Conscription of Immune Cells by Light-Activatable Silencing NK-Derived Exosome (LASNEO) for Synergetic Tumor Eradication

Current advance of nanotechnology in diagnosis and treatment for malignant tumors

Cancer remains a significant risk to human health. Nanomedicine is a new multidisciplinary field that is garnering a lot of interest and investigation. Nanomedicine shows great potential for cancer diagnosis and treatment. Specifically engineered nanoparticles can be employed as contrast agents in cancer diagnostics to enable high sensitivity and high-resolution tumor detection by imaging examinations. Novel approaches for tumor labeling and detection are also made possible by the use of nanoprobes and nanobiosensors. The achievement of targeted medication delivery in cancer therapy can be accomplished through the rational design and manufacture of nanodrug carriers. Nanoparticles have the capability to effectively transport medications or gene fragments to tumor tissues via passive or active targeting processes, thus enhancing treatment outcomes while minimizing harm to healthy tissues. Simultaneously, nanoparticles can be employed in the context of radiation sensitization and photothermal therapy to enhance the therapeutic efficacy of malignant tumors. This review presents a literature overview and summary of how nanotechnology is used in the diagnosis and treatment of malignant tumors. According to oncological diseases originating from different systems of the body and combining the pathophysiological features of cancers at different sites, we review the most recent developments in nanotechnology applications. Finally, we briefly discuss the prospects and challenges of nanotechnology in cancer.

Intracellularly Synthesized Artificial Exosome Treats Acute Lung Injury

Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), induce high morbidity and mortality rates, which challenge the present approaches for the treatment of ALI/ARDS. The clinically used photosensitizer verteporfin (VER) exhibits great potential in the treatment of acute lung injury and acute respiratory distress syndrome (ALI/ARDS) by regulating macrophage polarization and reducing inflammation. Nevertheless, its hydrophobic characteristics, nonspecificity, and constrained bioavailability hinder its therapeutic efficacy. In this work, we developed a type of VER-cored artificial exosome (EVM), which was produced by using mesoporous silica nanoparticles (MSNs) to load VER, followed by the exocytosis of internalized VER-MSNs from mouse bone marrow-derived mesenchymal stem cells (mBMSCs) without further modification. Both in vitro and in vivo assessments confirmed the powerful anti-inflammation induced by EVM. EVM also showed significant higher accumulation to inflammatory lungs compared with healthy ones, which was beneficial to the treatment of ALI/ARDS. EVM improved pulmonary function, attenuated lung injury, and reduced mortality in ALI mice with high levels of biocompatibility, exhibiting a 5-fold higher survival rate than the control. This type of artificial exosome emitted near-infrared light in the presence of laser activation, which endowed EVM with trackable ability both in vitro and in vivo. Our work developed a type of clinically used photosensitizer-loaded artificial exosome with membrane integrity and traceability. To the best of our knowledge, this kind of intracellularly synthesized artificial exosome was developed and showed great potential in ALI/ARDS therapy.

Polymer-DNA Carriers Co-Deliver Photosensitizer and siRNA for Light-Promoted Gene Transfection and Hypoxia-Relieved Photodynamic Therapy

Photochemical internalization is an efficient strategy relying on photodynamic reactions to promote siRNA endosomal escape for the success of RNA-interference gene regulation, which makes gene-photodynamic combined therapy highly synergistic and efficient. However, it is still desired to explore capable carriers to improve the delivery efficiency of the immiscible siRNA and organic photosensitizers simultaneously. Herein, we employ a micellar nanostructure (PSNA) self-assembled from polymer-DNA molecular chimeras to fulfill this task. PSNA can plentifully load photosensitizers in its hydrophobic core simply by the nanoprecipitation method. Moreover, it can organize siRNA self-assembly by the densely packed DNA shell, which leads to a higher loading capacity than the typical electrostatic condensation method. The experimental results prove that this PSNA carrier can greatly facilitate siRNA escape from the endosome/lysosome and enhance transfection. Accordingly, the PSNA-administrated therapy exhibits a significantly improved anti-tumor efficacy owing to the highly efficient co-delivery capability.

