Intravesical In Situ Immunostimulatory Gel for Triple Therapy of Bladder Cancer

The new era of lung cancer therapy: Combining immunotherapy with ferroptosis

Ferroptosis is an unconventional programmed cell death mode caused by phospholipid peroxidation dependent on iron. Emerging immunotherapies (especially immune checkpoint inhibitors) have the potential to enhance lung cancer patients' long-term survival. Although immunotherapy has yielded significant positive applications in some patients, there are still many mechanisms that can cause lung cancer cells to evade immunity, thus leading to the failure of targeted therapies. Immune-tolerant cancer cells are insensitive to conventional death pathways such as apoptosis and necrosis, whereas mesenchymal and metastasis-prone cancer cells are particularly vulnerable to ferroptosis, which plays a vital role in mediating immune tolerance resistance by tumors and immune cells. As a result, triggering lung cancer cell ferroptosis holds significant therapeutic potential for drug-resistant malignancies. Here, we summarize the mechanisms underlying the suppression of ferroptosis in lung cancer, highlight its function in the lung cancer immune microenvironment, and propose possible therapeutic strategies.

NIR-II light powered hydrogel nanomotor for intravesical instillation with enhanced bladder cancer therapy

Intravesical instillation is the common therapeutic strategy for bladder cancer. Besides chemo drugs, nanoparticles are used as intravesical instillation reagents, offering appealing therapeutic approaches for bladder cancer treatment. Metal oxide nanoparticle based chemodynamic therapy (CDT) converts tumor intracellular hydrogen peroxide to ROS with cancer cell-specific toxicity, which makes it a promising approach for the intravesical instillation of bladder cancer. However, the limited penetration of nanoparticle based therapeutic agents into the mucosa layer of the bladder wall poses a great challenge for the clinical application of CDT in intravesical instillation. Herein, we developed a 1064 nm NIR-II light driven hydrogel nanomotor for the CDT for bladder cancer via intravesical instillation. The hydrogel nanomotor was synthesized via microfluidics, wrapped with a lipid bilayer, and encapsulates CuO2 nanoparticles as a CDT reagent and core-shell structured Fe3O4@Cu9S8 nanoparticles as a fuel reagent with asymmetric distribution in the nanomotor (LipGel-NM). An NIR-II light irradiation of 1064 nm drives the active motion of LipGel-NMs, thus facilitating their distribution in the bladder and deep penetration into the mucosa layer of the bladder wall. After FA-mediated endocytosis in bladder cancer cells, CuO2 is released from LipGel-NMs due to the acidic intracellular environment for CDT. The NIR-II light powered active motion of LipGel-NMs effectively enhances CDT, providing a promising strategy for bladder cancer therapy.

Ironing out the role of ferroptosis in immunity

Ferroptosis is a type of regulated cell death that drives the pathophysiology of many diseases. Oxidative stress is detectable in many types of regulated cell death, but only ferroptosis involves lipid peroxidation and iron dependency. Ferroptosis originates and propagates from several organelles, including the mitochondria, endoplasmic reticulum, Golgi, and lysosomes. Recent data have revealed that immune cells can both induce and undergo ferroptosis. A mechanistic understanding of how ferroptosis regulates immunity is critical to understanding how ferroptosis controls immune responses and how this is dysregulated in disease. Translationally, more work is needed to produce ferroptosis-modulating immunotherapeutics. This review focuses on the role of ferroptosis in immune-related diseases, including infection, autoimmune diseases, and cancer. We discuss how ferroptosis is regulated in immunity, how this regulation contributes to disease pathogenesis, and how targeting ferroptosis may lead to novel therapies.

The roles of ferroptosis in cancer: Tumor suppression, tumor microenvironment, and therapeutic interventions

In cancer treatment, the recurrent challenge of inducing apoptosis through conventional therapeutic modalities, often thwarted by therapy resistance, emphasizes the critical need to explore alternative cell death pathways. Ferroptosis, an iron-dependent form of regulated cell death triggered by the lethal accumulation of lipid peroxides on cellular membranes, has emerged as one such promising frontier in oncology. Induction of ferroptosis not only suppresses tumor growth but also holds potential for augmenting immunotherapy responses and surmounting resistance to existing cancer therapies. This review navigates the role of ferroptosis in tumor suppression. Furthermore, we delve into the complex role of ferroptosis within the tumor microenvironment and its interplay with antitumor immunity, offering insights into the prospect of targeting ferroptosis as a strategic approach in cancer therapy.

Harnessing ferroptosis for enhanced sarcoma treatment: mechanisms, progress and prospects

Sarcoma is a malignant tumor that originates from mesenchymal tissue. The common treatment for sarcoma is surgery supplemented with radiotherapy and chemotherapy. However, patients have a 5-year survival rate of only approximately 60%, and sarcoma cells are highly resistant to chemotherapy. Ferroptosis is an iron-dependent nonapoptotic type of regulated programmed cell death that is closely related to the pathophysiological processes underlying tumorigenesis, neurological diseases and other conditions. Moreover, ferroptosis is mediated via multiple regulatory pathways that may be targets for disease therapy. Recent studies have shown that the induction of ferroptosis is an effective way to kill sarcoma cells and reduce their resistance to chemotherapeutic drugs. Moreover, ferroptosis-related genes are related to the immune system, and their expression can be used to predict sarcoma prognosis. In this review, we describe the molecular mechanism underlying ferroptosis in detail, systematically summarize recent research progress with respect to ferroptosis application as a sarcoma treatment in various contexts, and point out gaps in the theoretical research on ferroptosis, challenges to its clinical application, potential resolutions of these challenges to promote ferroptosis as an efficient, reliable and novel method of clinical sarcoma treatment.

Photonic control of image-guided ferroptosis cancer nanomedicine

Photonic nanomaterials, characterized by their remarkable photonic tunability, empower a diverse range of applications, including cutting-edge advances in cancer nanomedicine. Recently, ferroptosis has emerged as a promising alternative strategy for effectively killing cancer cells with minimizing therapeutic resistance. Novel design of photonic nanomaterials that can integrate photoresponsive-ferroptosis inducers, -diagnostic imaging, and -synergistic components provide significant benefits to effectively trigger local ferroptosis. This review provides a comprehensive overview of recent advancements in photonic nanomaterials for image-guided ferroptosis cancer nanomedicine, offering insights into their strengths, constraints, and their potential as a future paradigm in cancer treatment.

