Engineering Macrophages for Cancer Immunotherapy and Drug Delivery

Pancreatic Stellate Cells and the Targeted Therapeutic Strategies in Chronic Pancreatitis

Chronic pancreatitis (CP) is a disease characterized by inflammatory recurrence that accompanies the development of pancreatic fibrosis. As the mystery of CP pathogenesis is gradually revealed, accumulating evidence suggests that the activation of pancreatic stellate cells (PSCs) and the appearance of a myofibroblast-like phenotype are the key gatekeepers in the development of CP. Targeting PSCs to prevent their activation and conversion to a myofibroblast-like phenotype, as well as increasing antioxidant capacity to counteract ongoing oxidative stress, are effective strategies for preventing or treating CP. Therefore, we reviewed the crosstalk between CP and pancreatic fibrosis, summarized the activation mechanisms of PSCs, and investigated potential CP therapeutic strategies targeting PSCs, including, but not limited to, anti-fibrosis therapy, antioxidant therapy, and gene therapy. Meanwhile, the above therapeutic strategies are selected in order to update the available phytopharmaceuticals as novel complementary or alternative approaches for the prevention and treatment of CP to clarify their potential mechanisms of action and their relevant molecular targets, aiming to provide the most comprehensive therapeutic treatment direction for CP and to bring new hope to CP patients.

Macrophage fusion event as one prerequisite for inorganic nanoparticle-induced antitumor response

While most nanomaterials are designed to assist tumor therapy, some inorganic nanoparticles have been reported to impede cancer development. We assume that the immune response elicited by these foreign nanoparticles might be associated with the remodeling of immune landscape in the tumor microenvironment (TME). We studied representative inorganic nanoparticles widely used in the biomedical field and first demonstrated that needle-shaped hydroxyapatite (n-nHA), granule-shaped hydroxyapatite, and silicon dioxide can effectively impair tumor progression in vivo. Substantial multinucleated giant cells (MNGCs) were formed around these antitumor nanoparticles, while the ratio of monocytes and macrophages was decreased in the TME. We found that high expression of the STXBP6 protein induced by n-nHA-treated macrophages triggers autophagy, which markedly promotes macrophage fusion into MNGCs. In this way, extensive depletion of tumor-associated macrophages in the TME was achieved, which suppressed tumor growth and metastasis. This intrinsic antitumor immunity of inorganic nanoparticles should not be neglected when designing future nanomedicines to treat cancer.

d-lactate modulates M2 tumor-associated macrophages and remodels immunosuppressive tumor microenvironment for hepatocellular carcinoma

The polarization of tumor-associated macrophages (TAMs) from M2 to M1 phenotype demonstrates great potential for remodeling the immunosuppressive tumor microenvironment (TME) of hepatocellular carcinoma (HCC). d-lactate (DL; a gut microbiome metabolite) acts as an endogenous immunomodulatory agent that enhances Kupffer cells for clearance of pathogens. In this study, the potential of DL for transformation of M2 TAMs to M1 was confirmed, and the mechanisms underlying such polarization were mainly due to the modulation of phosphatidylinositol 3-kinase/protein kinase B pathway. A poly(lactide-co-glycolide) nanoparticle (NP) was used to load DL, and the DL-loaded NP was modified with HCC membrane and M2 macrophage-binding peptide (M2pep), forming a nanoformulation (DL@NP-M-M2pep). DL@NP-M-M2pep transformed M2 TAMs to M1 and remodeled the immunosuppressive TME in HCC mice, promoting the efficacy of anti-CD47 antibody for long-term animal survival. These findings reveal a potential TAM modulatory function of DL and provide a combinatorial strategy for HCC immunotherapy.

Potential therapeutic targets of macrophages in inhibiting immune damage and fibrotic processes in musculoskeletal diseases

Macrophages are a heterogeneous cell type with high plasticity, exhibiting unique activation characteristics that modulate the progression and resolution of diseases, serving as a key mediator in maintaining tissue homeostasis. Macrophages display a variety of activation states in response to stimuli in the local environment, with their subpopulations and biological functions being dependent on the local microenvironment. Resident tissue macrophages exhibit distinct transcriptional profiles and functions, all of which are essential for maintaining internal homeostasis. Dysfunctional macrophage subpopulations, or an imbalance in the M1/M2 subpopulation ratio, contribute to the pathogenesis of diseases. In skeletal muscle disorders, immune and inflammatory damage, as well as fibrosis induced by macrophages, are prominent pathological features. Therefore, targeting macrophages is of great significance for maintaining tissue homeostasis and treating skeletal muscle disorders. In this review, we discuss the receptor-ligand interactions regulating macrophages and identify potential targets for inhibiting collateral damage and fibrosis in skeletal muscle disorders. Furthermore, we explore strategies for modulating macrophages to maintain tissue homeostasis.

Cuproptosis-related lncRNAs potentially predict prognosis and therapy sensitivity of breast cancer

Background: Cuproptosis-related lncRNAs regulate the biological functions of various cancers. However, the role of cuproptosis-related lncRNAs in breast cancer remains unclear. In this study, we investigated the biological functions and clinical applications of cuproptosis-related lncRNAs in breast cancer. Methods: The Cancer Genome Atlas (TCGA) database and the GSE20685 dataset were used for screening cuproptosis-related lncRNAs. Colony formation and CCK-8 kit assays were performed for detecting the proliferative function of cuproptosis-related lncRNAs, whereas wound healing, migration, and invasion assays were performed for detecting the metastatic regulation of cuproptosis-related lncRNAs in breast cancer. Finally, a prognostic cuproptosis-related lncRNA model was constructed using LASSO Cox regression analysis for detecting survival and sensitivity to conventional treatment (endocrine therapy, chemotherapy, and radiotherapy) and novel therapy (PARP and CDK4/6 inhibitors). Results: In this study, we screened six cuproptosis-related lncRNAs associated with the survival of patients with breast cancer. Biofunctional experiments indicated that cuproptosis-related lncRNAs play essential roles in regulating the proliferation and metastasis of breast cancer cells. Finally, we applied a model of six cuproptosis-related lncRNAs to classify the patients into high- and low-risk groups. High-risk group patients exhibited worse survival rates (p < 0.001) and lower sensitivity to chemotherapy, endocrine therapy, and radiation therapy. Compared with high-risk patients, low-risk patients exhibited a lower expression of CDK4/6 inhibitor-resistant biomarkers (CCNE1, E2F1, and E2F2) and PARP inhibitor-resistant biomarkers (BRCA1/BRCA2), indicating that patients in the low-risk group were more suitable for PARP inhibitor and CDK4/6 inhibitor application. Conclusion: Cuproptosis-related lncRNAs are essential for regulating the biological functions of breast cancer, and they have the potential to predict prognosis and sensitivity of breast cancer to various therapies.

Extracellular vesicles in the treatment and diagnosis of breast cancer: a status update

Breast cancer is one of the leading causes of cancer-related death in women. Currently, the treatment of breast cancer is limited by the lack of effectively targeted therapy and patients often suffer from higher severity, metastasis, and resistance. Extracellular vesicles (EVs) consist of lipid bilayers that encapsulate a complex cargo, including proteins, nucleic acids, and metabolites. These bioactive cargoes have been found to play crucial roles in breast cancer initiation and progression. Moreover, EV cargoes play pivotal roles in converting mammary cells to carcinogenic cells and metastatic foci by extensively inducing proliferation, angiogenesis, pre-metastatic niche formation, migration, and chemoresistance. The present update review mainly discusses EVs cargoes released from breast cancer cells and tumor-derived EVs in the breast cancer microenvironment, focusing on proliferation, metastasis, chemoresistance, and their clinical potential as effective biomarkers.

Worldwide productivity and research trend of publications concerning tumor immune microenvironment (TIME): a bibliometric study

BACKGROUND

As the complexity and diversity of the tumor immune microenvironment (TIME) are becoming better understood, burgeoning research has progressed in this field. However, there is a scarcity of literature specifically focused on the bibliometric analysis of this topic. This study sought to investigate the development pattern of TIME-related research from 2006 to September 14, 2022, from a bibliometric perspective.

METHODS

We acquired both articles and reviews related to TIME from the Web of Science Core Collection (WoSCC) (retrieved on September 14, 2022). R package "Bibliometrix" was used to calculate the basic bibliometric features, present the collaborative conditions of countries and authors, and generate a three-field plot to show the relationships among authors, affiliations, and keywords. VOSviewer was utilized for co-authorship analysis of country and institution and keyword co-occurrence analysis. CiteSpace was used for citation burst analysis of keywords and cited references. In addition, Microsoft Office Excel 2019 was used to develop an exponential model to fit the cumulative publication numbers.