Exosomes-based immunotherapy for cancer: Effective components in the naïve and engineered forms

Today, cancer treatment is one of the main challenges for researchers. The main cause of tumor cell formation is mutations that lead to uncontrolled proliferation and inhibition of apoptosis in malignant cells. Tumor cells also create a microenvironment that can suppress the immune system cells' responses through various methods, including producing soluble factors and cell-to-cell communication. After being produced from tumor cells, exosomes can also affect the functions of other cells in this microenvironment. Various studies have shown that exosomes from different sources, including tumor cells and immune cells, can be used to treat cancers due to their characteristics. Since tumor cells are rich sources of various types of tumor peptides, they can induce anti-tumor responses. Immune cells also produce exosomes that mimic the functions of their cells of origin, such that exosomes derived from NK cells and CTLs can directly lead to their apoptosis after merging with tumor cells. However, many researchers have pointed out that naïve exosomes have a limited therapeutic function, and their therapeutic potential can be increased by manipulating and engineering them. There are various methods to modify exosomes and improve their therapeutic potential. In general, these methods are divided into two parts, which include changing the cell of origin of the exosome and encapsulating the exosome to carry different drugs. In this review, we will discuss the studies on the therapeutic use of naive and engineered exosomes and provide an update on new studies in this field.

Natural Killer-Based Therapy: A Prospective Thought for Cancer Treatment Related to Diversified Drug Delivery Pathways

Immunotherapy has been a research hotspot due to its low side effects, long-lasting efficacy, and wide anti-tumor spectrum. Recently, NK cell-based immunotherapy has gained broad attention for its unique immunological character of tumor identification and eradication and low risk of graft-versus-host disease and cytokine storm. With the cooperation of a drug delivery system (DDS), NK cells activate tumoricidal activity by adjusting the balance of the activating and inhibitory signals on their surface after drug-loaded DDS administration. Moreover, NK cells or NK-derived exosomes can also be applied as drug carriers for distinct modification to promote NK activation and exert anti-tumor effects. In this review, we first introduce the source and classification of NK cells and describe the common activating and inhibitory receptors on their surface. Then, we summarize the strategies for activating NK cells in vivo through various DDSs. Finally, the application prospects of NK cells in tumor immunotherapy are also discussed.

Natural killer cell-derived exosome-based cancer therapy: from biological roles to clinical significance and implications

Natural killer (NK) cells are important immune cells in the organism and are the third major type of lymphocytes besides T cells and B cells, which play an important function in cancer therapy. In addition to retaining the tumor cell killing function of natural killer cells, natural killer cell-derived exosomes cells also have the characteristics of high safety, wide source, easy to preserve and transport. At the same time, natural killer cell-derived exosomes are easy to modify, and the engineered exosomes can be used in combination with a variety of current cancer therapies, which not only enhances the therapeutic efficacy, but also significantly reduces the side effects. Therefore, this review summarizes the source, isolation and modification strategies of natural killer cell-derived exosomes and the combined application of natural killer cell-derived engineered exosomes with other antitumor therapies, which is expected to accelerate the clinical translation process of natural killer cell-derived engineered exosomes in cancer therapy.

NK cells as powerful therapeutic tool in cancer immunotherapy

BACKGROUND

Natural killer (NK) cells have gained considerable attention and hold great potential for their application in tumor immunotherapy. This is mainly due to their MHC-unrestricted and pan-specific recognition capabilities, as well as their ability to rapidly respond to and eliminate target cells. To artificially generate therapeutic NK cells, various materials can be utilized, such as peripheral blood mononuclear cells (PBMCs), umbilical cord blood (UCB), induced pluripotent stem cells (iPSCs), and NK cell lines. Exploiting the therapeutic potential of NK cells to treat tumors through in vivo and in vitro therapeutic modalities has yielded positive therapeutic results.

CONCLUSION

This review provides a comprehensive description of NK cell therapeutic approaches for tumors and discusses the current problems associated with these therapeutic approaches and the prospects of NK cell therapy for tumors.

