Cargo-free immunomodulatory nanoparticles combined with anti-PD-1 antibody for treating metastatic breast cancer

Shifting cold to hot tumors by nanoparticle-loaded drugs and products

Cold tumors lack antitumor immunity and are resistant to therapy, representing a major challenge in cancer medicine. Because of the immunosuppressive spirit of the tumor microenvironment (TME), this form of tumor has a low response to immunotherapy, radiotherapy, and also chemotherapy. Cold tumors have low infiltration of immune cells and a high expression of co-inhibitory molecules, such as immune checkpoints and immunosuppressive molecules. Therefore, targeting TME and remodeling immunity in cold tumors can improve the chance of tumor repression after therapy. However, tumor stroma prevents the infiltration of inflammatory cells and hinders the penetration of diverse molecules and drugs. Nanoparticles are an intriguing tool for the delivery of immune modulatory agents and shifting cold to hot tumors. In this review article, we discuss the mechanisms underlying the ability of nanoparticles loaded with different drugs and products to modulate TME and enhance immune cell infiltration. We also focus on newest progresses in the design and development of nanoparticle-based strategies for changing cold to hot tumors. These include the use of nanoparticles for targeted delivery of immunomodulatory agents, such as cytokines, small molecules, and checkpoint inhibitors, and for co-delivery of chemotherapy drugs and immunomodulatory agents. Furthermore, we discuss the potential of nanoparticles for enhancing the efficacy of cancer vaccines and cell therapy for overcoming resistance to treatment.

Harnessing biomaterial architecture to drive anticancer innate immunity

Immunomodulation is a powerful therapeutic approach that harnesses the body's own immune system and reprograms it to treat diseases, such as cancer. Innate immunity is key in mobilizing the rest of the immune system to respond to disease and is thus an attractive target for immunomodulation. Biomaterials have widely been employed as vehicles to deliver immunomodulatory therapeutic cargo to immune cells and raise robust antitumor immunity. However, it is key to consider the design of biomaterial chemical and physical structure, as it has direct impacts on innate immune activation and antigen presentation to stimulate downstream adaptive immunity. Herein, we highlight the widespread importance of structure-driven biomaterial design for the delivery of immunomodulatory cargo to innate immune cells. The incorporation of precise structural elements can be harnessed to improve delivery kinetics, uptake, and the targeting of biomaterials into innate immune cells, and enhance immune activation against cancer through temporal and spatial processing of cargo to overcome the immunosuppressive tumor microenvironment. Structural design of immunomodulatory biomaterials will profoundly improve the efficacy of current cancer immunotherapies by maximizing the impact of the innate immune system and thus has far-reaching translational potential against other diseases.

A synthetic metastatic niche reveals antitumor neutrophils drive breast cancer metastatic dormancy in the lungs

Biomaterial scaffolds mimicking the environment in metastatic organs can deconstruct complex signals and facilitate the study of cancer progression and metastasis. Here we report that a subcutaneous scaffold implant in mouse models of metastatic breast cancer in female mice recruits lung-tropic circulating tumor cells yet suppresses their growth through potent in situ antitumor immunity. In contrast, the lung, the endogenous metastatic organ for these models, develops lethal metastases in aggressive breast cancer, with less aggressive tumor models developing dormant lungs suppressing tumor growth. Our study reveals multifaceted roles of neutrophils in regulating metastasis. Breast cancer-educated neutrophils infiltrate the scaffold implants and lungs, secreting the same signal to attract lung-tropic circulating tumor cells. Second, antitumor and pro-tumor neutrophils are selectively recruited to the dormant scaffolds and lungs, respectively, responding to distinct groups of chemoattractants to establish activated or suppressive immune environments that direct different fates of cancer cells.

Metallic Nanoparticles: Their Potential Role in Breast Cancer Immunotherapy via Trained Immunity Provocation

Owing to drawbacks in the current common cancer therapies including surgery, chemotherapy and radiotherapy, the development of more reliable, low toxic, cost-effective and specific approaches such as immunotherapy is crucial. Breast cancer is among the leading causes of morbidity and mortality with a developed anticancer resistance. Accordingly, we attempted to uncover the efficacy of metallic nanoparticles (MNPs)-based breast cancer immunotherapy emphasizing trained immunity provocation or innate immunity adaptation. Due to the immunosuppressive nature of the tumor microenvironment (TME) and the poor infiltration of immune cells, the potentiation of an immune response or direct combat is a goal employing NPs as a burgeoning field. During the recent decades, the adaptation of the innate immunity responses against infectious diseases and cancer has been recognized. Although the data is in a scarcity with regard to a trained immunity function in breast cancer cells' elimination, this study introduced the potential of this arm of immunity adaptation using MNPs.

