immobilized chitinase exhibited a threefold increase in enzymatic activity compared to its free form. Additionally, the chitinase/Co-MOF complex demonstrated enhanced biological control efficacy, effectively inhibiting Tribolium castaneum and multiple pathogenic microorganisms, including Pseudomonas aeruginosa, Aspergillus flavus, Aspergillus terreus, and Beauveria bassiana. These findings highlight the potential of chitinase/Co-MOF as a promising agent for antimicrobial and pest control applications.

Nanoparticles in the battle against Candida auris biofilms: current advances and future prospects

Candida auris has emerged as a significant global health threat due to its multidrug resistance and ability to form robust biofilms, particularly on medical devices and hospital surfaces. Biofilms protect C. auris from antifungal treatments and the host immune response, making infections persistent and difficult to control. This review explores the potential of nanoparticles to overcome the limitations of traditional antifungal therapies in combating C. auris biofilms. Nanoparticles, with their unique physicochemical properties, offer promising strategies to penetrate biofilm matrices, deliver antifungal agents, and disrupt biofilm structure. Various types of nanoparticles, including metallic, polymeric, lipid-based, and cyclodextrin-based, demonstrate enhanced biofilm penetration and antifungal activity. Their ability to generate reactive oxygen species, disrupt cell adhesion, and release antifungals in a controlled manner makes them ideal candidates for biofilm-targeted therapies. This review presents the current advancements in nanoparticle-based solutions, emphasizing the need for further research into their mechanisms of action, safety, and clinical application. By addressing the challenge of C. auris biofilms specifically, this review provides a critical synthesis of existing knowledge and identifies future directions for developing effective antifungal therapies using nanotechnology.