Study on the preparation and drug release property of soybean selenoprotein/carboxymethyl chitosan composite hydrogel

Soybean selenoprotein/carboxymethyl chitosan (SSP/CMCS) composite hydrogel obtained by the crosslinking of genipin was evaluated for caffeine release. The gelation process of the hydrogel was investigated by resonance Rayleigh scattering spectra and viscosity methods. The hydrogels presented a compact network structure, which was observed by positive fluorescence microscopy (PFM). The structural properties of the hydrogel were revealed by fluorescence and FT-IR. The swelling characteristic of the hydrogel and its application in the slow release of caffeine were also studied. These results indicate that there is obvious interaction between SSP and CMCS by the addition of genipin, and the CMCS/SSP solution experiences a significant sol-gel phase transition process upon polymerization. The swelling ratio and release of caffeine slow down obviously at pH 1.2. However, larger swelling and more drug release can be observed at pH 7.4. The experimental values of the empiric diffusional exponent show that the release profiles abide by the non-Fickian diffusion process under both investigated pH conditions. The hydrogel, which is pale transparent with light yellow color at room temperature, can be formulated to be a suitable carrier for site-specific drug delivery.