Rerouting nanoparticles to bone marrow via neutrophil hitchhiking

Macrophage-Mediated Liquid Metal Nanoparticles for Enhanced Tumor Accumulation and Inhibition

In most studies, the penetration of nanoparticles into tumors was mainly dependent on the enhanced permeability and retention (ERP) effect. However, the penetration of nanoparticles would be limited by tumor-dense structure, immune system, and other factors. To solve these problems, macrophages with active tropism to tumor tissues, loaded nanoparticles with photothermal therapy, and chemotherapy were designed. In detail, liquid metal (gallium indium alloy) nanoparticles were modified with mesoporous silica and then embedded with the chemotherapeutic drug sorafenib (LM@Si/SO) for photothermal therapy and chemotherapy. After that, the LM@Si/SO nanoparticles were carried by the mouse macrophage RAW264.7 cell line (LM@Si/SO@R) to increase the accumulation of the nanoparticles in the tumor site and improve the tumor immune microenvironment. With the enhanced tumor accumulation, LM@Si/SO@R exhibited excellent antitumor ability in vitro and in vivo. Thus, these strategies via the cell carrier to enhance tumor therapeutic efficiency had the potential for the improvement of tumor therapy.

In Situ Aggregated Nanomanganese Enhances Radiation-Induced Antitumor Immunity

Radiosensitizers play a pivotal role in enhancing radiotherapy (RT). One of the challenges in RT is the limited accumulation of nanoradiosensitizers and the difficulty in activating antitumor immunity. Herein, a smart strategy was used to achieve in situ aggregation of nanomanganese adjuvants (MnAuNP-C&B) to enhance RT-induced antitumor immunity. The aggregated MnAuNP-C&B system overcomes the shortcomings of small-sized nanoparticles that easily flow back into blood vessels and diffuse into surrounding tissues, and it also prolongs the retention time of nanomanganese within cancer cells and tumors. The MnAuNP-C&B system significantly enhances the radiosensitization effect in RT. Additionally, the pH-responsive disassembly of MnAuNP-C&B triggers the release of Mn2+, further promoting RT-induced activation of the STING pathway and eliciting robust antitumor immunity. Overall, our study presents a smart strategy wherein in situ aggregation of nanomanganese effectively inhibits tumor growth through radiosensitization and the activation of antitumor immunity.

Neutrophil hitchhiking: Riding the drug delivery wave to treat diseases

Neutrophils are a crucial component of the innate immune system and play a pivotal role in various physiological processes. From a physical perspective, hitchhiking is considered a phenomenon of efficient transportation. The combination of neutrophils and hitchhikers has given rise to effective delivery systems both in vivo and in vitro, thus neutrophils hitchhiking become a novel approach to disease treatment. This article provides an overview of the innovative and feasible application of neutrophils as drug carriers. It explores the mechanisms underlying neutrophil function, elucidates the mechanism of drug delivery mediated by neutrophil-hitchhiking, and discusses the potential applications of this strategy in the treatment of cancer, immune diseases, inflammatory diseases, and other medical conditions.