Advances in nano-immunotherapy for hematological malignancies

Hematological malignancies (HMs) encompass a diverse group of blood neoplasms with significant morbidity and mortality. Immunotherapy has emerged as a validated and crucial treatment modality for patients with HMs. Despite notable advancements having been made in understanding and implementing immunotherapy for HMs over the past decade, several challenges persist. These challenges include immune-related adverse effects, the precise biodistribution and elimination of therapeutic antigens in vivo, immune tolerance of tumors, and immune evasion by tumor cells within the tumor microenvironment (TME). Nanotechnology, with its capacity to manipulate material properties at the nanometer scale, has the potential to tackle these obstacles and revolutionize treatment outcomes by improving various aspects such as drug targeting and stability. The convergence of nanotechnology and immunotherapy has given rise to nano-immunotherapy, a specialized branch of anti-tumor therapy. Nanotechnology has found applications in chimeric antigen receptor T cell (CAR-T) therapy, cancer vaccines, immune checkpoint inhibitors, and other immunotherapeutic strategies for HMs. In this review, we delineate recent developments and discuss current challenges in the field of nano-immunotherapy for HMs, offering novel insights into the potential of nanotechnology-based therapeutic approaches for these diseases.

Genetically engineered cell-derived nanovesicles for cancer immunotherapy

The emergence of immunotherapy has marked a new epoch in cancer treatment, presenting substantial clinical benefits. Extracellular vesicles (EVs), as natural nanocarriers, can deliver biologically active agents in cancer therapy with their inherent biocompatibility and negligible immunogenicity. However, natural EVs have limitations such as inadequate targeting capability, low loading efficacy, and unpredictable side effects. Through progress in genetic engineering, EVs have been modified for enhanced delivery of immunomodulatory agents and antigen presentation with specific cancer targeting ability, deepening the role of EVs in cancer immunotherapy. This review briefly describes typical EV sources, isolation methods, and adjustable targeting of EVs. Furthermore, this review highlights the genetic engineering strategies developed for delivering immunomodulatory agents and antigen presentation in EV-based systems. The prospects and challenges of genetically engineered EVs as cancer immunotherapy in clinical translation are also discussed.

Application of exosomes in tumor immunity: recent progresses

Exosomes are small extracellular vesicles secreted by cells, ranging in size from 30 to 150 nm. They contain proteins, nucleic acids, lipids, and other bioactive molecules, which play a crucial role in intercellular communication and material transfer. In tumor immunity, exosomes present various functions while the following two are of great importance: regulating the immune response and serving as delivery carriers. This review starts with the introduction of the formation, compositions, functions, isolation, characterization, and applications of exosomes, and subsequently discusses the current status of exosomes in tumor immunotherapy, and the recent applications of exosome-based tumor immunity regulation and antitumor drug delivery. Finally, current challenge and future prospects are proposed and hope to demonstrate inspiration for targeted readers in the field.

Extracellular vesicles and cancer stemness in hepatocellular carcinoma - is there a link?

Hepatocellular carcinoma (HCC) is a highly aggressive malignancy, with high recurrence rates and notorious resistance to conventional chemotherapy. Cancer stemness refers to the stem-cell-like phenotype of cancer cells and has been recognized to play important roles in different aspects of hepatocarcinogenesis. Small extracellular vesicles (sEVs) are small membranous particles secreted by cells that can transfer bioactive molecules, such as nucleic acids, proteins, lipids, and metabolites, to neighboring or distant cells. Recent studies have highlighted the role of sEVs in modulating different aspects of the cancer stemness properties of HCC. Furthermore, sEVs derived from diverse cellular sources, such as cancer cells, stromal cells, and immune cells, contribute to the maintenance of the cancer stemness phenotype in HCC. Through cargo transfer, specific signaling pathways are activated within the recipient cells, thus promoting the stemness properties. Additionally, sEVs can govern the secretion of growth factors from non-cancer cells to further maintain their stemness features. Clinically, plasma sEVs may hold promise as potential biomarkers for HCC diagnosis and treatment prediction. Understanding the underlying mechanisms by which sEVs promote cancer stemness in HCC is crucial, as targeting sEV-mediated communication may offer novel strategies in treatment and improve patient outcome.

