A pH‐Responsive Biodegradable High‐Strength Hydrogel as Potential Gastric Resident Filler. Issue 10 (25th July 2018) - Wu, Tengling
Abstract: In this study, a pH‐responsive biodegradable high‐strength hydrogel [poly(2‐vinyl‐4, 6‐diamino‐1, 3, 5‐triazine) (PVDT)‐methacrylated gelatin (GelMA)] is synthesized by copolymerization of hydrogen bonding monomer 2‐vinyl‐4, 6‐diamino‐1, 3, 5‐triazine (VDT) and GelMA. The PVDT‐GelMA hydrogel exhibits up to 1.87 MPa tensile stress, 420% breaking strain, 7.24 MPa Young's modulus, and 13.9 MPa compressive strength at 80% strain at pH 7.4, and declines sharply in mechanical performance at pH 1.2 due to the breakup of hydrogen bonding. The strength that the PVDT‐GelMA hydrogel maintains in an acid medium is still superior to that of gastric pressure. This hydrogel can be completely degraded in simulated gastric fluid owing to the synergistic effect of acid swelling and enzymolysis. In a rabbit model experiment, the PVDT‐GelMA hydrogel can reside in the stomach for about 48 h, and no in vivo toxicity is detected in its metabolites, showing an appealing potential as a gastric filler or depot for bariatric interventions and drug delivery. Abstract : A pH‐responsive biodegradable high‐strength hydrogel can reside in a rabbits' stomach for about 48 h, maintain superior mechanical strengths to gastric pressure, and is eventually completely degraded without causing intestinal obstruction. This hydrogel holds an appealing potential as a gastric filler or depot for bariatric interventions and drug delivery.