Intratumoral immunotherapy using platelet-cloaked nanoparticles enhances antitumor immunity in solid tumors

Nat Commun. 2021 Mar 31;12(1):1999. doi: 10.1038/s41467-021-22311-z.

Abstract

Intratumoral immunotherapy is an emerging modality for the treatment of solid tumors. Toll-like receptor (TLR) agonists have shown promise for eliciting immune responses, but systemic administration often results in the development of adverse side effects. Herein, we investigate whether localized delivery of the TLR agonist, resiquimod (R848), via platelet membrane-coated nanoparticles (PNP-R848) elicits antitumor responses. The membrane coating provides a means of enhancing interactions with the tumor microenvironment, thereby maximizing the activity of R848. Intratumoral administration of PNP-R848 strongly enhances local immune activation and leads to complete tumor regression in a colorectal tumor model, while providing protection against repeated tumor re-challenges. Moreover, treatment of an aggressive breast cancer model with intratumoral PNP-R848 delays tumor growth and inhibits lung metastasis. Our findings highlight the promise of locally delivering immunostimulatory payloads using biomimetic nanocarriers, which possess advantages such as enhanced biocompatibility and natural targeting affinities.

MeSH terms

  • Animals
  • Blood Platelets / chemistry
  • Blood Platelets / metabolism
  • Breast Neoplasms / immunology
  • Breast Neoplasms / pathology
  • Breast Neoplasms / therapy
  • Cell Line, Tumor
  • Cell Membrane / chemistry
  • Cell Membrane / metabolism
  • Cells, Cultured
  • Female
  • HT29 Cells
  • Humans
  • Imidazoles / chemistry
  • Imidazoles / immunology
  • Imidazoles / therapeutic use*
  • Immunotherapy / methods*
  • Lung Neoplasms / immunology
  • Lung Neoplasms / prevention & control
  • Lung Neoplasms / secondary
  • Mice
  • Mice, Inbred C57BL
  • Nanoparticles / chemistry
  • Nanoparticles / therapeutic use*
  • Neoplasms / immunology
  • Neoplasms / pathology
  • Neoplasms / therapy*
  • Treatment Outcome
  • Tumor Microenvironment / drug effects*
  • Tumor Microenvironment / immunology

Substances

  • Imidazoles
  • resiquimod