Roles of tumor-associated macrophages in anti-PD-1/PD-L1 immunotherapy for solid cancers

In recent years, tumor immunotherapy has made significant progress. However, tumor immunotherapy, particularly immune checkpoint inhibitors (e.g., PD-1/PD-L1 inhibitors), benefits only a tiny proportion of patients in solid cancers. The tumor microenvironment (TME) acts a significant role in tumor immunotherapy. Studies reported that tumor-associated macrophages (TAMs), as one of the main components of TME, seriously affected the therapeutic effect of PD-1/PD-L1 inhibitors. In this review, we analyzed TAMs from epigenetic and single-cell perspectives and introduced the role and mechanisms of TAMs in anti-programmed death protein 1(anti-PD-1) therapy. In addition, we summarized combination regimens that enhance the efficacy of tumor PD-1/PD-L1 inhibitors and elaborated on the role of the TAMs in different solid cancers. Eventually, the clinical value of TAMs by influencing the therapeutic effect of tumor PD-1/PD-L1 inhibitors was discussed. These above are beneficial to elucidate poor therapeutic effect of PD-1/PD-L1 inhibitors in solid tumors from the point of view of TAMs and explore the strategies to improve its objective remission rate of solid cancers.

Emerging Trends in Nano-Driven Immunotherapy for Treatment of Cancer

Despite advancements in the development of anticancer medications and therapies, cancer still has the greatest fatality rate due to a dismal prognosis. Traditional cancer therapies include chemotherapy, radiotherapy, and targeted therapy. The conventional treatments have a number of shortcomings, such as a lack of selectivity, non-specific cytotoxicity, suboptimal drug delivery to tumour locations, and multi-drug resistance, which results in a less potent/ineffective therapeutic outcome. Cancer immunotherapy is an emerging and promising strategy to elicit a pronounced immune response against cancer. Immunotherapy stimulates the immune system with cancer-specific antigens or immune checkpoint inhibitors to overcome the immune suppressive tumour microenvironment and kill the cancer cells. However, delivery of the antigen or immune checkpoint inhibitors and activation of the immune response need to circumvent the issues pertaining to short lifetimes and effect times, as well as adverse effects associated with off-targeting, suboptimal, or hyperactivation of the immune system. Additional challenges posed by the tumour suppressive microenvironment are less tumour immunogenicity and the inhibition of effector T cells. The evolution of nanotechnology in recent years has paved the way for improving treatment efficacy by facilitating site-specific and sustained delivery of the therapeutic moiety to elicit a robust immune response. The amenability of nanoparticles towards surface functionalization and tuneable physicochemical properties, size, shape, and surfaces charge have been successfully harnessed for immunotherapy, as well as combination therapy, against cancer. In this review, we have summarized the recent advancements made in choosing different nanomaterial combinations and their modifications made to enable their interaction with different molecular and cellular targets for efficient immunotherapy. This review also highlights recent trends in immunotherapy strategies to be used independently, as well as in combination, for the destruction of cancer cells, as well as prevent metastasis and recurrence.

Nanoparticle-Delivered Transforming Growth Factor-β1 siRNA Induces PD-1 against Gastric Cancer by Transforming the Phenotype of the Tumor Immune Microenvironment

Immune checkpoint blockade (ICB) is currently considered to be an important therapeutic method, which obtained FDA approval for clinical use in gastric cancer in 2017. As a new mechanism, it was found that the effect of αPDL1 could be improved by blocking the TGF-β1 signaling pathway, which converts the tumor immune microenvironment from the "immune-excluded phenotype" to the "immune-inflamed phenotype". Based on this phenomenon, this project was designed to prepare TGF-β1-siRNA-loaded PEG-PCL nanoparticles conjugated to αPDL1 (siTGF-β1-αPDL1-PEG-PCL) since we have linked similar antibodies to PEG-PCL previously. Therefore, MFC tumor-engrafted mice were established to simulate the biological characteristics of converting the phenotype of the immune microenvironment, and to study the anti-tumor effect and possible molecular mechanism. In this study, αPDL1 antibody conjugates markedly increased the cell uptake of NPs. The produced αPDL1-PEG-PCL NPs efficiently reduced the amounts of TGF-β1 mRNA in MFC cells, converting the immune microenvironment of MFC tumors engrafted mice from the "immune-excluded phenotype" to the "immune-inflamed phenotype". PDL1-harboring gastric cancer had increased susceptibility to αPDL1. The value of this drug-controlled release system targeting the tumor microenvironment in immune checkpoint therapy of gastric cancer would provide a scientific basis for clinically applying nucleic acid drugs.

