Lipid based self-assembled nanostructures for therapeutic delivery applications

The evolution of lipid nanoparticles (LNPs) has been remarkably interesting and in beneficent directions for food and health industries working towards human well being. Since the discovery of the first-generation lipid based self-assembled nanostructures, i.e., liposomes in the 1960s, it has witnessed significant advances in their development and distinctive potential in different application domains. Based on the composition and structure, these lipid based structures have varied from liposome to lipid nanoparticles such as nanostructured lipid carriers (NLCs) and solid lipid nanoparticles (SLN) to overcome certain limitation pertaining to their use in different fields. The outstanding application of LNPs as therapeutic delivery systems has made them key players to treat different human disorders including the fatal cancers. Their life-saving global contribution has recently been witnessed in the form of mRNA vaccines against deadly COVID-19. They have also significantly served purpose in other domains such as biomedical imaging, cosmetics, nutrition, and agriculture. Their prominent role is in the area of anticancer therapy as delivery vectors for nucleic acids and drugs. Some issues with respect to the cellular delivery of drugs and genes, such as circulation time and stability have been somewhat resolved, but the unmet goal of site-specific substantial delivery remains the main focus in LNPs development research. Despite the promise shown by LNPs in animal studies and the fact that technological advances in LNPs research have made the approval possible of a few formulations, therapeutic outcomes in human are not satisfactory. The LNPs technology has managed to survive due to possible tailoring of their properties by virtue of the possibility of altering the composition and modifying the surface. Therefore, enormous scientific endeavours are on the rise to transform lipid structures, composition along with tinkering with surface of LNPs. The alternative methods to guide LNPs coupled with advances in small molecule nucleic acid therapeutics and drug development technology to make the entry possible to specific cells may be effective in cancer therapy. The development is very promising; however enduring efforts are required till the goal is reached.

Impact of Ayurvedic drug Tinospora cordifolia in hyperlipidemia induced dysbiosis

Gut microbiota broadly impacts human health, but urinary microbial metabolites remain largely undefined. The concentration of microbial metabolites can be directly correlated with microbial populations in the human gut to define disease states. Tinospora cordifolia (Willd.) Miers ex Hook. F. & Thoms is being used for ages in the Indian ayurvedic system of medicine and it has hypolipidemic and hypoglycaemic activity. Present study investigate the MS-based metabolomics variations of possible gut microbiota associated metabolites in hyperlipidemia (HPL) and HPL treated with Tinospora cordifolia extract (TCE) (TRT). Twenty-four HPL male patients and 10 age-matched controls (HLT) were enrolled. Early morning fasting blood and urine samples were collected on days 0 and 14th of TCE treatment and subjected to lipid profiling and Q-TOF-MS analysis. Multivariate analysis showed urinary levels of urocanic acid, hydroxyphenylacetate, linolenic acid, phenylpropionate, hypoxanthine, and indole acetate produced by Peptostreptococcs asaccharolyticus, Clostridium difficile, Faecalibacterium prausnitzii, Bifidobacterium, Subdoligranulum, Lactobacillus, Clostridium sporogenes, E. coli were depleted in HPL patients as compared to healthy controls. In contrast, levels of serotonin, acetylleucine, hippuric acid, and arabinitol were found to be increased (>2.0 fold, p<0.005). However, TCE treatment reverted the levels of these metabolites and therefore, gut microflora. Also, Cloacibacterium haliotis, Lactobacillus, Clostridium, and Bifidobacterium population decreased in HPL patients. Increased secretion of yeast or Candida albicans associated metabolites was because of their increased population. Hence, TCE treatment enhanced the growth of useful gut microbiota in hyperlipidemia patients.