Current and Potential Roles of Ferroptosis in Bladder Cancer

Ferroptosis, a type of regulated cell death driven by iron-dependent lipid peroxidation, is mainly initiated by extramitochondrial lipid peroxidation due to the accumulation of iron-dependent reactive oxygen species. Ferroptosis is a prevalent and primitive form of cell death. Numerous cellular metabolic processes regulate ferroptosis, including redox homeostasis, iron regulation, mitochondrial activity, amino acid metabolism, lipid metabolism, and various disease-related signaling pathways. Ferroptosis plays a pivotal role in cancer therapy, particularly in the eradication of aggressive malignancies resistant to conventional treatments. Multiple studies have explored the connection between ferroptosis and bladder cancer, focusing on its incidence and treatment outcomes. Several biomolecules and tumor-associated signaling pathways, such as p53, heat shock protein 1, nuclear receptor coactivator 4, RAS-RAF-MEK, phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin, and the Hippo-tafazzin signaling system, exert a moderating influence on ferroptosis in bladder cancer. Ferroptosis inducers, including erastin, artemisinin, conjugated polymer nanoparticles, and quinazolinyl-arylurea derivatives, hold promise for enhancing the effectiveness of conventional anticancer medications in bladder cancer treatment. Combining conventional therapeutic drugs and treatment methods related to ferroptosis offers a promising approach for the treatment of bladder cancer. In this review, we analyze the research on ferroptosis to augment the efficacy of bladder cancer treatment.

Engineered Macrophages Tune Intratumoral Cytokines through Precisely Controlled Self-Pyroptosis to Enhance Bladder Cancer Immunotherapy

Engineered macrophages are a promising tool for drug delivery and immunotherapy in cancer treatment. However, simultaneous targeted enrichment and controllable immunological activation of these macrophages at the tumor site remains challenging. As a solution, macrophages loaded with an advanced nanoparticle encapsulating CpG-conjugated magnetic nanoclusters (MNC) with indocyanine green (ICG) and nigericin (NIG) (MNC-ICG-NIG@SiO2 (MINS)), utilizing Se─Se bond-modified SiO2 , are designed and applied in bladder cancer, which is typically managed surgically, followed by Bacillus Calmette-Guerin (BCG) adjuvant instillation therapy. Upon intravenous administration, BCG-mediated tumor-localized inflammation leads to targeted accumulation of MINS@MΦ. MINS@MΦ accumulates within the tumor tissue and is immunologically activated through laser irradiation, leading to ICG-mediated generation of reactive oxygen species, Se─Se bond cleavage, and subsequent NIG release to induce self-pyroptosis. Consequently, MINS@MΦ releases Fe2+ ions and CpG, thus promoting the M1 polarization of tumor-associated macrophages and secretion of appropriate antitumor cytokines. However, without intervention, MINS@MΦ undergoes apoptosis in the bloodstream after 48 h without eliciting any immune response. Therefore, this innovative approach optimizes and enhances the efficacy of BCG immunotherapy by precisely modulating the cytokines for effective bladder cancer treatment without inducing a systemic inflammatory response.

Four Ounces Can Move a Thousand Pounds: The Enormous Value of Nanomaterials in Tumor Immunotherapy

The application of nanomaterials in healthcare has emerged as a promising strategy due to their unique structural diversity, surface properties, and compositional diversity. In particular, nanomaterials have found a significant role in improving drug delivery and inhibiting the growth and metastasis of tumor cells. Moreover, recent studies have highlighted their potential in modulating the tumor microenvironment (TME) and enhancing the activity of immune cells to improve tumor therapy efficacy. Various types of nanomaterials are currently utilized as drug carriers, immunosuppressants, immune activators, immunoassay reagents, and more for tumor immunotherapy. Necessarily, nanomaterials used for tumor immunotherapy can be grouped into two categories: organic and inorganic nanomaterials. Though both have shown the ability to achieve the purpose of tumor immunotherapy, their composition and structural properties result in differences in their mechanisms and modes of action. Organic nanomaterials can be further divided into organic polymers, cell membranes, nanoemulsion-modified, and hydrogel forms. At the same time, inorganic nanomaterials can be broadly classified as nonmetallic and metallic nanomaterials. The current work aims to explore the mechanisms of action of these different types of nanomaterials and their prospects for promoting tumor immunotherapy.

The crosstalk between ferroptosis and anti-tumor immunity in the tumor microenvironment: molecular mechanisms and therapeutic controversy

The advent of immunotherapy has significantly reshaped the landscape of cancer treatment, greatly enhancing therapeutic outcomes for multiple types of cancer. However, only a small subset of individuals respond to it, underscoring the urgent need for new methods to improve its response rate. Ferroptosis, a recently discovered form of programmed cell death, has emerged as a promising approach for anti-tumor therapy, with targeting ferroptosis to kill tumors seen as a potentially effective strategy. Numerous studies suggest that inducing ferroptosis can synergistically enhance the effects of immunotherapy, paving the way for a promising combined treatment method in the future. Nevertheless, recent research has raised concerns about the potential negative impacts on anti-tumor immunity as a consequence of inducing ferroptosis, leading to conflicting views within the scientific community about the interplay between ferroptosis and anti-tumor immunity, thereby underscoring the necessity of a comprehensive review of the existing literature on this relationship. Previous reviews on ferroptosis have touched on related content, many focusing primarily on the promoting role of ferroptosis on anti-tumor immunity while overlooking recent evidence on the inhibitory effects of ferroptosis on immunity. Others have concentrated solely on discussing related content either from the perspective of cancer cells and ferroptosis or from immune cells and ferroptosis. Given that both cancer cells and immune cells exist in the tumor microenvironment, a one-sided discussion cannot comprehensively summarize this topic. Therefore, from the perspectives of both tumor cells and tumor-infiltrating immune cells, we systematically summarize the current conflicting views on the interplay between ferroptosis and anti-tumor immunity, intending to provide potential explanations and identify the work needed to establish a translational basis for combined ferroptosis-targeted therapy and immunotherapy in treating tumors.