RESULTS

A total of 2545 publications on TIME were included, and the annual publication trend exhibited a significant increase over time. China and Fudan University were the most productive country and institution, with the highest number of publications of 1495 and 396, respectively. Frontiers in Oncology held the highest number of publications. A number of authors were recognized as the main contributors in this field. The clustering analysis revealed six clusters of keywords that highlighted the research hot spots in the fields of basic medical research, immunotherapy, and various cancer types separately.

CONCLUSIONS

This research analyzed 16 years of TIME-related research and sketched out a basic knowledge framework that includes publications, countries, journals, authors, institutions, and keywords. The finding revealed that the current research hot spots of the TIME domain lie in "TIME and cancer prognosis", "cancer immunotherapy", and "immune checkpoint". Our researchers identified the following areas: "immune checkpoint-based immunotherapy", "precise immunotherapy" and "immunocyte pattern", which may emerge as frontiers and focal points in the upcoming years, offering valuable avenues for further exploration.

Targeting of Annexin A1 in Tumor-associated Macrophages as a therapeutic strategy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common aggressive, malignant tumor with limited treatment options. Currently, immunotherapies have low success rates in the treatment of HCC. Annexin A1 (ANXA1) is a protein related to inflammation, immunity and tumorigenesis. However, the role of ANXA1 in liver tumorigenesis remains unknown. Therefore, we sought to explore the feasibility of ANXA1 as a therapeutic target for HCC. Here, we analyzed ANXA1 expression and localization by HCC microarray and immunofluorescence experiments. Using an in vitro culture system, monocytic cell lines and primary macrophages were employed to investigate the biological functions of cocultured HCC cells and cocultured T cells. In vivo, Ac2-26, human recombinant ANXA1 (hrANXA1), and cell depletion (macrophages or CD8 + T cells) experiments were further conducted to investigate the role of ANXA1 in the tumor microenvironment (TME). We found that ANXA1 was overexpressed in mesenchymal cells, especially macrophages, in human liver cancer. Moreover, the expression of ANXA1 in mesenchymal cells was positively correlated with programmed death-ligand 1 expression. Knockdown of ANXA1 expression inhibited HCC cell proliferation and migration by increasing the M1/M2 macrophage ratio and promoting T-cell activation. hrANXA1 promoted malignant growth and metastasis in mice by increasing the infiltration and M2 polarization of tumor-associated macrophages (TAMs), generating an immunosuppressive TME and suppressing the antitumor CD8 + T-cell response. Together, our findings reveal that ANXA1 may be an independent prognostic factor for HCC and demonstrate the clinical translational significance of ANXA1 for tumor immunotherapy in HCC.

A Curcumin-Modified Coordination Polymers with ROS Scavenging and Macrophage Phenotype Regulating Properties for Efficient Ulcerative Colitis Treatment

Overexpression of classically activated macrophages (M1) subtypes and assessed reactive oxygen species (ROS) levels are often observed in patients with ulcerative colitis. At present, the treatment system of these two problems has yet to be established. Here, the chemotherapy drug curcumin (CCM) is decorated with Prussian blue analogs in a straightforward and cost-saving manner. Modified CCM can be released in inflammatory tissue (acidic environment), eventually causing M1 macrophages to transform into M2 macrophages and inhibiting pro-inflammatory factors. Co(III) and Fe(II) have abundant valence variations, and the lower REDOX potential in CCM-CoFe PBA enables ROS clearance through multi-nanomase activity. In addition, CCM-CoFe PBA effectively alleviated the symptoms of UC mice induced by DSS and inhibited the progression of the disease. Therefore, the present material may be used as a new therapeutic agent for UC.

Engineered Macrophages-Based uPA-Scavenger Load Gemcitabine to Prompt Robust Treating Cancer Metastasis

The majority of cancer patients die of metastasis rather than primary tumors, and most patients may have already completed the cryptic metastatic process at the time of diagnosis, making them intractable for therapeutic intervention. The urokinase-type plasminogen activator (uPA) system is proved to drive cancer metastasis. However, current blocking agents such as uPA inhibitors or antibodies are far from satisfactory due to poor pharmacokinetics and especially have to face multiplex mechanisms of metastasis. Herein, an effective strategy is proposed to develop a uPA-scavenger macrophage (uPAR-MΦ), followed by loading chemotherapeutics with nanoparticles (GEM@PLGA) to confront cancer metastasis. Interestingly, significant elimination of uPA by uPAR-MΦ is demonstrated by transwell analysis on tumor cells in vitro and enzyme-linked immunosorbent assay detection in peripheral blood of mice with metastatic tumors, contributing to significant inhibition of migration of tumor cells and occurrence of metastatic tumor lesions in mice. Moreover, uPAR-MΦ loaded with GEM@PLGA shows a robust antimetastasis effect and significantly prolonged survival in 4T1-tumor-bearing mice models. This work provides a novel living drug platform for realizing a potent treatment strategy to patients suffering from cancer metastasis, which can be further expanded to handle other tumor metastasis markers mediating cancer metastasis.

Tools and techniques for the discovery of therapeutic aptamers: recent advances

INTRODUCTION

The pursuit of novel therapeutic agents for serious diseases such as cancer has been a global endeavor. Aptamers characteristic of high affinity, programmability, low immunogenicity, and rapid permeability hold great promise for the treatment of diseases. Yet obtaining the approval for therapeutic aptamers remains challenging. Consequently, researchers are increasingly devoted to exploring innovative strategies and technologies to advance the development of these therapeutic aptamers.

AREAS COVERED

The authors provide a comprehensive summary of the recent progress of the SELEX (Systematic Evolution of Ligands by EXponential enrichment) technique, and how the integration of modern tools has facilitated the identification of therapeutic aptamers. Additionally, the engineering of aptamers to enhance their functional attributes, such as inhibiting and targeting, is discussed, demonstrating the potential to broaden their scope of utility.

EXPERT OPINION

The grand potential of aptamers and the insufficient development of relevant drugs have spurred countless efforts for stimulating their discovery and application in the therapeutic field. While SELEX techniques have undergone significant developments with the aid of advanced analysis instruments and ingeniously updated aptameric engineering strategies, several challenges still impede their clinical translation. A key challenge lies in the insufficient understanding of binding conformation and susceptibility to degradation under physiological conditions. Despite the hurdles, our opinion is optimistic. With continued progress in overcoming these obstacles, the widespread utilization of aptamers for clinical therapy is envisioned to become a reality soon.

Exploration of the effect of PUM1/Cripto-1 pathway on ferroptosis by regulating macrophage polarization in allogeneic blood transfused mice

BACKGROUND

To study the link between macrophage polarization, PUM1/Cripto-1 pathway and ferroptosis in the allogeneic blood transfusion setting.

METHODS

This is an exploratory research. The purpose of this study was to investigate the effect of PUM1/Cripto-1 pathway on ferroptosis by regulating macrophage polarization in allogeneic blood transfused mice. Establish in vitro cell models and in vivo rat models. To find out whether PUM1 and Cripto-1 were expressed, RT-qPCR and Western blot analyses were employed. The macrophage polarization markers iNOS, TNF-, IL-1, IL-6, Arg-1, and IL-10 were utilized to identify M1 and M2 macrophages. JC-1 staining was used to detect ATP membrane potential in peripheral blood macrophages.

RESULTS

In animal experiments, expression of Cripto-1 was negatively regulated by PUM1 and promoted M1 type polarization of macrophages. Allogeneic blood transfusion assured good state of macrophage mitochondria. Allogeneic blood transfusion inhibited ferroptosis in macrophages by affecting the PUM1/Cripto-1 pathway. In cell experiments, PUM1 regulated Cripto-1 in mouse macrophage RAW264.7. Polarization of RAW264.7 cells was regulated by the PUM1/Cripto-1 pathway. The effect of PUM1/Cripto-1 pathway on macrophage ferroptosis in cell experiments was consistent with that in animal experiments.

CONCLUSIONS

In this study, through in vivo cell experiments and in vitro animal experiments, it was successfully proved that PUM1/Cripto-1 pathway affected ferroptosis by regulating macrophage polarization in allogeneic blood transfused mice.

