Spray pyrolisis deposition and characterization of Cd-TiO2 thin film for photocatalytic and photovoltaic applications

In the present paper, an innovative approach to enhance the photocatalytic efficiency and energy of photovoltaics by modifying the surface morphology of a TiO2 is demonstrated.The photovoltaic device provides sustainable power efficiency in TiO2 (TO) and Cd-TiO2 (CTO) thin films grown through spray pyrolysis. The structural and optical properties of the prepared undoped and Cd doped TiO2 thin films were studied. The morphology and content of the pro­duced samples were studied using scanning electron microscopy (SEM with EDAX). A UV-Vis spectrophotometer was used to record the optical absorption spectra of TiO2 nanoparticles. XRD analysis showed that TO and CTO had anatase structure, and the average crystalline size was calculated as 132.0 nm.The photocatalytic efficiency of TO and CTO for degradation of Rodhamine B (RhB) dye was examined. Also, power-voltage (P-V) and photocurrent-voltage (I-V) output current intensity relations were discussed

Customer satisfaction and competitiveness in the Chinese E-retailing: structural equation modeling (SEM) approach to identify the role of quality factors

This paper attempts to study the impact of customer satisfaction and the Chinese electronic retailers (E-retailers) competitiveness using quality factors. Two conceptual models based on asset-process-performance (APP) competitive theoretical framework have been proposed. The proposed models include E-retailers strategic factors such as logistics, quality and customer satisfaction equivalent to asset, process and performance entities of the APP framework. Using an empirical survey from a young population, this study, with the support of structural equation modeling (SEM) identifies reliability in service quality and purchasing experience in e-service quality as dominant customer satisfaction factors. This study uses both exploratory and confirmatory factor analysis and suggests that to be competitive Chinese E-retailers have to focus more on the delivery of products (logistics) compared to other intangible service quality factors. On theoretical front, this study is a novel attempt to validate the APP framework for E-retailers’ competitiveness. On the practical front, the outcome of the study would be highly beneficial to the Chinese E-retailers to fine tune their strategy to satisfy the growing demand. Furthermore, this study can supplement government policy makers to regulate the growing volatile market

Multifunctional iron oxide nanoparticles for diagnostics, therapy and macromolecule delivery

In recent years, multifunctional nanoparticles (NPs) consisting of either metal (e.g. Au), or magnetic NP (e.g. iron oxide) with other fluorescent components such as quantum dots (QDs) or organic dyes have been emerging as versatile candidate systems for cancer diagnosis, therapy, and macromolecule delivery such as micro ribonucleic acid (microRNA). This review intends to highlight the recent advances in the synthesis and application of multifunctional NPs (mainly iron oxide) in theranostics, an area used to combine therapeutics and diagnostics. The recent applications of NPs in miRNA delivery are also reviewed.ASTAR (Agency for Sci., Tech. and Research, S’pore)Published versio

MicroRNAs : the next generation therapeutic targets in human diseases

MicroRNAs (miRNAs), an abundant class of ~22-nucleotide non-coding RNAs, regulate the expression of genes at post transcriptional level. MiRNAs are important regulators of eukaryotic gene expression and therefore implicated in a wide range of biological processes. The miRNA- related genetic alterations are possibly more implicated human diseases than currently appreciated. Genetic variants in miRNA target sites, called miRNA genes are identified to be associated with human diseases. This review discusses about the role of micro-RNA genes in various human diseases such as neurodegenerative disorders, cardio-vascular diseases, and metabolic disorders, and how they can be targeted as a new therapeutic tool in future with reference to drug discoveries/ development.Published versio

Silica-coated Mn-doped ZnS nanocrystals for cancer theranostics

Doped nanocrystals such as manganese-doped zinc sulfide (ZnS:Mn) are useful nanomedicine probes for cancer cell labeling and anticancer drug delivery. However, the synthesis and retention of fluorescence of these nanocrystals is highly indispensable for efficient cell theranostics. Herein, we report a modified synthesis of highly fluorescent hydrophobic ZnS:Mn nanocrystals with the advent of dual ligands. Our results demonstrate that the alkylamine ligand with the carbon chain length of C18 promotes the diffusion of Mn from the surface into the interior of ZnS nanocrystals. Optical measurements show that the quantum yield of Mn (QYMn) can reach as high as 80% in the presence of a dual ligand combination of oleylamine-octadecylamine because of the increased probability of 4T1→ 6A1emission, originating from the energy transfer of ligated nanocrystals. These doped nanocrystals after ligand exchange of organic ligands with glutathione exhibited a high retention of quantum yield (QY: ~50-60%), and further coating with silica showed the QY of ~35-40%. Finally, we show the application of these doped nanocrystals for cancer theranostics such as HeLa cell labeling and anti-cancer drug delivery.Agency for Science, Technology and Research (A*STAR)We acknowledge funding from the Joint Council Office, A*STAR, Singapore (grant no. JCOAG03-FG03). We thank the core facilities (XRD, TEM) support staff at the Institute of Materials Research and Engineering (IMRE, Singapore). E.H.A. and S.T.S. acknowledge the National Institution of Education (NIE) and LKC School of Medicine NTU, respectively, for their support in completing and publishing this work

