Abstract:This paper reports the antifungal properties of zinc oxide nanoparticles (ZnO NPs) on Candida albicans ATCC 1023 through the study of growth inhibitory effects of ZnO NPs on C. albicans and the effect of the nanoparticles on the surface of C. albicans. The growth inhibitory effects of ZnO NPs (5, 10, 20, 40, 80, and 160 µg/mL) on C. albicans at 24 h were determined through the reduction in suspension turbidity and colony count. Fourier transform infrared (FTIR) analysis was carried out to establish the functio… Show more
“…On the other hand, no activity was shown by CuCl 2 alone and its presence did not significantly affect the WT activity, although Cu 2+ can form stable complexes with calcitermin even at pH 5.4. Of note, previous studies showed that both Zn 2+ and Cu 2+ ions possess antifungal activity per se at concentrations consistent with those used in our study, showing similar minimal inhibitory concentrations, although Zn 2+ was generally proven to be more effective compared to Cu 2+ 29 – 31 . Our results confirmed the Zn 2+ anti- C. albicans activity, whereas a marked antifungal activity by Cu 2+ ion was not evidenced.…”
The main limitation to the use of antimicrobial peptides (AMPs) as regular drugs, against antibiotic and antifungal resistance, mainly relates to their rapid degradation by proteolytic enzymes. The introduction of suitable structural changes in the peptide chain can make the peptide less susceptible to the action of proteases, thus overcoming this problem. To improve the plasma stability of calcitermin, a metal-chelating AMP present in the human respiratory tract and investigated in the present study, C- and/or N- terminal modifications have been introduced in the native sequence. Evaluation of peptide stability has been performed to determine the half-life times in human plasma of both native calcitermin and its derivatives. However, the protection of the peptide termini can also affect its metal coordination behaviour. Thus, the characterization of Zn2+ and Cu2+ complexes has been performed by means of several techniques, including potentiometry, high-resolution mass spectrometry, UV–Vis, circular dichroism and EPR. On the basis of the obtained results, it was possible to compare the biological activity of the studied systems, taking into account both the metal-binding ability and the peptide stability to search for a link among them. A significant result of this study is that the N-terminal protection increases the calcitermin half-life over seven times and the formation of metal complexes confers resistance towards degradation almost doubling its half-life.
“…On the other hand, no activity was shown by CuCl 2 alone and its presence did not significantly affect the WT activity, although Cu 2+ can form stable complexes with calcitermin even at pH 5.4. Of note, previous studies showed that both Zn 2+ and Cu 2+ ions possess antifungal activity per se at concentrations consistent with those used in our study, showing similar minimal inhibitory concentrations, although Zn 2+ was generally proven to be more effective compared to Cu 2+ 29 – 31 . Our results confirmed the Zn 2+ anti- C. albicans activity, whereas a marked antifungal activity by Cu 2+ ion was not evidenced.…”
The main limitation to the use of antimicrobial peptides (AMPs) as regular drugs, against antibiotic and antifungal resistance, mainly relates to their rapid degradation by proteolytic enzymes. The introduction of suitable structural changes in the peptide chain can make the peptide less susceptible to the action of proteases, thus overcoming this problem. To improve the plasma stability of calcitermin, a metal-chelating AMP present in the human respiratory tract and investigated in the present study, C- and/or N- terminal modifications have been introduced in the native sequence. Evaluation of peptide stability has been performed to determine the half-life times in human plasma of both native calcitermin and its derivatives. However, the protection of the peptide termini can also affect its metal coordination behaviour. Thus, the characterization of Zn2+ and Cu2+ complexes has been performed by means of several techniques, including potentiometry, high-resolution mass spectrometry, UV–Vis, circular dichroism and EPR. On the basis of the obtained results, it was possible to compare the biological activity of the studied systems, taking into account both the metal-binding ability and the peptide stability to search for a link among them. A significant result of this study is that the N-terminal protection increases the calcitermin half-life over seven times and the formation of metal complexes confers resistance towards degradation almost doubling its half-life.
