Fungal resistance and the environmental degradation posed by conventional fungicides necessitate the need to develop new antifungal agents that can inhibit fungal growth. This study sought to prepare ...biofungicides by leveraging on the antifungal activity of copper‐metal organic framework (Cu‐MOF) and dialdehyde chitosan (Cs) isolated from black soldier flies (BSF). Cs were oxidized using potassium periodate to obtain dialdehyde Cs (OCs) and thereafter, Cu‐MOF was loaded resulting in Cu‐MOF‐OCs. Fourier Transform Infrared spectrophotometer (FT‐IR) and powder X‐ray diffraction (XRD) confirmed the presence of carbonyl functional groups in OCs and sharp intense peaks associated with Cu that interacted. The changes in surface morphology and the presence of Cu in the MOFs as obtained with Scanning Electron Microscope‐ Energy Dispersive X‐ray (SEM‐EDX), indicated the successful loading of Cu‐MOF on the oxidized Cs. Thermogravimetric analysis (TGA) showed a loss of approximately 31.51 % of the loaded OCs and 40.72 % framework around ∼200 to ∼300 °C and ∼410 to ∼475 °C respectively. The antifungal activity of OCs, Cu‐MOF, and Cu‐MOF‐OCs against Aspergillus brasiliensis and Candida albicans was performed using the plate count method and the results suggested that MOF modulated the antifungal activity exerted by the OCs.
Dialdehyde chitosan loaded with Copper Metal‐Organic Framework (Cu‐MOF) is proving to be an effective fungicide against agricultural pathogens as it can inhibit the Aspergillus brasiliensis and Candida albicans. This work demonstrates that when functionalized by selective periodate oxidation, chitosan extracted from black soldier flies yields dialdehyde chitosan and modulates the antifungal activity exerted by the MOF.
Determining whether tea extracts are effective in removing Candida albicans (C. albicans) from dentures is of interest. This study aimed to investigate the antifungal effect of tea extracts on C. ...albicans. One green tea (Anji white tea, AGW) and 2 oolong teas (Tie Guan Yin, TGY; Da Hong Pao, DHP) of different concentrations were tested. C. albicans suspensions were inoculated on the plates and the numbers of colony-forming units (CFU) in the culture medium were used to screen for the optimum tea extracts. Polymethyl methacrylate (PMMA) specimens that contained C. albicans biofilms were then treated with the tea extracts and the numbers of CFU were counted. The antifungal activities of the tea extracts were not significantly correlated with their catechin concentrations. Although AGW at 10.0 mg/mL and DHP at 2.5 mg/mL significantly inhibited C. albicans in the culture medium, the extracts failed to exert inhibitory effects against C. albicans biofilms on the PMMA surfaces.
Candida albicans is an opportunistic fungal pathogen that colonizes many human mucosal and is the major infectious specie in biomedical devices. Although Ti and its alloys have been used to ...manufacture biomedical devices, some drawbacks can allow the attachment fungi and/or bacteria. The thermochemical treatment by lasers of the metallic materials is attractive strategies to improve the antimicrobial properties of their surfaces. In this study, thermochemical treatment by laser were performed on Ti–6Al–4V sample. Its microstructural characterization by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), roughness profile, and X-ray diffraction (XRD) revealed the morphological changes of the laser-treated surfaces with formation of TiN, besides TiO2. Antimicrobial assays were performed against C. albicans fungi. It was found that laser processing route produced inhibitory potential of C. albicans biofilm on treated surfaces, with almost complete inhibition of biofilm (20% of viable cells). Thus, the thermochemical treatment by laser is a potential tool for surface modification of Ti alloy to be employed in biomedical components.
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•We report the laser thermochemical treatment of the Ti alloy.•The improve of the biocompatibility of the laser-treated surface was investigated.•It is observed that the laser-treated surface inhibited the C. albicans biofilm growth.•Changes in the morphology of cells grown on the laser-treated surfaces were observed.
Role of biofilm in disease development and enhance tolerance to antifungal drugs among Candida species has necessitated search for new anti-fungal treatment strategy. Interference in pathogenic ...biofilm development by new antifungal compounds is considered as an attractive anti-infective strategy. Therefore, the objective of this study was to evaluate Thymus vulgaris essential oil and its major active compound, thymol for their potential to inhibit and eradicate biofilms alone and in combination with antifungal drugs against Candida spp. with especial reference to Candida tropicalis. Anti-candidal efficacy of T. vulgaris and thymol in terms of minimum inhibitory concentration (MIC) was first determined to select the sub-MICs against C. albicans and C. tropicalis. Biofilm formation in the presence and absence of test agents was determined in 96-well microtiter plate by XTT reduction assay and effect of essential oils at sub-MICs of the test agents on biofilm development on glass surface was analysed by light and scanning electron microscopy. Synergistic interaction between essential oils and antifungal drugs were studied by checkerboard method. Effect of sub-MIC of T. vulgaris (0.5×MIC) and thymol (0.5×MIC) on biofilm formation showed a significant reduction (P<0.05) in biofilms. Light microscopy and SEM studies revealed disaggregation and deformed shape of C. albicans biofilm cells and reduced hyphae formation in C. tropicalis biofilm cells at sub-MICs of thymol. Significant effect of T. vulgaris and thymol was also recorded on pre-formed biofilms of both C. albicans and C. tropicalis. T. vulgaris and thymol also showed synergy with fluconazole against both in planktonic and biofilm mode of growth of C. albicans and C. tropicalis. However, synergy with amphotericin B is clearly evident only in planktonic Candida cells. Thyme oil and thymol alone or in combination with antifungal drugs can act as promising antibiofilm agent against drug resistant strains of Candida species and needs further in vivo study to synergise its therapeutic efficacy.