Targeting tumor-associated macrophages: Novel insights into immunotherapy of skin cancer

BACKGROUND

The incidence of skin cancer is currently increasing, and conventional treatment options inadequately address the demands of disease management. Fortunately, the recent rapid advancement of immunotherapy, particularly immune checkpoint inhibitors (ICIs), has ushered in a new era for numerous cancer patients. However, the efficacy of immunotherapy remains suboptimal due to the impact of the tumor microenvironment (TME). Tumor-associated macrophages (TAMs), a major component of the TME, play crucial roles in tumor invasion, metastasis, angiogenesis, and immune evasion, significantly impacting tumor development. Consequently, TAMs have gained considerable attention in recent years, and their roles have been extensively studied in various tumors. However, the specific roles of TAMs and their regulatory mechanisms in skin cancer remain unclear.

AIM OF REVIEW

This paper aims to elucidate the origin and classification of TAMs, investigate the interactions between TAMs and various immune cells, comprehensively understand the precise mechanisms by which TAMs contribute to the pathogenesis of different types of skin cancer, and finally discuss current strategies for targeting TAMs in the treatment of skin cancer.

KEY SCIENTIFIC CONCEPTS OF OVERVIEW

With a specific emphasis on the interrelationship between TAMs and skin cancer, this paper posits that therapeutic modalities centered on TAMs hold promise in augmenting and harmonizing with prevailing clinical interventions for skin cancer, thereby charting a novel trajectory for advancing the landscape of immunotherapeutic approaches for skin cancer.

Immunoregulatory functions and therapeutic potential of natural killer cell-derived extracellular vesicles in chronic diseases

Extracellular vesicles (EVs) have been proven to play a significant immunoregulatory role in many chronic diseases, such as cancer and immune disorders. Among them, EVs derived from NK cells are an essential component of the immune cell functions. These EVs have been demonstrated to carry a variety of toxic proteins and nucleic acids derived from NK cells and play a therapeutic role in diseases like malignancies, liver fibrosis, and lung injury. However, natural NK-derived EVs (NKEVs) have certain limitations in disease treatment, such as low yield and poor targeting. Concurrently, NK cells exhibit characteristics of memory-like NK cells, which have stronger proliferative capacity, increased IFN-γ production, and enhanced cytotoxicity, making them more advantageous for disease treatment. Recent research has shifted its focus towards engineered extracellular vesicles and their potential to improve the efficiency, specificity, and safety of disease treatments. In this review, we will discuss the characteristics of NK-derived EVs and the latest advancements in disease therapy. Specifically, we will compare different cellular sources of NKEVs and explore the current status and prospects of memory-like NK cell-derived EVs and engineered NKEVs.

NK cell-based tumor immunotherapy

Natural killer (NK) cells display a unique inherent ability to identify and eliminate virus-infected cells and tumor cells. They are particularly powerful for elimination of hematological cancers, and have attracted considerable interests for therapy of solid tumors. However, the treatment of solid tumors with NK cells are less effective, which can be attributed to the very complicated immunosuppressive microenvironment that may lead to the inactivation, insufficient expansion, short life, and the poor tumor infiltration of NK cells. Fortunately, the development of advanced nanotechnology has provided potential solutions to these issues, and could improve the immunotherapy efficacy of NK cells. In this review, we summarize the activation and inhibition mechanisms of NK cells in solid tumors, and the recent advances in NK cell-based tumor immunotherapy boosted by diverse nanomaterials. We also propose the challenges and opportunities for the clinical application of NK cell-based tumor immunotherapy.

Exosomes as a modulator of immune resistance in human cancers

In the tumor microenvironment (TME), exosomes secreted by cells form interactive networks between the tumor cells and immune cells, thereby regulating immune signaling cascades in the TME. As key messengers of cell-to-cell communication in the TME, exosomes not only take charge of tumor cell antigen presentation to the immune cells, but also regulate the activities of immune cells, inhibit immune function, and, especially, promote immune resistance, all of which affects the therapeutic outcomes of tumors. Exosomes, which are small-sized vesicles, possess some remarkable advantages, including strong biological activity, a lack of immunogenicity and toxicity, and a strong targeting ability. Based on these characteristics, research on exosomes as biomarkers or carriers of tumor therapeutic drugs has become a research hotspot in related fields. This review describes the role of exosomes in cell communications in the TME, summarizes the effectiveness of exosome-based immunotherapy in overcoming immune resistance in cancer treatment, and systematically summarizes and discusses the characteristics of exosomes from different cell sources. Furthermore, the prospects and challenges of exosome-related therapies are discussed.

