Biodegradable Nanoprodrugs: "Delivering" ROS to Cancer Cells for Molecular Dynamic Therapy

A universal nanoreactor triggering butterfly effect for encouraging Fenton/Fenton-like reactions and chemodynamic therapy

Fenton/Fenton-like reaction induced chemical dynamic therapy (CDT) has been widely recognized in tumor therapy. Due to the low efficiency of conversion from high-valent metal ions (M(n+1)+) to low-valent ions (Mn+) in the Fenton/Fenton-like catalytic process, enhancing the conversion efficiency safely and effectively would create a great opportunity for the clinical application of CDT. In the study, a universal nanoreactor (NR) consisting of liposome (Lip), tumor cell membrane (CM), and bis(2,4,5-trichloro-6-carboxyphenyl) oxalate (CPPO) is developed to tackle this challenge. The CPPO was first discovered to decompose under weak acidity and H2O2 conditions to generate carboxylic acids (R'COOH) and alcohols (R'OH) with reducibility, which will reduce M(n+1)+ to Mn+ and magnify the effect of CDT. Furthermore, glucose oxidase (GOx) was introduced to decompose glucose in tumor and generate H2O2 and glucose acid, which promote the degradation of CPPO, further strengthening the efficiency of CDT, leading to a butterfly effect. This demonstrated that the butterfly effect triggered by NR and GOx encourages Fenton/Fenton-like reactions of Fe3O4 and MoS2, thereby enhancing the tumor inhibition effect. The strategy of combining GOx and CPPO to strengthen the Fenton/Fenton-like reaction is a universal strategy, which provides a new and interesting perspective for CPPO in the application of CDT, reflecting the exquisite integration of Fenton chemistry and catalytic medicine.

A Fe2O3/CNx cascade nanoreactor with dual-enzyme-mimetic activities for cancer hypoxia relief to amplify chemo/photodynamic therapy

Reactive oxygen species (ROS)-mediated therapeutic strategies, including chemodynamic therapy (CDT), photodynamic therapy (PDT), and their combination, are effective for treating cancer. Developing a nanoreactor with combined functions of catalase (CAT) and peroxidase (POD) that can simultaneously convert excess H2O2 in tumors into O2 required for type II PDT and hydroxyl radicals (•OH) for CDT can help achieve combined therapy. Here, we reported on a safe Fe2O3/CNx nanoreactor with dual enzyme simulated activity, in which CNx sheet was the carrier and reducing agent to convert Fe2O3 to Fe2+. After modified by MgO2 and photosensitizer Ce6, MgO2-Fe2O3/CNx-Ce6 (MFCC) platform integrated multiple functions, including photosensitizer delivery, compensated H2O2 continuous supply, relieve of hypoxia, generation of •OH and consumption of GSH into a single formulation. Under 660 nm irradiation for 4 min, MFCC actives more ROS to conduct PDT/CDT, leading to the remarkable reduced survival rate of breast cancer cells to 14 %. Due to the enhanced permeability and retention (EPR) effect, MFCC can retain and accumulate at the tumor site of mice for a longer period that inhibit the expression of tumor angiogenic factors, suppress tumor neovascularization, and suppress the proliferation and growth of tumor cells.

Advances in H2O2-supplying materials for tumor therapy: synthesis, classification, mechanisms, and applications

Hydrogen peroxide (H2O2) as a reactive oxygen species produced by cellular metabolism can be used in antitumor therapy. However, the concentration of intracellular H2O2 limits its application. Some materials could enhance the concentration of intracellular H2O2 to strengthen antitumor therapy. In this review, the recent advances in H2O2-supplying materials in terms of promoting intracellular H2O2 production and exogenous H2O2 supply are summarized. Then the mechanism of H2O2-supplying materials for tumor therapy is discussed from three aspects: reconstruction of the tumor hypoxia microenvironment, enhancement of oxidative stress, and the intrinsic anti-tumor ability of H2O2-supplying materials. In addition, the application of H2O2-supplying materials for tumor therapy is discussed. Finally, the future of H2O2-supplying materials is presented. This review aims to provide a novel idea for the application of H2O2-supplying materials in tumor therapy.

Nanomaterial-assisted oncolytic bacteria in solid tumor diagnosis and therapeutics

Cancer presents a formidable challenge in modern medicine due to the intratumoral heterogeneity and the dynamic microenvironmental niche. Natural or genetically engineered oncolytic bacteria have always been hailed by scientists for their intrinsic tumor-targeting and oncolytic capacities. However, the immunogenicity and low toxicity inevitably constrain their application in clinical practice. When nanomaterials, characterized by distinctive physicochemical properties, are integrated with oncolytic bacteria, they achieve mutually complementary advantages and construct efficient and safe nanobiohybrids. In this review, we initially analyze the merits and drawbacks of conventional tumor therapeutic approaches, followed by a detailed examination of the precise oncolysis mechanisms employed by oncolytic bacteria. Subsequently, we focus on harnessing nanomaterial-assisted oncolytic bacteria (NAOB) to augment the effectiveness of tumor therapy and utilizing them as nanotheranostic agents for imaging-guided tumor treatment. Finally, by summarizing and analyzing the current deficiencies of NAOB, this review provides some innovative directions for developing nanobiohybrids, intending to infuse novel research concepts into the realm of solid tumor therapy.

Strategies for the development of metalloimmunotherapies

Metal ions play crucial roles in the regulation of immune pathways. In fact, metallodrugs have a long record of accomplishment as effective treatments for a wide range of diseases. Here we argue that the modulation of interactions of metal ions with molecules and cells involved in the immune system forms the basis of a new class of immunotherapies. By examining how metal ions modulate the innate and adaptive immune systems, as well as host-microbiota interactions, we discuss strategies for the development of such metalloimmunotherapies for the treatment of cancer and other immune-related diseases.

Cascade Self-Generation of Carbon Monoxide Triggered by Photoinduced Holes for Efficient Hypoxic Tumors Therapy

It still remains challenging to design multifunctional therapeutic reagents for effective cancer therapy under a unique tumor microenvironment including insufficient endogenous H2O2 and O2, low pH, and a high concentration of glutathione (GSH). In this work, a CO-based phototherapeutic system triggered by photogenerated holes, which consisted of ionic liquid (IL), the CO prodrug Mn2(CO)10, and iridium(III) porphyrin (IrPor) modified carbonized ZIF-8-doped graphitic carbon nitride nanocomposite (IL/ZCN@Ir(CO)), was designed for cascade hypoxic tumors. Upon light irradiation, the photogenerated holes on IL/ZCN@Ir(CO) oxidize water into H2O2, which subsequently induces Mn2(CO)10 to release CO. Meanwhile, IrPor can convert H2O2 to hydroxyl radical (•OH) and subsequent singlet oxygen (1O2), which further triggers CO release. Moreover, the degraded MnO2 shows activity for glutathione (GSH) depletion and mimics peroxidase, leading to GSH reduction and •OH production in tumors. Thus, this strategy can in situ release high concentrations of CO and reactive oxygen species (ROS) and deplete GSH to efficiently induce cell apoptosis under hypoxic conditions, which has a high inhibiting effect on the growth of tumors, offering an attractive strategy to amplify CO and ROS generation to meet therapeutic requirements in cancer treatment.