Gas sensing of partially oxidized Ti3C2Tx MXene in argon atmosphere

Multilayer accordion like Ti3C2Tx MXene is prepared by selective etching of Al layer from Ti3AlC2 MAX phase.  For better gas sensing responses, a minimal amount of TiO2 decoration is being carried out by annealing the Ti3C2Tx MXene in an argon atmosphere at 550 °C for 6 h. The X-ray diffraction pattern shows successful removal of Al layer and TiO2 decoration on Ti3C2Tx MXene surface which is well supported by field emission scanning electron microscope images. Due to TiO2 decoration, MXene shows semiconducting behaviour and corresponding bandgap is 3.2 eV. Resistance of TiO2 decorated MXene sample increases in presence of H2, CH4 and NO2 gases at room temperature. However, resistance of the sample decreases for H2, and CH4 gases and increases for NO2 gas at 100 °C which shows n-type semiconducting behaviour. Also, at 100 °C, sensitivity increases by one order to that of room temperature gas response of TiO2 decorated MXene sample.  

Recent advances in Materials development and design for Gas Sensing applications

The detection of specific gases in different settings have emerged an essential requirement towards management of different sectors such as industries, agriculture, laboratories, supply chains etc. The development of sensors using different materials play pivotal role in application of gas sensors in real time conditions. Many different type of materials have been studied, utilized and applied for the development of gas sensors. The compilation of research advances in the field of new gas sensors would provide better understanding towards applications of advanced functional materials. The current compilation encompasses recent trends in the area of nanostructured gas sensors. Various aspects of developing a gas sensor such as materials synthesis, characterization and optimization of sensor parameters, gas sensing methodologies, mechanistic studies, theoretical modeling and real-life applications are discussed. The research advances in form of concise reviews and original research articles in different gas sensing areas have been covered. The current research direction in developing novel materials, various technologies adopted to advance the sensing capabilities in order to realize an end user preferred device is elucidated. This effort is aimed at providing various avenues to a researcher where research can be focused in order to develop a gas sensor.

Defect mediated optical detection of ammonia using SnO2 nanoparticle

SnO2 with oxygen vacancies, an n-type gas sensing material used commercially as resistive sensors at high temperatures, suffers from the drift in voltage, contact resistances and poor selectivity. These prevailed defects in rutile SnO2 offer excellent optical properties which remain to be explored for the gas sensor. Apart from advantage of contactless operation with no direct voltage application, an optical method with the varied light energies is highly beneficial for excitations of the deep electronic states at ease, with opportunity to improve the sensor response measurement quickly in selective manner. In this direction, we report the synthesis and characterization of SnO2 nanostructures with emphasis on their Raman and photoluminescence properties. In subsequence, the crucial role of various defects in displaying the improved optical responses and selectivity for ammonia are highlighted.  

A comprehensive review on functionalized Hydroxyapatite nanostructures based gas sensors for environmental pollutant monitoring

The utilization of advanced sensing techniques for detecting and monitoring toxic gases in industry and the environment is a predominant action. For such applications, the sensor material should possess higher sensitivity, faster detection, and real-time operation. Mostly, metal oxides (MOs) are preferred for gas sensing purposes owing to their excellent sensing property, wide band-gap, electrical conductivity, and high surface reactivity. But, the same MOs lag in many perspectives like low selectivity, higher operating temperature (> 400 °C), more power consumption, and reduced stability. Since more emphasis is given to materials that operate at room temperatures like nano-hydroxyapatite (nHAp), it’s a bio-ceramic material used for chemical gas sensing. The nHAp is a matrix of rich calcium (Ca2+) and phosphate (PO43-) ions. In chemical gas sensors, the nHAp possess significant properties like large surface phosphate-hydroxide (P-OH) groups, ionic conductivity, porous nature, and ion exchange capability for effective gas molecule interaction. In this profound review, we discussed the nHAp structure with different fabrication techniques for gas sensing. Particularly, functionalized nHAp with MO and polymers were focused and their stability, sensitivity, selectivity, and adsorption rate are presented along with different mechanisms. Existing challenges and future perspectives of nHAp material are also highlighted.