Mollification of doxorubicin (DOX)-mediated cardiotoxicity using conjugated chitosan nanoparticles with supplementation of propionic acid

Doxorubicin is an extensively prescribed antineoplastic agent. It is also known for adverse effects, among which cardiotoxicity tops the list. The possible mechanism underlying doxorubicin (DOX)-mediated cardiotoxicity has been investigated in this study. Further, to reduce the DOX-mediated cardiotoxicity, DOX was conjugated with Chitosan Nanoparticles (DCNPs) and supplemented with propionic acid. Initially, the drug loading efficacy and conjugation of DOX with chitosan was confirmed by UV-Visible Spectroscopy (UV) and Fourier Transform Infrared Spectroscopy (FTIR). The average sizes of the synthesized Chitosan Nanoparticles (CNPs) and DCNPs were measured by Dynamic Light Scattering (DLS) analysis as 187.9 ± 1.05 nm and 277.3 ± 8.15 nm, respectively, and the zeta potential values were recorded as 55.2 ± 0.7 mV and 51.9 ± 1.0 mV, respectively. The size and shape of CNPs and DCNPs were recorded using a High-Resolution Electron Microscopy (HRTEM). The particles measured <30 nm and 33-84 nm, respectively. The toxic effects of DCNPs and propionic acid were evaluated in rat model. The data from the electrocardiogram (ECG), cardiac biomarkers, Peroxisome proliferator-activated receptor gamma (PPARγ) and histological observations indicated evidence of DOX-mediated cardiotoxicity, whereas the administration of DCNPs, as well as Propionic Acid (PA), brought about a restoration to normalcy and offered protection in the context of DOX-induced cardiotoxicity.Published versionIndian Council of Medical Research: 5/10FR/84/2020-RBMCH

Coordination chemistry of ligands: insights into the design of amyloid beta/tau-PET imaging probes and nanoparticles-based therapies for Alzheimer's disease

The diagnosis and therapy of neurodegenerative diseases are highly indispensable. In particular, the definitive clinical diagnosis and therapy of Alzheimer's disease (AD) remains a challenge. Despite the use of amyloid beta (Aβ) positron emission tomography (PET) gold standard [11C]-PiB, other approved benzothiazole ([18F]-flutemetamol) and stilbene derivative ([18F]-florbetaben and [18F]-florbetapir) based probes have been extensively studied and advocated as potential early Aβ PET radioligands for AD. Recent years have witnessed a burgeoning research activity in the development of radiotracers for tau neurofibrillary tangles (NFTs) binding using PET imaging, while monitoring the progression of disease. Notably, several tau PET ligands (e.g. [18F]-THK5351, [18F]-MK-6240, and [18F]-AV-1451, [18F]-RO-6958948, [18F]-JNJ-64326067, [18F]-PI-2620) showed high affinity and selective binding to tau pathology. Although early detection and progression of AD have been studied extensively using PET imaging, therapeutic approaches to the disease are scarce. Recently, nanoparticles (NPs) based therapeutic approaches have emerged. Coordination of ligands to the surface of organic NPs (e.g., flavonoids: green tea polyphenol- EGCG, curcumin), and inorganic NPs (e.g. Au, ZnO, CeO2) have been explored to decrease/inhibit the amyloid aggregation and tau hyperphosphorylation. This review focuses on (i) the importance of coordination chemistry of ligands in the design of PET imaging probes with specific binding affinities to Aβ and tau NFTs in AD, and (ii) the role of surface ligands and their coordination to NPs and functional molecules for the rational design of novel anti-AD reagents for therapeutic interventions.Nanyang Technological UniversityS.T.S., B.G., P.P. thank the support from Lee Kong Chian School of Medicine, Imaging Probe Development Platform, and Cognitive Neuro Imaging Centre (CONIC) at Nanyang Technological University (NTU) Singapore