Highly Effective Pyroelectric Catalysis for Simultaneous Tumor-Targeted Dynamic Therapy and Gentle Photothermal Therapy by Oxygen-Vacancy-Rich CeO2-BaTiO3 Nanorods

Pyroelectric nanostructures can effectively generate temperature-mediated reactive oxygen species (ROS) through the pyroelectric effect, providing promise for treating hypoxic tumors; and therefore, the synergistic application of photothermal therapy (PTT) and pyroelectric dynamic therapy (PEDT) presents an intriguing approach for cancer therapy. However, this method still faces challenges in improving pyroelectric catalysis and achieving precise tumor localization. In this study, a nano-heterojunction based on CeO2-BaTiO3 nanorods (IR1061@PCBNR) is reported, which exhibits highly effective pyroelectric catalysis for simultaneous tumor-targeted dynamic therapy and gentle photothermal therapy through the utilization of the rich oxygen vacancies. The oxygen vacancies create active sites that facilitate the migration of pyroelectrically-induced charge carriers, improving charge separation and ROS generation. IR1061@PCBNR also demonstrates high tumor penetration; while, minimizing damage to normal cells. This precise nanomedicine strategy holds great potential for advancing dynamic cancer therapies by overcoming the limitations of conventional approaches.

Tumour-microenvironment-responsive Na2S2O8 nanocrystals encapsulated in hollow organosilica-metal-phenolic networks for cycling persistent tumour-dynamic therapy

Traditional tumour-dynamic therapy still inevitably faces the critical challenge of limited reactive oxygen species (ROS)-generating efficiency due to tumour hypoxia, extreme pH condition for Fenton reaction, and unsustainable mono-catalytic reaction. To fight against these issues, we skilfully develop a tumour-microenvironment-driven yolk-shell nanoreactor to realize the high-efficiency persistent dynamic therapy via cascade-responsive dual cycling amplification of •SO4 -/•OH radicals. The nanoreactor with an ultrahigh payload of free radical initiator is designed by encapsulating the Na2S2O8 nanocrystals into hollow tetra-sulphide-introduced mesoporous silica (HTSMS) and afterward enclosed by epigallocatechin gallate (EG)-Fe(II) cross-linking. Within the tumour microenvironment, the intracellular glutathione (GSH) can trigger the tetra-sulphide cleavage of nanoreactors to explosively release Na+/S2O8 2 - /Fe2+ and EG. Then a sequence of cascade reactions will be activated to efficiently generate •SO4 - (Fe2+-catalyzed S2O8 2 - oxidation), proton (•SO4 --catalyzed H2O decomposition), and •OH (proton-intensified Fenton oxidation). Synchronously, the oxidation-generated Fe3+ will be in turn recovered into Fe2+ by excessive EG to circularly amplify •SO4 -/•OH radicals. The nanoreactors can also disrupt the intracellular osmolarity homeostasis by Na+ overload and weaken the ROS-scavenging systems by GSH exhaustion to further amplify oxidative stress. Our yolk-shell nanoreactors can efficiently eradicate tumours via multiple oxidative stress amplification, which will provide a perspective to explore dynamic therapy.

Nanocatalysts for modulating antitumor immunity: fabrication, mechanisms and applications

Immunotherapy harnesses the inherent immune system in the body to generate systemic antitumor immunity, offering a promising modality for defending against cancer. However, tumor immunosuppression and evasion seriously restrict the immune response rates in clinical settings. Catalytic nanomedicines can transform tumoral substances/metabolites into therapeutic products in situ, offering unique advantages in antitumor immunotherapy. Through catalytic reactions, both tumor eradication and immune regulation can be simultaneously achieved, favoring the development of systemic antitumor immunity. In recent years, with advancements in catalytic chemistry and nanotechnology, catalytic nanomedicines based on nanozymes, photocatalysts, sonocatalysts, Fenton catalysts, electrocatalysts, piezocatalysts, thermocatalysts and radiocatalysts have been rapidly developed with vast applications in cancer immunotherapy. This review provides an introduction to the fabrication of catalytic nanomedicines with an emphasis on their structures and engineering strategies. Furthermore, the catalytic substrates and state-of-the-art applications of nanocatalysts in cancer immunotherapy have also been outlined and discussed. The relationships between nanostructures and immune regulating performance of catalytic nanomedicines are highlighted to provide a deep understanding of their working mechanisms in the tumor microenvironment. Finally, the challenges and development trends are revealed, aiming to provide new insights for the future development of nanocatalysts in catalytic immunotherapy.

Nanocatalytic theranostics with intracellular mutual promotion for ferroptosis and chemo-photothermal therapy

The reactive oxygen species (ROS) produced through the Fenton reaction, induces lipid peroxide (LPO), causing cellular structural damage and ultimately triggering ferroptosis. However, the generation of ROS in the tumor microenvironment (TME) is limited by the catalytic efficiency of the Fenton reaction. Herein, a novel hollow mesoporous silica nanoparticle (HMSN) combined with multi-metal sulfide-doped mesoporous silica nanocatalyzers (NCs) was developed, namely MxSy-HMSN NCs (M represents Cu Mn and Fe, S denotes sulfur). The MxSy-HMSN can dramatically enhanced the ferroptosis by: (1) facilitating the conversion of H2O2 to ·OH through Fenton or Fenton-like reactions through co-catalysis; (2) weakening ROS scavenging systems by depleting the over expressed glutathione (GSH) in TME; (3) providing exceptional photothermal therapy to augment ferroptosis. The MxSy-HMSN can also act as smart cargos for anticancer drug-doxorubicin (DOX). The release of DOX is responsive to GSH/pH/Near-infrared Light (NIR) irradiation at the tumor lesion, significantly improving therapeutic outcomes while minimizing side effects. Additionally, the MxSy-HMSN has demonstrated excellent magnetic resonance imaging (MRI) potential. This smart MxSy-HMSN offer a synergetic approach combining ferroptosis with chemo-photothermal therapy and magnetic resonance imaging (MRI) diagnose, which could be an informative guideline for the design of future NCs.

