ZnSe and CdS Co-Sensitized TiO2 Nanorod Arrays as Photoanodes for Bias-Free Solar Hydrogen Evolution.

The efficient charge separation and surface state reactions are significant in enhancing the efficiency of photoelectrochemical hydrogen evolution. Herein, we report a ternary heterostructure consisting of CdS/ZnSe sensitized TiO2 nanorod as a photoanode. The heterojunction photoanode considerably widens the photon absorption spectral range and thereby enhances the photocurrent density up to 2 mA/cm2 at 1.23 V versus RHE which is 10 times higher than pristine TiO2 photoanode. The photoelectrochemical results demonstrate a high photocurrent density of 2 mA/cm2 with a photon-to-current conversion efficiency of 1.5 % at a very low applied bias (0.2 V vs RHE). The improved PEC performances of the multidimensional hybrid photoanode could be ascribed to the efficient visible-light absorption of ZnSe and CdS nanocrystals decorated on the surface of 1D TiO2 . The rapid electron-transfer properties owing to higher carrier density, low carrier transport resistance, and an extended lifetime of photoexcited carriers in the multidimensional ZnSe/CdS/TiO2 heterostructure with suppressed surface charge recombination are responsible for enhanced hydrogen evolution activities.

Dual drug loaded PLGA nanospheres for synergistic efficacy in breast cancer therapy.

Improved therapeutic effects can be achieved by the delivery of combination of drugs through multifunctional cell targeted nanocarrier systems. The present investigation reports the preparation of Poly (D,L-lactic-co-glycolic acid) (PLGA) nanospheres loaded with the novel combination such as Rutin (R) and Benzamide (B) as drugs using water-oil-water (w/o/w) emulsion method. Dual drug loaded PLGA nanospheres (R/B@PLGA) were stabilized by poly (vinyl alcohol) (PVA) coating and characterized in terms of morphology, size, surface charge, and structural chemistry by Scanning electron microscopy (SEM), Dynamic light scattering (DLS), Zeta potential analysis, UV-vis and Fourier transform infrared (FT-IR) spectroscopy. The inhibitory effects of rutin and benzamide on MDA-MB-231 (triple negative breast cancer-TNBC) cells using the drug loaded PLGA nanospheres as well as their non-toxic features were evaluated in vivo. The anticancer activity of the R/B@PLGA nanospheres through cell cycle disruption and apoptotic induction was assessed in vitro by flow cytometry analysis. Further, the in vitro antioxidant capacity, pH-based drug release and hemocompatible property were also investigated. It was shown that the R/B@PLGA nanospheres lacked genotoxic potential and they did not alter the antioxidant enzyme activities and histological features of zebrafish. Hence, this dual drug delivery system (DDS) not only actively targets multidrug-resistance (MDR) associated phenotype but also improves the therapeutic efficiency by its non-toxic nature towards enhanced cancer cell focused delivery and sustained release of therapeutic agents.

A novel rutin-fucoidan complex based phytotherapy for cervical cancer through achieving enhanced bioavailability and cancer cell apoptosis.

Recent studies on flavonoids forming complexes with macromolecules attract researchers due to their enhanced bioavailability as well as chemo-preventive efficacy. In this study, a flavonoid rutin (Ru) is non-covalently complexed with fucoidan (Fu) using the functional groups to obtain a therapeutic polymeric complex overcoming the limitations of bioavailability of rutin. The prepared novel rutin-fucoidan (Ru-Fu) complex is characterized for spectroscopic features, particle size and distribution analysis by DLS. It is shown that the complex displayed the nanostructural features that are different from that of the usual rutin-fucoidan mixture. The studies on drug release profiles at different pH (5.5, 6.8 and 7.4) show that the sustained release of compounds from complex occurs preferentially at the desired endosomal pH (5.5). Further, the chemopreventive potential of Ru-Fu complex is investigated against HeLa cells by cellular apoptotic assays and flow cytometric analysis. It showed that the complex is able to disrupt cell cycle regulation and has the ability to induce cellular apoptosis via nuclear fragmentation, ROS generation and mitochondrial potential loss. In vitro cell viability assay with Ru-Fu complex shows that the complex is biocompatible on normal cells. The hemolysis assay also reveals that the complex does not release hemoglobin from human red blood cells (RBCs). Thus, the study is envisaged to open up interests for developing such formulations against cervical cancer and other cancers.

A versatile effect of chitosan-silver nanocomposite for surface plasmonic photocatalytic and antibacterial activity.

Chitosan-silver (CS-Ag) nanocomposite was green synthesised without the aid of any external chemical-reducing agents. The synthesised nanocomposite was characterised by UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), and zeta potential analyser. The particle size of the synthesised CS-Ag nanocomposite was around 20 nm and was found to be thermally stable in comparison with pure chitosan. The prepared nanocomposite acts as a photocatalyst for dye decolourisation, with a maximum of 81% of methyl orange (MO) decolourisation that occurred under visible light irradiation. The kinetics was found to follow pseudo-first-order according to Langmuir-Hinshelwood (L-H) model. The nanocomposite also proved to be an excellent antimicrobial agent against both Gram-positive and Gram-negative bacteria, possessing a broad spectrum of antimicrobial activity. The zone of inhibition ranged between 16.000 ± 1.000 and 19.333 ± 1.155 (mm), proving its high susceptibility than chitosan itself. The minimum inhibitory concentration (MIC) values were from 8 to 64 µg/mL, whereas the minimum bactericidal concentration (MBC) values ranged from 16 to 128 µg/mL, with the highest antibacterial activity shown against Gram-positive Staphlococcus aureus. This report illustrates the eco-friendly approach for the reduction of silver using chitosan as a reducing agent, and its potential to dye decay and microbial contaminants.

Near infra-red laser mediated photothermal and antitumor efficacy of doxorubicin conjugated gold nanorods with reduced cardiotoxicity in swiss albino mice.

Development of a multifunctional drug delivering system without side effects and compromising its therapeutic efficacy is a major concern in anticancer research. Recently, we have developed and demonstrated doxorubicin conjugated gold nanorod (DOX@PSS-GNR) as a sustained drug delivery vehicle. Here, we investigate the biodistribution, antitumor and photothermal efficacy of DOX@PSS-GNR along with its potential impact on cardiotoxicity in in vivo. The studies revealed that the accumulation of Free DOX in myocardium was 4-fold reduced in DOX@PSS-GNR animals, which further minimizes its cardiotoxicity by decreasing cardiac injury via preservation of cardiac markers. Further, DOX@PSS-GNR exhibits effective antitumor efficacy against Dalton lymphoma ascites (DLA) as evidenced by cell cycle analysis, apoptotic signals and reduced tumor volume and weight. In addition, DOX@PSS-GNR exhibits higher photothermal response and dominates DLA growth upon 0.1 W/cm(2) laser irradiation. In conclusion, multifunctional DOX@PSS-GNR with improved therapeutic index and reduced cardiotoxicity represents a promising candidate for cancer treatment. FROM THE CLINICAL EDITOR: Doxorubicin is a widely used agent for cancer therapy. However, the side effects are still significant, despite the development of liposomal formulation. In this study, the authors investigated the use of doxorubicin conjugated gold nanorods (DOX@PSS-GNR) in terms of biodistribution, antitumor activity and systemic side effects. The much reduced cardiotoxicity of the new delivery system should provide an improved agent for future clinical use.