Disease-microenvironment modulation by bare- or engineered-exosome for rheumatoid arthritis treatment

BACKGROUND

Exosomes are extracellular vesicles secreted by eukaryotic cells and have been extensively studied for their surface markers and internal cargo with unique functions. A deeper understanding of exosomes has allowed their application in various research areas, particularly in diagnostics and therapy.

MAIN BODY

Exosomes have great potential as biomarkers and delivery vehicles for encapsulating therapeutic cargo. However, the limitations of bare exosomes, such as rapid phagocytic clearance and non-specific biodistribution after injection, pose significant challenges to their application as drug delivery systems. This review focuses on exosome-based drug delivery for treating rheumatoid arthritis, emphasizing pre/post-engineering approaches to overcome these challenges.

CONCLUSION

This review will serve as an essential resource for future studies to develop novel exosome-based therapeutic approaches for rheumatoid arthritis. Overall, the review highlights the potential of exosomes as a promising therapeutic approach for rheumatoid arthritis treatment.

Research progress in leveraging biomaterials for enhancing NK cell immunotherapy

NK cell immunotherapy is a promising antitumor therapeutic modality after the development of T cell immunotherapy. Structural modification of NK cells with biomaterials may provide a precise, efficient, and low-cost strategy to enhance NK cell immunotherapy. The biomaterial modification of NK cells can be divided into two strategies: surface engineering with biomaterials and intracellular modification. The surface engineering strategies include hydrophobic interaction of lipids, receptor-ligand interaction between membrane proteins, covalent binding to amino acid residues, click reaction and electrostatic interaction. The intracellular modification strategies are based on manipulation by nanotechnology using membranous materials from various sources of NK cells (such as exosome, vesicle and cytomembranes). Finally, the biomaterials-based strategies regulate the recruitment, recognition and cytotoxicity of NK cells in the solid tumor site in situ to boost the activity of NK cells in the tumor. This article reviews the recent research progress in enhancing NK cell therapy based on biomaterial modification, to provide a reference for further researches on engineering NK cell therapy with biomaterials.

Polyphotosensitizer-Based Nanoparticles with Michael Addition Acceptors Inhibiting GST Activity and Cisplatin Deactivation for Enhanced Chemotherapy and Photodynamic Immunotherapy

Glutathione S-transferase (GST), which is a key enzyme in the conjugation reaction of glutathione (GSH), is overexpressed in cancer cells, leading to cisplatin deactivation and ultimately drug resistance. In addition, many tumors are immune "cold tumors," limiting the application of immune checkpoint inhibitors. Herein, a reactive oxygen species (ROS)-responsive polyphotosensitizer-based nanoparticle (NP2) with Michael addition acceptors inhibiting GST activity and cisplatin deactivation is designed. Under the 808 nm light irradiation, on the one hand, the Michael addition acceptor in NP2 can react with GST and inhibit its activity, thereby decreasing the GSH conjugation and reducing the GSH-mediated deactivation of cisplatin and improving its chemotherapeutic effect. On the other hand, NP2+L induces more ROS production in prostate tumor cells, which can further induce type II immunogenic cell death (ICD) and stimulate a stronger antitumor immune response. It is found that NP2 under the 808 nm light irradiation (NP2+L) can increase PD-L1 expression on the surface of prostate cancer cells. Subsequently, NP2+L combined with PD-L1 treatment is found to simultaneously enhance the efficacies of chemotherapy and photodynamic immunotherapy in prostate tumors, providing a new paradigm for the clinical multimodal treatment of tumors.

Redox Signaling Modulates Activity of Immune Checkpoint Inhibitors in Cancer Patients

Although immunotherapy is already a staple of cancer care, many patients may not benefit from these cutting-edge treatments. A crucial field of research now focuses on figuring out how to improve treatment efficacy and assess the resistance mechanisms underlying this uneven response. For a good response, immune-based treatments, in particular immune checkpoint inhibitors, rely on a strong infiltration of T cells into the tumour microenvironment. The severe metabolic environment that immune cells must endure can drastically reduce effector activity. These immune dysregulation-related tumour-mediated perturbations include oxidative stress, which can encourage lipid peroxidation, ER stress, and T regulatory cells dysfunction. In this review, we have made an effort to characterize the status of immunological checkpoints, the degree of oxidative stress, and the part that latter plays in determining the therapeutic impact of immunological check point inhibitors in different neoplastic diseases. In the second section of the review, we will make an effort to assess new therapeutic possibilities that, by affecting redox signalling, may modify the effectiveness of immunological treatment.