3D-Printed Magnesium Peroxide-Incorporated Scaffolds with Sustained Oxygen Release and Enhanced Photothermal Performance for Osteosarcoma Multimodal Treatments

The hypoxic microenvironment in osteosarcoma inevitably compromises the antitumor effect and local bone defect repair, suggesting an urgent need for sustained oxygenation in the tumor. The currently reported oxygen-releasing materials have short oxygen-releasing cycles, harmful products, and limited antitumor effects simply by improving hypoxia. Therefore, the PCL/nHA/MgO2/PDA-integrated oxygen-releasing scaffold with a good photothermal therapy effect was innovatively constructed in this work to achieve tumor cell killing and bone regeneration functions simultaneously. The material distributes MgO2 powder evenly on the scaffold material through 3D printing technology and achieves the effect of continuous oxygen release (more than 3 weeks) through its slow reaction with water. The in vitro and in vivo results also indicate that the scaffold has good biocompatibility and sustained-release oxygen properties, which can effectively induce the proliferation and osteogenic differentiation of bone mesenchymal stem cells, achieving excellent bone defect repair. At the same time, in vitro cell experiments and subcutaneous tumorigenesis experiments also confirmed that local oxygen supply can promote osteosarcoma cell apoptosis, inhibit proliferation, and reduce the expression of heat shock protein 60, thereby enhancing the photothermal therapy effect of polydopamine and efficiently eliminating osteosarcoma. Taken together, this integrated functional scaffold provides a unique and efficient approach for antitumor and tumor-based bone defect repair for osteosarcoma treatment.

Robust and Multifunctional Therapeutic Nanoparticles against Peritonitis-Induced Sepsis

Apart from bacterial growth and endotoxin generation, the excessive production of reactive radicals linked with sepsis also has a substantial impact on triggering an inflammatory response and further treatment failure. Hence, the rational design and fabrication of robust and multifunctional nanoparticles (NPs) present a viable means of overcoming this dilemma. In this study, we used antibiotic polymyxin B (PMB) and antioxidant natural polyphenolic protocatechualdehyde (PCA) to construct robust and multifunctional NPs for sepsis treatment, leveraging the rich chemistries of PCA. The PMB release profile from the NPs demonstrated pH-responsive behavior, which allowed the NPs to exhibit effective bacterial killing and radical scavenging properties. Data from in vitro cells stimulated with H2O2 and lipopolysaccharide (LPS) showed the multifunctionalities of NPs, including intracellular reactive oxygen species (ROS) scavenging, elimination of the bacterial toxin LPS, inhibiting macrophage M1 polarization, and anti-inflammation capabilities. Additionally, in vivo studies further demonstrated that NPs could increase the effectiveness of sepsis treatment by lowering the bacterial survival ratio, the expression of the oxidative marker malondialdehyde (MDA), and the expression of inflammatory cytokine TNF-α. Overall, this work provides ideas of using those robust and multifunctional therapeutic NPs toward enhanced sepsis therapy efficiency.

Neutrophil Function Conversion Driven by Immune Switchpoint Regulator against Diabetes-Related Biofilm Infections

Reinforced biofilm structures and dysfunctional neutrophils induced by excessive oxidative stress contribute to the refractoriness of diabetes-related biofilm infections (DRBIs). Herein, in contrast to traditional antibacterial therapies, an immune switchpoint-driven neutrophil immune function conversion strategy based on a deoxyribonuclease I loaded vanadium carbide MXene (DNase-I@V2 C) nanoregulator is proposed to treat DRBIs via biofilm lysis and redirecting neutrophil functions from NETosis to phagocytosis in diabetes. Owing to its intrinsic superoxide dismutase/catalase-like activities, DNase-I@V2 C effectively scavenges reactive oxygen species (ROS) in a high oxidative stress microenvironment to maintain the biological activity of DNase-I. By increasing the depth of biofilm penetration of DNase-I, DNase-I@V2 C thoroughly degrades extracellular DNA and neutrophil extracellular traps (NETs) in extracellular polymeric substances, thus breaking the physical barrier of biofilms. More importantly, as an immune switchpoint regulator, DNase-I@V2 C can skew neutrophil functions from NETosis toward phagocytosis by intercepting ROS-NE/MPO-PAD4 and activating ROS-PI3K-AKT-mTOR pathways in diabetic microenvironment, thereby eliminating biofilm infections. Biofilm lysis and synergistic neutrophil function conversion exert favorable therapeutic effects on biofilm infections in vitro and in vivo. This study serves as a proof-of-principle demonstration of effectively achieving DRBIs with high therapeutic efficacy by regulating immune switchpoint to reverse neutrophil functions.

pH-Responsive Multifunctional Nanoplatforms with Reactive Oxygen Species-Controlled Release of CO for Enhanced Oncotherapy

Recently, various nanomaterials have drawn increasing attention for enhanced tumor therapy. However, a lack of tumor uptake and insufficient generation of cytotoxic agents have largely limited the antitumor efficacy in vivo. Herein, a multifunctional nanoplatform (IL@CPPor(CO)) was constructed with pH-responsive copper peroxide nanoparticles (CPNP) that are capable of self-supplying H2O2, a radical-sensitive carbonic oxide (CO) donor (Fe3(CO)12), photosensitizer Iridium(III) meso-tetra (N-methyl-4-pyridyl)porphyrin pentachloride (IrPor), and ionic liquid (IL) for enhanced oncotherapy. Under acidic conditions, the CPNP could decompose to release H2O2 and Cu2+. The concomitant generation of H2O2 could efficiently trigger Fe3(CO)12 to release the CO in situ. On the other hand, Cu2+ possesses both glutathione depletion and Fenton-like properties. In addition, IrPor has both peroxidase-like activity and photosensitizer properties to produce reactive oxygen species (ROS) in tumors. The released ROS could trigger the rapid intracellular release of CO. More importantly, released CO and ROS could promote cell apoptosis and improve the therapeutic efficacy. Moreover, due to the pH-dependent ROS generation property, the IL@CPPor(CO) exhibited high tumor accumulation, low toxicity, and good biocompatibility, which enabled effective tumor growth inhibition with minimal side effects in vivo. This work provides a novel multifunctional nanoplatform that combined photodynamic therapy with CDT and CO to improve therapeutic efficacy.

