Integrated cell membrane encapsulated PQDs-TK quantum dot nanoclusters with ROS-responsive triggering for efficient and visualized DNA delivery.

With the unique photo-physical properties and strong bio-compatibility. Quantum dots (QDs) have sparked interest in biomedical fields such as imaging, biosensing and therapeutics. However, the low stability and insufficient tumor specificity have largely constrained their potential biomedical applications. Here, we reported a cell membrane encapsulated PQDs-TK quantum dots nanoclusters (CM-PQDs-TK) gene delivery system with ROS-responsive triggering for efficient and visualized DNA delivery. CM-PQDs-TK possessed excellent DNA loading capacity and protective ability. The particle size and morphology change suggested that CM-PQDs-TK displayed superior ROS responsiveness. As expected, CM-PQDs-TK had an obvious nanocluster structure, and the particle size was stabilized in the range of 200-300 nm. Compared with PQDs and PQDs-TK, HlM-PQDs-TK/DNA encapsulated by Hela cell membrane has higher uptake efficiency and transfection ability, reaching 67.14 % and 63.41 % in 293 T cells, and the DNA transfection efficiency could still reach 43.98 % even in cancer cells (Hela cells). Moreover, flow cytometry and fluorescence microscopy showedthat nanoclusters could effectively enter tumor cells, and the internal DNA could be effectively released. In this process, PQDs-TK responded to high ROS in tumor cells and greatly improved DNA delivery efficiency. After loading DNA, cell membrane encapsulation technology was used to enhance its biocompatibility and targeting further. This work was anticipated to provide an in-depth understanding of the important role of PEI quantum dots in the field of ROS-responsive intelligent gene carriers and laid a foundation for the design and preparation of novel quantum dots gene carriers.