The intention of this study was to prepare zinc oxide nanoparticles (ZnO‐NPs) via bottom‐up approach and evaluate their physiochemical, antimicrobial and anticancer properties. ZnO‐NPs were first prepared by the direct precipitation method with zinc sulphate heptahydrate, followed by characterization tests using sophisticated analytical and imaging instruments. Upon characterization, ZnO‐NPs were studied for their antimicrobial activities against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa as well as their anticancer activity against breast cancer cell line (MDA‐MB 231). The ZnO‐NPs possessed a mean particle diameter of 225.2 nm and a zeta potential of −15.8 mV. A sharp absorption peak of ZnO was recorded at 354 nm via UV‐Visible spectroscopy. Hexagonal wurtzite shape of ZnO‐NPs has been observed and confirmed by Scanning Electron Microscopy (SEM) and X‐Ray diffraction (XRD). ZnO‐NPs exhibited excellent antimicrobial activity against the Gram‐positive bacteria, Staphylococcus aureus. In an in vitro cell cytotoxicity study, ZnO‐NPs showed a dose‐dependent relationship against MDA‐MB 231 breast cancer cells. It was observed that as the concentration of ZnO‐NPs increased (0.25 μg to 35 μg), there was a sharp reduction in the proliferation rate of the cancer cell line. Overall, our study reported successful synthesis of ZnO‐NPs, which can be efficient antibacterial and anticancer agents.
“…The prime possibility is due to the surface interaction of the zinc oxide nanoparticle with the fungal cell wall. FTIR analysis was used to point out the functional groups that were responsible for these interactions, which indicates the possible interaction of alcohol, amide, methyl, alkynes, and phosphate groups, present on the surface of the nanoparticle, with the yeast cell wall . The above listed interactions lead to the accumulation of the nanoparticle on the cell membrane that further leads to membrane disruption .…”
Section: Resultsmentioning
confidence: 99%
“…FTIR analysis was used to point out the functional groups that were responsible for these interactions, which indicates the possible interaction of alcohol, amide, methyl, alkynes, and phosphate groups, present on the surface of the nanoparticle, with the yeast cell wall. 45 The above listed interactions lead to the accumulation of the nanoparticle on the cell membrane that further leads to membrane disruption. 46 It is also suggested that the exposure to zinc oxide nanoparticles alters the cell structure like—breakage of hyphae, pitting of the cell wall, invagination of the surface, and cell membrane rupture.…”
Zinc oxide nanoparticles (ZnO-NPs) were biosynthesized by using the pericarp aqueous extract from Terminalia catappa Linn. These NPs were characterized using various analytical techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV) spectroscopy, dynamic light scattering (DLS), and scanning electron microscopy (SEM), and XRD studies of the nanoparticles reported mean size as 12.58 nm nanocrystals with highest purity. Further SEM analysis emphasized the nanoparticles to be spherical in shape. The functional groups responsible for capping and stabilizing the NPs were identified with FTIR studies. DLS studies of the synthesized NPs reported ζ potential as −10.1 mV and exhibited stable colloidal solution. These characterized ZnO-NPs were evaluated for various biological applications such as antibacterial, antifungal, antioxidant, genotoxic, biocompatibility, and larvicidal studies. To explore its multidimensional application in the field of medicine. NPs reported a potential antimicrobial activity at a concentration of 200 μg/mL against bacterial strains in the decreasing order of Streptococcus pyogenes > Streptococcus aureus > Streptococcus typhi > Streptococcus aeruginosa and against the fungi Candida albicans. In vitro studies of RBC hemolysis with varying concentrations of NPs confirm their biocompatibility with IC 50 value of 211.4 μg/mL. The synthesized NPs' DPPH free radical scavenging activity was examined to extend their antioxidant applications. The antiproliferation and genetic toxicity were studied with meristematic cells of Allium cepa reported with mitotic index (MI index) of 1.2% at the concentration of 1000 μg/mL. NPs exhibited excellent Larvicidal activity against Culex quinquefasciatus larvae with the highest mortality rate as 98% at 4 mg/L. Our findings elicit the therapeutic potentials of the synthesized zinc oxide NPs.
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