Cell Membrane Camouflaged Metal Oxide-Black Phosphorus Biomimetic Nanocomplex Enhances Photo-chemo-dynamic Ferroptosis

Dual-targeted delivery of temozolomide by multi-responsive nanoplatform via tumor microenvironment modulation for overcoming drug resistance to treat glioblastoma

Glioblastoma (GBM) is the most aggressive primary brain tumor with low survival rate. Currently, temozolomide (TMZ) is the first-line drug for GBM treatment of which efficacy is unfortunately hindered by short circulation time and drug resistance associated to hypoxia and redox tumor microenvironment. Herein, a dual-targeted and multi-responsive nanoplatform is developed by loading TMZ in hollow manganese dioxide nanoparticles functionalized by polydopamine and targeting ligands RAP12 for photothermal and receptor-mediated dual-targeted delivery, respectively. After accumulated in GBM tumor site, the nanoplatform could respond to tumor microenvironment and simultaneously release manganese ion (Mn2+), oxygen (O2) and TMZ. The hypoxia alleviation via O2 production, the redox balance disruption via glutathione consumption and the reactive oxygen species generation, together would down-regulate the expression of O6-methylguanine-DNA methyltransferase under TMZ medication, which is considered as the key to drug resistance. These strategies could synergistically alleviate hypoxia microenvironment and overcome TMZ resistance, further enhancing the anti-tumor effect of chemotherapy/chemodynamic therapy against GBM. Additionally, the released Mn2+ could also be utilized as a magnetic resonance imaging contrast agent for monitoring treatment efficiency. Our study demonstrated that this nanoplatform provides an alternative approach to the challenges including low delivery efficiency and drug resistance of chemotherapeutics, which eventually appears to be a potential avenue in GBM treatment.

Biomimetic MDSCs membrane coated black phosphorus nanosheets system for photothermal therapy/photodynamic therapy synergized chemotherapy of cancer

Photothermal therapy is favored by cancer researchers due to its advantages such as controllable initiation, direct killing and immune promotion. However, the low enrichment efficiency of photosensitizer in tumor site and the limited effect of single use limits the further development of photothermal therapy. Herein, a photo-responsive multifunctional nanosystem was designed for cancer therapy, in which myeloid-derived suppressor cell (MDSC) membrane vesicle encapsulated decitabine-loaded black phosphorous (BP) nanosheets (BP@ Decitabine @MDSCs, named BDM). The BDM demonstrated excellent biosafety and biochemical characteristics, providing a suitable microenvironment for cancer cell killing. First, the BDM achieves the ability to be highly enriched at tumor sites by inheriting the ability of MDSCs to actively target tumor microenvironment. And then, BP nanosheets achieves hyperthermia and induces mitochondrial damage by its photothermal and photodynamic properties, which enhancing anti-tumor immunity mediated by immunogenic cell death (ICD). Meanwhile, intra-tumoral release of decitabine induced G2/M cell cycle arrest, further promoting tumor cell apoptosis. In vivo, the BMD showed significant inhibition of tumor growth with down-regulation of PCNA expression and increased expression of high mobility group B1 (HMGB1), calreticulin (CRT) and caspase 3. Flow cytometry revealed significantly decreased infiltration of MDSCs and M2-macrophages along with an increased proportion of CD4+, CD8+ T cells as well as CD103+ DCs, suggesting a potentiated anti-tumor immune response. In summary, BDM realizes photothermal therapy/photodynamic therapy synergized chemotherapy for cancer.

The application of nanoparticles based on ferroptosis in cancer therapy

Ferroptosis is a new form of non-apoptotic programmed cell death. Due to its effectiveness in cancer treatment, there are increasing studies on the application of nanoparticles based on ferroptosis in cancer therapy. In this paper, we present a summary of the latest progress in nanoparticles based on ferroptosis for effective tumor therapy. We also describe the combined treatment of ferroptosis with other therapies, including chemotherapy, radiotherapy, phototherapy, immunotherapy, and gene therapy. This summary of drug delivery systems based on ferroptosis aims to provide a basis and inspire opinions for researchers concentrating on exploring this field. Finally, we present some prospects and challenges for the application of nanotherapies to clinical treatment by promoting ferroptosis in cancer cells.

