Mohammad A. Jafar Mazumder

Temperature-sensitive polymers for drug delivery

The ability to undergo rapid changes in response to subtle environmental cues make stimuli- responsive materials attractive candidates for minimally invasive, targeted and personalized drug delivery applications. This special report aims to highlight and provide a brief description of several of the significant natural and synthetic temperature-responsive materials that have clinical relevance for drug delivery applications. This report examines the advantages and disadvantages of natural versus synthetic materials and outlines various scaffold architectures that can be utilized with temperature-sensitive drug delivery materials. The authors provide a commentary on the current state of the field and provide their insight into future expectations for temperature-sensitive drug delivery, emphasizing the importance of the emergence of dual and multiresponsive systems capable of responding precisely to an expanding set of stimuli, thereby allowing the development of disease-specific drug delivery vehicles.

Imidazolines containing single-, twin- and triple-tailed hydrophobes and hydrophilic pendants (CH2CH2NH)nH as inhibitors of mild steel corrosion in CO2–0.5 M NaCl

Inhibition of mild steel corrosion in CO2–0.5 M NaCl (40 °C, 1 atm; 120 °C, 10 bar) by a new series of imidazolines having single-, twin- and triple-tailed phenyl substituents at C(2) and N(1) pendants of CH2CH2NH2 and (CH2CH2NH)2CH2CH2NH2 have been examined. Imidazolines containing twin-tailed (3,5-dioctyloxyphenyl) hydrophobes outperformed their single- and triple-tailed counterparts as well as two commercial imidazolines. The triamine pendant imparted better inhibition at higher temperature and pressure. The XPS study confirmed the presence of an imidazoline film covering the metal surface. The imidazolines prefer to be adsorbed on the metal surface rather than micellization.

Multi-component catalysts with spinel structure for the selective reduction of nitrogen oxide by ethylene in lean-exhaust gas streams

The Ga2O3-Al2O3-ZnO (GAZ) multi-component spinel powders with incorporated Cu2+, Co2+, Fe2+, Ni2+, Mn2+ and In2+ metal cations were synthesized by co-precipitation method from a mixed solution of nitrate salts. Spinel crystal structure of each composition was confirmed by XRD measurements. The multi-component oxide powders were tested in the reduction of nitrogen oxide (NO) under lean conditions. Among the catalysts tested, In2O3-containing GAZ with a pure spinel phase structure showed promising catalytic activity in the NO reduction in the presence of 10% H2O vapor. In addition, the effect of H2O vapor and SO2 on the selective reduction of NO over In2O3-GAZ/cordierite and In2O3-GAZ/metal honeycombs catalysts has been investigated.

Bio-Encapsulation for the Immune-Protection of Therapeutic Cells

The design of new technologies for treatment of human disorders is a complex and difficult task. The aim of this article is to explore state of art discussion of various techniques and materials involve in cell encapsulations. Encapsulation of cells within semi-permeable polymer shells or beads is a potentially powerful tool, and has long been explored as a promising approach for the treatment of several human diseases such as lysosomal storage disease (LSD), neurological disorders, Parkinsons disease, dwarfism, hemophilia, cancer and diabetes using immune-isolation gene therapy.

Biomedical Perspectives of Polyaniline Based Biosensors

Electrically conducting polymers (ECPs) are finding applications in various fields of science owing to their fascinating characteristic properties such as binding molecules, tuning their properties, direct communication to produce a range of analytical signals and new analytical applications. Polyaniline (PANI) is one such ECP that has been extensively used and investigated over the last decade for direct electron transfer leading towards fabrication of mediator-less biosensors. In this review article, significant attention has been paid to the various polymerization techniques of polyaniline as a transducer material, and their use in enzymes/biomolecules immobilization methods to study their bio-catalytic properties as a biosensor for potential biomedical applications.