Time-Sequential and Multi-Functional 3D Printed MgO2 /PLGA Scaffold Developed as a Novel Biodegradable and Bioactive Bone Substitute for Challenging Postsurgical Osteosarcoma Treatment

Osteosarcoma (OS) is the most commonly occurring primary bone malignant tumor. The clinical postsurgical OS treatment faces big challenges for the staged therapeutic requirements of early anti-tumor, anti-bacterial, and long-lasting osteogenesis. Herein, multi-functional bioactive scaffolds with time-sequential functions of preventing tumor recurrence, inhibiting bacterial infection, and promoting bone defect repair are designed as a novel strategy. Nanocomposite scaffold magnesium peroxide (MgO2 )/poly (lactide-co-glycolide) is prepared by low-temperature 3D printing for controllable releasing magnesium ions (Mg2+ ) and reactive oxygen species in a time-sequential manner. The scaffold with 20 wt% MgO2 (20MP) is verified with desired mechanical properties, as well as exhibits staged release behavior of bioactive elements with hydrogen peroxide (H2 O2 ) release for the first 3 weeks, and long-lasting Mg2+ release for 12 weeks. The released H2 O2 initiates chemodynamic therapy to induce apoptosis and ferroptosis in tumor cells, along with activating the anticancer immune microenvironment by M1 polarization of macrophages. The released Mg2+ subsequently enhances bone repair by activating the Wnt3a/GSK-3β/β-catenin signaling pathway to promote osteogenic differentiation of bone marrow mesenchymal stem cells and create osteopromotive immune microenvironment by M2 polarization of macrophages. In conclusion, the multi-functional 20MP scaffold demonstrates time-sequential therapeutic properties as an innovative strategy for OS-associated bone defect treatment.

Pathologically catalyzed physical coating restores the intestinal barrier for inflammatory bowel disease therapy

Intestinal epithelia impairment of inflammatory bowel disease (IBD) leads to the leakage of bacteria and antigens and the consequent persistent immune imbalance. Restoring the epithelial barrier is a promising therapeutic target but lacks effective and safe clinical interventions. By identifying the catalase (CAT) presence in the IBD pathological environment, we herein develop a CAT-catalyzed pathologically coating on the damaged epithelial barrier to inhibit intestinal leakage for IBD therapy. With the codelivery of CaO2 (a CAT substrate) and dopamine, the nanosystem can enable CAT-catalyzed oxygen (O2) production and in-situ polymerization of dopamine and then yield a thin and integrative polydopamine (PDA) coating on the intestinal barrier due to the highly adhesive property of PDA. In vivo study demonstrates that PDA coating provides not only a protective barrier by restricting intestinal leakage but also a favorable anti-inflammation effect. Beyond drug management, this work provides a physical repair strategy via catalyzed coating for IBD therapy.

Synergistic therapeutic effect of nanomotors triggered by Near-infrared light and acidic conditions of tumor

Due to the complexity of tumors, multimodal therapy for them has always been of concern to researchers. How to design a multifunctional drug nanoplatform with cascade effect and capable of responding to specific stimuli in the tumor microenvironment is the key to achieve efficient multimodal synergistic therapy of cancer. Here, we prepare a kind of GNRs@SiO2@PDA-CuO2-l-Arg (GSPRs-CL) nanomotors for systematic treatment of tumor. First, under near-infrared (NIR) irradiation, GSPRs-CL can generate heat and exhibit excellent photothermal therapy effect. Then under acidic conditions, CuO2 can be decomposed to release Cu2+ and generate H2O2, which not only complemented the limited endogenous H2O2 in cells, but also further triggered Fenton-like reaction, converting H2O2 into •OH to kill cancer cells, thereby achieving chemodynamic therapy. Furthermore, both endogenous and exogenous H2O2 can release nitric oxide (NO) in response to the occurrence of l-Arg of nanomotors to enhance gas therapy. In addition, as a dual-mode drive, NIR laser and NO can promote the penetration ability of nanomotors at tumor sites. The experimental results in vivo show that the drug nanoplatform had good biosafety and significant tumor killing effect triggered by NIR light and acidic conditions of tumor. It provide a promising strategy for the development of advanced drug nanoplatform for cancer therapy.

Strategies to engineer various nanocarrier-based hybrid catalysts for enhanced chemodynamic cancer therapy

Chemodynamic therapy (CDT) is a newly developed cancer-therapeutic modality that kills cancer cells by the highly toxic hydroxyl radical (˙OH) generated from the in situ triggered Fenton/Fenton-like reactions in an acidic and H2O2-overproduced tumor microenvironment (TME). By taking the advantage of the TME-activated catalytic reaction, CDT enables a highly specific and minimally-invasive cancer treatment without external energy input, whose efficiency mainly depends on the reactant concentrations of both the catalytic ions and H2O2, and the reaction conditions (including pH, temperature, and amount of glutathione). Unfortunately, it suffers from unsatisfactory therapy efficiency for clinical application because of the limited activators (i.e., mild acid pH and insufficient H2O2 content) and overexpressed reducing substance in TME. Currently, various synergistic strategies have been elaborately developed to increase the CDT efficiency by regulating the TME, enhancing the catalytic efficiency of catalysts, or combining with other therapeutic modalities. To realize these strategies, the construction of diverse nanocarriers to deliver Fenton catalysts and cooperatively therapeutic agents to tumors is the key prerequisite, which is now being studied but has not been thoroughly summarized. In particular, nanocarriers that can not only serve as carriers but are also active themselves for therapy are recently attracting increasing attention because of their less risk of toxicity and metabolic burden compared to nanocarriers without therapeutic capabilities. These therapy-active nanocarriers well meet the requirements of an ideal therapy system with maximum multifunctionality but minimal components. From this new perspective, in this review, we comprehensively summarize the very recent research progress on nanocarrier-based systems for enhanced CDT and the strategies of how to integrate various Fenton agents into the nanocarriers, with particular focus on the studies of therapy-active nanocarriers for the construction of CDT catalysts, aiming to guide the design of nanosystems with less components and more functionalities for enhanced CDT. Finally, the challenges and prospects of such a burgeoning cancer-theranostic modality are outlooked to provide inspirations for the further development and clinical translation of CDT.

Nanoscale Metal-Organic Frameworks Combined with Metal Nanoparticles and Metal Oxide/Peroxide to Relieve Tumor Hypoxia for Enhanced Photodynamic Therapy

Photodynamic therapy (PDT) is a clinically approved noninvasive tumor therapy that can selectively kill malignant tumor cells, with promising use in the treatment of various cancers. PDT is typically composed of three important parts: the specific wavelength of light, photosensitizer (PS), and oxygen. With the progressing investigation on PDT treatment, the most recent attention has focused on improving photodynamic efficiency. Tumor hypoxia has always been a critical factor hindering the efficacy of PDT. Nanoscale metal-organic frameworks (nMOF), the fourth generation of PS, present great potential in photodynamic therapy. In particular, nMOF combined with metal nanoparticles and metal oxide/peroxide has demonstrated unique properties for enhanced PDT. The metal and metal oxide nanoparticles can catalyze H2O2 to generate oxygen or automatically produces oxygen, alleviating the hypoxia and improving the photodynamic efficiency. Metal peroxide nanoparticles can spontaneously produce oxygen in water or under acidic conditions. Therefore, this Review summarizes the recent development of nMOF combined with metal nanoparticles (platinum nanoparticles and gold nanoparticles) and metal oxide/peroxide (manganese dioxide, ferric oxide, cerium oxide, calcium peroxide, and magnesium peroxide) for enhanced photodynamic therapy by alleviating tumor hypoxia. Finally, future perspectives of nMOF combined nanomaterials in PDT are put forward.

