Biodegradable, pH-sensitive P(CL-Pluronic-CL-co-MAA-MEG) hydrogel for 5-aminosalicylic acid delivery

In this paper, a series of biodegradable and pH-sensitive hydrogels from Pluronic, poly(ε-caprolactone) (PCL), and methylacrylic acid (MAA) polymer matrix was successfully prepared via UV-initiated free radical polymerization method. A scanning electron microscope was adopted to detect the internal microstructure of the prepared hydrogels at different pH values (pH 1.2 and pH 7.2). To investigate the pH-responsivity and hydrolytic degradation characterization of the hydrogel, detailed parameters including MAA and PCL polymers content, PEG content, BIS content and molecular weight of Pluronic have been employed in this work. The in vitro release behavior of hydrophobic 5-aminosalicylic acid drug was investigated in this paper, which indicated that this new kind of hydrogel with good pH-responsivity might have great potential applications in smart drug delivery systems, especially in colon targeting therapy.