Recent progress in Nanostructured Metal Oxides based NO2 gas sensing in India

The metal oxides are considered as an outstanding semiconductor material to sense several toxicants from the environment. In particular, the nanostructure containing rod, wire, and tube-like morphology of metal oxides were widely utilized to fabricate effective gas sensors worldwide. Out of number of toxicant, nitrogen dioxide (NO2) is one of the highly reactive gas, results from the burning of fuel from vehicles, power plants, and off-road equipment.The exposures to NO2 may giverise to the development of the respiratory diseases and leads to the death. Therefore, the efficient detection of NO2 gas is the urgent need of recent era. More than 5000 research articles were published on the NO2 gas sensing worldwide. The researchers from India is also contributed a lot to detect the NO2 gas via nanostructured metal oxides powder and thin films. The aim of the present article is to explore the recent advances of NO2 gas sensors based on metal oxide nanomaterials within the country. The review begins with the general introduction of metal oxide, gas sensorand NO2 gas sensor and followed by the broadly discussion of major research groups working in India and their finding in the fieldof nanostructured metal oxide for the fabrication of NO2 gas sensors. Moreover, various factors likegas concentrations, working temperature, morphologies, sensor response, selectivity, etc. of metal oxides were discussed in the present report. The report concludes with the future directions and opportunities in the field of detection of NO2 gas in India and world.

Methane sensing studies of ex-situ oxidized sputtered V2O5 nanostructured films: Effect of post oxidation duration

The effect of microstructural modifications of V2O5 thin films, obtained through alterations in post oxidation duration, on methane sensing behavior is reported for the first time. Three different oxidation times viz., 1 h, 3 h and 5 h yielded varied microstructure and vibrational properties as evident from XRD and Raman investigation. These changes in properties manifest as differences in gas sensing behavior. Methane sensing properties of V2O5 was investigated in temperature range from 100 to 300 °C and optimum operating temperature of 200 °C was identified for all three samples. Films oxidized for 1 h showed the highest response due to favorable surface conditions which are discussed. These results will help in tailoring microstructure towards device level application processes. 

Genome-wide mutation/SNP analysis, biological characteristics, and Pan-India prevalence of SARS-CoV-2 Variants of Concern

The origin of COVID-19 pandemic, caused by SARS-CoV-2, was traced to Wuhan, China. Thereafter, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evolved into various variants owing to genome-wide mutations, causing emergence of multiple variants, including Variant of Interest and Variant of Concern. Here, we discuss genomic architecture of SARS-CoV-2, as well as its multiple variants- alpha, beta, gamma, and delta, along with their biological properties, such as transmissibility, reduction in antibody-mediated neutralization, virulence, disease severity, vaccine effectiveness, and the prevalence across the India vis-à-vis world. Our data on VOC, pooled from the Global Initiative on Sharing All Influenza Data up to 31 October 2021, shows around 89% prevalence of delta VOC across various Indian States. Whereas alpha, beta, and gamma variants show 10.44%, 0.57%, and 0.11% prevalence, respectively. Compared with global scale, the reported Indian prevalence of alpha, beta, gamma, and delta are 0.40%, 0.63%, 0.04%, and 1.7%, respectively. Furthermore, prevalent vaccines of various natures show significantly reduced effectiveness against these VOCs, necessitating urgent need for development of effective prophylactic vaccines and potential therapy to contain the pandemic.

Recent development in carbon nanotubes based gas sensors

Technological expansion in nanotechnology have given upsurge to a new generation of functional organic nanomaterials with well-defined characteristics and controlled shape, allowing for a large number of possible applications. Innovative detection systems for the reliable and timely monitoring of dangerous gases in industrial processes and the environment are vital for maintaining optimum health and safety. In this context, semiconductor metal oxides, polymers, and carbon-based materials are often utilized materials for the applications of gas sensing. Metal oxide gas sensors are low-cost and have good sensitivity, however, they frequently demand higher working temperatures above ~120°C. Polymer-based gas sensors, on the other hand, are generally used to detect volatile organic compounds (VOCs) and have a high sensitivity and quick response, but they are prone to irreversibility and instability over time. Carbon-based gas sensors are becoming increasingly popular due to their unique characteristics and high sensitivity. Carbon nanostructures, such as carbon nanotubes (CNTs), are generally recognized as prospective nanomaterials for developing a new gas sensor with important nanotechnology implications. Carbon nanotubes have sparked a lot of interest because of their great surface-area-to-volume ratio, chemical inertness, nanoscale architecture, and hollow core, all of this makes them appealing for nanotechnology applications currently and in the future. This review work covers the current state-of-the-art work and advancements in gas sensors development based on organic nanomaterials; carbon nanotubes in particular.