An Injectable ROS-Responsive Self-Healing Hydrogel Based on tetra-poly(ethylene glycol)-b-oligo(l-methionine)

摘要

Abnormal physiological conditions provide an ideal stimulus for the design of responsive hydrogels which function as controlled and site-specific release of drugs. Here, an injectable reactive oxygen species (ROS) responsive selfhealing hydrogel based on tetra-poly(ethylene glycol)-b-oligo (l-methionine) (t-PEG_(56)-b-OMeth_n) synthesized by a novel and facile method is reported. The hydrophobic interactions between the side chains of l-methionine make the polymer chains crosslinked and lead to the formation of hydrogels which can be injected and self-healed, meanwhile, the cross-linker also provides a hydrophobic domain to encapsulate Dox. In presence of ROS, the side chain of l-methionine can be oxidized to methionine sulfoxide. The side chain of l-methionine is changed accordingly from hydrophobic to hydrophilic. As a result, both the hydrophobic domain and the hydrogel itself are destroyed. The controlled release of Dox by ROS at site-specific is realized. The excellent biocompatibility of hydrogel based on t-PEG_(56)-b-OMeth_n indicates the door of the potential application in controlled release of drug in a truly physiological environment.