A novel pH sensitive porous membrane carrier for various biomedical applications based on pHEMA/chitosan: Preparation and its drug release characteristics

The synthetic hydrogels based on pHEMA have been widely studied and used in biomedical fields. Numerous techniques exist for entrapment of drugs or proteins in the hydrogels. The suitable biomaterials for biomedical applications include poly(hydroxyethyl methacrylate), (pHEMA), and chitosan. In this work, a novel pH sensitive interpenetrating polymer networks (IPNs) were prepared in the membrane form by using 2-hydroxyethyl-methacrylate monomer (HEMA) and chitosan via UV initiated photo-polymerization in the presence of an initiator (i.e., alpha-alpha'-azo-isobutyronitrile; AIBN). UV-free-radical polymerization techniques are often used to synthesize hydrogels for controlled release applications. A series of HEMA and chitosan IPNs hydrogels were prepared and the equilibrium swelling studies were conducted to investigate swelling behaviors of the membrane according to the pH of the swelling medium. The swelling properties of the membrane were changed with the medium pH. The equilibrium water uptake is reached in about 60 min. The pHEMA/chitosan membrane thickness and density was measured to be 600 gm and 1.26 g cm(-3), respectively. Antibiotic release experiments were also performed with amoxicillin loaded pHEMA/chitosan membrane in physiological saline solution. The IPNs membrane loaded with 100mg antibiotic (i.e., amoxicillin) g hydrogel released around 80 % of the amoxicillin in 10 h at pH 7.4. The presented well-characterized novel pHEMA/chitosan membrane is a potential candidate for transdermal antibiotic carrier or a support in bioseparation.