Polymeric in situ forming depots for long-acting drug delivery systems

Polymeric in situ forming depots have emerged as highly promising drug delivery systems for long-acting applications. Their effectiveness is attributed to essential characteristics such as biocompatibility, biodegradability, and the ability to form a stable gel or solid upon injection. Moreover, they provide added versatility by complementing existing polymeric drug delivery systems like micro- and nanoparticles. The formulation's low viscosity facilitates manufacturing unit operations and enhances delivery efficiency, as it can be easily administered via hypodermic needles. The release mechanism of drugs from these systems can be predetermined using various functional polymers. To enable unique depot design, numerous strategies involving physiological and chemical stimuli have been explored. Important assessment criteria for in situ forming depots include biocompatibility, gel strength and syringeability, texture, biodegradation, release profile, and sterility. This review focuses on the fabrication approaches, key evaluation parameters, and pharmaceutical applications of in situ forming depots, considering perspectives from academia and industry. Additionally, insights about the future prospects of this technology are discussed.

Mucoadhesive gellan gum-based and carboxymethyl cellulose -based hydrogels containing gemcitabine and papain for bladder cancer treatment

Local treatment of bladder cancer faces several limitations such as short residence time or low permeation through urothelium tissue. The aim of this work was to develop patient-friendly mucoadhesive gel formulations combining gemcitabine and the enzyme papain for improved intravesical chemotherapy delivery. Hydrogels based on two different polysaccharides, gellan gum and sodium carboxymethylcellulose (CMC), were prepared with either native papain or papain nanoparticles (nanopapain) to explore for the first time their use as permeability enhancers through bladder tissue. Gel formulations were characterized regarding enzyme stability, rheological behavior, retention on bladder tissue and bioadhesion, drug release properties, permeation capacity, and biocompatibility. After 90 days of storage, the enzyme loaded in the CMC gels retained up to 83.5 ± 4.9 % of its activity in the absence of the drug, and up to 78.1 ± 5.3 with gemcitabine. The gels were mucoadhesive and the enzyme papain showed mucolytic action, which resulted in resistance against washing off from the urothelium and enhanced permeability of gemcitabine in the ex vivo tissue diffusion tests. Native papain shortened lag-time tissue penetration to 0.6 h and enhanced 2-fold drug permeability All formulations demonstrated pseudoplastic behavior and no irritability. Overall, the developed formulations have potential as an upgraded alternative to intravesical therapy for bladder cancer treatment.

Synergistic ferroptosis-starvation therapy for bladder cancer based on hyaluronic acid modified metal-organic frameworks

Bladder cancer (BCa) is one of the most common malignancies of the urinary tract. Metastasis and recurrence of BCa are the leading causes of poor prognosis, and only a few patients can benefit from current first-line treatments such as chemotherapy and immunotherapy. It is urgent to develop more effective therapeutic method with low side effects. Here, a cascade nanoreactor, ZIF-8/PdCuAu/GOx@HA (ZPG@H), is proposed for starvation therapy and ferroptosis of BCa. The ZPG@H nanoreactor was constructed by co-encapsulation of PdCuAu nanoparticles and glucose oxidase into zeolitic imidazolate framework-8 (ZIF-8) modified by hyaluronic acid. The vitro results indicated that ZPG@H enhanced intracellular reactive oxygen species levels and reduced mitochondrial depolarization in the tumor microenvironment. Therefore, the integrated advantages of starvation therapy and chemodynamic therapy endow ZPG@H with a perfect ferroptosis inducing ability. This effectiveness, combined with its excellent biocompatibility and biosafety, means that ZPG@H could make a critical contribution to the development of novel BCa treatments.

Inaugurating a novel adjuvant therapy in urological cancers: Ferroptosis

Ferroptosis, a distinctive form of programmed cell death, is involved in numerous diseases with specific characteristics, including certain cell morphology, functions, biochemistry, and genetics, that differ from other forms of programmed cell death, such as apoptosis. Many studies have explored ferroptosis and its associated mechanisms, drugs, and clinical applications in diseases such as kidney injury, stroke, ischemia-reperfusion injury, and prostate cancer. In this review, we summarize the regulatory mechanisms of some ferroptosis inducers, such as enzalutamide and erastin. These are current research focuses and have already been studied extensively. In summary, this review focuses on the use of ferroptosis induction as a therapeutic strategy for treating tumors of the urinary system.

Long-Term Retention Microbubbles with Three-Layer Structure for Floating Intravesical Instillation Delivery

Intravesical instillation is an effective treatment for bladder cancer. However, clinical anticancer agents always suffer rapid excretion by periodic urination, leading to low therapeutic efficacy. Prolonging the retention time of drugs in the bladder is the key challenge for intravesical instillation treatment. Herein, a facile and powerful surface cross-linking-freeze drying strategy is proposed to generate ultra-stable albumin bovine air microbubbles (BSA-MBs) that can float and adhere to the bladder wall to overcome the excretion of urination and exhibit a remarkable property of long-term retention in the bladder. More noteworthy, BSA-MBs are endowed with a specific three-layer structure, namely, the outer membrane, middle drug loading layer and inner air core, which makes them have a low density to easily float and possess a high drug loading capacity. Based on their unique superiorities, the therapeutic potential of doxorubicin (DOX)-loaded BSA-MBs (DOX-MBs) is exemplified by intravesical instillation for bladder cancer. After injection into the bladder, DOX-MBs can remain in the bladder for a long time and sustain the release of DOX in urine, exhibiting potent anticancer efficacy. Consequently, the prolonged retention of BSA-MBs in the bladder renders them as an effective floating drug delivery system for intravesical instillation therapy.

