Plausible Mechanistic Insights in Biofilm Eradication Potential against Candida spp. Using In Situ-Synthesized Tyrosol-Functionalized Chitosan Gold Nanoparticles as a Versatile Antifouling Coating on Implant Surfaces.

In the present study, tyrosol-functionalized chitosan gold nanoparticles (Chi-TY-AuNPs) were prepared as an alternative treatment strategy to combat fungal infections. Various biophysical techniques were used to characterize the synthesized Chi-TY-AuNPs. The antifungal and antibiofilm activities of Chi-TY-AuNPs were evaluated against Candida albicans and C. glabrata, and efforts have been made to elucidate the possible mechanism of action. Chi-TY-AuNPs showed a high fungicidal effect against both sessile and planktonic cells of Candida spp. Additionally, Chi-TY-AuNPs completely eradicated (100%) the mature biofilms of both the Candida spp. FESEM analysis highlighted the morphological alterations in Chi-TY-AuNP-treated Candida biofilm cells. The effect of Chi-TY-AuNPs on the ECM components showed significant reduction in protein content in the C. glabrata biofilm and substantial decrease in extracellular DNA content of both the Candida spp. ROS generation analysis using DCFDA-PI staining showed high ROS levels in both the Candida spp., whereas pronounced ROS production was observed in the Chi-TY-AuNP-treated C. glabrata biofilm. Biochemical analysis revealed decreased ergosterol content in Chi-TY-AuNP-treated C. glabrata cells, while inconsequential changes were observed in C. albican s. Furthermore, the transcriptional expression of selected genes (ergosterol biosynthesis, efflux, sterol importer, and glucan biogenesis) was reduced in C. glabrata in response to Chi-TY-AuNPs except ERG11 and CDR1. Conclusively, the result showed the biofilm inhibition and biofilm eradication efficacy of Chi-TY-AuNPs in both the Candida spp. Findings of the present study manifest Chi-TY-AuNPs as a potential therapeutic solution to Candida biofilm-related chronic infections and overcome biofilm antifungal resistance.

Synthesis of Multi-Color Fluorescent Carbon Dots From Mint Leaves: A Robust Bioimaging Agent with Potential Antioxidant Activity.

Carbon dots (C-dots), a promising luminescent nanomaterial with exceptional physico-chemical properties gaining enormous attention in recent years. Carbon dots having enhanced biocompatibility and multiple routes of synthesis offers a promising substitute to luminescent quantum dots (QD). Further, wavelength-controlled emission features of C-dots proved as a good candidate in the biolabeling applications. Herein, we are reporting a facile and one-step hydrothermal synthesis of biocompatible multi-color, Polyethyleneimine (PEI) surface passivated C-dots (CDP) from mint leaves as a green source. The morphological and optical properties of C-dots have been extensively studied by Zeta-sizer, Transmission electron microscopy (TEM), X-ray diffraction (XRD) pattern, Ultra violet (UV)-visible spectroscopy and fluorescence spectroscopic analysis. Furthermore, Fourier transform infrared (FT-IR) and X-Ray Photoelectron Spectroscopic (XPS) analysis have been performed for the understanding of surface states and chemical composition of C-dots. A comparative analysis in the biolabeling potentials of non-passivated C-dots (CD) and CDP was conducted in the breast cancer (MCF-7) cells and the concentration dependent cytotoxicity was estimated. Further, an enhanced antioxidant property was showed by CDP as compared to CD. In the present study, a practical implication of C-dots synthesized from a herbal source (mint) to serve as a novel agent for various biolabeling applications and antioxidant activity have been experimentally resolved. As synthesized CD and CDP can be, serve as better alternatives for imaging probe with improved biocompatibility.

Systematic approach of chromone skeleton for detecting Mg2+, ion: Applications for sustainable cytotoxicity and cell imaging possibilities.