Reactive oxygen species for therapeutic application: Role of piezoelectric materials

This perspective article emphasizes the significant role of reactive oxygen species (ROS) in in vivo remedial therapy of various diseases and complications, capitalizing on their potential reactivity. Among the various influencers, herein, piezoelectric materials driven ROS generation activity is primarily considered. Intrinsic non-centrosymmetry of piezoelectric materials makes them suitable for distinct dipole formation in the presence of external mechanical stimuli. Such characteristics prompt the positioning of opposite charged carriers to execute associated redox transformations that effectively participate to generate ROS in the aqueous media of the cell cytoplasm, organelles and nucleus. The immense reactivity of piezoelectric material driven ROS is fostered to terminate cellular toxicity or curtail tumor cell growth, due to their higher specificity. This perspective considers the conjugated performance of piezoelectric materials and ultrasound which can remotely generate electrical charges that promote ROS production for therapeutic application. In particular, a substantial synopsis is provided for the remedial activity of numerous piezocatalytic materials in tumor cell apoptosis, antibacterial treatment, dental care and neurological disorders. Subsequently, the report precisely demonstrates the methods involving various spectrophotometric approaches for the analysis of the ROS. Finally, the key challenges of piezoelectric material-based therapy are discussed and systematic future progress is outlined.

The Application of Biomedicine in Chemodynamic Therapy: From Material Design to Improved Strategies

Chemodynamic therapy (CDT) has garnered significant interest as an innovative approach for cancer treatment, owing to its notable tumor specificity and selectivity, minimal systemic toxicity and side effects, and absence of the requirement for field stimulation during treatment. This treatment utilizes nanocatalytic medicines containing transitional metals to release metal ions within tumor cells, subsequently initiating Fenton and Fenton-like reactions. These reactions convert hydrogen peroxide (H2O2) into hydroxyl radical (•OH) specifically within the acidic tumor microenvironment (TME), thereby inducing apoptosis in tumor cells. However, insufficient endogenous H2O2, the overexpressed reducing substances in the TME, and the weak acidity of solid tumors limit the performance of CDT and restrict its application in vivo. Therefore, a variety of nanozymes and strategies have been designed and developed in order to potentiate CDT against tumors, including the application of various nanozymes and different strategies to remodel TME for enhanced CDT (e.g., increasing the H2O2 level in situ, depleting reductive substances, and lowering the pH value). This review presents an overview of the design and development of various nanocatalysts and the corresponding strategies employed to enhance catalytic drug targeting in recent years. Additionally, it delves into the prospects and obstacles that lie ahead for the future advancement of CDT.

Radially Electrospun Fibrous Membrane Incorporated with Copper Peroxide Nanodots Capable of Self-Catalyzed Chemodynamic Therapy for Angiogenesis and Healing Acceleration of Diabetic Wounds

Vascular dysfunction severely hinders the healing process of diabetic wounds. Therefore, a radially structured fibrous membrane was fabricated through electrospinning by using a polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) mixed solution containing copper peroxide nanoparticles (CPs) as the chemodynamic therapy (CDT) agents, aiming to simultaneously accelerate tissue regeneration and angiogenesis. The fabricated membrane allowed for the in situ H₂O₂ generation activated by the acidic diabetic microenvironment and the subsequent Fenton-type reactions to realize 99.4% elimination against Staphylococcus aureus. Besides, the released Cu²⁺ ions significantly enhanced the expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in human umbilical vein endothelial cells (HUVECs), and they showed enhanced in vitro angiogenesis. Interestingly, the CP-embedded membrane also guided cell spreading and orientated migration of L929 fibroblasts along the fiber distribution through the radially aligned topology. The in vivo implantation indicated that the raidally structured membrane modified by CPs not only dramatically accelerated wound healing of diabetic Sprague-Dawley (SD) rats in 14 days but also promoted angiogenesis in wound sites. The combination of the in situ CDT with the radially structured morphology of the functional membrane is highly promising in applications to promote diabetic wound healing through anti-infection and revascularization.

In Situ Fabrication of Silver Peroxide Hybrid Ultrathin Co-Based Metal-Organic Frameworks for Enhanced Chemodynamic Antibacterial Therapy

Bacterial-induced infectious diseases have always caused an unavoidable problem and lead to an increasing threat to human health. Hence, there is an urgent need for effective antibacterial strategies to treat infectious diseases. Current methods are often ineffective and require large amounts of hydrogen peroxide (H₂O₂), with harmful effects on normal healthy tissue. Chemodynamic therapy (CDT) provides an ideal infection microenvironment (IME)-activated paradigm to tackle bacterial-related diseases. To take full advantage of the specificity of IME and enhanced CDT for wounds with bacterial infection, we have designed an intelligent antibacterial system that exploits nanocatalytic ZIF-67@Ag₂O₂ nanosheets. In this system, silver peroxide nanoparticles (Ag₂O₂ NPs) were grown on ultrathin zeolitic imidazolate framework-67 (ZIF-67) nanosheets by in situ oxidation, and then, ZIF-67@Ag₂O₂ nanosheets with the ability to self-generate H₂O₂ were triggered by the mildly acidic environment of IME. Lamellar ZIF-67 nanosheets were shown to rapidly degrade and release Co²⁺, allowing the conversion of less reactive H₂O₂ into the highly toxic reactive oxygen species hydroxyl radicals (^•OH) for enhanced CDT antibacterial properties. In vivo results revealed that the ZIF-67@Ag₂O₂ nanosheet system exhibits excellent antibacterial performance against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The proposed hybrid strategy demonstrates a promising therapeutic strategy to enable antibacterial agents with IME-responsive nanocatalytic activity to circumvent antibiotic resistance against bacterial infections.

Calcination-controlled performance optimization of iron-vanadium bimetallic oxide nanoparticles for synergistic tumor therapy

Calcination has been widely demonstrated as a favorable protocol for producing various inorganic nanomaterials for tumor therapy. However, little attention has been paid to its effect on the biotherapeutic efficacy of inorganic nanomaterials. Herein, we compare the effects of different calcination atmospheres on the therapeutic efficacy of Fe-V-O (FVO) nanomaterials. We find that compared with FVO nanomaterials synthesized by calcination in air, those prepared by argon calcination have a lower metallic valence state and a higher near-infrared light absorption capacity, hence resulting in significantly better biosafety and higher chemodynamic therapy (CDT)/photothermal therapy (PTT) efficacy. This study demonstrates that the therapeutic efficacy of inorganic nanomaterials can be optimized by employing different thermal treatment atmospheres, which provides new insights into the development of efficient anti-tumor agents.

