Design and manufacture of new hybrid hydrogel and superabsorbent polymer for controlled release of fulvic acid based on grafted xanthan gum/gelatin using electron irradiation and its use in fodder corn cultivation.

A humic acid-gelatin (HA-Gel) hydrogel, a gallic acid-xanthan gum (GA-XG) hydrogel, a HA-Gel/GA-XG hydrogel, and superabsorbent polymer (SAP) of HA-Gel/GA-XG/polyacrylamide (PAM) hydrogel were synthesized using electron beam irradiation method. The capability of synthesized hydrogels in loading and controlled release of fulvic acid (FA) was studied. The chemical and physical structure of sorbents was confirmed by various analyses. The effect of irradiation dose on mechanical properties, gel percentage, swelling, and absorbency under load (AUL) of the sorbents was investigated. By changing the hydrogel structures into the SAP form, its swelling capacity was increased from 37 to 320 g/g. Both hybrid hydrogel and SAP were reusable for up to 7 cycles. The maximum fertilizer loading capacities for SAP and hybrid hydrogel were 402.1 and, 175.5 mg g-1, respectively. In comparison to hydrogels, the SAP showed a slower FA-release performance. Thus, in soil media, 86 % of FA was released in 15-20 days from the hybrid hydrogel while with the SAP, 81 % of FA was released in 30-35 days. The significant improvement in the growth of fodder corn treated with FA-loaded SAP in the greenhouse media in comparison to the control groups showed the effective performance of the designed SAP, favoring its practical applications.

Doxycycline drug delivery using hydrogels of O-carboxymethyl chitosan conjugated with caffeic acid and its composite with polyacrylamide synthesized by electron beam irradiation.

Two hydrogels of O-carboxymethyl chitosan conjugated with caffeic acid and its composite with polyacrylamide were synthesized using electron beam irradiation. The synthesized hydrogels were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and mechanical properties studies. The hydrogels were loaded with doxycycline by swelling and its release was investigated in various media. The effect of the dose of electron beam irradiation and PAAm amount on the properties of hydrogels including swelling, drug loading, drug release, mechanical properties, and gel content were studied. The release of doxycycline form hydrogels in different media obeyed the mechanism of non-Fickian diffusion and best fitted to the Higuchi model and Korsmeyer-Peppas. In-vitro doxycycline release consideration indicated that the drug's release from composite hydrogel occurs with higher amounts than the other one. The cytotoxic study confirmed the non-toxicity of the prepared hydrogels dressing. Moreover, the growth inhibition of permissive bacteria against Staphylococcus aureus and Escherichia coli were observed for doxycycline-loaded hydrogels. So, the synthesized hydrogels are appropriate for practical application as a new antibacterial wound dressing.

Electron beam irradiation synthesis of porous and non-porous pectin based hydrogels for a tetracycline drug delivery system.

Electron beam irradiation was used for the synthesize of porous and non-porous pectin based hydrogels through conjugation of pectin with 5-hydroxytryptophan in the presence and absence of sodium dodecyl sulfate, respectively. The hydrogels were characterized by different methods. Tetracycline hydrochloride was loaded on the hydrogels by swelling equilibrium method and its release in different media was studied. The effect of SDS amount and electron beam irradiation dose on the swelling, drug loading, drug release, gel content, and mechanical properties were investigated. The release of drug form both hydrogels followed non-Fickian diffusion mechanism and was best fitted with the Korsmeyer-Peppas model. In vitro, drug release studies revealed that the release of drug from non-porous hydrogel is relatively slow while its release from porous hydrogel occurs with higher amounts and faster rate. Biocompatibility and cytotoxic analysis indicate that the prepared hydrogels dressing are non-thrombogenic, non-hemolytic and non-toxic. Furthermore, acceptable bacteria growth inhibition against Escherichia coli and Staphylococcus aureus were observed for both drug-loaded hydrogels. Thus, these hydrogels are suitable for the application of an antibacterial wound dressing.