The systematic studies of chromone appended novel chemosensors, favored to Mg2+ ion detection, these were analyzed and characterized by different spectroscopic techniques such as NMR, mass spectroscopy, FTIR and optical techniques. The binding demeanor of the ligands was executed with the library of metal ions and shown the good coordination with Mg2+ ion to the ligand's cavity. Both ligands demonstrated good binding behavior with Mg2+ ion. The ligands represented 1: 1 stoichiometry with Mg2+ ions through Job's plot. The low limit of detection of Mg2+ ion was determined as 2.56 × 10-6 and 1.28 × 10-6 for La and Lb respectively. No interference was occurred in Inference study by foreign metal ions that supported the specific detection of Mg2+ ion among the other metal ions. Further, the cytotoxicity assay test of these chromone appended ligands revealed that both ligands and their respective compound with Mg2+ ion shown negligible toxicity with HeLa cancer cell line. Further, due to the fluorescence properties of the ligands, with or without Mg2+ ion was successfully tested in bioimaging experiment of HeLa cancer cell lines and found that ligands with Mg2+ ions represented good imaging with HeLa cancer cell.

Enhanced antineoplastic/therapeutic efficacy using 5-fluorouracil-loaded calcium phosphate nanoparticles.

In the past few decades, the successful theranostic application of nanomaterials in drug delivery systems has significantly improved the antineoplastic potency of conventional anticancer therapy. Several mechanistic advantages of nanomaterials, such as enhanced permeability, retention, and low toxicity, as well as surface engineering with targeting moieties, can be used as a tool in enhancing the therapeutic efficacy of current approaches. Inorganic calcium phosphate nanoparticles have the potential to increase the therapeutic potential of antiproliferative drugs due to their excellent loading efficiency, biodegradable nature and controlled-release behaviour. Herein, we report a novel system of 5-fluorouracil (5-FU)-loaded calcium phosphate nanoparticles (CaP@5-FU NPs) synthesized via a reverse micelle method. The formation of monodispersed, spherical, crystalline nanoparticles with an approximate diameter of 160-180 nm was confirmed by different methods. The physicochemical characterization of the synthesized CaP@5-FU NPs was done with transmission electron microscopy (TEM), dynamic light scattering (DLS), field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The antineoplastic potential of the CaP@5-FU NPs against colorectal and lung cancer cells was reported. The CaP@5-FU NPs were found to inhibit half the population (IC50) of lung adenocarcinoma (A549) cells at 32 µg/mL and colorectal (HCT-15) cancer cells at 48.5 µg/mL treatment. The apoptotic induction of CaP@5-FU NPs was confirmed with acridine orange/ethidium bromide (AO/EB) staining and by examining the morphological changes with Hoechst and rhodamine B staining in a time-dependent manner. The apparent membrane bleb formation was observed in FE-SEM micrographs. The up-regulated proapoptotic and down-regulated antiapoptotic gene expressions were further confirmed with semiquantitative reverse transcriptase polymerase chain reaction (PCR). The increased intracellular reactive oxygen species (ROS) were quantified via flow cytometry upon CaP@5-FU NP treatment. Likewise, the cell cycle analysis was performed to confirm the enhanced apoptotic induction. Our study concludes that the calcium phosphate nanocarriers system, i.e. CaP@5-FU NPs, has higher antineoplastic potential as compared to 5-FU alone and can be used as an improved alternative to the antimitotic drug, which causes severe side effects when administrated alone.

Correction to "Facile and Green Synthesis of Multicolor Fluorescence Carbon Dots from Curcumin: In Vitro and in Vivo Bioimaging and Other Applications".

[This corrects the article DOI: 10.1021/acsomega.7b01323.].

Facile and Green Synthesis of Multicolor Fluorescence Carbon Dots from Curcumin: In Vitro and in Vivo Bioimaging and Other Applications.