Injectable zwitterionic cryogels for accurate and sustained chemoimmunotherapy

Chemoimmunotherapy is an effective method to treat cancer, and thus various vehicles have been constructed to co-deliver immune agents and anticancer drugs. But the immune induction process in vivo is highly susceptible to the influence of the material itself. To avoid immune reactions by the materials of delivery systems, herein, a new kind of zwitterionic cryogels (SH cryogels) with extremely low immunogenicity was prepared for chemoimmunotherapy of cancer. Their macroporous structure enabled the SH cryogels to have good compressibility and be injected through a conventional syringe. The loaded chemotherapeutic drugs and immune adjuvants were accurately, locally and long-termly released in the vicinity of tumors, enhancing the outcome of tumor therapy and minimizing the damage caused by the chemotherapeutic drugs to other organ tissues. In vivo tumor treatment experiments indicated that chemoimmunotherapy using the SH cryogel platform could inhibit the growth of breast cancer tumors to the greatest extent. Furthermore, macropores of SH cryogels supported cells to move freely in the cryogels, which could promote the dendritic cells to capture the in situ produced tumor antigens and present them to T cells. The ability to act as cradles for cell infiltration made the SH cryogels promising for applications as vaccine platforms.

Insights into the Safety and Versatility of 4D Printed Intravesical Drug Delivery Systems

This paper focuses on recent advancements in the development of 4D printed drug delivery systems (DDSs) for the intravesical administration of drugs. By coupling the effectiveness of local treatments with major compliance and long-lasting performance, they would represent a promising innovation for the current treatment of bladder pathologies. Being based on a shape-memory pharmaceutical-grade polyvinyl alcohol (PVA), these DDSs are manufactured in a bulky shape, can be programmed to take on a collapsed one suitable for insertion into a catheter and re-expand inside the target organ, following exposure to biological fluids at body temperature, while releasing their content. The biocompatibility of prototypes made of PVAs of different molecular weight, either uncoated or coated with Eudragit®-based formulations, was assessed by excluding relevant in vitro toxicity and inflammatory response using bladder cancer and human monocytic cell lines. Moreover, the feasibility of a novel configuration was preliminarily investigated, targeting the development of prototypes provided with inner reservoirs to be filled with different drug-containing formulations. Samples entailing two cavities, filled during the printing process, were successfully fabricated and showed, in simulated urine at body temperature, potential for controlled release, while maintaining the ability to recover about 70% of their original shape within 3 min.

Bibliometric analysis of ferroptosis: a comprehensive evaluation of its contribution to cancer immunity and immunotherapy

Background

In the past 5 years, ferroptosis-associated cancer immunity has been attracted significant research interest.

Objective

This study was performed to identify and analyze the global output trend for ferroptosis in cancer immunity.

Methods

Relevant studies were retrieved from the Web of Science Core Collection on Feb 10^th, 2023. The VOSviewer and Histcite softwares were utilized to perform the visual bibliometric and deep mining analyses.

Results

A total of 694 studies (530 articles (76.4%) and 164 (23.6%) review articles) were retrieved from the Web of Science Core Collection for visualization analyses. The top 3 key keywords were ferroptosis, prognosis and immunotherapy. The top 30 local citation score (LCS) authors were all collaborators of Zou Weiping. Deep mining of 51 nanoparticle-related articles showed that BIOMATERIALS was the most popular journal. The primary goal of gene signatures related to ferroptosis and cancer immunity was to establish prognostic predictions.

Conclusion

There has been a significant increase in ferroptosis-associated immune publications in the recent 3 years. The key research hotspots include mechanisms, prediction and therapeutic outcomes. The most influential article was from the Zou Weiping's group, which proposed that system xc-mediated ferroptosis is induced by CD8(+) T cell-secreted IFNγ after PD-L1 blockage for immunotherapy. The frontier of research in the field of ferroptosis-associated immune is the study on nanoparticle and gene signature The limitation of this bibliometric study is that publications on this topic are few.

Nanomaterials: small particles show huge possibilities for cancer immunotherapy

With the economy's globalization and the population's aging, cancer has become the leading cause of death in most countries. While imposing a considerable burden on society, the high morbidity and mortality rates have continuously prompted researchers to develop new oncology treatment options. Anti-tumor regimens have evolved from early single surgical treatment to combined (or not) chemoradiotherapy and then to the current stage of tumor immunotherapy. Tumor immunotherapy has undoubtedly pulled some patients back from the death. However, this strategy of activating or boosting the body's immune system hardly benefits most patients. It is limited by low bioavailability, low response rate and severe side effects. Thankfully, the rapid development of nanotechnology has broken through the bottleneck problem of anti-tumor immunotherapy. Multifunctional nanomaterials can not only kill tumors by combining anti-tumor drugs but also can be designed to enhance the body's immunity and thus achieve a multi-treatment effect. It is worth noting that the variety of nanomaterials, their modifiability, and the diversity of combinations allow them to shine in antitumor immunotherapy. In this paper, several nanobiotics commonly used in tumor immunotherapy at this stage are discussed, and they activate or enhance the body's immunity with their unique advantages. In conclusion, we reviewed recent advances in tumor immunotherapy based on nanomaterials, such as biological cell membrane modification, self-assembly, mesoporous, metal and hydrogels, to explore new directions and strategies for tumor immunotherapy.

Ferroptosis: A new therapeutic target for bladder cancer

Bladder cancer (BC) is the most frequent type of urinary system cancer. The prognosis of BC is poor due to high metastasis rates and multidrug resistance. Hence, development of novel therapies targeting BC cell death is urgently needed. As a novel cell death type with strong antitumor potential, ferroptosis has been investigated by many groups for its potential in BC treatment. As an iron-dependent cell death process, ferroptosis is characterized by excessive oxidative phospholipids. The molecular mechanisms of ferroptosis include iron overload and the system Xc-GSH-GPX4 signaling pathway. A recent study revealed that ferroptosis is involved in the metastasis, treatment, and prognosis of BC. Herein, in this review, we comprehensively summarize the mechanism of ferroptosis, address newly identified targets involved in ferroptosis, and discuss the potential of new clinical therapies targeting ferroptosis in BC.

