AIMTo design and synthesize a novel vector for colon-site specific drug delivery system and investigate the relationship between the biodegradation properties and composition of materials in the simulated colon fluid.

METHODSThe azocopolymer P (HEMA-MMA-MAA) was synthesized using 2-hydroxyethylmethacrylate (HEMA), methyl methacrylate (MMA) and methacrylic acid (MAA) as comonmer, azobisisobutyronitrilel (AIBN) as initiator, cross-linked with divinylazobezene (DVAB). The chemical structure of the synthesized series of azocopolymer is examined by UV, FTIR spectroscopy and nuclear magnetic resonance data. Their swelling behavior is evaluated by the swelling equilibrium parameter Q, the biodegradation tests of the materials were carried out at physiologically relevant buffer designed to mimic the colon environment. The biodegradation properties were assessed using the differential scanning calorimeters (DSC) and gel permeation chromatography (GPC) and the morphology on the surface of materials before and after degradation was observed by scanning electron microscopy (SEM).

RESULTSThe swelling equilibrium parameter Q increased with increasing the contents of HEMA and MAA in the materials. The degradation behavior was relevant to the ratio of three components in the copolymers.

CONCLUSIONThis materials may become a good carrier for the colon-site specific drug delivery system if the contents of commoners HEMA, MMA and MAA are adjusted reasonably.