Tunable Fluorescence-Responsive Double Hydrophilic Block Polymers Induced by the Formation of Pseudopolyrotaxanes with Cucurbit[7]Uril

• Main Authors: Xiumin Qiu, Xin Wang, Shengzhen Hou, Jin Zhang, Jing Zhou, Yebang Tan
• Format: Article
• Language: English
• Published: MDPI AG 2019-09-01
• Series: Polymers
• Subjects: supramolecular chemistry; host-guest system; self-assembly; aggregation-induced emission; cell imaging; drug delivery
• Online Access: https://www.mdpi.com/2073-4360/11/9/1470

There is an urgent need for new strategies that allow the simultaneous detection and control of drug delivery. By making use of supramolecular host-guest interactions, a kind of pseudopolyrotaxanes, as a visualizable nanoscale drug carrier has been constructed by self-assembly of cucurbit[7]uril (CB[7]) with methoxy poly(ethylene glycol)-<i>block</i>-quaternized poly(4-vinyl pyridine) (mPEG-<i>b</i>-QP4VP) using 4-(chloromethyl)benzonitrile. Simple addition of CB[7] into an aqueous solution of mPEG-<i>b</i>-QP4VP resulted in noncovalent attachment of CB[7] to 4-cyanobenzyl-containing polymers, transforming the nonemissive mPEG-<i>b</i>-QP4VP micelles into highly fluorescent micelles. These pseudopolyrotaxanes micelles exhibited remarkable supramolecular assembly-induced emission enhancement and excellent biocompatibility, showing great potential for bioimaging applications. In addition, the efficient cellular uptake of the developed pseudopolyrotaxanes micelles loaded with the anticancer drug doxorubicin was a promising platform for simultaneous cell imaging and drug delivery, thereby widening their application in cancer theranostics.