Low dose Radiation Enhanced Uptake of Drug-loaded Fluorescent Nanocarriers in Mesenchymal Stem Cells

• 1、State key Laboratory of Radiation Medicine and Protection,Soochow University，Su Zhou，215123
• 2、West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University,Cheng Du,610041

Abstract：Low-dose ionizing radiation (LDR) can promote biological behaviors of stem cells, such as proliferation and cytokine expression; however, its effect on nanoparticle uptake by stem cells is still a lack of report. Herein, the near-infrared fluorescent nanocarriers loaded with indocyanine green (ICG-NPs), fabricated via the double emulsion method, exhibited excellent suspension stability and biocompatibility. Human umbilical cord mesenchymal stem cells (MSCs) were irradiated with LDR and subsequently co-incubated with ICG-NPs to prepare ICG-NP-labeled stem cells. The results revealed that LDR exposure at varying absorbed doses enhanced the MSCs endocytosis of nanocarriers, resulting in higher cellular labeling efficiency under identical conditions. These findings demonstrated that LDR significantly enhanced the endocytic efficiency of stem cells toward nanocarriers while reducing the time required for effective labeling. Furthermore, low-dose irradiation promoted MSC proliferation and maintained the stemness. Thus, the combined strategy of LDR and nanocarriers offers a novel technical platform for long-term tracking and modulating of stem cell behaviors in therapeutic applications.

Keywords： Low-dose ionizing radiation Nanocarriers Mesenchymal Stem Cells