Nanotechnology Utilizing Ferroptosis Inducers in Cancer Treatment

Current cancer treatment options have presented numerous challenges in terms of reaching high efficacy. As a result, an immediate step must be taken to create novel therapies that can achieve more than satisfying outcomes in the fight against tumors. Ferroptosis, an emerging form of regulated cell death (RCD) that is reliant on iron and reactive oxygen species, has garnered significant attention in the field of cancer therapy. Ferroptosis has been reported to be induced by a variety of small molecule compounds known as ferroptosis inducers (FINs), as well as several licensed chemotherapy medicines. These compounds' low solubility, systemic toxicity, and limited capacity to target tumors are some of the significant limitations that have hindered their clinical effectiveness. A novel cancer therapy paradigm has been created by the hypothesis that ferroptosis induced by nanoparticles has superior preclinical properties to that induced by small drugs and can overcome apoptosis resistance. Knowing the different ideas behind the preparation of nanomaterials that target ferroptosis can be very helpful in generating new ideas. Simultaneously, more improvement in nanomaterial design is needed to make them appropriate for therapeutic treatment. This paper first discusses the fundamentals of nanomedicine-based ferroptosis to highlight the potential and characteristics of ferroptosis in the context of cancer treatment. The latest study on nanomedicine applications for ferroptosis-based anticancer therapy is then highlighted.

Optimized strategies of ROS-based nanodynamic therapies for tumor theranostics

Reactive oxygen species (ROS) play a crucial role in regulating the metabolism of tumor growth, metastasis, death and other biological processes. ROS-based nanodynamic therapies (NDTs) are becoming attractive due to non-invasive, low side effects and tumor-specific advantages. NDTs have rapidly developed into numerous branches, such as photodynamic therapy, chemodynamic therapy, sonodynamic therapy and so on. However, the complexity of the tumor microenvironment and the limitations of existing sensitizers have greatly restricted the therapeutic effects of NDTs, which heavily rely on ROS levels. To address the limitations of NDTs, various strategies have been developed to increase ROS yield, which is an urgent aspect for the positive development of NDTs. In this review, the nanodynamic potentiation strategies in terms of unique properties and universalities of NDTs are comprehensively outlined. We mainly summarize the current dilemmas faced by each NDT and the respective solutions. Meanwhile, the NDTs universalities-based potentiation strategies and NDTs-based combined treatments are elaborated. Finally, we conclude with a discussion of the key issues and challenges faced in the development and clinical transformation of NDTs.

Photodynamic Therapy Combined with Ferroptosis Is a Synergistic Antitumor Therapy Strategy

Ferroptosis is a programmed death mode that regulates redox homeostasis in cells, and recent studies suggest that it is a promising mode of tumor cell death. Ferroptosis is regulated by iron metabolism, lipid metabolism, and intracellular reducing substances, which is the mechanism basis of its combination with photodynamic therapy (PDT). PDT generates reactive oxygen species (ROS) and 1O2 through type I and type II photochemical reactions, and subsequently induces ferroptosis through the Fenton reaction and the peroxidation of cell membrane lipids. PDT kills tumor cells by generating excessive cytotoxic ROS. Due to the limited laser depth and photosensitizer enrichment, the systemic treatment effect of PDT is not good. Combining PDT with ferroptosis can compensate for these shortcomings. Nanoparticles constructed by photosensitizers and ferroptosis agonists are widely used in the field of combination therapy, and their targeting and biological safety can be improved through modification. These nanoparticles not only directly kill tumor cells but also further exert the synergistic effect of PDT and ferroptosis by activating antitumor immunity, improving the hypoxia microenvironment, and inhibiting the tumor angiogenesis. Ferroptosis-agonist-induced chemotherapy and PDT-induced ablation also have good clinical application prospects. In this review, we summarize the current research progress on PDT and ferroptosis and how PDT and ferroptosis promote each other.

Emerging 2D pnictogens: a novel multifunctional photonic nanoplatform for cutting-edge precision treatment

The elements of the pnictogen group, known as the 15th (VA) family in the periodic table, including phosphorus (P), arsenic (As), antimony (Sb) and bismuth (Bi), have been widely used by alchemists to treat various diseases since ancient times and hold a pivotal position in the history of medicine, owing to their diverse pharmacological activities. Recently, with the development of modern nanotechnology, pnictogen group elements appear in a more innovative form, namely two-dimensional (2D) pnictogens (i.e. phosphorene, arsenene, and bismuthene) with a unique layered crystal structure and extraordinary optoelectronic characteristics, which endow them with significant superiority as a novel multifunctional photonic nanoplatform for cutting-edge precision treatment of various diseases. The puckered layer structure with ultralarge surface area make them ideal drug and gene delivery vectors that can avoid degradation and reduce target effects. The anisotropic morphology allows their easier internalization by cells and may improve gene transfection efficiency. Tunable optoelectronic characteristics endow them with excellent phototherapy performance as well as the ability to act as an optical switch to initiate subsequent therapeutic events. This review provides a brief overview of the properties, preparation and surface modifications of 2D pnictogens, and then focuses on its applications in cutting-edge precision treatment as a novel multifunctional photonic nanoplatform, such as phototherapy, photonic medicine, photo-adjuvant immunotherapy and photo-assisted gene therapy. Finally, the challenges and future development trends for 2D pnictogens are provided. With a focus on 2D pnictogen-based multifunctional photonic nanoplatforms, this review may also provide profound insights for the next generation innovative precision therapy.

