Water-Dispersed Smart Eu(III)-Induced Nanocarriers of Polystyrene-b-Poly(acrylic Acid) for Co-delivery and pH-Responsive Controlled Release of Drug

Polymeric drug nanocarriers still face critical challenges, including poor water solubility, limited biocompatibility, insufficient drug loading capacity, uncontrolled drug release, and the lack of in situ sensing capabilities. This work aims to develop new polymeric drug nanocarriers with multifunctionalization of drug loading, releasing, and in situ sensing (D-LRS). Firstly, water-dispersible Eu 3+ -induced polymeric nanoaggregates (EIPAs) composed of EuCl 3 , 1,10-phenanthroline, and 2-thenoyltrifluoroacetone are synthesized as drug nanocarriers in a polystyrene- block -poly(acrylic acid) aqueous system. The as-synthesized EIPAs have an average diameter of 200   nm and intrinsic luminescence in an aqueous environment, as well as good biocompatibility. Secondly, both doxorubicin ( dox ) and paclitaxel ( pac ) are encapsulated with EIPAs for co-delivery, either separately or together, and the encapsulated drugs are found to be able to achieve pH-responsive controlled release. More importantly, the loading and releasing of the dox and pac drugs could be efficiently in situ monitored by tuning the emission intensity of EIPAs. Thanks to desired water solubility and biocompatibility, as well as intense aqua-luminescence and pH-responsive drug-releasing ability, the smart Eu 3+ -fluorescence-sensible drug carriers could have potential for D-LRS in the combinatory therapy of cancer.