Physically crosslinked poly(vinyl alcohol)-hyaluronic acid (PVA-HA) hydrogel membranes composed of different amounts of HA were prepared by freeze-thawing (F-T) method. F-T cycle was repeated for three consecutive cycles. HA was chosen and routinely utilized in the local treatment of chronic wounds, because of its advantages as, HA is endogenous and biodegradable polymer. Physicochemical properties of PVA-HA membranes such as, gel fraction (GF), swelling, mechanical properties, hydrolytic degradation and in vitro bio-evaluation tests were investigated. Results revealed that introducing HA into PVA structure affected significantly the physicochemical properties of membranes than the pristine PVA, because of its crosslinking interaction with PVA. With the increase of HA content in PVA hydrogel membranes, GF and mechanical stability of PVA-HA membranes decreased. However, the swelling behavior, mechanical flexibility, protein adsorption and hydrolytic degradation of PVA membrane increased. The HA content < 20% in PVA hydrogels showed high cell viability (%) and no toxicity was observed using microculture tetrazolium assay (MTT-assay). However, less cell viability was determined with high HA incorporation. PVA-HA-ampicillin free showed antimicrobial activity against Candida albicans as a result of HA presence. Thus, ampicillin-loaded wound dressing with PVA-HA membranes could be used as promising materials with easy forming and biologically evaluated for wound care. ]]>

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A copolymer hydrogel consisting of Polyacrylic Acid (PAAc) combined with an irradiated solution of carboxymethyl cellulose (CMC, 1 wt%) was prepared. The focus was on controlling the radiation degradation of CMC by exposing it to different six doses of γ‐irradiation from 0 up to 3 kGy. After the irradiation process, the six CMC solution samples were mixed with 10 vol% of Acrylic Acid (AAc) monomer and re‐irradiated at a dose of 25 kGy to begin the polymerization process. A scanning electron microscope (SEM) was used to image the macroporous structure of the obtained (CMC/PAAc) hydrogel. Moreover, the SEM image confirmed the interpenetrating and semi‐interpenetrating polymer network structure based on the irradiation process. The controlled release of urea is achieved due to the binding between urea and the functional groups of the investigated hydrogel by hydrogen bonds. The growth of common bean plant (Phaseolus vulgaris L.) and chlorophyll contents were increased when soils were treated with (CMC/PAAc) compared with soils with free hydrogel in water‐stress conditions.

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The important to synthesize a lower toxicity hydrogel with high biocompatibility to use in agricultural field. In this regard, the polymerization reaction of Poly vinylpyrrolidone and Poly acrylamide (PVP/PAAm) hydrogel has been obtained after exposed the copolymer and monomer mixture to dose of 30 kGy. The equilibrium swollen of the obtained hydrogel was 25 (g/g) after 60 min., has an advantage to use as soil conditioner. The hydrogels samples have been prepared in weight ratios 25:75, 50:50 and 75:25 (wt:wt). The crosslink density combining this with measurements of the swelling degree was depend on the copolymer concentration of two polymers. The morphology and the chemical structure of the PVP/PAAm hydrogels was characterized using Scanning electron microscope (SEM), Fourier transform infrared spectroscopy technique (FTIR), and X-ray diffraction (XRD). The PVP/PAAm hydrogels with ratio (75/25) were selected to evaluate the effectiveness on water holding capacity (WHC) in heavy metals and alkaline soil pH >9 for plating sunflower (Helianthus annuus).