Drug Release Study from Superabsorbent Hydrogel Based on Poly-2-acrylamido-2-methylpropanesulfonic Acid Grafted Collagen

摘要

The present work focused on the design of drug delivery system based on a pH-sensitive hydrogel. The hydrogels were prepared via graft copolymerization of 2-acrylamido-2-methylpropane sulfonic acid monomer onto collagen backbones by a free radical polymerization technique. Sodium bicarbonate was added to function as a foaming agent under acidic conditions, rendering the hydrogels to be porous. Porous structure of hydrogel was essential in this system to yield a large surface area so that acetaminophen release could be facilitated. The hydrogel thus prepared possessed a porous structure as determined by scanning electron microscopy. Due to the reversible swelling behaviour of the hydrogels, the synthesized networks can sense the environmental pH change and achieve an oscillatory release pattern. The concentration of released acetaminophen loaded was monitored at 245 nm on the UV spectrophotometer. Water absorption of the hydrogel could be switched on and off swiftly by control of pH of the surrounding environment. Therefore, the synthesized hydrogels in this work can be used as a drug delivery system and that the drug release can be controlled by the pH of solution.