preparation and characterization of hydrogel (2-hydroxyethyl methacrylate, methacrylamide) for insulin delivery

For diabetics, insulin replacement therapy by injection of insulin is a common and final treatment protocol. they must replace insulin with a subcutaneous insulin injection via a syringe up to four times a day. frequent daily injections over a long period would lead to swelling, redness, and itching at the injection site. in addition, the breaking up of fat in the skin impairs sensation and leads to cosmetic problems. to modify the undesirable effects and make the insulin orally absorbable, it was planned to add a hydrogel to the insulin. using the free radical polymerization method, 2-hydroxyethyl methacrylate (hema) and methacrylamide (maam) were used to synthesize the hydrogel at room temperature for four hours. potassium persulfate was applied as the initiator, and n,n’-methylene-bis-acrylamide (mbaa) as the crosslinker. insulin was prepared at a dilute concentration of 0.00001 m. the structural behavior and thermal properties of the synthesized hydrogels with and without insulin were analyzed by fourier transform infrared (ft-ir) spectroscopy, thermogravimetric analysis (tga), differential thermal gravimetric analysis (d-tga), and differential scanning calorimetry (dsc). the swelling kinetics were investigated at different ph values, and the optimal conditions were determined. the diffusion phenomenon of hydrogels with insulin in acidic, neutral, and basic media was calculated. insulin release was measured by uv-vis spectroscopy at different ph values. the optimum condition was found at a ph of 7. the porosity and morphology of the hydrogel, a 1:1 molar ratio of the feed composition, were analyzed using brunauer-emmett-teller (bet) theory  and scanning electron microscopy (sem).