Myeloid cell reprogramming alleviates immunosuppression and promotes clearance of metastatic lesions

Suppressive myeloid cells, including monocyte and neutrophil populations, play a vital role in the metastatic cascade and can inhibit the anti-tumor function of cytotoxic T-cells. Cargo-free polymeric nanoparticles (NPs) have been shown to modulate innate immune cell responses in multiple pathologies of aberrant inflammation. Here, we test the hypothesis that the intravenous administration of drug-free NPs in the 4T1 murine model of metastatic triple-negative breast cancer can reduce metastatic colonization of the lungs, the primary metastatic site, by targeting the pro-tumor immune cell mediators of metastatic progression. In vivo studies demonstrated that NP administration reprograms the immune milieu of the lungs and reduces pulmonary metastases. Single-cell RNA sequencing of the lungs revealed that intravenous NP administration alters myeloid cell phenotype and function, skewing populations toward inflammatory, anti-tumor phenotypes and away from pro-tumor phenotypes. Monocytes, neutrophils, and dendritic cells in the lungs of NP-treated mice upregulate gene pathways associated with IFN signaling, TNF signaling, and antigen presentation. In a T-cell deficient model, NP administration failed to abrogate pulmonary metastases, implicating the vital role of T-cells in the NP-mediated reduction of metastases. NPs delivered as an adjuvant therapy, following surgical resection of the primary tumor, led to clearance of established pulmonary metastases in all treated mice. Collectively, these results demonstrate that the in vivo administration of cargo-free NPs reprograms myeloid cell responses at the lungs and promotes the clearance of pulmonary metastases in a method of action dependent on functional T-cells.

Nanoparticles reduce monocytes within the lungs to improve outcomes after influenza virus infection in aged mice

Older people exhibit dysregulated innate immunity to respiratory viral infections, including influenza and SARS-CoV-2, and show an increase in morbidity and mortality. Nanoparticles are a potential practical therapeutic that could reduce exaggerated innate immune responses within the lungs during viral infection. However, such therapeutics have not been examined for effectiveness during respiratory viral infection, particular in aged hosts. Here, we employed a lethal model of influenza viral infection in vulnerable aged mice to examine the ability of biodegradable, cargo-free nanoparticles, designated ONP-302, to resolve innate immune dysfunction and improve outcomes during infection. We administered ONP-302 via i.v. injection to aged mice at day 3 after infection, when the hyperinflammatory innate immune response was already established. During infection, we found that ONP-302 treatment reduced the numbers of inflammatory monocytes within the lungs and increased their number in both the liver and spleen, without impacting viral clearance. Importantly, cargo-free nanoparticles reduced lung damage, reduced histological lung inflammation, and improved gas exchange and, ultimately, the clinical outcomes in influenza-infected aged mice. In conclusion, ONP-302 improves outcomes in influenza-infected aged mice. Thus, our study provides information concerning a practical therapeutic, which, if translated clinically, could improve disease outcomes for vulnerable older patients suffering from respiratory viral infections.

Trident Molecule with Nanobrush-Nanoparticle-Nanofiber Transition Property Spatially Suppresses Tumor Metastasis