State-of-the-Art Advances of Nanomedicine for Diagnosis and Treatment of Bladder Cancer

Bladder cancer is a common malignant tumor of the urinary system. Cystoscopy, urine cytology, and CT are the routine diagnostic methods. However, there are some problems such as low sensitivity and difficulty in staging, which must be urgently supplemented by novel diagnostic methods. Surgery, intravesical instillation, systemic chemotherapy, and radiotherapy are the main clinical treatments for bladder cancer. It is difficult for conventional treatment to deal with tumor recurrence, progression and drug resistance. In addition, the treatment agents usually have the defects of poor specific distribution ability to target tumor tissues and side effects. The rapid development of nanomedicine has brought hope for the treatment of bladder cancer in reducing side effects, enhancing tumor inhibition effects, and anti-drug resistance. Overall, we review the new progression of nano-platforms in the diagnosis and treatment of bladder cancer.

Microenvironment immune response induced by tumor ferroptosis—the application of nanomedicine

Ferroptosis is a non-apoptotic regulatory form of cell death that has sparked significant interest and research in cancer treatment and certain small chemical inducers have been used in the clinic. These inducers’s weak water solubility, poor targeting, rapid metabolism; and other undesirable characteristics; however, for therapeutic approaches that combine immunotherapy and ferroptosis, challenges such as medication delivery, the complexity of the tumor microenvironment, and immunosuppression remain. The targeted, low toxicity, and efficient distribution benefits of nanotechnology have considerably enhanced the therapeutic efficacy of combining immunotherapy with ferroptosis. This paper describes the distinct mechanism of ferroptosis in tumor therapy and immunotherapy, as well as the application and benefits of nanotechnology in the combination of tumor immunotherapy and ferroptosis.

Nanomaterials: A powerful tool for tumor immunotherapy

Cancer represents the leading global driver of death and is recognized as a critical obstacle to increasing life expectancy. In recent years, with the development of precision medicine, significant progress has been made in cancer treatment. Among them, various therapies developed with the help of the immune system have succeeded in clinical treatment, recognizing and killing cancer cells by stimulating or enhancing the body’s intrinsic immune system. However, low response rates and serious adverse effects, among others, have limited the use of immunotherapy. It also poses problems such as drug resistance and hyper-progression. Fortunately, thanks to the rapid development of nanotechnology, engineered multifunctional nanomaterials and biomaterials have brought breakthroughs in cancer immunotherapy. Unlike conventional cancer immunotherapy, nanomaterials can be rationally designed to trigger specific tumor-killing effects. Simultaneously, improved infiltration of immune cells into metastatic lesions enhances the efficiency of antigen submission and induces a sustained immune reaction. Such a strategy directly reverses the immunological condition of the primary tumor, arrests metastasis and inhibits tumor recurrence through postoperative immunotherapy. This paper discusses several types of nanoscale biomaterials for cancer immunotherapy, and they activate the immune system through material-specific advantages to provide novel therapeutic strategies. In summary, this article will review the latest advances in tumor immunotherapy based on self-assembled, mesoporous, cell membrane modified, metallic, and hydrogel nanomaterials to explore diverse tumor therapies.

Immunogenomic Characteristics of Cell-Death-Associated Genes with Prognostic Implications in Bladder Cancer

Bladder cancer is one of the most common genitourinary malignant cancers worldwide. Cell death processes, including apoptosis, ferroptosis, and necrosis, provide novel clinical and immunological insights promoting the management of precision medicine. Therefore, this study aimed to evaluate the transcriptomic profile of signatures in cell death pathways with significant prognostic implications in patients with bladder cancer from multiple independent cohorts (n = 1999). First, genes involved in apoptosis (n = 19), ferroptosis (n = 31), and necrosis (n = 6) were analyzed to evaluate the prognostic implications in bladder cancer. Significant genes were included to establish the cell-death index (CDI) of 36 genes that distinguished patients according to high and low risks. Survival analysis using the Kaplan-Meier curves clustered patients based on overall survival (18.8 vs. 96.7 months; hazard model [HR] = 3.12, P<00001). Cox proportional hazard model was significantly associated with a higher risk of mortality using 10 external independent cohorts in patients with CDI^high (HR = 1.31, 95% CI: 1.04–1.62). To explore immune parameters associated with CDI, microenvironment cell-population-counter algorithms indicated increased intratumoral heterogeneity and macrophage/monocyte infiltration and CD8⁺ T cells in patients with CDI^high group. Besides, the CDI^high group showed an increased expression of the following immune checkpoints: CD276, PD-L1, CTLA-4, and T-cell exhaustion signatures. Cytokine expression analysis revealed the highest association of IL-9R, IL-17A, IL-17F, GDF7, and IFNW1 with the high-risk group. In addition, 42 patients with BCa receiving immunotherapies were enrolled from a real-world cohort, and expression patterns of three CDI hub genes (DRD5, SCL2A14, and IGF1) were detected using immunohistochemical staining. Patients with triple-negative staining of tumor tissues had significantly higher tumor-associated macrophage abundance, PD-L1 expression, predicted immunocompromised microenvironment, and prominently progressive progression (HR = 4.316, P = 0.0028). In conclusion, this study highlights the immunoevasive tumor microenvironment characterized by the higher tumor-associated macrophage infiltration with the presence of immune checkpoint and T-cell exhaustion genes in patients with BCa at CDI^high risk who might suffer progression and be more suitable to benefit from immune checkpoint inhibitors or other immunotherapies.

Prognostic value and potential biological functions of ferroptosis‑related gene signature in bladder cancer

Bladder cancer (BC), as a genitourinary system tumor, is a highly prevalent tumor type. Ferroptosis is an iron-dependent oxidative cell death mechanism that is becoming increasingly recognized as a promising avenue for cancer therapy. However, further determination of the prospective prognostic value of ferroptosis for BC and investigation of the underlying mechanisms is required. The mRNA expression profiles and associated clinical data were downloaded from public databases such as The Cancer Genome Atlas, Gene Expression Omnibus and the IMvigor210 database. To construct a predictive formula, the least absolute shrinkage and selection operator Cox regression algorithm was used. In addition, a prognostic multigene signature was constructed using previously selected ferroptosis-related genes (FRGs). A total of 28 FRGs were differentially expressed between tumor and normal samples with |log2 fold change| >1 and adjusted P<0.05. A prognostic model was then established and it was validated in the GEO cohort using six genes: Glutamate-cysteine ligase modifier subunit, crystallin α-B, transferrin receptor, zinc finger E-box binding homeobox 1, squalene epoxidase and glucose-6-phosphate dehydrogenase (G6PD). Numerous important pathways involved in the development of the immune system and cancer were indicated to be significantly different between the two risk groups. In addition, it was discovered that G6PD expression subgroups that were associated with immunotherapy response in patients with BC had similar prognostic features to risk score subgroups. In the present study, a gene signature with a prognostic value for ferroptosis in BC was successfully developed and the potential value of G6PD was identified for future research.