CRISPR/Cas9 and Chlorophyll Coordination Micelles for Cancer Treatment by Genome Editing and Photodynamic Therapy

CRISPR/Cas9-based gene therapy and photodynamic therapy both show promise for cancer treatment but still have their drawbacks limited by tumor microenvironment and long treatment duration. Herein, CRISPR/Cas9 genome editing and photodynamic strategy for a synergistic anti-tumor therapeutic modality is merged. Chlorophyll (Chl) extracted from natural green vegetables is encapsulated in Pluronic F127 (F127) micelles and Histidine-tagged Cas9 can be effectively chelated onto micelles via metal coordination by simple incubation, affording Cas9-Chl@F127 micelles. Mg²⁺ acts as an enzyme cofactor to correlatively enhance Cas9 gene-editing activity. Upon laser irradiation, Chl as an effective photosensitizer generates reactive oxygen species (ROS) to kill tumor cells. Meanwhile, CRISPR/Cas9, mediated by dual deliberately designed gRNAs of APE1 and NRF2, can reprogram the tumor microenvironment by increasing the intracellular oxygen accumulation and impairing the oxidative defense system of tumor cells. Cas9-Chl@F127 micelles can responsively release Cas9 in the presence of abundant ATP or low pH in tumor cells. In a murine tumor model, Cas9-Chl@F127 complexed with dual gRNAs including APE1 and NRF2 significantly inhibits the tumor growth. Taken together, Cas9-Chl@F127 micelles, representing the first Chl-based green biomaterial for the delivery of Cas9, show great promise for the synergistic anti-tumor treatment by PDT and gene editing.

Opportunities and challenges of natural killer cell-derived extracellular vesicles

Extracellular vesicles (EVs) are increasingly recognized as important intermediaries of intercellular communication. They have significant roles in many physiological and pathological processes and show great promise as novel biomarkers of disease, therapeutic agents, and drug delivery tools. Existing studies have shown that natural killer cell-derived EVs (NEVs) can directly kill tumor cells and participate in the crosstalk of immune cells in the tumor microenvironment. NEVs own identical cytotoxic proteins, cytotoxic receptors, and cytokines as NK cells, which is the biological basis for their application in antitumor therapy. The nanoscale size and natural targeting property of NEVs enable precisely killing tumor cells. Moreover, endowing NEVs with a variety of fascinating capabilities via common engineering strategies has become a crucial direction for future research. Thus, here we provide a brief overview of the characteristics and physiological functions of the various types of NEVs, focusing on their production, isolation, functional characterization, and engineering strategies for their promising application as a cell-free modality for tumor immunotherapy.

Targeted implementation strategies of precise photodynamic therapy based on clinical and technical demands

With the development of materials science, photodynamic-based treatments have gradually entered clinics. Photodynamic therapy is ideal for cancer treatment due to its non-invasive and spatiotemporal properties and is the first to be widely promoted in clinical practice. However, the shortcomings resulting from the gap between technical and clinical demands, such as phototoxicity, low tissue permeability, and tissue hypoxia, limit its wide applications. This article reviews the available data regarding the pharmacological and clinical factors affecting the efficacy of photodynamic therapy, such as photosensitizers and oxygen supply, disease diagnosis, and other aspects of photodynamic therapy. In addition, the synergistic treatment of photodynamic therapy with surgery and nanotechnology is also discussed, which is expected to provide inspiration for the design of photodynamic therapy strategies.

A four oxidative stress gene prognostic model and integrated immunity-analysis in pancreatic adenocarcinoma

Background and aims

Pancreatic adenocarcinoma (PAAD) is highly aggressive and characterized by a poor prognosis. Oxidative stress has great impacts on the occurrence and development of tumors. However, the predictive role of oxidative stress related genes on PAAD patients' prognosis remains unclear. In this study, we aimed to construct a prognostic model for PAAD based on oxidative stress genes and to evaluate its predictive value.