Nanoparticle-mediated synergistic anticancer effect of ferroptosis and photodynamic therapy: Novel insights and perspectives

Current antitumor monotherapy has many limitations, highlighting the need for novel synergistic anticancer strategies. Ferroptosis is an iron-dependent form of nonapoptotic cell death that plays a pivotal regulatory role in tumorigenesis and treatment. Photodynamic therapy (PDT) causes irreversible chemical damage to target lesions and is widely used in antitumor therapy. However, PDT's effectiveness is usually hindered by several obstacles, such as hypoxia, excess glutathione (GSH), and tumor resistance. Ferroptosis improves the anticancer efficacy of PDT by increasing oxygen and reactive oxygen species (ROS) or reducing GSH levels, and PDT also enhances ferroptosis induction due to the ROS effect in the tumor microenvironment (TME). Strategies based on nanoparticles (NPs) can subtly exploit the potential synergy of ferroptosis and PDT. This review explores recent advances and current challenges in the landscape of the underlying mechanisms regulating ferroptosis and PDT, as well as nano delivery system-mediated synergistic anticancer activity. These include polymers, biomimetic materials, metal organic frameworks (MOFs), inorganics, and carrier-free NPs. Finally, we highlight future perspectives of this novel emerging paradigm in targeted cancer therapies.

Engineering nanoenzymes integrating Iron-based metal organic frameworks with Pt nanoparticles for enhanced Photodynamic-Ferroptosis therapy

Photodynamic therapy (PDT), as a promising strategy in cancer treatment that utilizes photosensitizers (PSs) to produce reactive oxygen species, has been widely used for eliminating cancer cells under specific wavelength light irradiation. However, the low aqueous solubility of PSs and special tumor microenvironments (TME), such as high glutathione (GSH) and tumor hypoxia remain challenges towards PDT for hypoxic tumor treatment. To address these problems, we constructed a novel nanoenzyme for enhanced PDT-ferroptosis therapy by integrating small Pt nanoparticles (Pt NPs) and near-infrared photosensitizer CyI into iron-based metal organic frameworks (MOFs). In addition, hyaluronic acid was adhered to the surface of the nanoenzymes to enhance the targeting ability. In this design, MOFs act not only as a delivery vector for PSs, but also a ferroptosis inducer. Pt NPs stabilized by MOFs were functioned as an oxygen (O₂) generator by catalyzing hydrogen peroxide into O₂ to relieve tumor hypoxia and increase singlet oxygen generation. In vitro and in vivo results demonstrated that under laser irradiation, this nanoenzyme could effectively relive the tumor hypoxia and decrease the level of GSH, resulting in enhanced PDT-ferroptosis therapy against hypoxic tumor. The proposed nanoenzymes represent an important advance in altering TME for improved clinical PDT-ferroptosis therapy, as well as their potential as effective theranostic agents for hypoxic tumors.

Ferroptosis: Promising approach for cancer and cancer immunotherapy

Ferroptosis is the cell death induced by ferrous ions and lipid peroxidation accumulation in tumor cells. Targeting ferroptosis, which is regulated by various metabolic and immune elements, might become a novel strategy for anti-tumor therapy. In this review, we will focus on the mechanism of ferroptosis and its interaction with cancer and tumor immune microenvironment, especially for the relationship between immune cells and ferroptosis. Also, we will discuss the latest preclinical progress of the collaboration between the ferroptosis-targeted drugs and immunotherapy, and the best potential conditions for their combined use. It will present a future insight on the possible value of ferroptosis in cancer immunotherapy.

