Development and Characterization of Stimuli Responsive Hydrogel Microcarriers for Oral Protein Delivery.by O'Connor, C; Steichen, S; Peppas, NA
J Biomed Mater Res A. 2017 Feb 8. doi: 10.1002/jbm.a.36030.
A family of pH-responsive terpolymers composed of methacrylic acid (MAA), N-vinyl pyrrolidone (NVP), and poly(ethylene glycol) monomethylether monomethacrylate (PEGMMA) have been developed and evaluated for their pH-responsive swelling behavior, protein loading capabilities, and cytocompatibility. These terpolymer hydrogels, designated as P((MAA-co-NVP)-g-EG), were synthesized with varying PEG chain lengths and monomer feed ratios. The incorporation of MAA into the terpolymer structure was quantified with potentiometric titration. Equilibrium and dynamic swelling studies confirmed the pH-responsive behavior of the hydrogel, with the system remaining collapsed/complexed in acidic pH conditions and swollen/decomplexed in neutral pH conditions. The ability of the hydrogels to partition protein into the swollen network was assessed for two model proteins of varying molecular weight: insulin and porcine growth hormone. Finally, the cytocompatibility of the hydrogels in the presence of two model intestinal cell lines was investigated and confirmed minimal cytotoxicity at and below 2.5 mg/mL. The developed P((MAA-co-NVP)-g-EG) hydrogels exhibit unique properties that could potentially be utilized for drug delivery and separation applications. This article is protected by copyright. All rights reserved.