Identification and Validation of a Metabolism-Related Prognostic Signature Associated with M2 Macrophage Infiltration in Gastric Cancer

High levels of M2 macrophage infiltration invariably contribute to poor cancer prognosis and can be manipulated by metabolic reprogramming in the tumor microenvironment. However, the metabolism-related genes (MRGs) affecting M2 macrophage infiltration and their clinical implications are not fully understood. In this study, we identified 173 MRGs associated with M2 macrophage infiltration in cases of gastric cancer (GC) using the TCGA and GEO databases. Twelve MRGs were eventually adopted as the prognostic signature to develop a risk model. In the high-risk group, the patients showed poorer survival outcomes than patients in the low-risk group. Additionally, the patients in the high-risk group were less sensitive to certain drugs, such as 5-Fluorouracil, Oxaliplatin, and Cisplatin. Risk scores were positively correlated with the infiltration of multiple immune cells, including CD8+ T cells and M2 macrophages. Furthermore, a difference was observed in the expression and distribution between the 12 signature genes in the tumor microenvironment through single-cell sequencing analysis. In vitro experiments proved that the M2 polarization of macrophages was suppressed by Sorcin-knockdown GC cells, thereby hindering the proliferation and migration of GC cells. These findings provide a valuable prognostic signature for evaluating clinical outcomes and corresponding treatment options and identifying potential targets for GC treatment.

LncRNA AL161431.1 predicts prognosis and drug response in head and neck squamous cell carcinoma

Background

Long non-coding RNAs (lncRNAs) are increasingly recognized as essential players in various biological processes due to their interactions with DNA, RNA, and protein. Emerging studies have demonstrated lncRNAs as prognostic biomarkers in multiple cancers. However, the prognostic effect of lncRNA AL161431.1 in head and neck squamous cell carcinoma (HNSCC) patients has not been reported.

Methods

In the present study, we conducted a series of analyses to identify and validate the prognostic value of lncRNA AL161431.1 in HNSCC, which included differential lncRNAs screening, survival analysis, Cox regression analysis, time ROCanalysis, nomogram prediction, enrichment analysis, tumor infiltration of immune cells, drug sensitivity analysis, and quantitative real-time polymerase chain reaction (qRT-PCR).

Results

In this study, we performed a comprehensive survival and predictive analysis and demonstrated that AL161431.1 was an independent prognostic factor of HNSCC, for which a high AL161431.1 level indicated poor survival in HNSCC. Functional enrichment analyses found that cell growth and immune-related pathways were significantly enriched in HNSCC, suggesting that AL161431.1 may play a role in tumor development and tumor microenvironment (TME). AL161431.1-related immune cells infiltration analysis demonstrated that AL161431.1 expression is significantly positively associated with M0 macrophages in HNSCC (P<0.001). Using "OncoPredict", we recognized chemotherapy drugs sensitive to the high expression group. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to identify the expression level of AL161431.1 in HNSCC, and the results further validated our findings.

Conclusions

Our findings suggest that AL161431.1 is a reliable prognostic marker for HNSCC and can potentially be an effective therapeutic target.

Integrated Single-Cell and Transcriptome Sequencing Analyses Identify Dipeptidase 2 as an Immune-Associated Prognostic Biomarker for Lung Adenocarcinoma

Dipeptidase 2 (DPEP2) is a dipeptidyl peptidase that plays an important role in the hydrolysis of leukotriene D4 (LTD4) to leukotriene E4 (LTE4). Previous studies have suggested that LTD4 promotes tumor progression and survival in non-small cell lung cancer (NSCLC). Therefore, we hypothesized that DPEP2 may play a pivotal role in this tumor. Given that lung adenocarcinoma (LUAD) is the most common subtype of NSCLC, our study aimed to examine the expression and function of DPEP2 in LUAD. Based on bioinformatics and the analysis of clinical samples, our findings revealed that DPEP2 is highly expressed in normal lung tissues, but downregulated in LUAD tissues, and its expression levels were significantly associated with clinical indicators of tumor grade and prognosis. Pathway enrichment analysis showed that DPEP2 is involved in biological processes such as chemokine signaling pathways, leukocyte trans-endothelial migration, and humoral immune responses in LUAD. In addition, DPEP2 expression was significantly associated with various immune cells, especially monocytes-macrophages. Single-cell transcriptome data further confirmed the expression of DPEP2 dominantly in macrophages from normal lung tissues. Analysis of the TCIA database revealed that high DPEP2 expression is associated with a stronger response to immune checkpoint inhibitors such as CTLA4 and PD1, and determines sensitivity to LUAD therapeutic agents. Furthermore, we found that DPEP2 inhibits the migration and invasion of LUAD cells. Therefore, DPEP2 may serve as a potential immune biomarker and therapeutic target for LUAD, providing novel therapeutic approaches for this disease.

Low molecular weight fucoidan modified nanoliposomes for the targeted delivery of the anti-inflammation natural product berberine

The inflammatory response is the basis of many diseases, such as atherosclerosis and ulcerative colitis. Inhibiting inflammatory response is the key to treating these diseases. Berberine hydrochloride (BBR), a natural product, has shown effective inflammation inhibitory activity. However, its distribution throughout the body results in a variety of serious side effects. Currently, there is a lack of targeted delivery systems for BBR to inflammatory sites. In view of the fact that the recruitment of inflammatory cells by activated vascular endothelial cells is a key step in inflammation development. Here, we design a system that can specifically deliver berberine to activated vascular endothelial cells. Low molecular weight fucoidan (LMWF), which can specifically bind to P-selectin, was coupled to PEGylated liposomes (LMWF-Lip), and BBR is encapsulated into LMWF-Lip (LMWF-Lip/BBR). In vitro, LMWF-Lip significantly increases the uptake by activated human umbilical vein endothelial cells (HUVEC). Injection of LMWF-Lip into the tail vein of rats can effectively accumulate in the swollen part of the foot, where it is internalized by the characteristics of activated vascular endothelial cells. LMWF-Lip/BBR can effectively inhibit the expression of P-selectin in activated vascular endothelial cells, and reduce the degree of foot edema and inflammatory response. In addition, compared with free BBR, the toxicity of BBR in LMWF-Lip/BBR to main organs was significantly reduced. These results suggest that wrapping BBR in LMWF-Lip can improve efficacy and reduce its systemic toxicity as a potential treatment for various diseases caused by inflammatory responses.

Systemic Tumor Suppression via Macrophage-Driven Automated Homing of Metal-Phenolic-Gated Nanosponges for Metastatic Melanoma

Cell-based therapies comprising the administration of living cells to patients for direct therapeutic activities have experienced remarkable success in the clinic, of which macrophages hold great potential for targeted drug delivery due to their inherent chemotactic mobility and homing ability to tumors with high efficiency. However, such targeted delivery of drugs through cellular systems remains a significant challenge due to the complexity of balancing high drug-loading with high accumulations in solid tumors. Herein, a tumor-targeting cellular drug delivery system (MAGN) by surface engineering of tumor-homing macrophages (Mφs) with biologically responsive nanosponges is reported. The pores of the nanosponges are blocked with iron-tannic acid complexes that serve as gatekeepers by holding encapsulated drugs until reaching the acidic tumor microenvironment. Molecular dynamics simulations and interfacial force studies are performed to provide mechanistic insights into the "ON-OFF" gating effect of the polyphenol-based supramolecular gatekeepers on the nanosponge channels. The cellular chemotaxis of the Mφ carriers enabled efficient tumor-targeted delivery of drugs and systemic suppression of tumor burden and lung metastases in vivo. The findings suggest that the MAGN platform offers a versatile strategy to efficiently load therapeutic drugs to treat advanced metastatic cancers with a high loading capacity of various therapeutic drugs.

Lipid-based nanoparticles for cancer immunotherapy

As the fourth most important cancer management strategy except surgery, chemotherapy and radiotherapy, cancer immunotherapy has been confirmed to elicit durable antitumor effects in the clinic by leveraging the patient's own immune system to eradicate the cancer cells. However, the limited population of patients who benefit from the current immunotherapies and the immune related adverse events hinder its development. The immunosuppressive microenvironment is the main cause of the failure, which leads to cancer immune evasion and immunity cycle blockade. Encouragingly, nanotechnology has been engineered to enhance the efficacy and reduce off-target toxicity of their therapeutic cargos by spatiotemporally controlling the biodistribution and release kinetics. Among them, lipid-based nanoparticles are the first nanomedicines to make clinical translation, which are now established platforms for diverse areas. In this perspective, we discuss the available lipid-based nanoparticles in research and market here, then describe their application in cancer immunotherapy, with special emphasis on the T cells-activated and macrophages-targeted delivery system. Through perpetuating each step of cancer immunity cycle, lipid-based nanoparticles can reduce immunosuppression and promote drug delivery to trigger robust antitumor response.