Metastasis-induced high mortality of cancers urgently demands new approaches to simultaneously inhibit primary tumor metastasis and distant tumor growth. Herein, by rational design of a trident molecule Nap-Phe-Phe-Lys(SA-CPT)-Lys(SA-HCQ)-Tyr(H₂PO₃)-OH (Nap-CPT-HCQ-Yp) with three functional "spears" (i.e., a phosphotyrosine motif for enzymatic self-assembly, camptothecin (CPT) motif for chemotherapy, and hydroxychloroquine (HCQ) motif for autophagy inhibition) and nanobrush-nanoparticle-nanofiber transition property, we propose a novel strategy of intracellular enzymatic nanofiber formation and synergistic autophagy inhibition-enhanced chemotherapy and immunotherapy for spatial suppression of tumor metastasis. Under sequential alkaline phosphatase catalysis and carboxylesterase hydrolysis, Nap-CPT-HCQ-Yp undergoes nanobrush-nanoparticle-nanofiber transition, accompanied by the releases of CPT and HCQ. The formed intracellular nanofibers effectively inhibit the metastasis and invasion behaviors of cancer cells. Meanwhile, the released CPT and HCQ synergistically induce a prominent therapeutic effect through autophagy inhibition-enhanced chemotherapy. Furthermore, chemotherapy of Nap-CPT-HCQ-Yp enhances immunogenic cell death, resulting in the activation of toxic T-cells. Finally, a combination of checkpoint blockade therapy and Nap-CPT-HCQ-Yp-mediated chemotherapy elicits systemic antitumor immunity, thereby achieving efficient inhibitions of primary tumors as well as distant tumors in a breast tumor model. Our work offers a simple and feasible strategy for the design of "smart" multifunctional prodrugs to spatially suppress tumor metastasis.

Targeting the PD-1/PD-L1 axis for cancer treatment: a review on nanotechnology

Although nanomedicines have been in the oncology field for almost three decades with the introduction of doxil, only a few nanomedicine products have reached approval. Can nanotechnology be a realistic tool to reduce the number of hospital beds? At present, several clinically approved anti-PD-1/PD-L1 antibodies or CAR T cell-based therapies are available; however, the immunotherapy field is far from mature. Will immunotherapy be the fourth pillar of cancer treatment? In this review, we summarized the current status of immunotherapy using PD-1/PD-L1-targeting nanocarriers. The knowledge on material science, therapeutic agents and formulation designs could pave the way for high-efficacy treatment outcomes.

Molecular imaging of tumor-associated macrophages in cancer immunotherapy

Tumor-associated macrophages (TAMs), the most abundant inflammatory cell group in the tumor microenvironment, play an essential role in tumor immune regulation. The infiltration degree of TAMs in the tumor microenvironment is closely related to tumor growth and metastasis, and TAMs have become a promising target in tumor immunotherapy. Molecular imaging is a new interdisciplinary subject that combines medical imaging technology with molecular biology, nuclear medicine, radiation medicine, and computer science. The latest progress in molecular imaging allows the biological processes of cells to be visualized in vivo, which makes it possible to better understand the density and distribution of macrophages in the tumor microenvironment. This review mainly discusses the application of targeting TAM in tumor immunotherapy and the imaging characteristics and progress of targeting TAM molecular probes using various imaging techniques.

Nano dimensions/adjuvants in COVID-19 vaccines

A favorable outcome of the COVID-19 crisis might be achieved with massive vaccination. The proposed vaccines contain several different vaccine active principles (VAP), such as inactivated virus, antigen, mRNA, and DNA, which are associated with either standard adjuvants or nanomaterials (NM) such as liposomes in Moderna's and BioNTech/Pfizer's vaccines. COVID-19 vaccine adjuvants may be chosen among liposomes or other types of NM composed for example of graphene oxide, carbon nanotubes, micelles, exosomes, membrane vesicles, polymers, or metallic NM, taking inspiration from cancer nano-vaccines, whose adjuvants may share some of their properties with those of viral vaccines. The mechanisms of action of nano-adjuvants are based on the facilitation by NM of targeting certain regions of immune interest such as the mucus, lymph nodes, and zones of infection or blood irrigation, the possible modulation of the type of attachment of the VAP to NM, in particular VAP positioning on the NM external surface to favor VAP presentation to antigen presenting cells (APC) or VAP encapsulation within NM to prevent VAP degradation, and the possibility to adjust the nature of the immune response by tuning the physico-chemical properties of NM such as their size, surface charge, or composition. The use of NM as adjuvants or the presence of nano-dimensions in COVID-19 vaccines does not only have the potential to improve the vaccine benefit/risk ratio, but also to reduce the dose of vaccine necessary to reach full efficacy. It could therefore ease the overall spread of COVID-19 vaccines within a sufficiently large portion of the world population to exit the current crisis.

