Neutrophil-Mediated Delivery of Nanocrystal Drugs via Photoinduced Inflammation Enhances Cancer Therapy

Engineering and Targeting Neutrophils for Cancer Therapy

Neutrophils are the most abundant white blood cells in the circulation and act as the first line of defense against infections. Increasing evidence suggests that neutrophils possess heterogeneous phenotypes and functional plasticity in human health and diseases, including cancer. Neutrophils play multifaceted roles in cancer development and progression, and an N1/N2 paradigm of neutrophils in cancer is proposed, where N1 neutrophils exert anti-tumor properties while N2 neutrophils display tumor-supportive and immune-suppressive functions. Selective activation of beneficial neutrophil population and targeted inhibition or re-polarization of tumor-promoting neutrophils has shown an important potential in tumor therapy. In addition, due to the natural inflammation-responsive and physical barrier-crossing abilities, neutrophils and their derivatives (membranes and extracellular vesicles (EVs)) are regarded as advanced drug delivery carriers for enhanced tumor targeting and improved therapeutic efficacy. In this review, the recent advances in engineering neutrophils for drug delivery and targeting neutrophils for remodeling tumor microenvironment (TME) are comprehensively presented. This review will provide a broad understanding of the potential of neutrophils in cancer therapy.

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.

Irreversible Electroporation-Induced Inflammation Facilitates Neutrophil-Mediated Drug Delivery to Enhance Pancreatic Cancer Therapy

Pancreatic cancer is a deadly disease with a five-year overall survival rate of around 11%. Chemotherapy is a cornerstone in the treatment of this malignancy, but the intratumoral delivery of chemotherapy drugs is impaired by the highly fibrotic tumor-associated stroma. Irreversible electroporation (IRE) is an ablative technique for treating locally advanced pancreatic cancer. During a typical IRE procedure, high-intensity electric pulses are released to kill tumor cells through the irreversible disruption of the cytoplasm membranes. IRE also induces rapid tumor infiltration by neutrophils and offers an opportunity for neutrophil-mediated drug delivery. We herein showed that the IRE-induced neutrophil trafficking was facilitated by the upregulation of neutrophil chemotaxis and migration as well as the release of several chemoattractants. Doxorubicin-loaded bovine serum albumin nanoparticles were prepared and loaded into neutrophils at a ratio of 9.9 ± 1.2 to 11.7 ± 2.0 pg of doxorubicin per cell. The resultant formulation (NP@NEs) efficiently accumulated in the IRE-treated KPC-A377 murine pancreatic tumors with an uptake value of 10.7 ± 1.5 (percent of injected dose per gram of tissue, abbreviated as %ID/g) at 48 h after intravenous injection. In both Panc02 and KPC-A377 murine pancreatic tumor models, the combination of IRE + NP@NEs inhibited tumor growth more effectively than either monotherapy. The tumors treated with the combination also exhibited the lowest frequency of Ki67+ proliferating cells and the highest abundance of terminal deoxynucleotidyl transferase dUTP nick end labeling+ (TUNEL+) apoptotic cells among the experiment groups. Minimal treatment-associated toxicity was observed. Our findings suggest that neutrophil-mediated delivery of chemotherapy drugs is a useful tool to enhance the response of pancreatic cancer to IRE.

Nanotherapeutics for prostate cancer treatment: A comprehensive review

Prostate cancer (PCa) is the most prevalent solid organ malignancy and seriously affects male health. The adverse effects of prostate cancer therapeutics can cause secondary damage to patients. Nanotherapeutics, which have special targeting abilities and controlled therapeutic release profiles, may serve as alternative agents for PCa treatment. At present, many nanotherapeutics have been developed to treat PCa and have shown better treatment effects in animals than traditional therapeutics. Although PCa nanotherapeutics are highly attractive, few successful cases have been reported in clinical practice. To help researchers design valuable nanotherapeutics for PCa treatment and avoid useless efforts, herein, we first reviewed the strategies and challenges involved in prostate cancer treatment. Subsequently, we presented a comprehensive review of nanotherapeutics for PCa treatment, including their targeting methods, controlled release strategies, therapeutic approaches and mechanisms. Finally, we proposed the future prospects of nanotherapeutics for PCa treatment.

