Remediation of environmentally hazardous organophosphates by artificial metalloenzymes

Organophosphates constitute environmentally hazardous molecules that are commonly used in agriculture and various industries and as chemical warfare agents. They are extremely stable compounds with a half-life of up to thousands of years. Because of the lack of a protection against their harmful activities in the environment, recently intensive efforts have been made to design synthetic molecules for their hydrolytic degradation. These molecules include both peptidic (short peptides, three-stranded coiled coils, and four-helix bundles) and nonpeptidic (polyoxometalates, metal–organic frameworks, and organometallic complexes) compounds that are often inspired by the catalytic cores of hydrolytic enzymes. However, because of their structural simplicity, the current synthetic analogs are significantly less efficient than natural enzymes. They lack the effective combination of various chemical factors that provides enormous rate acceleration to enzymes. In this review, we discuss the recent progress made in the design of enzymatic mimics with potential applications in the decontamination of organophosphates. [Display omitted

Peptide hydrogel with self-healing and redox-responsive properties

We have rationally designed a peptide that assembles into a redox-responsive, antimicrobial metallohydrogel. The resulting self-healing material can be rapidly reduced by ascorbate under physiological conditions and demonstrates a remarkable 160-fold change in hydrogel stiffness upon reduction. We provide a computational model of the hydrogel, explaining why position of nitrogen in non-natural amino acid pyridyl-alanine results in drastically different gelation properties of peptides with metal ions. Given its antimicrobial and rheological properties, the newly designed hydrogel can be used for removable wound dressing application, addressing a major unmet need in clinical care

FORMULATION OF CURCUMIN NANOSUSPENSION USING BOX-BEHNKEN DESIGN AND STUDY OF IMPACT OF DRYING TECHNIQUES ON ITS POWDER CHARACTERISTICS

  Objective: The objective of this study was to formulate curcumin nanosuspension (NS) using Box-Behnken design (BBD) and solvent-antisolvent technique to overcome the challenges related to its poor dissolution rate.Methods: Sodium lauryl sulfate (SLS) and poly vinyl pyrrolidone K-60 (PVPK-60) have been used as a surfactant and polymer, respectively, to stabilize the NS. Ethanol was used as solvent to dissolve curcumin and water was used as antisolvent. The study revealed that SLS to curcumin ratio, PVPK-60 to curcumin ratio, solvent to antisolvent ratio and speed of mixing were the critical parameters that affected particle size and zeta potential of the formulation. Hence, based on Box- BBD, 25 formulations were prepared by varying these critical parameters. The optimized batch of CRM NS was further solidified using spray drying as well as rotary evaporation techniques to have a better insight for selection of solidification process in terms of retention of particle size, charge, flow, dissolution, and stability.Results: About 39.47 folds decrease in particle size of raw CRM was observed after conversion into NS. Further, about 53.57 and 45.45 folds decrease in particle size was observed after spray drying and rotary evaporation. Both the dried nanoparticles have shown comparatively higher solubility, powder flow, and dissolution rate as that of raw CRM. Powder X-ray diffraction study revealed the formation of amorphous nanoparticles. Accelerated stability study revealed that nanoparticles dried by spray drying were able to retain the properties such as particle size, flow, and dissolution rate as compared to rotary evaporated powders.Conclusion: It can be concluded that spray drying technique could offer many advantages while loading CRM nanoparticles into tablets for their oral administration