Early detection is the critical phase in the prognostic strategy of various life-threatening maladies like infectious diseases and cancer. The mortality rate caused by these diseases could be considerably reduced if they were diagnosed in the early stages of disease development. Carbon dots (C-dots), a relatively new and promising candidate in the fluorescent nanomaterial category, possess a perceptible impact on various bioapplications. Herein, we report a one-step facile hydrothermal synthesis that yields a novel surface-passivated carbon dot (CDP) from curcumin (as a green substrate) displaying high aqueous solubility. The physico-chemical characterization of thus synthesized C-dots was accomplished by an UV-visible spectrophotometer, fluorescence spectrophotometer, zetasizer, TEM, and FE-SEM to understand the formation of carbon dots with a 4-5 nm size near spherical nanoparticle with high colloidal stability. E. coli DH5α was engaged as the Gram-negative test organism and S. aureus as the Gram-positive in the biolabeling of bacteria. Cancer cell lines including colon cancer (HCT-15), lung cancer (A549), and mouse fibroblast (NIH 3T3) were evaluated and resulted in good biolabeling potential and less cytotoxicity. Zebrafish (ASWT) embryos as an animal model system were bioimaged, and in vivo toxicity was inferred. Moreover, the synthesized C-dots were shown to have free radical scavenging activity in a dose-dependent manner. The unpassivated C-dots (CD) were found to sense ferric ions at the micromolar concentration level. The findings of our study suggest that the multifunctional potentiality of CDPs serves as high-performance optical nanoprobes and can be a suitable alternative for various biolabeling and contrasting agents.

Multifunctional CdSNPs@ZIF-8: Potential Antibacterial Agent against GFP-Expressing Escherichia coli and Staphylococcus aureus and Efficient Photocatalyst for Degradation of Methylene Blue.

Multifunctional novel core-shell composites, CdSNPs@ZIF-8, have been synthesized by in situ encapsulation of different amounts of CdSNPs (150, 300, and 500 µL suspension of CdSNPs in methanol) in ZIF-8 at room temperature. These composites have been characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM), and diffuse reflectance spectroscopy techniques and Brunauer-Emmett-Teller surface analysis. XPS and HRTEM indicate the encapsulation of CdSNPs within ZIF-8 crystal without disturbing the crystal order of ZIF-8. The average size of embedded CdSNPs (determined by the particle size distribution from HRTEM) is found to be 16.34 nm. CdSNPs@ZIF-8 showed potential to be used as an antibacterial agent against the broad spectrum of bacterial strains such as Gram-positive Staphylococcus aureus and Gram-negative green fluorescent protein-expressing Escherichia coli in aqueous medium, as evident by various biophysical experiments, viz., 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, optical density and fluorescence spectroscopic studies, fluorescence and optical microscopic image analysis, disk diffusion assay, field emission scanning electron microscopy, and flow cytometry for reactive oxygen species induction assay. Further, the composite has been used as an efficient photocatalyst for the degradation of organic pollutants, such as methylene blue dye, in aqueous medium and found that the core-shell composite, CdSNPs@ZIF-8 (150 µL) (abbreviated as NC-1) (5 mg), exhibited higher photocatalytic activity (≈1.8 times) than CdSNPs for degradation of 90% of methylene blue (10 mL of 10 ppm) at pH ≥ 7 due to the synergetic effect. Therefore, in situ encapsulation of CdSNPs in ZIF-8 provides an easy executable measure for purification of wastewater effluents for the effective photocatalytic degradation of organic pollutants as well as to remove the bacterial contamination under sunlight.

Molecular encapsulator-appended poly(vinyl alcohol) shroud on ferrite nanoparticles. Augmented cancer-drug loading and anticancer property.

Magnetic nanoparticles (MNPs) have the potency to deliver cancer drugs assisted by the application of a magnetic field. In this paper, we present the design of magnesium ferrite nanoparticles of size suitable for drug delivery. A coating polymer, poly(vinyl alcohol), tethered with a tapered cone-shaped cyclic oligosachcharide, ß-cyclodextrin (ß-CD) is synthesized and used to wrap and disperse the MNPs. The magnetic properties are explored using vibrating sample magnetometry and Mössbauer spectroscopy. The ∑130 nm MNPs, shrouded with the PVA-CD conjugate allows a high amount of the cancer drug, camptothecin, to be loaded on the nanocarrier. Cytotoxicity studies reveal that the loaded drug retains its potency against HEK 293 cells and the cells are sensitive to the treatment by the drug-loaded nanocarrier.