An iron oxyhydroxide-based nanosystem sensitizes ferroptosis by a "Three-Pronged" strategy in breast cancer stem cells

The anti-apoptotic mechanism of breast cancer stem cells (BCSCs) makes it an obstacle to traditional apoptosis as the primary way of death. Ferroptosis is a recently reported mode of programmed cell death caused by the accumulation of iron-dependent lipid peroxidation (LPO) in cells. High dependence on iron makes BCSCs more sensitive to ferroptosis. However, the high level of the Prominin2 protein and high concentration of GSH in BCSCs make BCSCs able to efflux excess iron ions and clear LPO, which limits the therapeutic efficacy of ferroptosis in BCSCs. To overcome this obstacle, we designed a hyaluronic acid (HA)-coated siProminin2-loaded FeOOH nanoparticle (FeOOH/siPROM2@HA) to amplify ferroptosis. The FeOOH/siPROM2@HA is stable under physiologically neutral conditions but generates Fe³⁺ in an acidic microenvironment; meanwhile, the released siProminin2 inhibits its efflux, and then Fe³⁺ undergoes a redox reaction with endogenous GSH to produce Fe²⁺, which initiates the Fenton reaction-based ferroptosis by LPO elevation. Both in vitro and in vivo studies showed that these pH-sensitive NPs significantly inhibited tumor growth by downregulating glutathione peroxidase 4 (GPX4). Overall, this work demonstrates a "three-pronged" strategy for amplified ferroptotic therapy by simultaneously promoting intracellular iron, inhibiting iron efflux, and depleting GSH, which presents a potential strategy for CSC-targeted cancer therapy. STATEMENT OF SIGNIFICANCE: As the root of recurrence and metastasis, breast cancer stem cells (BCSCs) are resistant to traditional apoptotic death, so it is urgent to explore a new death mode for BCSCs. It has been reported that BCSCs are highly iron-dependent and, therefore, more sensitive to ferroptosis; however, the therapeutic efficacy is greatly limited by the overexpression of Prominin2 in BCSCs, which is correlated with resistance to ferroptosis by exocytosis of iron ions. In this work, we designed a hyaluronic acid-coated siProminin2-loaded FeOOH nano-drug (FeOOH/siPROM2@HA) to accelerate ferroptosis of BCSCs by simultaneously increasing iron ion content, inhibiting iron efflux, and scavenging GSH. This "three-pronged" strategy has significant implications for BCSC-targeted cancer therapy.

Membrane-camouflaged biomimetic nanoparticles as potential immunomodulatory solutions for sepsis: An overview

Sepsis is a life-threatening organ dysfunction due to dysregulated host responses induced by infection. The presence of immune disturbance is key to the onset and development of sepsis but has remarkably limited therapeutic options. Advances in biomedical nanotechnology have provided innovative approaches to rebalancing the host immunity. In particular, the technique of membrane-coating has demonstrated remarkable improvements to therapeutic nanoparticles (NPs) in terms of tolerance and stability while also improving their biomimetic performance for immunomodulatory purposes. This development has led to the emergence of using cell-membrane-based biomimetic NPs in treating sepsis-associated immunologic derangements. In this minireview, we present an overview of the recent advances in membrane-camouflaged biomimetic NPs, highlighting their multifaceted immunomodulatory effects in sepsis such as anti-infection, vaccination, inflammation control, reversing of immunosuppression, and targeted delivery of immunomodulatory agents.

Smart Metabolism Nanovalve Reprograms Cancer Energy Homeostasis for Maximizing Photometabolism Therapy

Better understanding of important roles of metabolic reprogramming in therapeutic resistance provides insights into advancing cancer treatment. Herein, we present a photoactive metabolic reprogramming strategy (termed as photometabolism therapy, PMT), in which photoregulation of mitochondria leads to cancer cell metabolic crisis, and consequently overcomes therapeutic resistance while improving treatment efficacy. In specific, a stimuli-responsive metabolism NanoValve is developed for improving cascade cancer therapy through blocking mitochondrial energy supply. NanoValve is composed of an onion-like architecture with a gold nanorod core, a mesoporous silica shell encapsulating photosensitizer chlorin e6 and oxygen-saturated perfluorocarbon, and cationic liposomal coating with MMP2-cleavable polyethylene glycol corona, which together initiate mitochondria-specific PMT. NanoValve selectively responds to tumor-overexpressed MMP2 and achieves size decrease and charge reversal, which consequently enhances tumor penetration, cancer cell uptake, endosome escape, and most critically, mitochondrial accumulation. Importantly, NanoValve-mediated phototherapy can strongly destruct mitochondrial energy metabolism, thereby minimizing therapy resistance. Particularly, perfluorocarbon supplies oxygen to further overcome the tumor hypoxia-associated therapeutic barrier and maximizes synergistic anticancer effects. In vivo studies show that NanoValve can effectively eliminate tumors without side effects, thereby dramatically prolonging the survival of tumor-bearing mice. Thus, NanoValve provides a modular PMT approach and has the potential of advancing the treatment of malignancy.