shohreh asgari

A new method for the synthesis of double network hydrogel of polyacrylamide (PAM)-alginate (alg) with novel properties is described. A cooking oil, as an organic phase, and a solution consisting of sodium-alginate (Na-alg), acrylamide (AM), crosslinker, and initiator in water, as water phase, are used to produce Water in Oil (W/O) emulsion, stabilized by polyethylene glycol sorbitan monolaurate (Tween 80) at room temperature. CaCl2 nanoparticles are synthesized and dispersed in an oil medium and finally added to the emulsion. To obtain double network hydrogel, crosslinking agent N, Nʼ-methylenebisacrylamide (MBA), and Ca2+ cations are used for crosslinking of acrylamide and alginate polymers, respectively. Ca2+ nanoparticles in the oil phase move towards the aqueous droplets interface where dissolve into them and cause the formation of alginate networks. Furthermore, aqueous droplets, which contained a solution of AM, MBA, and ammonium persulfate (APS, as an initiator), act in the role of a reaction loci, and polymerization of AM are carried in these loci at 60 °C. These two polymer networks, synthesized in aqueous droplets, are interpenetrated to each other, and depending on the size of droplets, submicron double network hydrogel particles are formed. Prepared particles were employed for entrapping and releasing the model anticancer drug doxorubicin (DOX). The obtained double network hydrogels were characterized by Scanning Electron Microscopy (SEM), Fourier Transform InfraRed (FT-IR) spectroscopy, ThermoGravimetric Analysis (TGA), and Dynamic Light Scattering (DLS). In addition, swelling properties in water, adsorption, and release of model drugs were also studied.

The purpose of this study was to prepare a Double Network (DN) hydrogel made with sodium-alginate (Na-alg) natural polysaccharide and polyacrylamide (PAM) chains that target control release of anticancer drug. To this aim, the entitled submicron particles of double network hydrogels exhibit exceptional properties. A two-step strategy was used to obtain alginate/PAM hydrogels crosslinked by Ca2+ cations and N, Nʼ-methylenebisacrylamide (MBA) as different types of crosslinker. Particles of DN alginate / PAM were employed for entrapping and releasing the model drug 5-fluorouracil (5-FU) as an anticancer drug. Scanning Electron Microscopy (SEM), Fourier Transform InfraRed (FT-IR) spectroscopy, ThermoGravimetric Analysis (TGA), Dynamic Light Scattering (DLS), swelling properties, drug entrapment efficiency, and drug release studies were also done. The particles showed porous structure, good swelling ability, and aqueous dispersibility with a size in the range of 280 nm. The resulting hydrogel was subsequently loaded with 5-FU and released patterns carried in 7.4 pH and 5.8 pH at a temperature of 37 ºC. The controlled drug release behavior was noticed and the finding of the study suggested that the alginate/PAM double network hydrogel is a promising carrier for 5-FU delivery.

Boron is very important micronutrient for plants and animals, which menas essential for growth of them in very small quantities. This is the element of special attention as its deficiency and excess are harmful for many plants and the gap between both these level is very narrow. In humans, small amount of boron occur in all tissues but an excess of boron may lead to damage of nervous system. Therefore, boron concentration in drinking water and wastewater is regulated in many countries. The recommended boron content in drinking water according to world health organization (WHO) guideline is 0.5 and according to this limit, the removal of boron from aqueous solution and water is of great environmental and health public health concern. Recently different methods to separate boron from water have been developed. Among them the more effective methods are adsorption processes, membrane processes and hybrid processes. In this manuscript, we presenting knowledge on boron, its properties, sources, effects on environment, plants, animals and new methods for its removal.