Multifunctional nanoplatforms application in the transcatheter chemoembolization against hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has the sixth-highest new incidence and fourth-highest mortality worldwide. Transarterial chemoembolization (TACE) is one of the primary treatment strategies for unresectable HCC. However, the therapeutic effect is still unsatisfactory due to the insufficient distribution of antineoplastic drugs in tumor tissues and the worsened post-embolization tumor microenvironment (TME, e.g., hypoxia and reduced pH). Recently, using nanomaterials as a drug delivery platform for TACE therapy of HCC has been a research hotspot. With the development of nanotechnology, multifunctional nanoplatforms have been developed to embolize the tumor vasculature, creating conditions for improving the distribution and bioavailability of drugs in tumor tissues. Currently, the researchers are focusing on functionalizing nanomaterials to achieve high drug loading efficacy, thorough vascular embolization, tumor targeting, controlled sustained release of drugs, and real-time imaging in the TACE process to facilitate precise embolization and enable therapeutic procedures follow-up imaging of tumor lesions. Herein, we summarized the recent advances and applications of functionalized nanomaterials based on TACE against HCC, believing that developing these functionalized nanoplatforms may be a promising approach for improving the TACE therapeutic effect of HCC.

Reactive oxygen species-upregulating nanomedicines towards enhanced cancer therapy

Reactive oxygen species (ROS) play a crucial role in physiological and pathological processes, emerging as a therapeutic target in cancer. Owing to the high concentration of ROS in solid tumor tissues, ROS-based treatments, such as photodynamic therapy and chemodynamic therapy, and ROS-responsive drug delivery systems have been widely explored to powerfully and specifically suppress tumors. However, their anticancer efficacy is still hampered by the heterogeneous ROS levels, and thus comprehensively upregulating the ROS levels in tumor tissues can ensure an enhanced therapeutic effect, which can further sensitize and/or synergize with other therapies to inhibit tumor growth and metastasis. Herein, we review the recently emerging drug delivery strategies and technologies for increasing the H₂O₂, ˙OH, ¹O₂, and ˙O₂^- concentrations in cancer cells, including the efficient delivery of natural enzymes, nanozymes, small molecular biological molecules, and nanoscale Fenton-reagents and semiconductors and neutralization of intracellular antioxidant substances and localized input of mechanical and electromagnetic waves (such as ultrasound, near infrared light, microwaves, and X-rays). The applications of these ROS-upregulating nanosystems in enhancing and synergizing cancer therapies including chemotherapy, chemodynamic therapy, phototherapy, and immunotherapy are surveyed. In addition, we discuss the challenges of ROS-upregulating systems and the prospects for future studies.

A Forward Vision for Chemodynamic Therapy: Issues and Opportunities

Since the insight to fuse Fenton chemistry and nanomedicine into cancer therapy, great signs of progress have been made in the field of chemodynamic therapy (CDT). However, the exact mechanism of CDT is obscured by the unique tumor chemical environment and inevitable nanoparticle-cell interactions, thus impeding further development. In this Scientific Perspective, the significance of CDT is clarified, the complex mechanism is deconstructed into primitive chemical and biological interactions, and the mechanism research directions based on the chemical kinetics and biological signaling pathways are discussed in detail. Moreover, beneficial outlooks are presented to enlighten the evolution of next-generation CDT. Hopefully, this Scientific Perspective can inspire new ideas and advances for CDT and provide a reference for breaking down the interdisciplinary barriers in the field of nanomedicine.

O2-Supplying Nanozymes Alleviate Hypoxia and Deplete Lactate to Eliminate Tumors and Activate Antitumor Immunity

Direct hypoxia alleviation and lactate depletion in the tumor microenvironment (TME) are promising for effective cancer therapy but still very challenging. To address this challenge, the current research directly reshapes the TME for inhibiting tumor growth and activating the antitumor immunity using a drug-free nanozyme. Herein, the acid-sensitive nanozymes were constructed based on peroxidized layered double hydroxide nanoparticles for O₂ self-supply and self-boosted lactate depletion. The coloading of partially cross-linked catalase and lactate oxidase enabled the acid-sensitive nanozymes to promote three reactions, that is, (1) H₂O₂ generation from MgO₂ hydrolysis (30% at pH 7.4 vs 63% at pH 6.0 in 8 h); (2) O₂ generation from H₂O₂ (12% at pH 7.4 vs 21% at pH 6.0 in 2 h); and (3) lactate depletion by in situ generated O₂ (50% under hypoxia vs 75% under normoxia in 24 h in vitro) in parallel or tandem. These promoted reactions together efficiently induced colon cancer cell apoptosis under the hypoxic conditions, significantly inhibited tumor growth (>95%), and suppressed distant tumor growth upon seven administrations in every 3 days and moreover transformed the immunosuppressive tumor into "hot" one in the colon tumor-bearing mouse model. This is the first example for a nanozyme that supplies sufficient O₂ for hypoxia relief and lactate depletion, thus providing a new insight into drug-free nanomaterial-mediated TME-targeted cancer therapy.

Targeting Tumor Microenvironment by Metal Peroxide Nanoparticles in Cancer Therapy

Solid tumors have a unique tumor microenvironment (TME), which includes hypoxia, low acidity, and high hydrogen peroxide and glutathione (GSH) levels, among others. These unique factors, which offer favourable microenvironments and nourishment for tumor development and spread, also serve as a gateway for specific and successful cancer therapies. A good example is metal peroxide structures which have been synthesized and utilized to enhance oxygen supply and they have shown great promise in the alleviation of hypoxia. In a hypoxic environment, certain oxygen-dependent treatments such as photodynamic therapy and radiotherapy fail to respond and therefore modulating the hypoxic tumor microenvironment has been found to enhance the antitumor impact of certain drugs. Under acidic environments, the hydrogen peroxide produced by the reaction of metal peroxides with water not only induces oxidative stress but also produces additional oxygen. This is achieved since hydrogen peroxide acts as a reactive substrate for molecules such as catalyse enzymes, alleviating tumor hypoxia observed in the tumor microenvironment. Metal ions released in the process can also offer distinct bioactivity in their own right. Metal peroxides used in anticancer therapy are a rapidly evolving field, and there is good evidence that they are a good option for regulating the tumor microenvironment in cancer therapy. In this regard, the synthesis and mechanisms behind the successful application of metal peroxides to specifically target the tumor microenvironment are highlighted in this review. Various characteristics of TME such as angiogenesis, inflammation, hypoxia, acidity levels, and metal ion homeostasis are addressed in this regard, together with certain forms of synergistic combination treatments.