The blood-brain barrier: structure, regulation, and drug delivery

Blood-brain barrier (BBB) is a natural protective membrane that prevents central nervous system (CNS) from toxins and pathogens in blood. However, the presence of BBB complicates the pharmacotherapy for CNS disorders as the most chemical drugs and biopharmaceuticals have been impeded to enter the brain. Insufficient drug delivery into the brain leads to low therapeutic efficacy as well as aggravated side effects due to the accumulation in other organs and tissues. Recent breakthrough in materials science and nanotechnology provides a library of advanced materials with customized structure and property serving as a powerful toolkit for targeted drug delivery. In-depth research in the field of anatomical and pathological study on brain and BBB further facilitates the development of brain-targeted strategies for enhanced BBB crossing. In this review, the physiological structure and different cells contributing to this barrier are summarized. Various emerging strategies for permeability regulation and BBB crossing including passive transcytosis, intranasal administration, ligands conjugation, membrane coating, stimuli-triggered BBB disruption, and other strategies to overcome BBB obstacle are highlighted. Versatile drug delivery systems ranging from organic, inorganic, and biologics-derived materials with their synthesis procedures and unique physio-chemical properties are summarized and analyzed. This review aims to provide an up-to-date and comprehensive guideline for researchers in diverse fields, offering perspectives on further development of brain-targeted drug delivery system.

TREM-1 as a potential prognostic biomarker associated with immune infiltration in clear cell renal cell carcinoma

BACKGROUND

The tumor immune microenvironment plays a crucial role in the efficacy of various therapeutics. However, their correlation is not yet completely understood in Clear cell renal cell carcinoma (ccRCC). This study aimed to investigate the potential of TREM-1 as a potential novel biomarker for ccRCC.

METHODS

We constructed a ccRCC immune prognostic signature. The clinical characteristics, the status of the tumor microenvironment, and immune infiltration were analyzed through the ESTIMATE and CIBERSORT algorithms for the hub gene, while the Gene Set Enrichment Analysis and PPI analysis were performed to predict the function of the hub gene. Immunohistochemical staining was used to detect the expression of TREM-1 in renal clear cell carcinoma tissues.

RESULTS

The CIBERSORT and ESTIMATE algorithms revealed that TREM-1 was correlated with the infiltration of 12 types of immune cells. Therefore, it was determined that TREM-1 was involved in numerous classical pathways in the immune response via GSEA analysis. In Immunohistochemical staining, we found that the expression of TREM-1 was significantly upregulated with increasing tumor grade in renal clear cell carcinoma, and elevated TREM-1 expression was associated with poor prognosis.

CONCLUSIONS

The results suggest that TREM-1 may act as an implicit novel prognostic biomarker in ccRCC that could be utilized to facilitate immunotherapeutic strategy.

Fatty acids metabolism affects the therapeutic effect of anti-PD-1/PD-L1 in tumor immune microenvironment in clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is a highly invasive and metastatic subtype of kidney malignancy and is correlated with metabolic reprogramming for adaptation to the tumor microenvironment comprising infiltrated immune cells and immunomodulatory molecules. The role of immune cells in the tumor microenvironment (TME) and their association with abnormal fatty acids metabolism in ccRCC remains poorly understood.

METHOD

RNA-seq and clinical data of KIRC from The Cancer Genome Atlas (TCGA) and E-MTAB-1980 from the ArrayExpress dataset. The Nivolumab group and Everolimus group of the CheckMate 025 study, the Atezolizumab arm of IMmotion150 and the Atezolizumab plus Bevacizumab group of IMmotion151 cohort were obtained for subsequent analysis. After differential expression genes identification, the signature was constructed through univariate Cox proportional hazard regression and simultaneously the least absolute shrinkage and selection operator (Lasso) analysis and the predictive performance of our signature was assessed by using receiver operating characteristic (ROC), Kaplan-Meier (KM) survival analysis, nomogram, drug sensitivity analysis, immunotherapeutic effect analysis and enrichment analysis. Immunohistochemistry (IHC), qPCR and western blot were performed to measure related mRNA or protein expression. Biological features were evaluated by wound healing, cell migration and invasion assays and colony formation test and analyzed using coculture assay and flow cytometry.

RESULTS

Twenty fatty acids metabolism-related mRNA signatures were constructed in TCGA and possessed a strong predictive performance demonstrated through time-dependent ROC and KM survival analysis. Notably, the high-risk group exhibited an impaired response to anti-PD-1/PD-L1 (Programmed death-1 receptor/Programmed death-1 receptor-ligand) therapy compared to the low-risk group. The overall levels of the immune score were higher in the high-risk group. Additionally, drug sensitivity analysis observed that the model could effectively predict efficacy and sensitivity to chemotherapy. Enrichment analysis revealed that the IL6-JAK-STAT3 signaling pathway was a major pathway. IL4I1 could promote ccRCC cells' malignant features through JAK1/STAT3 signaling pathway and M2-like macrophage polarization.

CONCLUSION

The study elucidates that targeting fatty acids metabolism can affect the therapeutic effect of PD-1/PD-L1 in TME and related signal pathways. The model can effectively predict the response to several treatment options, underscoring its potential clinical utility.

Macrophages in immunoregulation and therapeutics

Macrophages exist in various tissues, several body cavities, and around mucosal surfaces and are a vital part of the innate immune system for host defense against many pathogens and cancers. Macrophages possess binary M1/M2 macrophage polarization settings, which perform a central role in an array of immune tasks via intrinsic signal cascades and, therefore, must be precisely regulated. Many crucial questions about macrophage signaling and immune modulation are yet to be uncovered. In addition, the clinical importance of tumor-associated macrophages is becoming more widely recognized as significant progress has been made in understanding their biology. Moreover, they are an integral part of the tumor microenvironment, playing a part in the regulation of a wide variety of processes including angiogenesis, extracellular matrix transformation, cancer cell proliferation, metastasis, immunosuppression, and resistance to chemotherapeutic and checkpoint blockade immunotherapies. Herein, we discuss immune regulation in macrophage polarization and signaling, mechanical stresses and modulation, metabolic signaling pathways, mitochondrial and transcriptional, and epigenetic regulation. Furthermore, we have broadly extended the understanding of macrophages in extracellular traps and the essential roles of autophagy and aging in regulating macrophage functions. Moreover, we discussed recent advances in macrophages-mediated immune regulation of autoimmune diseases and tumorigenesis. Lastly, we discussed targeted macrophage therapy to portray prospective targets for therapeutic strategies in health and diseases.

Current Principles, Challenges, and New Metrics in pH-Responsive Drug Delivery Systems for Systemic Cancer Therapy

The paradigm of drug delivery via particulate formulations is one of the leading ideas that enable overcoming limitations of traditional chemotherapeutic agents. The trend toward more complex multifunctional drug carriers is well-traced in the literature. Nowadays, the prospectiveness of stimuli-responsive systems capable of controlled cargo release in the lesion nidus is widely accepted. Both endogenous and exogenous stimuli are employed for this purpose; however, endogenous pH is the most common trigger. Unfortunately, scientists encounter multiple challenges on the way to the implementation of this idea related to the vehicles' accumulation in off-target tissues, their immunogenicity, the complexity of drug delivery to intracellular targets, and finally, the difficulties in the fabrication of carriers matching all imposed requirements. Here, we discuss fundamental strategies for pH-responsive drug delivery, as well as limitations related to such carriers' application, and reveal the main problems, weaknesses, and reasons for poor clinical results. Moreover, we attempted to formulate the profiles of an "ideal" drug carrier in the frame of different strategies drawing on the example of metal-comprising materials and considered recently published studies through the lens of these profiles. We believe that this approach will facilitate the formulation of the main challenges facing researchers and the identification of the most promising trends in technology development.

Cellular Drug Delivery System for Disease Treatment

The application of variable novel drug delivery system has shown a flowering trend in recent years. Among them, the cell-based drug delivery system (DDS) utilizes the unique physiological function of cells to deliver drugs to the lesion area, which is the most complex and intelligent DDS at present. Compared with the traditional DDS, the cell-based DDS has the potential of prolonged circulation in body. Cellular DDS is expected to be the best carrier to realize multifunctional drug delivery. This paper introduces and analyzes common cellular DDSs such as blood cells, immune cells, stem cells, tumor cells and bacteria as well as relevant research examples in recent years. We hope that this review can provide a reference for future research on cell vectors and promote the innovative development and clinical transformation of cell-based DDS.