A Twindrive Precise Delivery System of Platelet-Neutrophil Hybrid Membrane Regulates Macrophage Combined with CD47 Blocking for Postoperative Immunotherapy

During wound healing after cancer surgery, platelets, neutrophils, and macrophages accumulate at the wound site and induce important pathophysiological features. Utilizing these pathophysiological features, the development of targeted delivery systems for postoperative tumor immunotherapy is an important strategy. Herein, a twindrive precise delivery system of hybrid membrane combined with CD47 blocking is developed for targeted delivery and targeted regulation to induce postoperative immunotherapy. The precise delivery system consists of IR820-modified platelet-neutrophil hybrid membranes loaded with R848 nanoparticles. Based on the pathological characteristics of platelet aggregation and neutrophil tendency caused by the wound inflammatory microenvironment after tumor surgery, the twindrive delivery system could achieve targeted delivery and targeted regulation of immune drugs to tumor sites. After precise delivery guided by fluorescence imaging, R848 is targeted to reprogram M2 macrophages into M1 macrophages, stimulate dendritic cell maturation as an adjuvant, and then activate T cell immunity. R848 polarization and CD47 blockade together enhanced the phagocytosis function of macrophages, which combined with T cell-mediated cellular immune response to finally effectively inhibit postsurgical tumor recurrence, metastasis, and prolonged survival time. It develops a targeted delivery and regulatory system for cell-specific responses to the pathophysiological features of wound healing for postoperative immunotherapy.

In situ cellular hitchhiking of nanoparticles for drug delivery

Since the inception of the concept of "magic bullet", nanoparticles have evolved to be one of the most effective carriers in drug delivery. Nanoparticles improve the therapeutic efficacy of drugs offering benefits to treating various diseases. Unlike free drugs which freely diffuse and distribute through the body, nanoparticles protect the body from the drug by reducing non-specific interactions while also improving the drug's pharmacokinetics. Despite acquiring some FDA approvals, further clinical application of nanoparticles is majorly hindered by its limited ability to overcome biological barriers resulting in uncontrolled biodistribution and high clearance. The use of cell-inspired systems has emerged as a promising approach to overcome this challenge as cells are biocompatible and have improved access to tissues and organs. One of such is the hitchhiking of nanoparticles to circulating cells such that they are recognized as 'self' components evading clearance and resulting in site-specific drug delivery. In this review, we discuss the concept of nanoparticle cellular hitchhiking, highlighting its advantages, the principles governing the process and the challenges currently limiting its clinical translation. We also discuss in situ hitchhiking as a tool for overcoming these challenges and the considerations to be taken to guide research efforts in advancing this promising technology.

Advance Progress in Assembly Mechanisms of Carrier-Free Nanodrugs for Cancer Treatment

Nanocarriers have been widely studied and applied in the field of cancer treatment. However, conventional nanocarriers still suffer from complicated preparation processes, low drug loading, and potential toxicity of carriers themselves. To tackle the hindrance, carrier-free nanodrugs with biological activity have received increasing attention in cancer therapy. Extensive efforts have been made to exploit new self-assembly methods and mechanisms to expand the scope of carrier-free nanodrugs with enhanced therapeutic performance. In this review, we summarize the advanced progress and applications of carrier-free nanodrugs based on different types of assembly mechanisms and strategies, which involved noncovalent interactions, a combination of covalent bonds and noncovalent interactions, and metal ions-coordinated self-assembly. These carrier-free nanodrugs are introduced in detail according to their assembly and antitumor applications. Finally, the prospects and existing challenges of carrier-free nanodrugs in future development and clinical application are discussed. We hope that this comprehensive review will provide new insights into the rational design of more effective carrier-free nanodrug systems and advancing clinical cancer and other diseases (e.g., bacterial infections) infection treatment.