Electrospun Polyacrylonitrile (PAN) Templated 2D Nanofibrous Mats: A Platform toward Practical Applications for Dye Removal and Bacterial Disinfection.

The fabrication of polymeric nanofibers and its potential versatility instigated to foster smart hybrid nanomaterials for the removal of environmental pollutants. In this pursuit, in this research work, polyacrylonitrile (PAN)-based two-dimensional (2D) nanofibrous mats with polyethyleneimine (PEI)/Fe and quaternary ammonium (QA)/Fe as hybrid fillers were prepared by the electrospinning process for the effective dye removal and bacterial disinfection. The characteristics of the fabricated nanomaterials were extensively explored by several analytical techniques such as field emission-scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller analysis. Magnetic and thermal properties were investigated by superconducting quantum interference device and thermogravimetric measurements. The kinetic and isothermal models affirmed the adsorption behavior of the PAN-PEI/Fe nanofibers, and further regenerative studies substantiated the sustainability of the mats for the removal of industrial dye effluents. Subsequently, the magnetic-QA-loaded PAN nanofiber mats exhibited bactericidal killing efficacy of 99 and 89.5% in both Staphylococcus aureus and green fluorescence protein expressing Escherichia coli bacterial models evaluated from the conventional quantitative bacterial colony-counting assay. Disk diffusion method and microscopic investigations corroborated the disinfection efficacy with zone of inhibitions of ∼23 and 33 mm, respectively. Interestingly, in vitro cell culture studies conducted in BHK-21 and NIH 3T3 cell lines demonstrated the cytocompatibility, and the in vivo toxicity investigations using the zebrafish models necessitated the real-time application of these nanofibrous mats. Therefore, the comprehensive study of the fabricated PAN-templated functionalized 2D nanofibrous mats affirmed to be competent for the remediation of industrial dye effluents and bacteria in water bodies.

Niclosamide loaded biodegradable chitosan nanocargoes: an in vitro study for potential application in cancer therapy.

Chitosan nanoparticles can advance the pharmacological and therapeutic properties of chemotherapeutic agents by controlling release rates and targeted delivery process, which eliminates the limitations of conventional anti-cancer therapies and they are also safe as well as cost-effective. The aim of present study is to explore the anti-tumour effect of niclosamide in lung and breast cancer cell lines using biocompatible and biodegradable carrier where nanoparticles loaded with hydrophobic drug (niclosamide) were synthesized, characterized and applied as a stable anti-cancer agent. Niclosamide loaded chitosan nanoparticles (Nic-Chi Np's) of size approximately 100-120 nm in diameter containing hydrophobic anti-cancer drug, i.e. niclosamide, were prepared. Physico-chemical characterization confirms that the prepared nanoparticles are spherical, monodispersed and stable in aqueous systems. The therapeutic efficacy of Nic-Chi Np's was evaluated against breast cancer cell line (MCF-7) and human lung cancer cell line (A549). MTT assay reveals the cell viability of the prepared Nic-Chi Np's against A549 and MCF-7 cells and obtained an IC50 value of 8.75 µM and 7.5 µM, respectively. Acridine orange/ethidium bromide dual staining results verified the loss of the majority of the cells by apoptosis. Flow cytometer analysis quantified the generation of intracellular reactive oxygen species (ROS) and signified that exposure to a higher concentration (2 × IC50) of Nic-Chi Np's resulted in elevated ROS generation. Notably, Nic-Chi Np treatment showed more apoptosis and cell death in MCF-7 as compared to A549. Further, the remarkable induction of apoptosis by Nic-Chi Np's was confirmed by semi-quantitative reverse transcription polymerase chain reaction, scanning electron microscopy and cell-cycle analysis. Thus, Nic-Chi Np's may have a great potential even at low concentration for anti-cancer therapy and may replace or substitute more toxic anti-mitotic drugs in the near future.