Macrophage polarization in bone implant repair: A review

Macrophages (MΦ) are highly adaptable and functionally polarized cells that play a crucial role in various physiological and pathological processes. Typically, MΦ differentiate into two distinct subsets: the proinflammatory (M1) and anti-inflammatory (M2) phenotypes. Due to their potent immunomodulatory and anti-inflammatory properties, MΦ have garnered significant attention in recent decades. In the context of bone implant repair, the immunomodulatory function of MΦ is of paramount importance. Depending on their polarization phenotype, MΦ can exert varying effects on osteogenesis, angiogenesis, and the inflammatory response around the implant. This paper provides an overview of the immunomodulatory and inflammatory effects of MΦ polarization in the repair of bone implants.

The CD47-SIRPα axis is a promising target for cancer immunotherapies

Cluster of differentiation 47(CD47) is a transmembrane protein that is ubiquitously found on the surface of many cells in the body and uniquely overexpressed by both solid and hematologic malignant cells. CD47 interacts with signal-regulatory protein α (SIRPα), to trigger a "don't eat me" signal and thereby achieve cancer immune escape by inhibiting macrophage-mediated phagocytosis. Thus, blocking the CD47-SIRPα phagocytosis checkpoint, for release of the innate immune system, is a current research focus. Indeed, targeting the CD47-SIRPα axis as a cancer immunotherapy has shown promising efficacies in pre-clinical outcomes. Here, we first reviewed the origin, structure, and function of the CD47-SIRPα axis. Then, we reviewed its role as a target for cancer immunotherapies, as well as the factors regulating CD47-SIRPα axis-based immunotherapies. We specifically focused on the mechanism and progress of CD47-SIRPα axis-based immunotherapies and their combination with other treatment strategies. Finally, we discussed the challenges and directions for future research and identified potential CD47-SIRPα axis-based therapies that are suitable for clinical application.

Identification of immune cell infiltration profiles in renal cell carcinoma and their clinical significance

Renal cell carcinoma (RCC) is the most common malignancy of the urinary system, accounting for 3.7% of all new malignancies. The prognosis of RCC patients is still poor, especially patients in advanced stage. Limited studies have fully clarified the role of immune cell infiltration profiles in the prognosis and immunotherapy of RCC. In current study, we evaluated the abundance of the 22 tumor-infiltrating immune cells (TIICs) with CIBERSORT methods. The correlation between TIICs and clinicopathological parameters, tumor immune dysfunction and exclusion (TIDE) score and immunophenoscore (IPS) of RCC patients were also explored. Significant correlations were obtained between TIICs subpopulation and specific clinicopathologic parameters of RCC, including age, gender, tumor grade, clinical stage, T stage and distant metastasis. Moreover, RCC patients with high level of memory activated CD4 T cells, follicular helper T cells and regulatory T cells had a worse overall survival (OS) rate. RCC patients with high level of CD 8 + T cells and M1 macrophages had a lower TIDE score and higher anti-CTLA IPS, higher anti-PD1 IPS as well as higher anti-PD1/CTLA4 IPS. Our results clarified the immune cell infiltration profiles of RCC. RCC patients with high level of CD 8 + T cell and M1 macrophages had a lower TIDE score and higher IPS, suggesting that RCC patients with high level of CD 8 + T cell and M1 macrophages may benefit from immunotherapy.

Crosstalk between macrophages and cardiac cells after myocardial infarction

Cardiovascular diseases, such as myocardial infarction (MI), are a leading cause of death worldwide. Acute MI (AMI) inflicts massive injury to the coronary microcirculation, causing large-scale cardiomyocyte death due to ischemia and hypoxia. Inflammatory cells such as monocytes and macrophages migrate to the damaged area to clear away dead cells post-MI. Macrophages are pleiotropic cells of the innate immune system, which play an essential role in the initial inflammatory response that occurs following MI, inducing subsequent damage and facilitating recovery. Besides their recognized role within the immune response, macrophages participate in crosstalk with other cells (including cardiomyocytes, fibroblasts, immune cells, and vascular endothelial cells) to coordinate post-MI processes within cardiac tissue. Macrophage-secreted exosomes have recently attracted increasing attention, which has led to a more elaborate understanding of macrophage function. Currently, the functional roles of macrophages in the microenvironment of the infarcted heart, particularly with regard to their interaction with surrounding cells, remain unclear. Understanding the specific mechanisms that mediate this crosstalk is essential in treating MI. In this review, we discuss the origin of macrophages, changes in their distribution post-MI, phenotypic and functional plasticity, as well as the specific signaling pathways involved, with a focus on the crosstalk with other cells in the heart. Thus, we provide a new perspective on the treatment of MI. Further in-depth research is required to elucidate the mechanisms underlying crosstalk between macrophages and other cells within cardiac tissue for the identification of potential therapeutic targets. Video Abstract.

Catalytic Nanomedicine as a Therapeutic Approach to Brain Tumors: Main Hypotheses for Mechanisms of Action

Glioblastoma multiforme (GBM) is the most aggressive primary malignant tumor of the brain. Although there are currently a wide variety of therapeutic approaches focused on tumor elimination, such as radiotherapy, chemotherapy, and tumor field therapy, among others, the main approach involves surgery to remove the GBM. However, since tumor growth occurs in normal brain tissue, complete removal is impossible, and patients end up requiring additional treatments after surgery. In this line, Catalytic Nanomedicine has achieved important advances in developing bionanocatalysts, brain-tissue-biocompatible catalytic nanostructures capable of destabilizing the genetic material of malignant cells, causing their apoptosis. Previous work has demonstrated the efficacy of bionanocatalysts and their selectivity for cancer cells without affecting surrounding healthy tissue cells. The present review provides a detailed description of these nanoparticles and their potential mechanisms of action as antineoplastic agents, covering the most recent research and hypotheses from their incorporation into the tumor bed, internalization via endocytosis, specific chemotaxis by mitochondrial and nuclear genetic material, and activation of programmed cell death. In addition, a case report of a patient with GBM treated with the bionanocatalysts following tumor removal surgery is described. Finally, the gaps in knowledge that must be bridged before the clinical translation of these compounds with such a promising future are detailed.

Nanoparticle-Mediated CD47-SIRPα Blockade and Calreticulin Exposure for Improved Cancer Chemo-Immunotherapy

Enabling macrophages to phagocytose tumor cells holds great potential for cancer therapy but suffers from tremendous challenges because the tumor cells upregulate antiphagocytosis molecules (such as CD47) on their surface. The blockade of CD47 alone is insufficient to stimulate tumor cell phagocytosis in solid tumors due to the lack of "eat me" signals. Herein, a degradable mesoporous silica nanoparticle (MSN) is reported to simultaneously deliver anti-CD47 antibodies (aCD47) and doxorubicin (DOX) for cancer chemo-immunotherapy. The codelivery nanocarrier aCD47-DMSN was constructed by accommodating DOX within the mesoporous cavity, while adsorbing aCD47 on the surface of MSN. aCD47 blocks the CD47-SIRPα axis to disable the "don't eat me" signal, while DOX induces immunogenic tumor cell death (ICD) for calreticulin exposure as an "eat me" signal. This design facilitated the phagocytosis of tumor cells by macrophages, which enhanced antigen cross-presentation and elicited efficient T cell-mediated immune response. In 4T1 and B16F10 murine tumor models, aCD47-DMSN generated a strong antitumor effect after intravenous injection by increasing tumor-infiltration of CD8⁺ T cells. Taken together, this study offers a nanoplatform to modulate the phagocytosis of macrophages for efficacious cancer chemo-immunotherapy.

Macrophage membrane-coated nanovesicles for dual-targeted drug delivery to inhibit tumor and induce macrophage polarization

Background

Immunosuppressive M2 macrophages in the tumor microenvironment (TME) can mediate the therapeutic resistance of tumors, and seriously affect the clinical efficacy and prognosis of tumor patients. This study aims to develop a novel drug delivery system for dual-targeting tumor and macrophages to inhibit tumor and induce macrophage polarization.

Methods

The anti-tumor effects of methyltransferase like 14 (METTL14) were investigated both in vitro and in vivo. The underlying mechanisms of METTL14 regulating macrophages were also explored in this study. We further constructed the cyclic (Arg-Gly-Asp) (cRGD) peptide modified macrophage membrane-coated nanovesicles to co-deliver METTL14 and the TLR4 agonist.

Results

We found that METTL14 significantly inhibits the growth of tumor in vitro. METTL14 might downregulate TICAM2 and inhibit the Toll-like receptor 4 (TLR4) pathway of macrophages, meanwhile, the combination of METTL14 and the TLR4 agonist could induce M1 polarization of macrophages. Macrophage membrane-coated nanovesicles are characterized by easy modification, drug loading, and dual-targeting tumor and macrophages, and cRGD modification can further enhance its targeting ability. It showed that the nanovesicles could improve the in vivo stability of METTL14, and dual-target tumor and macrophages to inhibit tumor and induce M1 polarization of macrophages.