Modeling lead concentration in drinking water of residential plumbing pipes and hot water tanks

Drinking water is a potential source of exposure to lead (Pb), which can pose risk to humans. The regulatory agencies often monitor Pb in water treatment plants (WTP) and/or water distribution systems (WDS). However, people are exposed to tap water inside the house while water may stay in the plumbing premise for several hours prior to reaching the tap. Depending on stagnation period and plumbing premise, concentrations of Pb in tap water can be significantly higher than the WDS leading to higher intake of Pb than the values from WDS or WTP. In this study, concentrations of Pb and water quality parameters were investigated in WDS, plumbing pipe (PP) and hot water tanks (HWT) for 7months. The samples were collected and analyzed on bi-weekly basis for 7 times a day. Several linear, non-linear and neural network models were developed for predicting Pb in PP and HWT. The models were validated using the additional data, which were not used for model development. The concentrations of Pb in PP and HWT were 1-1.17 and 1-1.21 times the Pb in WDS respectively. Concentrations of Pb were higher in summer than winter. The models showed moderate to excellent performance (R2=0.85-0.99) in predicting Pb in PP and HWT. The correlation coefficients (r) with the validation data were in the ranges of 0.76-0.90 and 0.97-0.99 for PP and HWT respectively. The models can be used for predicting Pb in tap water, which can assist to better protect the humans.

A new resin embedded with chelating motifs of biogenic methionine for the removal of Hg(II) at ppb levels

Cyclopolymerization of N,N-diallylmethionine hydrochloride, derived from the biogenic amino acid methionine, (90 mol%) and cross-linker tetraallylpiperazinium dichloride (10 mol%) in presence of an azo-initiator afforded pH-responsive cross-linked polyzwitterion (CPZ). The structural morphology of the resin (i.e. CPZ) was examined by the BET and FESEM-EDX analyses. The methionine embedded resin demonstrated remarkable efficacies for the removal of Hg(II) ions at ppb levels. A 50 mg-dose of the resin immersed in aqueous medium (18 mL) could reduce the concentration of Hg(II) from 200 and 400 ppb to 1.8 and 4.4 ppb, respectively, within 15 min. The resin has also proven to be remarkably effective in the removal of several toxic and priority metal pollutants from industrial wastewater. The Hg(II) adsorption followed pseudo second-order process with Ea of 48.1 kJ mol-1. The initial rapid adsorption of metal ions and subsequent slower adsorption was attributed to film and intraparticle diffusion, respectively. The SEM-EDX analyses revealed the attachment of Hg(II) ions onto the resin. The favorability of the endothermic adsorption was ensured by the negative ΔGº values. The efficient adsorption/desorption process confirmed the recyclability of the resin. The current resin demonstrated superior metal removal capacities as compared to several other adsorbents in recent works.

Andrographolide engineered gold nanoparticle to overcome drug resistant visceral leishmaniasis

Abstract Visceral leishmaniasis (VL) is World Health Organization designated most serious leishmaniasis with an annual mortality rate of 50,000. Even after country specific eradication programs, the disease continues to multiply with added complexities like resistance development, drug hypersensitivity and associated infections. Newer therapeutic interventions are urgently warranted to control the spread. Present study aims to arrive at terpenoid andrographolide engineered gold nanoparticle (AGAunps) facile synthesis and its efficacy evaluations against wild and drug resistant VL strains for the first time. Molecular bio-organic conjugation of AGAunp was confirmed in FT-IR and EDAX studies. Nano-gold plasmon response was recorded at 543 nm and the average size in TEM was 14 nm. SAED pattern and XRD observations proved fcc crystalline structure of nano-gold. AGAunp recorded spherical geometry in AFM and TEM. PDI value of 0.137 revealed the monodisperse nature of the nano-scale population. AGAunp exhibited strong antileishmanicidal effect both against wild type (IC50 19 ± 1.7 µM) and sodium stibogluconate (IC50 55 ± 7.3 µM)/paromomycin (IC50 41 ± 6 µM) resistant strains. Complete macrophage uptake AGAunp’s occured within two hours exposure. AGAunp macrophage cytotoxicity was significantly lower as compared to Amphotericin-B. Low toxic Andrographolide engineered gold nanoparticle emerged as promising alternatives in the control of wild and drug resistant VL. Graphical Abstract

Gold Nanotubes from Organic Scaffolds for Biomedical Applications

Nanoparticles are the cutting edge of the rapidly developing field of nanotechnology, which enables visualization and manipulation of matter down to the atomic level. Their unique size to volume ratio, shape and thermal stability make these materials superior, and rapidly usable in various bio-medical applications. This brief review summarize the recent advances in the field of applied nanomaterials with an emphasis in designing nanoscale devices with pre-defined structure, and their potential applications in the field of biology and medicine.