Autophagy, ferroptosis, pyroptosis, and necroptosis in tumor immunotherapy

In recent years, immunotherapy represented by immune checkpoint inhibitors (ICIs) has led to unprecedented breakthroughs in cancer treatment. However, the fact that many tumors respond poorly or even not to ICIs, partly caused by the absence of tumor-infiltrating lymphocytes (TILs), significantly limits the application of ICIs. Converting these immune “cold” tumors into “hot” tumors that may respond to ICIs is an unsolved question in cancer immunotherapy. Since it is a general characteristic of cancers to resist apoptosis, induction of non-apoptotic regulated cell death (RCD) is emerging as a new cancer treatment strategy. Recently, several studies have revealed the interaction between non-apoptotic RCD and antitumor immunity. Specifically, autophagy, ferroptosis, pyroptosis, and necroptosis exhibit synergistic antitumor immune responses while possibly exerting inhibitory effects on antitumor immune responses. Thus, targeted therapies (inducers or inhibitors) against autophagy, ferroptosis, pyroptosis, and necroptosis in combination with immunotherapy may exert potent antitumor activity, even in tumors resistant to ICIs. This review summarizes the multilevel relationship between antitumor immunity and non-apoptotic RCD, including autophagy, ferroptosis, pyroptosis, and necroptosis, and the potential targeting application of non-apoptotic RCD to improve the efficacy of immunotherapy in malignancy.

Bioengineered nanogels for cancer immunotherapy

Recent years have witnessed increasingly rapid advances in nanocarrier-based biomedicine aimed at improving treatment paradigms for cancer. Nanogels serve as multipurpose and constructed vectors formed via intramolecular cross-linking to generate drug delivery systems, which is attributed predominantly to their satisfactory biocompatibility, bio-responsiveness, high stability, and low toxicity. Recently, immunotherapy has experienced unprecedented growth and has become the preferred strategy for cancer treatment, and mainly involves the mobilisation of the immune system and an enhanced anti-tumour immunity of the tumour microenvironment. Despite the inspiring success, immunotherapeutic strategies are limited due to the low response rates and immune-related adverse events. Like other nanomedicines, nanogels are comparably limited by lower focal enrichment rates upon introduction into the organism via injection. Because nanogels are three-dimensional cross-linked aqueous materials that exhibit similar properties to natural tissues and are structurally stable, they can comfortably cope with shear forces and serum proteins in the bloodstream, and the longer circulation life increases the chance of nanogel accumulation in the tumour, conferring deep tumour penetration. The large specific surface area can reduce or eliminate off-target effects by introducing stimuli-responsive functional groups, allowing multiple physical and chemical modifications for specific purposes to improve targeting to specific immune cell subpopulations or immune organs, increasing the bioavailability of the drug, and conferring a low immune-related adverse events on nanogel therapies. The slow release upon reaching the tumour site facilitates long-term awakening of the host's immune system, ultimately achieving enhanced therapeutic effects. As an effective candidate for cancer immunotherapy, nanogel-based immunotherapy has been widely used. In this review, we mainly summarize the recent advances of nanogel-based immunotherapy to deliver immunomodulatory small molecule drugs, antibodies, genes and cytokines, to target antigen presenting cells, form cancer vaccines, and enable chimeric antigen receptor (CAR)-T cell therapy. Future challenges as well as expected and feasible prospects for clinical treatment are also highlighted.

In Situ Constructed Nano-Drug Depots through Intracellular Hydrolytic Condensation for Chemotherapy of Bladder Cancer

Intravesical administration of first-line drugs has shown failure in the treatment of bladder cancer owing to the poor tumor retention time of chemotherapeutics. Herein, we report an intracellular hydrolytic condensation (IHC) system to construct long-term retentive nano-drug depots in situ, wherein sustained drug release results in highly efficient suppression of bladder cancer. Briefly, the designed doxorubicin (Dox)-silane conjugates self-assemble into silane-based prodrug nanoparticles, which condense into silicon particle-based nano-drug depots inside tumor cells. Significantly, we demonstrate that the IHC system possesses highly potent antitumor efficacy, which leads to the regression and eradication of large established tumors and simultaneously extends the overall survival of air pouch bladder cancer mice compared with that of mice treated with Dox. The concept of intracellular hydrolytic condensation can be extended via conjugating other chemotherapeutic drugs, which may facilitate rational design of novel nanomedicines for augmentation of chemotherapy.

Multifunctional Nanomaterials for Ferroptotic Cancer Therapy

Patient outcomes from the current clinical cancer therapy remain still far from satisfactory. However, in recent years, several biomedical discoveries and nanotechnological innovations have been made, so there is an impetus to combine these with conventional treatments to improve patient experience and disease prognosis. Ferroptosis, a term first coined in 2012, is an iron-dependent regulated cell death (RCD) based on the production of reactive oxygen species (ROS) and the consequent oxidization of polyunsaturated fatty acids (PUFAs). Many nanomaterials that can induce ferroptosis have been explored for applications in cancer therapy. In this review, we summarize the recent developments in ferroptosis-based nanomaterials for cancer therapy and discuss the future of ferroptosis, nanomedicine, and cancer therapy.

Biological applications of chiral inorganic nanomaterials

Chirality is common in nature and plays the essential role in maintaining physiological process. Chiral inorganic nanomaterials with intense optical activity have attracted more attention due to amazing properties in recent years. Over the past decades, many efforts have been paid to the preparation and chirality origin of chiral nanomaterials; furthermore, emerging biological applications have been investigated widely. This review mainly summarizes recent advances in chiral nanomaterials. The top-down and bottom-up preparation methods and chirality origin of chiral nanomaterials are introduced; besides, the biological applications, such as sensing, therapy, and catalysis, will be introduced comprehensively. Finally, we also provide a perspective on the biomedical applications of chiral nanomaterials.

