ZIF-8-Encapsulated Pexidartinib Delivery via Targeted Peptide-Modified M1 Macrophages Attenuates MDSC-Mediated Immunosuppression in Osteosarcoma

Small. 2024 Jul;20(29):e2309038. doi: 10.1002/smll.202309038. Epub 2024 Mar 8.

Abstract

Adoptive cellular therapy is a promising strategy for cancer treatment. However, the effectiveness of this therapy is limited by its intricate and immunosuppressive tumor microenvironment. In this study, a targeted therapeutic strategy for macrophage loading of drugs is presented to enhance anti-tumor efficacy of macrophages. K7M2-target peptide (KTP) is used to modify macrophages to enhance their affinity for tumors. Pexidartinib-loaded ZIF-8 nanoparticles (P@ZIF-8) are loaded into macrophages to synergistically alleviate the immunosuppressive tumor microenvironment synergistically. Thus, the M1 macrophages decorated with KTP carried P@ZIF-8 and are named P@ZIF/M1-KTP. The tumor volumes in the P@ZIF/M1-KTP group are significantly smaller than those in the other groups, indicating that P@ZIF/M1-KTP exhibited enhanced anti-tumor efficacy. Mechanistically, an increased ratio of CD4+ T cells and a decreased ratio of MDSCs in the tumor tissues after treatment with P@ZIF/M1-KTP indicated that it can alleviate the immunosuppressive tumor microenvironment. RNA-seq further confirms the enhanced immune cell function. Consequently, P@ZIF/M1-KTP has great potential as a novel adoptive cellular therapeutic strategy for tumors.

Keywords: immunotherapy; macrophage; osteosarcoma; target.

MeSH terms

  • Aminopyridines / chemistry
  • Aminopyridines / pharmacology
  • Animals
  • Cell Line, Tumor
  • Drug Delivery Systems
  • Humans
  • Immunosuppression Therapy
  • Macrophages* / drug effects
  • Macrophages* / metabolism
  • Mice
  • Myeloid-Derived Suppressor Cells* / drug effects
  • Myeloid-Derived Suppressor Cells* / metabolism
  • Nanoparticles / chemistry
  • Osteosarcoma* / drug therapy
  • Osteosarcoma* / pathology
  • Osteosarcoma* / therapy
  • Peptides* / chemistry
  • Pyrroles / chemistry
  • Pyrroles / pharmacology
  • Tumor Microenvironment* / drug effects
  • Zeolites* / chemistry

Substances

  • pexidartinib
  • Peptides
  • Zeolites
  • Aminopyridines
  • Pyrroles