Photohermal Microswimmer Penetrate Cell Membrane with Cavitation Bubble

TL;DR

This paper demonstrates that photo-thermal cavitation bubbles generated by laser-activated microswimmers can penetrate cell membranes and deliver genetic material, advancing noninvasive biomedical micromotor applications.

Contribution

It introduces a novel method using laser-induced cavitation bubbles to control microswimmer propulsion and achieve cell membrane penetration for drug and gene delivery.

Findings

Laser power controls microswimmer motion and explosion.

Cavitation bubbles enable precise cell membrane penetration.

Successful gene transfection in cells using loaded microswimmers.

Abstract

Self-propelled micromotors can efficiently convert ambient energy into mechanical motion, which is of great interest for its potential biomedical applications in delivering therapeutics noninvasively. However, navigating these micromotors through biological barriers remains a significant challenge as most micromotors do not provide sufficient disruption forces in in-vivo conditions. In this study, we employed focused scanning laser from conventional confocal microscope to manipulate carbon microbottle based microswimmers. With the increasing of the laser power, the microswimmers' motions translates from autonomous to directional, and finally the high power laser induced the microswimmer explosions, which effectively deliveres microbottle fragments through the cell membrane. It is revealed that photothermally-induced cavitation bubbles enable the propulsion of microbottles in liquids, where the motion direction can be precisely regulated by the scanning orientation of the laser. Furthermore, the membrane penetration ability of the microbottles promised potential applications in drug delivery and cellular injections. As microbottles navigate toward cells, we strategically increase the laser power to trigger their explosion. By loading microswimmers with transfection genes, cytoplasmic transfection can be realized, which is demonstrated by successful gene transfection of GPF in cells. Our findings open new possibilities for cell injection and gene transfection using micromotors.