Advances of Light/Ultrasound/Magnetic-Responsive Nanoprobes for Visualized Theranostics of Urinary Tumors

Light/ultrasound/magnetic-responsive nanomaterials exhibit excellent performance in imaging and therapy and play an important role in precision theranostics of tumors. In contrast to deep organs, urinary organs (such as bladder and prostate) can easily be studied via intervention mode, which has greatly brought promising applications of stimuli-responsive nanoprobes in visualized theranostics of urinary tumors. Therefore, it has been very critical to develop stimuli-responsive nanoprobes with high safety, stability, and reliability against urinary tumors. In this review, recent advances in light/ultrasound/magnetic-responsive nanoprobes in visualized theranostics of urinary tumors are summarized, including magnetic resonance/fluorescence/ultrasound/photoacoustic imaging and multimodal imaging, photothermal/photodynamic/sonodynamic therapy and combination therapy, and single-modal/multimodal-imaging-guided visualized theranostics. Finally, the future perspectives of light/ultrasound/magnetic-responsive nanoprobes against urinary tumors are also prospected.

Emerging Nanoparticle Strategies for Modulating Tumor-Associated Macrophage Polarization

Immunotherapy has made great progress in recent years, yet the efficacy of solid tumors remains far less than expected. One of the main hurdles is to overcome the immune-suppressive tumor microenvironment (TME). Among all cells in TME, tumor-associated macrophages (TAMs) play pivotal roles because of their abundance, multifaceted interactions to adaptive and host immune systems, as well as their context-dependent plasticity. Underlying the highly plastic characteristic, lots of research interests are focused on repolarizing TAMs from M2-like pro-tumor phenotype towards M1-like antitumoral ones. Nanotechnology offers great opportunities for targeting and modulating TAM polarization to mount the therapeutic efficacy in cancer immunotherapy. Here, this mini-review highlights those emerging nano-approaches for TAM repolarization in the last three years.

Intravesical Mucoadhesive Hydrogel Induces Chemoresistant Bladder Cancer Ferroptosis through Delivering Iron Oxide Nanoparticles in a Three-Tier Strategy

Bladder cancer (BCa) is the most costly solid tumor owing to its high recurrence. Relapsed cancer is known to acquire chemoresistant features after standard intravesical chemotherapy. This cancer state is vulnerable to ferroptosis, which occurs when lipid peroxides generated by iron metabolism accumulate to lethal levels. Increasing the labile iron pool (LIP) by iron oxide nanoparticles (IONPs) promises to inhibit chemoresistant BCa (CRBCa), but systemically administered IONPs do not sufficiently accumulate at the tumor site. Therefore, their efficacy is weakened. Here, we present a three-tier delivery strategy through a mucoadhesive hydrogel platform conveying hyaluronic acid-coated IONPs (IONP-HA). When instilled, the hydrogel platform first adhered to the interface of the tumor surface, sustainably releasing IONP-HA. Subsequently, the tumor stiffness and interstitial fluid pressure were reduced by photothermal therapy, promoting IONP-HA diffusion into the deep cancer tissue. As CRBCa expressed high levels of CD44, the last delivery tier was achieved through antibody-mediated endocytosis to increase the LIP, ultimately inducing ferroptosis. This three-tiered strategy delivered the IONPs stepwise from anatomical to cellular levels and increased the iron content by up to 50-fold from that of systematic administration, which presents a potential regimen for CRBCa.

LncRNA RP11-89 facilitates tumorigenesis and ferroptosis resistance through PROM2-activated iron export by sponging miR-129-5p in bladder cancer

Long non-coding RNAs (lncRNAs) act as important regulators of tumorigenesis and development in bladder cancer. However, the underlying molecular mechanisms remain elusive. We previously identified a novel lncRNA signature related to immunity and progression in bladder cancer. Here we further explored the function of RP11-89, a lncRNA discovered in the previous signature. Loss- and gain-of function experiments were performed using CCK-8 assay, flow cytometry, Transwell assays, scratch tests and subcutaneous nude mouse models. High-throughput RNA sequencing was conducted to identify dysregulated genes in bladder cancer cells with RP11-89 knockdown or overexpression. Regulation of RP11-89 on miR-129-5p and PROM2 was explored through luciferase reporter assay, RIP assay and RNA pull-down assay. RP11-89 promoted cell proliferation, migration and tumorigenesis and inhibited cell cycle arrest via the miR-129-5p/PROM2 axis. We found that RP11-89 "sponges" miR-129-5p and upregulates PROM2. Elevated PROM2 in cells was associated with attenuated ferroptosis through iron export, formation of multivesicular bodies and less mitochondrial abnormalities. We demonstrated that RP11-89 is a novel tumorigenic regulator that inhibits ferroptosis via PROM2-activated iron export. RP11-89 may serve as a potential biomarker for targeted therapy in bladder cancer.

A Novel Ferroptosis-Related Prognostic Signature Reveals Macrophage Infiltration and EMT Status in Bladder Cancer

Bladder cancer (BC) belongs to one of the most common and highly heterogeneous malignancies. Ferroptosis is a newly discovered regulated cell death (RCD), characterized by accumulation of toxic lipid peroxides, and plays a crucial role in tumor progression. Here, we conducted a comprehensive analysis on the transcriptomics data of ferroptosis-related genes in BC based on The Cancer Genome Atlas (TCGA) and three Gene Expression Omnibus (GEO) datasets. In our study, a 6-gene signature was identified based on the potential prognostic ferroptotic regulatory genes. Furthermore, our signature revealed a good independent prognostic ability in BC. Patients with low-risk score exhibited higher FGFR3 mutation rates while high risk score had a positive association with higher RB1 mutation rates. Meanwhile, higher proportions of macrophages were observed in high BC risk group simultaneously with four methods. Unexpectedly, the risk score showed a significant positive correlation with epithelial-mesenchymal transition (EMT) status. Functional assays indicated that CRYAB and SQLE knockdown was associated with attenuated invasion capacity. Our study revealed a ferroptosis-related risk model for predicting prognostic and BC progression. Our results indicate that targeting ferroptosis may be a therapeutic strategy for BC.

