Emerging Nanoparticle Strategies for Modulating Tumor-Associated Macrophage Polarization.

Lu Shi,Hongchen Gu

doi:10.3390/biom11121912

Abstract

Immunotherapy has made great progress in recent years, yet the efficacy of solid tumors remains far less than expected. One of the main hurdles is to overcome the immune-suppressive tumor microenvironment (TME). Among all cells in TME, tumor-associated macrophages (TAMs) play pivotal roles because of their abundance, multifaceted interactions to adaptive and host immune systems, as well as their context-dependent plasticity. Underlying the highly plastic characteristic, lots of research interests are focused on repolarizing TAMs from M2-like pro-tumor phenotype towards M1-like antitumoral ones. Nanotechnology offers great opportunities for targeting and modulating TAM polarization to mount the therapeutic efficacy in cancer immunotherapy. Here, this mini-review highlights those emerging nano-approaches for TAM repolarization in the last three years.

Highlights

In the past decade, immunotherapy has shown great therapeutic efficacy in treating several kinds of malignancies, especially in hematological malignancy, lymphomas and skin cancer
Owing to this nanometer size and other properties, nanoparticles have several advantages in biomedical fields, including: (i) relatively high surface area to increase loading efficiency [30]; (ii) tunable parameters to achieve specific targeting, systemic toxicity reducing and fine-tuned application in diagnosis and treatment [31,32]; (iii) relatively stable structure to provide a shield for the cargos to prevent drugs from early degradation [33,34]
Given that macrophages might be a potential target to promote efficacy in immunotherapy, various approaches have been leveraged to cut off the loop by repolarizing macrophages towards an anti-tumor subtype

Summary

Introduction

Immunotherapy has shown great therapeutic efficacy in treating several kinds of malignancies, especially in hematological malignancy, lymphomas and skin cancer. A nanoparticle is defined as a particle with submicron size in any dimension by the International Union of Pure and Applied Chemistry (IUPAC) [29] Owing to this nanometer size and other properties, nanoparticles have several advantages in biomedical fields, including: (i) relatively high surface area to increase loading efficiency (compared to micro-scale particles) [30]; (ii) tunable parameters to achieve specific targeting, systemic toxicity reducing and fine-tuned application in diagnosis and treatment (compared to free drugs or other reagents) [31,32]; (iii) relatively stable structure to provide a shield for the cargos to prevent drugs from early degradation (compared to free macromolecules for therapeutic usage) [33,34]. Challenges and hurdles in this burgeoning field are mentioned at the end

Polymeric Nanoparticles and Macrophage Repolarization

Lipid-Based Nanomaterials and Macrophage Repolarization

Inorganic Nanoparticles and Macrophage Repolarization

Other Nanomaterials

Findings

Conclusion and Perspective