Masked Delivery of Allergen in Nanoparticles Safely Attenuates Anaphylactic Response in Murine Models of Peanut Allergy

Food allergy is a growing health concern worldwide. Current allergen-specific immunotherapy (AIT) approaches require frequent dosing over extended periods of time and may induce anaphylaxis due to allergen-effector cell interactions. A critical need remains to develop novel approaches that refine AIT for the treatment of food allergies. Previous studies show that poly(lactide-co-glycolide) (PLG) nanoscale particles (NP) effectively suppress Th1- and Th17-driven immune pathologies. However, their ability to suppress the distinct Th2-polarized immune responses driving food allergy are unknown. Herein, we describe the safety and efficacy of NPs containing encapsulated peanut allergen in desensitizing murine models of peanut allergy. Peanut extract encapsulation allowed for the safe intravenous delivery of allergen relative to non-encapsulated approaches. Application of 2–3 doses, without the need for dose escalation, was sufficient to achieve prophylactic and therapeutic efficacy, which correlated with suppression of Th2-mediated disease and reduced mast cell degranulation. Efficacy was associated with strong reductions in a broad panel of Th1, Th2, and Th17 cytokines. These results demonstrate the ability of PLG NPs to suppress allergen-specific immune responses to induce a more tolerogenic phenotype, conferring protection from intragastric allergen challenge. These promising studies represent a step forward in the development of improved immunotherapies for food allergy.

Targeting innate immune system by nanoparticles for cancer immunotherapy

Various cancer therapies have advanced remarkably over the past decade. Unlike the direct therapeutic targeting of tumor cells, cancer immunotherapy is a new strategy that boosts the host's immune system...

Phagocytic Uptake of Polymeric Particles by Immune Cells under Flow Conditions

Particles injected intravenously are thought to be cleared by macrophages residing in the liver and spleen, but they also encounter circulating immune cells. It remains to be established if the circulating cells can take up particles while flowing and if the uptake capacity is similar under static and flow conditions. Here, we use an in vitro peristaltic pump setup that mimics pulsatile blood flow to determine if immune cells take up particles under constant fluidic flow. We use polystyrene particles of varying sizes as the model of a polymeric particle for these studies. Our results show that the immune cells do phagocytose under flow conditions. We demonstrate that cell lines representing myeloid cells, primary human neutrophils, and monocytes take up submicrometer-sized particles at similar or better rates under flow compared to static conditions. Experiments with whole human blood show that, even under the crowding effects of red blood cells, neutrophils and monocytes take up particles while flowing. Together, these data suggest that circulating immune cells are likely to phagocytose intravenously injected particulates, which has implications for the design of particles to evade or target these cells.

Advances of nanomedicines in breast cancer metastasis treatment targeting different metastatic stages

Breast cancer is the most common tumor in women, and the metastasis further increases the malignancy with extremely high mortality. However, there is almost no effective method in the clinic to completely inhibit breast cancer metastasis due to the dynamic multistep process with complex pathways and scattered occurring site. Nowadays, nanomedicines have been evidenced with great potential in treating cancer metastasis. In this review, we summarize the latest research advances of nanomedicines in anti-metastasis treatment. Strategies are categorized according to the metastasis dynamics, including primary tumor, circulating tumor cells, pre-metastatic niches and secondary tumor. In each different stage of metastasis process, nanomedicines are designed specifically with different functions. At the end of the review, we give our perspectives on current limitations and future directions in anti-metastasis therapy. We expect the review provides comprehensive understandings of anti-metastasis therapy for breast cancer, and boosts the clinical translation in the future to improve women's health.

Construction of a prognostic signature of autophagy-related lncRNAs in non-small-cell lung cancer

Background

Autophagy inhibits tumorigenesis by limiting inflammation. LncRNAs regulate gene expression at various levels as RNAs; thus, both autophagy and lncRNAs are closely related to the occurrence and development of tumours.

Methods

A total of 232 autophagy-related genes were used to construct a coexpression network to extract autophagy-related lncRNAs. A prognostic signature was constructed by multivariate regression analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was applied to analyse enrichment in cancer-related pathways. Immune infiltration analysis was used to analyse the relationship between the prognostic signature and the tumour microenvironment.

Results

Nine autophagy-related lncRNAs were used to construct a prognostic model for non-small-cell lung cancer. The median risk score was used to discriminate the high- and low-risk groups, and the low-risk group was found to have better survival. Because KEGG pathway analysis showed that the prognostic signature was enriched in some immune pathways, further analysis of immune infiltration was conducted, and it was found that the prognostic signature did play a unique role in the immune microenvironment. Additionally, the prognostic signature was associated with clinical factors.

Conclusion

We constructed a prognostic model of autophagy-related lncRNAs that can predict the prognosis of non-small-cell lung cancer.