Biomimetic Nanotheranostics Camouflaged with Cancer Cell Membranes Integrating Persistent Oxygen Supply and Homotypic Targeting for Hypoxic Tumor Elimination.

Treatment resistance of the tumors to photodynamic therapy (PDT) owing to O deficiency largely compromised the therapeutic efficacy, which could be addressed modulating oxygen levels by using O self-enriched nanosystems. Here, we report on augmenting the O-evolving strategy based on a biomimetic, catalytic nanovehicle (named as N/P@MCC), constructed by the catalase-immobilized hollow mesoporous nanospheres by enveloping a cancer cell membrane (CCM), which acts as an efficient nanocontainer to accommodate nitrogen-doped graphene quantum dots (N-GQDs) and protoporphyrin IX (PpIX). Inheriting the virtues of biomimetic CCM cloaking, the CCM-derived shell conferred N/P@MCC nanovehicles with highly specific self-recognition and homotypic targeting toward cancerous cells, ensuring tumor-specific accumulation and superior circulation durations. N-GQDs, for the first time, have been evidenced as a new dual-functional nanoagents with PTT and PDT capacities, enabling the generation of O for PDT and inducing local low-temperature hyperthermia for thermally ablating cancer cells and infrared thermal imaging (IRT). Leveraging the intrinsic catalytic features of catalase, such N/P@MCC nanovehicles effectively scavenged the excessive HO to sustainably evolve oxygen for a synchronous O self-supply and hypoxia alleviation, with an additional benefit because the resulting O bubbles could function as an echo amplifier, leading to the sufficient echogenic reflectivity for ultrasound imaging. Concurrently, the elevated O reacted with N-GQDs and PpIX to elicit a maximally increased O output for augmented PDT. Significantly, the ultrasound imaging coupled with fluorescence imaging, IRT, performs a tumor-modulated trimodal bioimaging effect. Overall, this offers a paradigm to rationally explore O self-supply strategies focused on versatile nanotheranostics for hypoxic tumor elimination.