(158u) Genetically engineered biohybrid micromotors for high-load, highly stable, and highly active drug delivery for solid tumors

Cell-driven drug delivery system is a promising drug delivery strategy. This method combines living cells/bacteria with different excellent characteristics and drugs, which can effectively overcome the low bioavailability, weak targeting performance of traditional nanodrugs, and tissue penetration. Since the specific response to the target lesion, it can not only achieve efficient active targeted delivery of drugs, but also reduce toxic and side effects on normal tissues. It has been successfully used in drug presentation with promising applications in the field of disease diagnosis and treatment.

However, the use of living cells as drug carriers is still in its infancy. Considering the method of drug loading, the physical method is unstable while the chemical method is limited to the loading capacity, resulting in a low drug loading rate. In the complex fluid environment of the body, the loading stability of drugs is greatly challenged under the action of various shear forces. The propulsion of living cells for drug delivery should ensure cell activity and function. However, cell modification, integration, and drugs may affect the movement of the cells, thereby affecting its access to the lesion site and the efficiency.

This work constructed biohybrid micromotors using living cells as carriers such as spiral microalgae/magnetotactic bacteria. Free damage of cells with high capacity of drug loading was achieved through fine surface modification methods and genetic engineering. Active propulsion combined with external remote magnetic field control was used to treat solid tumors under the stimulation of low oxygen and low pH microenvironment. This work combined multi-modal control methods to achieve a conceptual verification of a new control method for cell/bacteria active drug delivery, which provides new ideas for the efficient treatment of solid tumors in deep tissue.