Self‐Propelled Magnetic Dendrite‐Shaped Microrobots for Photodynamic Prostate Cancer Therapy

Abstract

Photocatalytic micromotors that exhibit wireless and controllable motion by light have been extensively explored for cancer treatment by photodynamic therapy (PDT). However, overexpressed glutathione (GSH) in the tumor microenvironment can downregulate the reactive oxygen species (ROS) level for cancer therapy. Herein, we present dendrite-shaped light-powered hematite microrobots as an effective GSH depletion agent for PDT of prostate cancer cells. These hematite microrobots can display negative phototactic motion under light irradiation and flexible actuation in a defined path controlled by an external magnetic field. Non-contact transportation of micro-sized cells can be achieved by manipulating the microrobot's motion. In addition, the biocompatible microrobots induce GSH depletion and greatly enhance PDT performance. The proposed dendrite-shaped hematite microrobots contribute to developing dual light/magnetic field-powered micromachines for the biomedical field.

Light-powered swarming phoretic antimony chalcogenide-based microrobots with “on-the-fly” photodegradation abilities

“…EDTA is a commonly used scavenger that interacts with photogenerated holes and hinders the formation of OH˙ radicals. 59 As clearly demonstrated in Fig. S6,† the presence of the scavenger significantly decreased the efficiency of photocatalytic degradation of quinoline yellow; the absorbance decreased by 22% after two hours This observation supports the assumption that the ROS, especially OH˙ radicals are generated upon exposure of the microrobots under UV illumination providing the degradation abilities.…”

“…EDTA is a commonly used scavenger that interacts with photogenerated holes and hinders the formation of OH • radicals. 59 As clearly demonstrated in Fig. S6, † the presence of the scavenger significantly decreased the efficiency of photo-…”

In vivoapplications of micro/nanorobots

“…49 Among these sources, magnetic actuation is the leading way to precisely manipulate micro/ nanorobots with high degrees of freedom (DoF). 50,51 Given the high penetration ability of magnetic fields, this approach is…”

Multifunctional and multimodality theranostic nanomedicine for enhanced phototherapy

“…(2) the hypoxic microenvironment of the tumor leading to an insufficient O 2 supply during treatment, which limits the therapeutic efficiency of PDT; [5][6][7] and (3) the high level of reducing substances in cancer cells, such as glutathione (GSH), which can consume ROS produced by PDT. [8][9][10] Therefore, alleviating the tumor hypoxic microenvironment and reducing the level of reducing substances in tumor cells are the key to improving the effect of PDT. 11 Much effort has been made to improve PDT efficiency by alleviating the tumor hypoxic microenvironment.…”

“…2,3 However, PDT still faces many problems in therapeutic application, 4 such as (1) the limited penetration depth of light; (2) the hypoxic microenvironment of the tumor leading to an insufficient O 2 supply during treatment, which limits the therapeutic efficiency of PDT; 5–7 and (3) the high level of reducing substances in cancer cells, such as glutathione (GSH), which can consume ROS produced by PDT. 8–10 Therefore, alleviating the tumor hypoxic microenvironment and reducing the level of reducing substances in tumor cells are the key to improving the effect of PDT. 11…”