Acoustic and magnetic hybrid actuated immune cell robot for target and kill cancer cells

Abstract

Macrophage immunotherapy is a promising clinical approach to treat cancer. However, low targeting efficiency severely limits the immunotherapeutic effect of macrophages. Here, we report a unique macrophage robot that can target and kill cancer cells using a combination of external acoustic and magnetic fields. First, the inactive macrophages (Mø) are magnetized by endocytosis of the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\gamma$</tex> -Fe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> nanoparticles (FeNPs). Then, the magnetized M⊘can be moved towards the capillary wall under the influence of an acoustic radiation force generated from a lead zirconate titanate piezoelectric (PZT) transducer. Finally, the magnetized cells rotate forward under the action of alternating magnetic fields (AMF). During the process of magnetizing macrophages, FeNPs activate the anti-tumor immune activity of macrophages (M1) to induce cancer cell death. Overall, the present study highlights a novel cell robot that can target and kill cancer cells. Considering that the nanoparticles, macrophages, magnetic fields, and ultrasound technology have all been FDA approved for clinical settings, our targeted delivery system has tremendous clinical translational potential.