Acidity/carbon Dioxide-Sensitive Triblock Polymer-Grafted Photoactivated Vesicles for Programmed Release of Chemotherapeutic Drugs Against Glioblastoma

Controllable release of chemotherapeutic drugs in tumor sites remains a big challenge for precision ther-apy. Herein, we developed acidity/carbon dioxide (H +/CO2)-sensitive poly (ethylene glycol) -b-poly (2-(diisopropylamino) ethyl methacrylate)-b-polystyrene triblock polymer (PEG-b-PDPA-b-PS) grafted pho-toactivated vesicles for programmed release of chemotherapeutic drugs against glioblastoma. In brief, gold nanoparticles (GNPs) were firstly tethered with the H +/CO2-sensitive PEG-b-PDPA-b-PS polymer. Next, the CO2 precursor (ammonium bicarbonate, NH4HCO3) and doxorubicin (DOX) were loaded during self-assembly process of PEG-b-PDPA-b-PS-tethered GNPs, thus obtaining the multifunctional gold vesicles (denoted as GVND). The programmed multi-stimuli responsive drug release by GVND was undergone in multiple steps as follows: 1) the vesicular architecture of GVND was first swelled in tumor acidic mi-croenvironment, 2) the GVND were partially broken under near-infrared (NIR) laser irradiation, 3) the mild hyperthermia generated by GV triggered the thermal decomposition of encapsulated NH4HCO3, lead-ing to the in situ generation of CO2, 4) the generated CO2 reacted with PDPA of PEG-b-PDPA-b-PS, chang-ing the hydrophilicity and hydrophobicity of GVND, thus vastly breaking its vesicular architecture, finally resulting in a "bomb-like" release of DOX in tumor tissues. Such a multi-stimuli responsive programmed drug delivery and mild hyperthermia under NIR laser activation displayed strong antitumor efficacy and completely eradicated U87MG glioblastoma tumor. This work presented a promising strategy to realize precision drug delivery for chemotherapy against glioblastoma.Statement of significance center dot An acidity/carbon dioxide-sensitive triblock polymer is synthesized.center dot Multi-stimuli responsive gold vesicles (GVND) co-loaded with ammonium bicarbonate (NH4HCO3) and doxorubicin (DOX) are prepared.center dot The GVND are progressively responsive to tumor acidic microenvironment, light irradiation, and the in situ generated CO2.center dot The GVND have the potential to be used for multi-stimuli responsive programmed release of DOX against glioblastoma.(c) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.