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

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. Methods: M1 was used as a live vector for delivering NPs and further to investigate the effect of NPs loaded M1 on PTT efficiency. Non-activated macrophage (M Phi) was stimulated by lipopolysaccharide (LPS) into M1 and assessed for tumor cell phagocytic capacity towards NPs 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 M Phi. 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/cm(2). 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 M Phi. Conclusion: Our study demonstrated the potential role of M1 as a live vector for enhancing the feasibility of PTT in cancer treatment. (C) 2021 The Authors. Published by Elsevier B.V. on behalf of Cairo University.

Automated summary

Activated M1 macrophages demonstrated higher uptake capacity and active infiltration towards NPs compared to non-activated M Phi macrophages. Using M1 as live vector led to a more rapid reduction in tumor size, indicating higher efficacy of PTT with NPs-loaded M1.