A series of zinc(II) phthalocyanines (ZnPcs) mono-substituted and tetra-substituted with morpholinyl moieties and their quaternized derivatives have been synthesized and evaluated for their ...antifungal photodynamic activities toward Candida albicans. The α-substituted, quaternized, and mono-substituted ZnPcs are found to have higher antifungal photoactivity than β-substituted, neutral, and tetra-substituted counterparts. The cationic α-mono-substituted ZnPc (6a) exhibits the highest photocytotoxicity. Moreover, it is more potent than axially di-substituted analogue. The different photocytotoxicities of these compounds have also been rationalized by investigating their spectroscopic and photochemical properties, aggregation trend, partition coefficients, and cellular uptake. The IC90 value of 6a against C. albicans cells is as low as 3.3 μM with a light dose of 27 J cm−2, meaning that 6a is a promising candidate as the antifungal photosensitizer for future investigations.
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•A series of ZnPcs substituted with morpholineyl moieties have been synthesized.•The structure-activity relationships of these compounds have been discussed.•The cellular uptake and photocytotoxicity increased after quaternization.•The cationic ZnPc 6a shows the highest photocytotoxicity against C. albicans.
Background: Candida albicans (C. albicans) is an opportunistic pathogen that can be found in the oral cavity and other parts of the body. This species is the main cause of oral candidiasis and forms ...a biofilm as its virulence factor. Due to increasing cases of antifungal resistance, research is needed on methods to control Candida biofilm formation. Brotowali (Tinospora crispa L.) is known to be antifungal, antiseptic and antiparasitic. Purpose: The purpose of this study is to analyse the ability of brotowali stem extract to inhibit Candida biofilm formation. Methods: The susceptibility of C. albicans to this extract was examined by a minimum inhibitory concentration (MIC) test using the broth microdilution method. A bacterial adherence assay was performed by similar methods of the MIC assay. A brotowali stem extract of various concentrations were incubated in a yeast peptone dextrose broth medium and stimulated with a C. albicans suspension. The 0.1% crystal violet was used to stain the adherent fungi and measured using a microplate reader at 595 nm. Scanning electron microscopy (SEM) was performed to provide a general overview of the biofilm formation. Results: The MIC value for the brotowali stem extract was at a concentration of 5,000 μg/ml. Moreover, this extract inhibited fungal adherence starting at a concentration of 250 μg/ml. Observation using SEM confirmed these results. Statistical analysis using one-way analysis of variance demonstrated a significant difference of C. albicans adherence following stimulation with brotowali extract (p < 0.005). Conclusion: Brotowali stem extract can inhibit C. albicans biofilm formation at an optimal concentration of 1,000 μg/ml.
A new series of silicon(IV) phthalocyanines (SiPcs) axially di-substituted with piperidinyl moieties (compounds 1, 2a, and 3a) and their N-methylated derivatives (compounds 2b and 3b) have been ...synthesized and characterized. Meanwhile, an analogue di-substituted with cyclohexyl groups (compound 4) has also been prepared as a control. The antifungal photoactivities of these SiPcs toward Candida albicans were found to follow the order: 2b ＞ 3a ≈ 3b ＞ 1 ≈ 2a ＞ 4. The structure–activity relationship of these phthalocyanines has been discussed by investigating their photophysical and photochemical properties, partition coefficient, and cellular uptake. The cationic phthalocyanine 2b shows the highest photodynamic activity against C. albicans causing 4 log10 reduction of this fungus at 100 μM, which could be attributed to its high singlet oxygen yields, less aggregation in aqueous media, and relatively efficient cellular uptake.
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•A series of SiPcs axially substituted with piperidinyl moieties has been synthesized.•The structure–activity relationships of these compounds has been discussed.•The methylation of piperidinyl groups can enhance the photosensitizing activities.•The cellular uptake toward C. albicans decreased after the methylation.•One of cationic compounds shows the highest photocytotoxicity against C. albicans.
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