Conclusions

This study anticipates achieving the dual purposes of tumor inhibition and macrophage polarization, and providing a new therapeutic strategy for tumors.

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Methyltransferase like 14 (METTL14) significantly inhibits the growth of tumor in vitro.

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The combination of METTL14 and TLR4 agonist could induce M1 polarization of macrophages.

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We constructed the cyclic (Arg-Gly-Asp) (cRGD) peptide modified macrophage membrane-coated nanovesicles to co-deliver METTL14 and TLR4 agonist.

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This nanovesicles could dual-target tumor and macrophages to inhibit tumor and induce M1 polarization of macrophages.

The Antitumor Potential of λ-Carrageenan Oligosaccharides on Gastric Carcinoma by Immunomodulation

Gastric carcinoma is a frequently detected malignancy worldwide, while its mainstream drugs usually result in some adverse reactions, including immunosuppression. λ-carrageenan oligosaccharides (COS) have attracted increasing attention as potential anticancer agents due to their ability to enhance immune function. Our current work assessed the antitumor mechanism of λ-COS using BGC-823 cells. Our findings indicated that λ-COS alone did not have a significant impact on BGC-823 cells in vitro; however, it was effective in inhibiting tumor growth in vivo. When THP-1 cells were pre-incubated with λ-COS and used to condition the medium, BGC-823 cells in vitro displayed a concentration-dependent induction of cell apoptosis, nuclear damage, and the collapse of mitochondrial transmembrane potential. These findings suggested that the antineoplastic effect of λ-COS was primarily due to its immunoenhancement property. Treatment with λ-COS was found to significantly enhance the phagocytic capability of macrophages, increase the secretion of TNF-α and IFN-γ, and improve the indexes of spleen and thymus in BALB/c mice. In addition, λ-COS was found to inhibit the growth of BGC-823-derived tumors in vitro by activating the Par-4 signaling pathway, which may be stimulated by the combination of TNF-α and IFN-γ. When used in combination with 5-FU, λ-COS demonstrated enhanced anti-gastric carcinoma activity and improved the immunosuppression induced by 5-FU alone. These findings suggested that λ-COS could be used as an immune-modulating agent for chemotherapy.

Pathological characteristics and tumour immune microenvironment of lung malignancies with RET rearrangement

BACKGROUND

For patients with lung malignancies with RET rearrangement, the efficacy of immune checkpoint inhibitors is limited. The characteristics of the tumour immune microenvironment (TIME) and molecular pathological features of these patients have not been well elucidated. We aimed to investigate their clinical outcomes and explore characteristics of TIME, using multiplex immunohistochemistry technology (mIHC).

PATIENTS AND METHODS

The pathology and TIME characteristics of 29 patients with lung malignancies with RET rearrangement were retrospectively analysed, and their relationships with clinical efficacy and prognosis were investigated. Gene detection relied on high-throughput sequencing, and TIME detection was based on mIHC.

RESULTS

Of 29 patients, 25(86%) had adenocarcinoma, and the acinar type accounted for the greatest percentage of patients, followed by the solid type, regardless of whether the disease was early or locally advanced and metastatic. In addition, we report a novel KIF5B-RET(k24:R8) rearrangement in pulmonary sarcoma. The density of CD8+ T cells in tumour stroma in early-stage patients was significantly higher than that in locally advanced and metastatic patients (P = 0.014). The proportion of M2 macrophages in tumour stroma was significantly higher than that in tumour parenchyma (P = 0.046). Although the difference was not statistically significant (P = 0.098), patients positive for M2 macrophage infiltration into the tumour parenchyma (≥5%) may have a better prognosis. Seven patients received immunotherapy and disease control rate was 85.7%.

CONCLUSIONS

A novel KIF5B-RET rearrangement variant in pulmonary sarcoma shows similar TIME characteristics to lung cancer. amongst patients with lung malignancies with RET rearrangement, patients with M2 macrophage infiltration into the tumour parenchyma may have a better prognosis, but further studies with larger cohorts are needed.

Tumor-Associated Macrophage Subsets: Shaping Polarization and Targeting

The tumor microenvironment (TME) is a critical regulator of tumor growth, progression, and metastasis. Among the innate immune cells recruited to the tumor site, macrophages are the most abundant cell population and are present at all stages of tumor progression. They undergo M1/M2 polarization in response to signals derived from TME. M1 macrophages suppress tumor growth, while their M2 counterparts exert pro-tumoral effects by promoting tumor growth, angiogenesis, metastasis, and resistance to current therapies. Several subsets of the M2 phenotype have been observed, often denoted as M2a, M2b, M2c, and M2d. These are induced by different stimuli and differ in phenotypes as well as functions. In this review, we discuss the key features of each M2 subset, their implications in cancers, and highlight the strategies that are being developed to harness TAMs for cancer treatment.

Bionic lipoprotein loaded with chloroquine-mediated blocking immune escape improves antitumor immunotherapy

Tumor immunotherapy hold great promise for eradicating tumors. However, immune escape and the immunosuppressive microenvironment of tumor usually limit the efficiency of tumor immunotherapy. Therefore, simultaneously blocking immune escape and improving immunosuppressive microenvironment are the current problems to be solved urgently. Among them, CD47 on cancer cells membrane could bind to signal regulatory protein α (SIRPα) on macrophages membrane and sent out "don't eat me" signal, which was an important pathway of immune escape. The large number of M2-type macrophages in tumor microenvironment was a significant factor contributing to the immunosuppressive microenvironment. Here, we present a drug loading system for enhancing cancer immunotherapy, comprising CD47 antibody (aCD47) and chloroquine (CQ) with Bionic lipoprotein (BLP) carrier (BLP-CQ-aCD47). On the one hand, as drug delivery carrier, BLP could allow CQ to be preferentially taken up by M2-type macrophages, thereby efficiently polarized M2-type tumor-promoting cells into M1-type anti-tumor cells. On the other hand, blocking CD47 from binding to SIRPα could block the "don't eat me" signal, and improve the phagocytosis of macrophages to tumor cells. Taken together, BLP-CQ-aCD47 could block immune escape, improve immunosuppressive microenvironment of tumor, and induce a strong immune response without substantial systemic toxicity. Therefore, it provides a new idea for tumor immunotherapy.

The role of tumor-derived extracellular vesicles containing noncoding RNAs in mediating immune cell function and its implications from bench to bedside

Extracellular vesicles (EVs) are membrane-encapsulated vesicles released by almost all cell types, which participate in intercellular communication by delivering different types of molecular cargoes, such as non-coding RNAs (ncRNAs). Accumulating evidence suggests that tumor-derived EVs act as a bridge for intercellular crosstalk between tumor cells and surrounding cells, including immune cells. Tumor-derived EVs containing ncRNAs (TEV-ncRNAs) mediate intercellular crosstalk to manipulate immune responses and affect the malignant phenotypes of cancer cells. In this review, we summarize the double-edged roles and the underlying mechanisms of TEV-ncRNAs in regulating innate and adaptive immune cells. We also highlight the advantages of using TEV-ncRNAs in liquid biopsies for cancer diagnosis and prognosis. Moreover, we outline the use of engineered EVs to deliver ncRNAs and other therapeutic agents for cancer therapy.

X-ray-Guided In Situ Genetic Engineering of Macrophages for Sustained Cancer Immunotherapy

Effective repolarization of macrophages has emerged as a promising approach for anticancer therapy. However, there are very few studies on the effect of reprogramming macrophages from M2 phenotype to M1 phenotype without reconversion while maintaining an activated M1 phenotype. Moreover, these immunomodulatory methods have serious drawbacks due to the activation of normal monocytic cells. Therefore, it remains a challenge to selectively reprogram tumor-associated macrophages (TAMs) without systemic toxicities. Here, X-ray-guided and triggered remote control of a CRISPR/Cas9 genome editing system (X-CC9) that exclusively activates therapeutic agents at tumor sites is established. Under X-ray irradiation, X-CC9 selectively enhances M2-to-M1 repolarization within the tumor microenvironment, and significantly improves antitumor efficacy with robust immune responses in two animal models. This strategy provides an ideal method for improving the safety of macrophage polarization and may constitute a promising immunotherapy strategy.

