Adenosine triphosphate-responsive carbon dots nanoreactors for T₁-weighted magnetic resonance imaging-guided tumor chemodynamic therapy

There are various strategies to conduct tumor microenvironment (TME) stimulus-responsive (e.g., acid, H₂O₂ or glutathione) nanoreactors for increasing the efficiency of chemodynamic therapy (CDT). Among these, the exploitation of adenosine triphosphate (ATP, another over-expressed biomarker in TME)-responsive nanoreactors for tumor CDT is still challenging. Herein, the ATP-responsive iron-doped CDs (FeCDs) were firstly prepared and then co-assembled with glucose oxidase (GOx) to obtain FeCDs/GOx liposomes as ATP-responsive nanoreactors. Under TME conditions, the nanoreactors initially released FeCDs and GOx. Subsequently, with the existence of ATP, iron ions were rapidly released from the FeCDs to trigger Fenton/Fenton-like reactions for generating ·OH. Meanwhile, the T₁-weighted magnetic resonance imaging (MRI) was achieved due to the released iron ions. Moreover, the GOx converted endogenous glucose in tumor to gluconic acid and H₂O₂ to satisfy the requirement of ·OH generation. In vitro as well as in vivo experiments illustrated that the obtained ATP-responsive CD nanoreactors could be used as a versatile nanotheranostics for simultaneously T₁-weighted MRI-guided tumor CDT. This work presents a new ATP-responsive nanoreactor with self-supplied H₂O₂ for multifunctional nanotheranostic applications.