Methods

The Cancer Genome Atlas (TCGA) and three Gene Expression Omnibus (GEO) datasets were used to identify differentially expressed oxidative stress genes. Univariate Cox regression, Kaplan-Meier and multivariate Cox regression analysis were used to select genes and to construct a prognosis model. According to the median value of the model's risk score, patients were divided into high and low risk groups, and gene set enrichment analysis (GSEA), immune infiltration and immunotherapy effect, drug resistance and the expression of immune checkpoint related genes and synthetic driver genes of T cell proliferation were analyzed. Finally, the mRNA and protein levels of four genes in PAAD were verified by the clinical proteomic tumor analysis consortium (CPTAC) database and the immunostaining of patients' tissue.

Results

55 differentially expressed oxidative stress genes were identified, and four genes including MET, FYN, CTTN and CDK1 were selected to construct a prognosis model. GESA indicated that immune related pathways, metabolic pathways and DNA repair pathways were significantly enriched in the high risk group as compared to the low risk group. The frequency of genetic mutations was also significantly higher in high risk groups than that in low risk groups. Moreover, the infiltration level of 23 immune cells as well as the expression of immune checkpoint related and synthetic driver genes of T cell proliferation were significantly altered, with the better immunotherapy effect occurring in low risk group. In patient PAAD tissues, the mRNA and protein levels of these four genes were up-regulated.

Conclusion

We have successfully constructed a four oxidative stress gene prognostic model that has important predictive value for PAAD patients, and this model might be a promising guidance for prognostic prediction and efficacy monitoring in clinical individualized therapy.

Effect of tumor microenvironment on ferroptosis: inhibition or promotion

Ferroptosis is a type of lipid peroxidation-induced, iron-dependent programmed cell death. Emerging evidence suggests that ferroptosis is intimately connected to tumorigenesis, development, treatment and plays a major role in tumor immune regulation. This study focused on the connection between ferroptosis and immune regulation, which may offer a theoretical basis for targeting ferroptosis and tumor immunotherapy.

Cold Nanozyme for Precise Enzymatic Antitumor Immunity

Precise catalysis is pursued for the biomedical applications of artificial enzymes. It is feasible to precisely control the catalysis of artificial enzymes via tunning the temperature-dependent enzymatic kinetics. The safety window of cold temperatures (4-37 °C) for the human body is much wider than that of thermal temperatures (37-42 °C). Although the development of cold-activated artificial enzymes is promising, there is currently a lack of suitable candidates. Herein, a cold-activated artificial enzyme is presented with Bi₂Fe₄O₉ nanosheets (NSs) as a paradigm. The as-obtained Bi₂Fe₄O₉ NSs possess glutathione oxidase (GSHOx)-like activity under cold temperature due to their pyroelectricity. Bi₂Fe₄O₉ NSs trigger the cold-enzymatic death of tumor cells via apoptosis and ferroptosis, and minimize the off-target toxicity to normal tissues. Moreover, an interventional device is fabricated to intelligently and remotely control the enzymatic activity of Bi₂Fe₄O₉ NSs on a smartphone. With Bi₂Fe₄O₉ NSs as an in situ vaccine, systemic antitumor immunity is successfully activated to suppress tumor metastasis and relapse. Moreover, blood biochemistry analysis and histological examination indicate the high biosafety of Bi₂Fe₄O₉ NSs for in vivo applications. This cold nanozyme provides a strategy for cancer vaccines, which can benefit the precise control over catalytic nanomedicines.