Gene Reprogramming Armed Macrophage Membrane-Camouflaged Nanoplatform Enhances Bionic Targeted Drug Delivery to Solid Tumor for Synergistic Therapy

Efficient drug delivery to solid tumors remains a challenge. HER2-positive (HER2⁺) tumors are an aggressive cancer subtype with a resistance to therapy, high risk of relapse, and poor prognosis. Although nanomedicine technology shows obvious advantages in tumor treatment, its potential clinical translation is still impeded by the unsatisfactory delivery and therapeutic efficacy. In this study, a gene reprogramming macrophage membrane-encapsulated drug-loading nanoplatform was developed for HER2⁺ cancer therapy based on the co-assembly of poly (lactic-co-glycolic acid) (PLGA) nanoparticles and engineered modified macrophage membranes. In this nanoplatform, near-infrared (NIR) fluorescent dye ICG or chemotherapeutic drug doxorubicin (DOX) was loaded into the PLGA cores, and an anti-HER2 affibody was stably expressed on the membrane of macrophages. In comparison to the nanoparticles with conventional macrophage membrane coating, the ICG/DOX@AMNP nanoparticles armed with anti-HER2 affibody showed excellent HER2-targeting ability both in vitro and in vivo. Small animal imaging studies confirmed the improved pharmacokinetics of drug delivery and specific distribution of the ICG/DOX@AMNPs in HER2⁺ tumors. Mechanistically, compared with DOX@NPs or DOX@MNPs nanoparticles, DOX@AMNPs exhibited synergistic inhibition of HER2⁺ cancer cells or mice tumor growth by inducing apoptosis and blocking the PI3K/AKT signaling pathway. Altogether, this study proposes a promising biomimetic nanoplatform for the efficient targeted delivery of chemotherapeutic agents to HER2⁺ tumors, demonstrating its great potential for solid tumor therapy.

Inflammation and Microbiota Regulation Potentiate Pneumonia Therapy by Biomimetic Bacteria and Macrophage Membrane Nanosystem

While conventional nanosystems can target infected lung tissue, they cannot achieve precise cellular targeting and enhanced therapy by modulating inflammation and microbiota for effective therapy. Here, we designed a nucleus-targeted nanosystem with adenosine triphosphate (ATP) and reactive oxygen species stimuli-response to treat pneumonia coinfected with bacteria and virus that is enhanced through inflammation and microbiota regulation. The nucleus-targeted biomimetic nanosystem was prepared through the combined bacteria-macrophage membrane and loaded hypericin and ATP-responsive dibenzyl oxalate (MMHP) subsequently. The MMHP despoiled the Mg2+ of intracellular cytoplasm in bacteria to achieve an effective bactericidal performance. Meanwhile, MMHP can target the cell nucleus and inhibit the H1N1 virus duplication by inhibiting the activity of nucleoprotein. MMHP possessed an immunomodulatory ability to reduce the inflammatory response and activate CD8+ T cells for assisted infection elimination. During the mice model, the MMHP effectively treated pneumonia coinfected with Staphylococcus aureus and H1N1 virus. Meanwhile, MMHP mediated the composition of gut microbiota to enhance the pneumonia therapy. Therefore, the dual stimuli-responsive MMHP possessed promising clinical translational potential to therapy infectious pneumonia.

Emerging role of engineered exosomes in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. NAFLD comprises a continuum of liver abnormalities from nonalcoholic fatty liver to nonalcoholic steatohepatitis, and can even lead to cirrhosis and liver cancer. However, a well-established treatment for NAFLD has yet to be identified. Exosomes have become an ideal drug delivery tool because of their high transmissibility, low immunogenicity, easy accessibility and targeting. Exosomes with specific modifications, known as engineered exosomes, have the potential to treat a variety of diseases. Here, we review the treatment of NAFLD with engineered exosomes and the potential use of exosomes as biomarkers and therapeutic targets for NAFLD.

Exploring Monocytes-Macrophages in Immune Microenvironment of Glioblastoma for the Design of Novel Therapeutic Strategies

Gliomas are primary malignant brain tumors. These tumors seem to be more and more frequent, not only because of a true increase in their incidence, but also due to the increase in life expectancy of the general population. Among gliomas, malignant gliomas and more specifically glioblastomas (GBM) are a challenge in their diagnosis and treatment. There are few effective therapies for these tumors, and patients with GBM fare poorly, even after aggressive surgery, chemotherapy, and radiation. Over the last decade, it is now appreciated that these tumors are composed of numerous distinct tumoral and non-tumoral cell populations, which could each influence the overall tumor biology and response to therapies. Monocytes have been proved to actively participate in tumor growth, giving rise to the support of tumor-associated macrophages (TAMs). In GBM, TAMs represent up to one half of the tumor mass cells, including both infiltrating macrophages and resident brain microglia. Infiltrating macrophages/monocytes constituted ~ 85% of the total TAM population, they have immune functions, and they can release a wide array of growth factors and cytokines in response to those factors produced by tumor and non-tumor cells from the tumor microenvironment (TME). A brief review of the literature shows that this cell population has been increasingly studied in GBM TME to understand its role in tumor progression and therapeutic resistance. Through the knowledge of its biology and protumoral function, the development of therapeutic strategies that employ their recruitment as well as the modulation of their immunological phenotype, and even the eradication of the cell population, can be harnessed for therapeutic benefit. This revision aims to summarize GBM TME and localization in tumor niches with special focus on TAM population, its origin and functions in tumor progression and resistance to conventional and experimental GBM treatments. Moreover, recent advances on the development of TAM cell targeting and new cellular therapeutic strategies based on monocyte/macrophages recruitment to eradicate GBM are discussed as complementary therapeutics.

Surface hydrolysis-designed AuNPs-zwitterionic-glucose as a novel tool for targeting macrophage visualization and delivery into infarcted hearts

Macrophages, innate immune cells, are key players in the maintenance of myocardial homeostasis under normal conditions and tissue repair after injury. The infiltration of macrophages into the injured heart makes them a potentially appealing vehicle for noninvasive imaging and targeted drug delivery of myocardial infarction (MI). In this study, we demonstrated the use of surface hydrolysis-designed AuNPs-zwitterionic-glucose to label macrophages and track their infiltration into isoproterenol hydrochloride (ISO)-induced MI sites noninvasively using CT. The AuNPs-zwitterionic-glucose did not affect the viability or cytokine release of macrophages and were highly taken up by these cells. The in vivo CT images were obtained on Day 4, Day 6, Day 7, and Day 9, and the attenuation was seen to increase in the heart over time compared to the Day 4 scan. In vitro analysis also confirmed the presence of macrophages around injured cardiomyocytes. Additionally, we also addressed the concern of cell tracking or merely AuNP tracking, which is the inherent problem for any form of nanoparticle-labeled cell tracking by using zwitterionic and glucose-functionalized AuNPs. The glucose coated on the surface of AuNPs-zwit-glucose will be hydrolyzed in macrophages, forming only zwitterionic protected AuNPs that cannot be taken up again by endogenous cells in vivo. This will greatly improve the accuracy and precision of imaging and target delivery. We believe this is the first study to noninvasively visualize the infiltration of macrophages into MI hearts using CT, which could be used for imaging and evaluating the possibility of macrophage-mediated delivery in infarcted hearts.

Pan-cancer analysis identifies PD-L2 as a tumor promotor in the tumor microenvironment

BACKGROUND

Programmed cell death protein 1 (PD-1) receptor has two ligands,programmed death-ligand 1 (PD-L1) and PD-L2. When compared with PD-L1, PD-L2 has not received much attention, and its role remains unclear.

METHODS

The expression profiles of pdcd1lg2 (PD-L2-encoding gene) mRNA and PD-L2 protein were analyzed using TCGA, ICGC, and HPA databases. Kaplan-Meier and Cox regression analyses were used to assess the prognostic significance of PD-L2. We used GSEA, Spearman's correlation analysis and PPI network to explore the biological functions of PD-L2. PD-L2-associated immune cell infiltration was evaluated using the ESTIMATE algorithm and TIMER 2.0. The expressions of PD-L2 in tumor-associated macrophages (TAMs) in human colon cancer samples, and in mice in an immunocompetent syngeneic setting were verified using scRNA-seq datasets, multiplex immunofluorescence staining, and flow cytometry. After fluorescence-activated cell sorting, flow cytometry and qRT-PCR and transwell and colony formation assays were used to evaluate the phenotype and functions of PD-L2+TAMs. Immune checkpoint inhibitors (ICIs) therapy prediction analysis was performed using TIDE and TISMO. Last, a series of targeted small-molecule drugs with promising therapeutic effects were predicted using the GSCA platform.

