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Synthesis, characterization, and evaluation of enzymatically degradable poly( N ‐isopropylacrylamide‐ co ‐acrylic acid) hydrogels for colon‐specific drug delivery
Author(s) -
Li Shengfang,
Liu Xianli
Publication year - 2008
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.1162
Subject(s) - self healing hydrogels , poly(n isopropylacrylamide) , acrylic acid , bovine serum albumin , swelling , polymer chemistry , buffer solution , drug delivery , materials science , monomer , nuclear chemistry , drug carrier , chemistry , chromatography , polymer , copolymer , nanotechnology , composite material
The enzymatically degradable poly( N ‐isopropylacrylamide‐ co ‐acrylic acid) hydrogels were prepared using 4,4 ′ ‐bis(methacryloylamino)azobenzene (BMAAB) as the crosslinker. It was found that the incorporated N ‐isopropylacrylamide (NIPAAm) monomer did not change the enzymatic degradation of hydrogel, but remarkably enhanced the loading of protein drug. The hydrogels exhibited a phase transition temperature between 4°C (refrigerator temperature) and 37°C (human body temperature). Bovine serum albumin (BSA) as a model drug was loaded into the hydrogels by soaking the gels in a pH 7.4 buffer solution at 4°C, where the hydrogel was in a swollen status. The high swelling of hydrogels at 4°C enhanced the loading of BSA (loading capability, ca . 144.5 mg BSA/g gel). The drug was released gradually in the pH 7.4 buffer solution at 37°C, where the hydrogel was in a shrunken state. In contrast, the enzymatic degradation of hydrogels resulted in complete release of BSA in pH 7.4 buffer solution containing the cecal suspension at 37°C (cumulative release: ca . 100 mg BSA/g gel after 4 days). Copyright © 2008 John Wiley & Sons, Ltd.