A Novel Ferroptosis-Related Gene Model for Overall Survival Predictions of Bladder Urothelial Carcinoma Patients

Introduction

Bladder cancer is the most common urinary tract malignancy, and 90% of bladder tumors are urothelial cell carcinomas. Ferroptosis is a new form of cell death discovered in recent years, which is an iron-dependent form of cell death characterized by the lethal intracellular accumulation of lipid-based reactive oxygen species. Ferroptosis is considered to be a double-edged sword for cancer and cancer therapy.

Materials and Methods

In the current study, expression profiles of bladder cancer (BLCA) specimens were obtained from The Cancer Genome Atlas (TCGA) RNA-Seq database. Ferroptosis-related genes were downloaded from the FerrDb website. The ferroptosis-related differentially expressed genes (DEGs) which were related to overall survival (OS) were first identified. The least absolute shrinkage and selection operator (LASSO) and multivariate Cox regression methods were utilized to develop a ferroptosis-related prognostic model (FRPM). In addition, a nomogram model based on FRPM and clinicopathological features was successfully constructed and validated. In addition, gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and single-sample gene set enrichment analysis (ssGSEA) methods were utilized in this study in order to compare the DEGs between the high-risk and low-risk groups. This study also adopted RT-qPCR, CCK-8 assay, and scratch assay methods to perform experimental verification processes.

Results and Discussion

A 7-gene FRPM was constructed in this research investigation in order to stratify the patients into two groups according to their risk scores. The results of this study’s survival analysis and time-dependent receiver operating characteristic (ROC) analysis demonstrated that the model had achieved a stable performance level. This multivariate Cox regression results revealed that the FRPM was an independent prognostic predictor for the OS of BLCA patients and the results were displayed using a nomogram. In addition, the ROC analysis, concordance index (C-index), calibration plots, and decision curve analysis (DCA) curves further indicated that this study’s nomogram method enabled valuable prediction results. The functional enrichment analysis results suggested that the DEGs between the high- and low-risk groups played vital roles in the progression of the ferroptosis. Also, the ssGSEA indicated that the immune status was different between the two groups. This study found that the RT-qPCR results had confirmed the differential expressions of DEGs in the tissue samples, and the CCK-8 assay and scratch assay results confirmed the promoting effects of SCD on the proliferation and migration of tumor cells.

Conclusions

This study defined a novel prognostic model of seven ferroptosis-related genes, which proved to be independently associated with the OS of BLCA. A nomogram method was developed for the purpose of providing further insight into the accurate predictions of BLCA prognoses.

Ferroptosis in the tumor microenvironment: perspectives for immunotherapy

Targeting ferroptosis, which provokes lipid peroxidation in cancer cells, presents potentially new avenues for anticancer therapy. Recent studies have begun to explore how immune cells in the tumor microenvironment (TME) respond and adapt to lethal lipid peroxides (LPOs). A better understanding of this process in the TME is likely to uncover another side of ferroptosis in cancer immunity and promote the development of ferroptosis-targeted therapy. This Opinion article overviews the main metabolic processes in ferroptosis, summarizes the emerging roles of ferroptosis not only in immune cells in the TME but also in the crosstalk between tumor cells and immune cells, and presents a perspective on the targeting of ferroptosis in cancer immunotherapy.

The Epithelial to Mesenchymal Transition Related Gene Calumenin Is an Adverse Prognostic Factor of Bladder Cancer Correlated With Tumor Microenvironment Remodeling, Gene Mutation, and Ferroptosis

The tumor microenvironment (TME) plays a critical regulatory role in bladder cancer (BLCA) progression and metastasis. Epithelial-mesenchymal transition (EMT) presents as an essential mechanism of tumor invasion and metastasis. Accumulating pieces of evidence indicated that several microenvironmental factors, including fibroblasts, endothelial, and immune cells, induced EMT in tumor cells. As a hallmark gene of the EMT process, calumenin (CALU) was previously reported to directly impact cancer metastasis. However, the functions and molecular mechanisms of CALU have been rarely reported in BLCA. By multi-omics bioinformatics analysis of 408 TCGA BLCA patients, we demonstrated that CALU was an independent risk factor for BLCA outcome. Subsequently, we verified the correlation of CALU with cancer-associated fibroblasts (CAFs) and tumor-infiltrating immune cells. The results suggested a positive correlation of CALU with CAFs, CD8+ T cells and macrophages. Also, CALU was significantly associated with multiple immune checkpoint-related genes, which ultimately influenced patients' responsiveness to immunotherapy. Further, we found that the impact of CALU on BLCA prognosis might also be correlated with gene mutations and ferroptosis. Finally, we validated the roles of CALU by single-cell RNA sequencing, PCR and immunohistochemistry. In conclusion, we found that CALU affected BLCA prognosis associated with multiple mechanisms, including TME remodeling, gene mutation and ferroptosis. Further studies on CALU may provide new targets for BLCA immunotherapy and precision medicine.

Manipulating macrophage polarization in cancer patients: From nanoparticles to human chimeric antigen receptor macrophages

Chimeric antigen receptor (CAR) T cell treatment has provided notable results in hematological tumors. Unfortunately, this evidence has not been translated into improved outcomes in solid malignancies so far, where several reports have suggested that T cells encounter substantial difficulties in penetrating and surviving in the tumor microenvironment (TME). Thus, researchers have recently investigated other immune cell types as CAR platforms, in order to overcome the limitations of CAR T cells. Among them, CAR-macrophages (M) technology has emerged as a novel perspective for cancer patients, on the basis of preclinical studies observing that CAR expression in human macrophages could play a crucial role in enhancing phagocytosis, polarizing M2 to M1 phenotype, and stimulating T cell anti-tumor activity. Herein, we provide an overview of current scenario of CAR-Ms in several solid tumors, also focusing on the biological rationale behind this promising therapeutic approach and future research directions in this setting.