Smart biomaterials for enhancing cancer therapy by overcoming tumor hypoxia: a review

Hypoxia is a distinctive feature of most solid tumors due to insufficient oxygen supply of the abnormal vasculature, which cannot work with the demands of the fast proliferation of cancer cells. One of the main obstacles to limiting the efficacy of cancer medicines is tumor hypoxia. Thus, oxygen is a vital parameter for controlling the efficacy of different types of cancer therapy, such as chemotherapy (CT), photodynamic therapy (PDT), photothermal therapy (PTT), immunotherapy (IT), and radiotherapy (RT). Numerous technologies have attracted much attention for enhancing oxygen distribution in humans and improving the efficacy of cancer treatment. Such technologies include treatment with hyperbaric oxygen therapy (HBO), delivering oxygen by polysaccharides (e.g., cellulose, gelatin, alginate, and silk) and other biocompatible synthetic polymers (e.g., PMMA, PLA, PVA, PVP and PCL), decreasing oxygen consumption, producing oxygen in situ in tumors, and using polymeric systems as oxygen carriers. Herein, this review provides an overview of the relationship between hypoxia in tumor cells and its role in the limitation of different cancer therapies alongside the numerous strategies for oxygen delivery using polysaccharides and other biomaterials as carriers and for oxygen generation.

Bioheterojunction-Engineered Polyetheretherketone Implants With Diabetic Infectious Micromilieu Twin-Engine Powered Disinfection for Boosted Osteogenicity

Diabetic infectious micromilieu (DIM) leads to a critical failure rate of osseointegration by virtue of two main peculiarities: high levels of topical glucose and inevitable infection. To tackle the daunting issue, a bioheterojunction-engineered orthopedic polyetheretherketone (PEEK) implant consisting of copper sulfide/graphene oxide (CuS/GO) bioheterojunctions (bioHJs) and glucose oxidase (GOx) is conceived and developed for DIM enhanced disinfection and boosted osseointegration. Under hyperglycemic micromilieu, GOx can convert surrounding glucose into hydrogen peroxide (H₂ O₂ ). Then, upon infectious micromilieu, the bioHJs enable the catalyzation of H₂ O₂ to highly germicidal hydroxyl radical (·OH). As a result, the engineered implants massacre pathogenic bacteria through DIM twin-engine powered photo-chemodynamic therapy in vitro and in vivo. In addition, the engineered implants considerably facilitate cell viability and osteogenic activity of osteoblasts under a hyperglycemic microenvironment via synergistic induction of copper ions (Cu²⁺ ) and GO. In vivo studies using bone defect models of diabetic rats at 4 and 8 weeks further authenticate that bioHJ-engineering PEEK implants substantially elevate their osseointegration through biofilm elimination and vascularization, as well as macrophage reprogramming. Altogether, the present study puts forward a tactic that arms orthopedic implants with DIM twin-engine powered antibacterial and formidable osteogenic capacities for diabetic stalled osseointegration.

Ultrasmall zirconium carbide nanodots for synergistic photothermal-radiotherapy of glioma

Glioma is characterized by highly invasive, progressive, and lethal features. In addition, conventional treatments have been poorly effective in treating glioma. To overcome this challenge, synergistic therapies combining radiotherapy (RT) with photothermal therapy (PTT) have been proposed and extensively explored as a highly feasible cancer treatment strategy. Herein, ultrasmall zirconium carbide (ZrC) nanodots were successfully synthesized with high near-infrared absorption and strong photon attenuation for synergistic PTT-RT of glioma. ZrC-PVP nanodots with an average size of approximately 4.36 nm were prepared by the liquid exfoliation method and modified with the surfactant polyvinylpyrrolidone (PVP), with a satisfactory absorption and photothermal conversion efficiency (53.4%) in the near-infrared region. Furthermore, ZrC-PVP nanodots can also act as radiosensitizers to kill residual tumor cells after mild PTT due to their excellent photon attenuating ability, thus achieving a significant synergistic therapeutic effect by combining RT and PTT. Most importantly, both in vitro and in vivo experimental results further validate the high biosafety of ZrC-PVP NDs at the injected dose. This work systematically evaluates the feasibility of ZrC-PVP NDs for glioma treatment and provides evidence of the application of zirconium-based nanomaterials in photothermal radiotherapy.

Boosting Chemodynamic Therapy by Tumor-Targeting and Cellular Redox Homeostasis-Disrupting Nanoparticles

Chemodynamic therapy (CDT) that kills tumor cells by converting low-reactivity H₂O₂ into highly toxic hydroxyl radicals (•OH) is an emerging tumor therapeutic modality, but its therapeutic efficacy is largely limited by both the lack of tumor targeting and redox homeostasis in tumor cells. Herein, we report Cu²⁺-encapsulated and GalNAc-imprinted biodegradable silica nanoparticles (nanoMIP) for boosting CDT. In this strategy, the Cu²⁺ was first encapsulated into disulfide-bridged silica nanoparticles with a high loading capacity of ∼18.3%, followed by in situ functionalization via molecular imprinting using GalNAc as a template. Such a nanovector could specifically target tumor cells overexpressing the Tn antigen to promote the cellular uptake. After internalization into tumor cells, the degradation of nanoMIP occurred in response to the tumor microenvironment, spontaneously releasing Cu²⁺/Cu⁺ via redox cycles, which in turn promoted highly potent GSH depletion and triggered •OH generation by a Fenton-like reaction. Notably, we found that the catalase activity could be effectively inhibited by the produced Cu⁺, which indirectly upregulated the endogenous H₂O₂ level. As a result, the "maladjusted" tumor cells lost the resistance against •OH damage, finally resulting in the apoptosis of tumor cells. In vitro and in vivo experiments demonstrated that our nanoMIP exhibited excellent cytotoxicity against tumor cells and high efficacy of tumor inhibition in the xenograft tumor model with negligible side effects. Taken together, our study provides not only a promising strategy for maximizing the CDT efficacy but also a new insight for developing MIP-based nanomedicine.

