Morphology tailoring and temperature sensitivity control of waist cross-linked micelles and evaluation of their application as intelligent drug carriers

Abstract

A novel type of waist cross-linked micelle (WCM) was developed as an intelligent drug carrier via the self-assembly guiding free radical polymerization of an amphiphilic oligomer: octadecyl, polyethylene glycol butenedioates (O–B–EGs). By changing the concentration of O–B–EG reaction solution, WCMs with monolayer, compound and vesicle-like morphologies were obtained. These WCMs showed controllable temperature responsive properties. DLS and UV-vis analyses indicate that the critical temperatures at which WCMs show an abrupt change in particle size evidently increases with the increase in the molecular weight of the PEG chains. Direct switching of the release of pyrene in WCMs is also realized by a slight change of temperature. Pyrene is released rapidly at the temperatures around the critical temperature of the WCMs, but a further increase in temperature shuts down the release of pyrene. More importantly, these WCMs exhibit reversible and rapid pyrene releasing-absorbing behavior. We suggest that these excellent properties endow WCMs with great potential in drug encapsulation and controlled release