Unprotonatable and ROS-Sensitive Nanocarrier for NIR Spatially Activated siRNA Therapy with Synergistic Drug Effect

Although small interfering RNA (siRNA) therapy has achieved great progress, unwanted gene inhibition in normal tissues severely limits its extensive clinical applications due to uncontrolled siRNA biodistribution. Herein, a spatially controlled siRNA activation strategy is developed to achieve tumor-specific siRNA therapy without gene inhibition in the normal tissues. The quaternary ammonium moieties are conjugated to amphiphilic copolymers via reactive oxygen species (ROS)-sensitive thioketal (TK) linkers for co-delivery of siRNA and photosensitizer chlorin e6 (Ce6), showing excellent siRNA complexation capacity and near infrared (NIR)-controlled siRNA release. In the normal tissue, siRNAs are trapped and degraded in the endo-lysosomes due to the unprotonatable property of quaternary ammonium moiety, showing the siRNA activity "off" state. When NIR irradiation is spatially applied to the tumor tissue, the NIR irradiation/Ce6-induced ROS trigger siRNA endo-lysosomal escape and cytosolic release through the photochemical internalization effect and cleavage of TK bonds, respectively, showing the siRNA activity "on" state. The siRNA-mediated glutathione peroxidase 4 gene inhibition enhances ROS accumulation. The synergistic antitumor activity of Ce6 photodynamic therapy and gene inhibition is confirmed in vivo. Spatially controlled tumor-specific siRNA activation and co-delivery with Ce6 using unprotonatable and ROS-sensitive cationic nanocarriers provide a feasible strategy for tumor-specific siRNA therapy with synergistic drug effects.

Cheminformatics Modeling of Gene Silencing for Both Natural and Chemically Modified siRNAs

In designing effective siRNAs for a specific mRNA target, it is critically important to have predictive models for the potency of siRNAs. None of the published methods characterized the chemical structures of individual nucleotides constituting a siRNA molecule; therefore, they cannot predict the potency of gene silencing by chemically modified siRNAs (cm-siRNA). We propose a new approach that can predict the potency of gene silencing by cm-siRNAs, which characterizes each nucleotide (NT) using 12 BCUT cheminformatics descriptors describing its charge distribution, hydrophobic and polar properties. Thus, a 21-NT siRNA molecule is described by 252 descriptors resulting from concatenating all the BCUT values of its composing nucleotides. Partial Least Square is employed to develop statistical models. The Huesken data (2431 natural siRNA molecules) were used to perform model building and evaluation for natural siRNAs. Our results were comparable with or superior to those from Huesken’s algorithm. The Bramsen dataset (48 cm-siRNAs) was used to build and test the models for cm-siRNAs. The predictive r² of the resulting models reached 0.65 (or Pearson r values of 0.82). Thus, this new method can be used to successfully model gene silencing potency by both natural and chemically modified siRNA molecules.

Extracellular vesicles as a novel photosensitive drug delivery system for enhanced photodynamic therapy

Photodynamic therapy (PDT) is a promising non-invasive therapeutic approach that utilizes photosensitizers (PSs) to generate highly reactive oxygen species (ROS), including singlet oxygen, for removal of targeted cells. PDT has been proven efficacious for the treatment of several diseases, including cancer, cardiovascular disease, inflammatory bowel disease, and diabetic ocular disease. However, the therapeutic efficacy of PDT is limited and often accompanied by side effects, largely due to non-specific delivery of PSs beyond the desired lesion site. Over the past decade, despite various nanoparticular drug delivery systems developed have markedly improved the treatment efficacy while reducing the off-target effects of PSs, concerns over the safety and toxicity of synthetic nanomaterials following intravenous administration are raised. Extracellular vesicles (EVs), a type of nanoparticle released from cells, are emerging as a natural drug delivery system for PSs in light of EV's potentially low immunogenicity and biocompatibility compared with other nanoparticles. This review aims to provide an overview of the research progress in PS delivery systems and propose EVs as an alternative PS delivery system for PDT. Moreover, the challenges and future perspectives of EVs for PS delivery are discussed.

Emerging innovations on exosome-based onco-therapeutics

Exosomes, nano-sized extracellular vesicles for intercellular communications, are gaining rapid momentum as a novel strategy for the diagnosis and therapeutics of a spectrum of diseases including cancers. Secreted by various cell sources, exosomes pertain numerous functionalities from their parental cells and have enhanced stability that enable them with many features favorable for clinical use and commercialization. This paper focuses on the possible roles of exosomes in cancer therapeutics and reviews current exosome-based innovations toward enhanced cancer management and challenges that limit their clinical translation. Importantly, this paper casts insights on how cold atmospheric plasma, an emerging anticancer strategy, may aid in innovations on exosome-based onco-therapeutics toward improved control over cancers.