Application of M1 macrophage as a live vector in delivering nanoparticles for in vivo photothermal treatment

Abstract Introduction To enhance photothermal treatment (PTT) efficiency, a delivery method that uses cell vector for nanoparticles (NPs) delivery has drawn attention and studied widely in recent years. Objectives In this study, we demonstrated the feasibility of M1 activated macrophage as a live vector for delivering NPs and investigated the effect of NPs loaded M1 stimulated by Lipopolysaccharide on PTT efficiency in vivo. Results We found M1 exhibited a 20-fold higher uptake capacity of NPs per cell volume and 2.9-fold more active infiltration into the tumor site, compared with non-activated macrophage MФ. We injected M1 cells peritumorally and observed that these cells penetrated into the tumor mass within 12 h. Then, we conducted PTT using irradiation of a near-infrared laser for 1 min at 1 W/cm2. As a result, we confirmed that using M1 as an active live vector led to a more rapid reduction in tumor size within 1 day indicating that the efficacy of PTT with NPs-loaded M1 is higher than that with NPs-loaded MФ. Conclusion Our study demonstrated the potential role of M1 as a live vector for enhancing the feasibility of PTT in cancer treatment.