Effect of Gamma Radiation on the Adsorption Capacity and Regeneration / Desorption of Sulphate and Phosphate Ions Using Smart Hydrogel.

Co-polymeric hydrogels containing poly (Acrylamide /Epichlorohydrine) P(AAm/EPI) with different acrylamide and Epichlorohydrine content were fabricated by gamma radiation at different irradiation doses as adsorbent materials for wastewater treatment. The mechanisms of radiation-induced crosslinking of hydrogel in aqueous solution has been evaluated. The gel contents and the swelling/diffusion kinetic parameters were evaluated at different irradiation doses, and the result confirm a non-fichian mechanism. The shape, surface morphology, and porosity of P (AAm/ Epi) hydrogel were characterized by scanning electron microscope (SEM). Adsorption experiments were carried out for the removal of sulphate and phosphate ions from wastewater using P(AAm/EPI) hydrogels as adsorbent materials. The isotherm data were analyzed by Freundlich equation. The equilibrium isotherm results show a better fitting (R2 > 0.9) to the Freundlich model for all anions. The calculated regeneration efficiency (%) values of sulphate and phosphate ions found to be ranged between 63.2 (%) and 46 (%).The relatively higher regeneration efficiency (%) and keeping the hydrogels its shape without any deformation promising to use the same hydrogels further times which decrease the economic cost.

Developments on Synthesis and Applications of Sulfobetaine Derivatives: A Brief Review

Zwitterionic polymers are material families characterized by high dipole moment and highly charged groups. Zwitterionic materials simultaneously possess an equimolar number of cationic and anionic moieties, maintaining overall electroneutrality and high hydrophilicity. Zwitterionic is categorized into three groups: phosphobetaine, carboxybetaine, and sulfobetaine that could form dense and stable hydration shells through the strong ion-dipole interaction among water molecules and zwitterions. As a result of their remarkable hydration capability, low interfacial energy, and marvelous antifouling capacities, these materials have been applied as adsorbing agents, biomedical applications, electronics, hydrogels, and antifouling for membrane separation and marine coatings. This review is focused on polysulfobetaine, which contains sulfonate as a negatively charged group, and quaternary ammonium as a positively charged group. Polysulfobetaine is the most promising one to be applied in the industry since it is commercially available and its monomers are easily prepared. The comparisons of several polysulfobetaine derivatives as antimicrobial, antifouling, surfactant and detergents, biomedical and electronic application, surface modification, and smart hydrogel are presented in this review.

Synthesis and Characterization of New Biodegradable Injectable Thermosensitive Smart Hydrogels for 5-Fluorouracil Delivery

In this paper, injectable, thermosensitive smart hydrogel local drug delivery systems (LDDSs) releasing the model antitumour drug 5-fluorouracil (5-FU) were developed. The systems were based on biodegradable triblock copolymers synthesized via ring opening polymerization (ROP) of ε-caprolactone (CL) in the presence of poly(ethylene glycol) (PEG) and zirconium(IV) acetylacetonate (Zr(acac)4), as co-initiator and catalyst, respectively. The structure, molecular weight (Mn) and molecular weight distribution (Đ) of the synthesized materials was studied in detail using nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) techniques; the optimal synthesis conditions were determined. The structure corresponded well to the theoretical assumptions. The produced hydrogels demonstrated a sharp sol–gel transition at temperature close to physiological value, forming a stable gel with good mechanical properties at 37 °C. The kinetics and mechanism of in vitro 5-FU release were characterized by zero order, first order, Higuchi and Korsmeyer–Peppas mathematical models. The obtained results indicate good release control; the kinetics were generally defined as first order according to the predominant diffusion mechanism; and the total drug release time was approximately 12 h. The copolymers were considered to be biodegradable and non-toxic; the resulting hydrogels appear to be promising as short-term LDDSs, potentially useful in antitumor therapy.

This Review Recent Advances in Chitosan and Alginate‐Based Hydrogels for Wound Healing Application

Wound healing is a complicated yet necessary event that takes place in both animals and human beings for the body to repair itself due to injury. Wound healing involves various stages that ensure the restoration of the injured tissue at the end of the process. Wound dressing material acts as a protective extracellular barrier against potential damage to the injury and microbial invasion. Naturally, polysaccharides (chitosan and alginate) have inherent properties that have made them attractive for their usage in wound healing therapy. Alginate and chitosan have been used to develop novel wound healing and smart biomaterials due to various functionalities such as reducing swelling, non-toxic nature, biocompatibility, antimicrobial potential, and maintenance moist environment, ability to absorb wound fluid, and skin regeneration promotion. Functionalization of polysaccharides is one of the many approaches that have been used to modify and enhance the wound healing properties of these biomaterials. Many studies have been done to modify the polysaccharide hydrogels. Some of these are highlighted in this paper. The designing and development of smart hydrogels that react to their environment have recently sparked a significant scientific and pharmaceutical interest. Smart hydrogel development has been the primary focal area for developing highly advanced and sophisticated wound healing therapeutic technologies. This paper seeks to comprehensively shed light on the advancements of functionalized chitosan and alginate-based hydrogels and their applicability in wound healing therapeutics. In addition to this, thus identifying critical drawbacks faced in existing hydrogel systems and how prospective technologies enable digitally controlled bio-platforms coupled with biomaterials to improve wound care. This review hopes to stimulate and encourage researchers to identify future avenues worth investigation.