RESULTS

PD-L2 was expressed in all the common human cancer types and deteriorated outcomes in multiple cancers. PPI network and Spearman's correlation analysis revealed that PD-L2 was closely associated with many immune molecules. Moreover, both GSEA results of KEGG pathways and GSEA results for Reactome analysis indicated that PD-L2 expression played an important role in cancer immune response. Further analysis showed that PD-L2 expression was strongly associated with the infiltration of immune cells in tumor tissue in almost all cancer types, among which macrophages were the most positively associated with PD-L2 in colon cancer. According to the results mentioned above, we verified the expression of PD-L2 in TAMs in colon cancer and found that PD-L2+TAMs population was not static. Additionally, PD-L2+TAMs exhibited protumor M2 phenotype and increased the migration, invasion, and proliferative capacity of colon cancer cells. Furthermore, PD-L2 had a substantial predictive value for ICIs therapy cohorts.

CONCLUSION

PD-L2 in the TME, especially expressed on TAMs, could be applied as a potential therapeutic target.

The role of the ferroptosis pathway in the regulation of polysaccharides for human health: A review

Polysaccharides are natural polymers with ketone or aldehyde groups that are widely found in plants, animals, and microorganisms. They exhibit various biological activities and have potential development value in the food and pharmaceutical fields. Ferroptosis is a recently discovered modality that modulates cell death and has attracted considerable attention because it is considered to be involved in many pathophysiological processes. The inhibition of ferroptosis by reducing intracellular iron accumulation and lipid peroxidation may provide potential protective strategies against related pathologies. Ferroptosis is also involved in the physiological activities of polysaccharides, and its regulatory mechanism varies according to different physiological activities. However, a systematic summary on the involvement of ferroptosis in the physiological activities of polysaccharides is currently lacking. Therefore, this review systematically summarized the relationship between the physiological activities of polysaccharides and ferroptosis and focused on the regulatory mechanism of ferroptosis, with respect to the anti-cancer, anti-inflammatory, antioxidant, and immunomodulatory activities of all polysaccharides. The primary objective was to find new polysaccharide-related therapeutic breakthroughs for related diseases and to provide a reference for further research on polysaccharides-based therapeutics.

Macrophages in aseptic loosening: Characteristics, functions, and mechanisms

Aseptic loosening (AL) is the most common complication of total joint arthroplasty (TJA). Both local inflammatory response and subsequent osteolysis around the prosthesis are the fundamental causes of disease pathology. As the earliest change of cell behavior, polarizations of macrophages play an essential role in the pathogenesis of AL, including regulating inflammatory responses and related pathological bone remodeling. The direction of macrophage polarization is closely dependent on the microenvironment of the periprosthetic tissue. When the classically activated macrophages (M1) are characterized by the augmented ability to produce proinflammatory cytokines, the primary functions of alternatively activated macrophages (M2) are related to inflammatory relief and tissue repair. Yet, both M1 macrophages and M2 macrophages are involved in the occurrence and development of AL, and a comprehensive understanding of polarized behaviors and inducing factors would help in identifying specific therapies. In recent years, studies have witnessed novel discoveries regarding the role of macrophages in AL pathology, the shifts between polarized phenotype during disease progression, as well as local mediators and signaling pathways responsible for regulations in macrophages and subsequent osteoclasts (OCs). In this review, we summarize recent progress on macrophage polarization and related mechanisms during the development of AL and discuss new findings and concepts in the context of existing work.

Reversing Immune Suppression and Potentiating Photothermal Immunotherapy via Bispecific Immune Checkpoint Inhibitor Loaded Hollow Polydopamine Nanospheres

Despite the great achievements of immune checkpoint blockade (ICB) therapy on programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) axis, ICB monotherapy still faces obstacles in eradicating solid tumors due to the lack of tumor-associated antigens or tumor-specific cytotoxicity. Photothermal therapy (PTT) is a potential therapeutic modality because it can noninvasively kill tumor cells by thermal ablation and generate both tumor-specific cytotoxicity and immunogenicity, which holds great feasibility to improve the efficiency of ICB by providing complementary immunomodulation. Except for the PD-1/PD-L1 axis, the cluster of differentiation 47 (CD47)/signal regulatory protein alpha (SIRPα) pathway has been considered as a novel strategy of tumor cells to evade the surveillance of macrophages and inactivate the immune response of PD-L1 blockade therapy. Therefore, it is necessary to synergize the antitumor effect of dual-targeting PD-L1 and CD47. Although promising, the application of PD-L1/CD47 bispecific antibodies, especially in combination with PTT, remains a formidable problem, due to the low objective response, activity loss at relatively high temperature, or nonvisualization. Herein, instead of using antibodies, we use MK-8628 (MK) to down-regulate both PD-L1 and CD47 simultaneously through halting the active transcription of oncogene c-MYC, leading to elicitation of the immune response. The hollow polydopamine (HPDA) nanospheres are introduced as a biocompatible nanoplatform with high loading capacity and magnetic resonance imaging (MRI) ability to deliver MK and induce PTT (HPDA@MK). Compared to preinjection, HPDA@MK exhibits the strongest MRI signal at 6 h postintravenous injection to guide the precise combined treatment time. However, due to the local delivery and controlled release of inhibitors, HPDA@MK down-regulates c-MYC/PD-L1/CD47, promotes the activation and recruitment of cytotoxic T cells, regulates the M2 macrophages polarization in tumor sites, and especially boosts the combined therapeutic efficacy. Collectively, our work presents a simple but distinctive approach for c-MYC/PD-L1/CD47-targeted immunotherapy combined with PTT that may provide a desirable and feasible strategy for the treatment of other clinical solid tumors.

Neutrophil extracellular traps primed intercellular communication in cancer progression as a promising therapeutic target

In addition to the anti-infection response, neutrophils are linked to tumor progression through the secretion of inflammation components and neutrophil extracellular traps (NETs) formation. NET is a web-like structure constituted by a chromatin scaffold coated with specific nuclear and cytoplasmic proteins, such as histone and granule peptides. Increasing evidence has demonstrated that NETs are favorable factors to promote tumor growth, invasion, migration, and immunosuppression. However, the cell-cell interaction between NETs and other cells (tumor cells and immune cells) is complicated and poorly studied. This work is the first review to focus on the intercellular communication mediated by NETs in cancer. We summarized the complex cell-cell interaction between NETs and other cells in the tumor microenvironment. We also address the significance of NETs as both prognostic/predictive biomarkers and molecular targets for cancer therapy. Moreover, we presented a comprehensive landscape of cancer immunity, improving the therapeutic efficacy for advanced cancer in the future.

Macrophage membrane biomimetic drug delivery system: for inflammation targeted therapy

In recent years, there have been many exciting developments in the biomedical applications of the macrophage membrane bionic drug delivery system (MM-Bio-DDS). Macrophages, as an important immune cell, are involved in initiating and regulating the specific immune response of the body. Therefore, the inflammatory process related to macrophages is an important goal in the diagnosis and treatment of many diseases. In this review, we first summarise the different methods of preparation, characterisation, release profiles and natural advantages of using macrophages as a drug delivery system (DDS). Second, we introduce the processes of various chronic inflammatory diseases and the role of macrophages in them, specifically clarifying how the MM-Bio-DDS provides a wide and effective treatment for the targeted inflammatory site. Finally, based on the existing research, we propose the application prospect and existing challenges of the MM-Bio-DDS, especially the problems in clinical transformation, to provide new ideas for the development and utilisation of the MM-Bio-DDS in targeted drug delivery for inflammation and the treatment of diseases.

Vesicular Antibodies: Shedding Light on Antibody Therapeutics with Cell Membrane Nanotechnology

The high stability of antibodies and their ability to precisely bind to antigens and endogenous immune receptors, as well as their susceptibility to protein engineering, enable antibody-based therapeutics to be widely applied in cancer, inflammation, infection, and other disorders. Nevertheless, the application of traditional antibody-based therapeutics has certain limitations, such as high price, limited permeability, and protein engineering complexity. Recent breakthroughs in cell membrane nanotechnology have deepened the understanding of the critical role of membrane protein receptors in disease treatment, enabling vesicular-antibody-based therapeutics. Here, the concept of vesicular antibodies that are obtained by modifying target antibodies onto cell membranes for biomedical applications is proposed. Given that an antibody is basically a protein, as an extension of this concept, vesicles or membrane-coated nanoparticles that use surface antibodies and protein receptors on cell membranes for biomedical applications as vesicular antibodies are defined. Furthermore, several engineering strategies for vesicular antibodies are summarized and how vesicular antibodies can be used in a variety of situations is highlighted. In addition, current challenges and future prospects of vesicular antibodies are also discussed. It is anticipated this perspective will provide new insights on the development of next-generation antibodies for enhanced therapeutics.