Exploring the efficacy and future potential of polypyrrole/metal oxide nanocomposites for electromagnetic interference shielding: a review.

With recent advancements in technology, the emission of electromagnetic radiation has emerged as a significant issue due to electromagnetic interferences. These interferences include various undesirable emissions that can degrade the performance of equipment and structures. If left unresolved, these complications can create extra damage to the security operations and communication systems of numerous electronic devices. Various studies have been conducted to address these issues. In recent years, electrically conductive polypyrrole has gained a unique position because of its many advantageous properties. The absorption of microwaves and the electromagnetic interference (EMI) shielding characteristics of electrically conductive polypyrrole can be described in relation to its great electrical conductivity with strong relaxation and polarization effects due to the existence of strong bonds or localized charges. In the present review, advancements in electromagnetic interference shielding with conjugated polypyrrole and its nanocomposites with metal oxides are discussed and correlated with various properties such as dielectric properties, magnetic properties, electrical conductivity, and microwave adsorption properties. This review also focuses on identifying the most suitable polypyrrole-based metal oxide nanocomposites for electromagnetic interference shielding applications.

Synthesis and evaluation of amylose-mefenamic acid conjugates as colon-targeting prodrugs.

Aim: Amide-linked amylose-based prodrugs were developed for colon-targeted release of mefenamic acid. Materials & methods: Activation of prodrug was studied spectrophotometrically, enzyme-linked immunosorbent assay appraised cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) inhibition at different concentrations of the prodrug, the behavior of prodrug under physiological conditions was monitored by scanning electron microscopy. Results: Prodrug was poorly activated in the enzyme-free simulated gastric media and simulated intestinal media (SIM) but preincubation in pancreatin followed by treatment in aminopeptidase containing SIM led to a significant activation of prodrug. Conclusion: Amide-linked amylose-mefenamic acid conjugates showed a slow release in simulated gastric media and a controlled release in SIM with pancreatin playing an important role in drug release.

Targeted delivery of fenamates with aminated starch.

Aim: To develop controlled-release tablets based on aminated starch. Materials & methods: Aminated starch was characterized with Fourier transform infrared and x-ray diffraction. Thermogravimetric analysis confirmed the preferential oxidation of crystalline region of starch. Results: The tablets achieved an initial fast release of fenamates, which slows down after 12 h. Drug release was not completed in the simulated intestinal media, which may be due to the stability of imine bond in aminated starch at weakly acidic pH. Drug release was completed in simulated acidic media due to the hydrolysis of imine functionality at strongly acidic pH. Conclusion: Aminated starch with an imine functionality may serve as intestine targeted, controlled drug-delivery system. Mucoadhesive potential of tablets further supports this observation.

Investigating purification and activity analysis of urease enzyme extracted from jack bean source: A green chemistry approach.

Urease is an enzyme of historical importance in the field of biochemistry, generally microbial and plant urease is the primary sources of urease. The significant applications of urease enzyme are found to be foremost in food industry, medical equipment's and biosensors. In this work, urease has been extracted from Jack bean meal using ammonium sulphate and acetone precipitation. A significant amount of urease was precipitated and concentrated at 60% saturated solution of ammonium sulphate. The obtained precipitates were dissolved in 50 mM phosphate buffer (pH 8) after centrifugation, and subjected to sodium dodecyl-sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to determine the molecular weight of urease. Results obtained from the SDS-PAGE were validated using Zymography. Anion exchange chromatography was used to separate the desired protein at different pH (7.0, 7.5 and 8.0). The eluted fractions were assessed for urease activity using phenol-nitroprusside dependent ammonia release assay. Under these assay conditions, one unit of urease activity was calibrated as the amount of enzyme liberating 1 µM of NH3 from urea per unit time. The eluted fraction and Zymography analysis show the purified urease observed at 90 kDa and activity of purified urease, respectively. The obtained results for specific activity (173.67Units mg) and % purification (99.71%) for urease has been compared with the available literature, which are found to be in close relation with existing results. The proposed method is a novel approach which has recorded highest % purification and specific activity. Furthermore, it can be suitable for extracting urease from jack bean source for various industrial applications.

An insight into Cadmium poisoning and its removal from aqueous sources by Graphene Adsorbents.

Graphene alone, in modified form or its composites had find their explicit position in the field of adsorption technology and hence assist in detection and removal of heavy metals like Cd (permissible limit 0.1 mg/L), which can cause various physiological problems if entered in variety of biota. Attributed to their unique physiognomies graphene-based adsorbent had classed themselves superior as compared to other carbonaceous adsorbent like CNT's or activated carbon, etc. This assessment summarizes the validity of graphene and its composite as a superior adsorbent for decontamination of Cd from aqueous environment; in addition, this evaluation also pronounces the toxicity profile of trace graphene and necessity of regeneration of the adsorbent.

Silver nanoparticles as antimicrobial therapeutics: current perspectives and future challenges.

Utility of silver metal in antimicrobial therapy is an accepted practice since ages that faded with time because of the identification of a few silver resistant strains in the contemporary era. A successive development of antibiotics soon followed. However, due to an indiscriminate and unregulated use coupled with poor legal control measures and a dearth of expertise in handling the critical episodes, the antibiotics era has already seen a steep decline in the past decades due to the evolution of multi-drug resistant 'superbugs' which pose a sizeable challenge to manage with. Due to limited options in the pipeline and no clear strategy in the forefront, the aspirations for novel, MDR focused drug discovery to target the 'superbugs' arose which once again led to the rise of AgNPs in antimicrobial research. In this review, we have focused on the green routes for the synthesis of AgNPs, the mode of microbial inhibition by AgNPs, synergistic effect of AgNPs with antibiotics and future challenges for the development of nano-silver-based therapeutics.