In situ forming hydrogels based on oxidized hydroxypropyl cellulose and Jeffamines

Oligo(hydroxypropyl)-substituted polysaccharides can be chemoselectively oxidized to introduce ketone groups at the termini of the side chains. These ketone-substituted polysaccharides, including oxidized hydroxypropyl cellulose, have been shown to be suitable components for preparation of in situ forming, all-polysaccharide hydrogels where chitosan is the reactive partner. This class of hydrogels exhibits several advantages including injectability, the ability to self-heal, and the absence of small molecule crosslinkers, therefore they have considerable promise for biomedical applications. Their strong potential inspires us to broaden the range of their application to include thermoresponsive hydrogels. Herein, we design and prepare a series of oxidized hydroxypropyl cellulose hydrogels by reaction with Jeffamines. Jeffamines themselves are polyethylene oxide-b-polypropylene oxide-b-polyethylene oxide triblock copolymers with two terminal amines. They display thermal responsivity, and are biocompatible with some tissues and under some circumstances. The mechanical properties of these Jeffamine/oxidized hydroxypropyl cellulose hydrogels were characterized by rheometry, revealing that hydrogel storage modulus could be tuned (3, 300–21, 000 Pa) by controlling temperature (25–60 °C) and Jeffamine chain length (600, 900, 1900 g/mol). Furthermore, these hydrogels display self-healing properties and high swelling ratios. Hydrogel microstructures were characterized by scanning electron microscopy. We investigated the potential for drug incorporation into the hydrogels. Overall, this study demonstrated synthesis and potential of these Jeffamine/oxidized hydroxypropyl cellulose hydrogels for in situ formation and thermally responsive behavior, thereby broadening the family of oxidized hydroxypropyl cellulose-based hydrogels.