Treating Multi-Drug-Resistant Bacterial Infections by Functionalized Nano-Bismuth Sulfide through the Synergy of Immunotherapy and Bacteria-Sensitive Phototherapy

Owing to its flexibility and high treatment efficiency, phototherapy is rapidly emerging for treating bacteria-induced diseases, but how to improve the sensitivity of bacteria to reactive oxygen species (ROS) and heat simultaneously to kill bacteria under mild conditions is still a challenge. Herein, we designed a NIR light catalyst (Bi₂S₃-S-nitrosothiol-acetylcholine (BSNA)) by transforming ^•O₂^- into peroxynitrite in situ, which can enhance the bacterial sensibility to ROS and heat and kill bacteria under a mild temperature. The transformed peroxynitrite in situ possessed a stronger ability to penetrate cell membranes and antioxidant capacity. The BSNA nanoparticles (NPs) inhibited the bacterial glucose metabolic process through down-regulated xerC/xerD expression and disrupted the HSP70/HSP90 secondary structure through nitrifying TYR179. Additionally, the synergistic effect of the designed BSNA and clinical antibiotics increased the antibacterial activity. In the case of tetracycline-class antibiotics, BSNA NPs induced phenolic hydroxyl group structure changes and inhibited the interaction between tetracycline and targeted t-RNA recombinant protein. Besides, BSNA stimulated production of more CD8⁺ T cells and reduced common complications in peritonitis, which provided immunotherapy activity. The targeted and anti-infective effect of BSNA suggested that we propose a nanotherapeutic strategy to achieve more efficient synergistic therapy under mild temperatures.

A hollow Co3-xCuxS4 with glutathione depleting and photothermal properties for synergistic dual-enhanced chemodynamic/photothermal cancer therapy

Chemodynamic therapy has become an emerging cancer treatment strategy, in which tumor cells are killed through toxic reactive oxygen species (ROS), especially hydroxyl radicals (˙OH) produced by the Fenton reaction. Nevertheless, low ROS generation efficiency and ROS depletion by cellular antioxidant systems are still the main obstacles in chemodynamic therapy. In the present work, we propose a dually enhanced chemodynamic therapy obtained by inhibiting ˙OH consumption and promoting ˙OH production based on the administration of bimetallic sulfide Co_3-xCu_xS₄ nanoparticles functionalized by polyethylene glycol. These bimetallic nanoparticles display glutathione depleting and photothermal properties. The nanoparticles are gradually degraded in a tumor microenvironment, resulting in Co²⁺ and Cu²⁺ release. The released Co²⁺ triggers a Fenton-like reaction that turns endogenous hydrogen peroxide into highly toxic ˙OH. In the cellular environment, Cu²⁺ ions are reduced to Cu⁺ by endogenous GSH, which decreases the intracellular antioxidant capacity and additionally up-regulates ˙OH production via the Cu⁺-induced Fenton-like reaction. Moreover, under near-infrared light irradiation, the bimetallic nanoparticles display a photothermal conversion efficacy of 46.7%, which not only improves chemodynamic therapy via boosting a Fenton-like reaction but results in photothermal therapy through hyperthermia. Both in vitro cancer cell killing and in vivo tumor ablation experiments show that the bimetallic nanoparticles display outstanding therapeutic efficacy and negligible systemic toxicity, indicating their anticancer potential.

Chemical Factory-Guaranteed Enhanced Chemodynamic Therapy for Orthotopic Liver Cancer

In the field of nanomedicine, there is a tendency of matching designed nanomaterials with a suitable type of orthotopic cancer model, not just a casual subcutaneous one. Under this condition, knowing the specific features of the chosen cancer model is the priority, then introducing a proper therapy strategy using designed nanomaterials. Here, the Fenton chemistry is combined with zinc peroxide nanoparticles in the treatment of orthotopic liver cancer which has a "chemical factory" including that liver is the main place for iron storage, metabolism, and also the main metabolic sites for the majority of ingested substances, guaranteeing customized and enhanced chemodynamic therapy and normal liver cells protection as well. The good results in vitro and in vivo can set an inspiring example for exploring and utilizing suitable nanomaterials in corresponding cancer models, ensuring well-fitness of nanomaterials for disease and satisfactory therapeutic effect.

Albumin-Stabilized Manganese Oxide/Semiconducting Polymer Nanocomposites for Photothermal-Chemodynamic Therapy of Hepatic Carcinoma

Hepatic carcinoma is one of the most common cancers worldwide, while its treatment remains a great challenge. Traditional therapeutic methods often have disadvantages such as limited therapeutic efficacy and potential side effects. In this study, we report the construction of bovine serum albumin (BSA)–stabilized manganese oxide (MnO2)/semiconducting polymer (SP) nanocomposites to combine photothermal therapy (PTT) and chemodynamic therapy (CDT) for treatment of hepatic carcinoma in living mouse models. Such nanocomposites are composed of BSA, SP, and MnO2 as the stabilizer, PTT, and CDT agent, respectively. SP produced local heat under near-infrared (NIR) laser irradiation for PTT, and MnO2 nanoparticles mediated CDT in the tumor microenvironment, leading to apoptosis of cancer cells. Such nanocomposite-mediated combinational therapy showed a much higher efficacy in inhibiting growth of subcutaneous HepG2 tumors in nude mice than sole treatment. This study thus provides a multifunctional nanoplatform for safe and effective treatment of hepatic carcinoma.

TPEN selectively eliminates lymphoblastic B cells from bone marrow pediatric acute lymphoblastic leukemia patients

B-cell acute lymphoblastic leukemia (B-ALL) is a hematologic disorder characterized by the abnormal proliferation and accumulation of immature B-lymphoblasts arrested at various stages of differentiation. Despite advances in treatment, a significant percentage of pediatric patients with precursor B-ALL still relapse. Therefore, alternative therapies are needed to improve the cure rates for pediatric patients. TPEN (N, N, N', N'-tetrakis(2-pyridylmethyl)-ethylenediamine) is a pro-oxidant agent capable of selectively inducing apoptosis in leukemia cell lines. Consequently, it has been suggested that TPEN could be a potential agent for oxidative therapy. However, it is not yet known whether TPEN can selectively destroy leukemia cells in a more disease-like model, for example, the bloodstream and bone marrow (BM), ex vivo. This investigation is an extension of a previous study that dealt with the effect of TPEN on ex vivo isolated/purified refractory B-ALL cells. Here, we evaluated the effect of TPEN on whole BM from nonleukemic patients (control) or pediatric patients diagnosed with de novo B-ALL or refractory B-ALL cells by analyzing the hematopoietic cell lineage marker CD34/CD19. Although TPEN was innocuous to nonleukemic BM (n = 3), we found that TPEN significantly induced apoptosis in de novo (n = 5) and refractory B-ALL (n = 6) leukemic cell populations. Moreover, TPEN significantly increased the counts of cells positive for the oxidation of the stress sensor protein DJ-1, a sign of the formation of H₂O₂, and significantly increased the counts of cells positive for the pro-apoptotic proteins TP53, PUMA, and CASPASE-3 (CASP-3), indicative of apoptosis, in B-ALL cells. We demonstrate that TPEN selectively eliminates B-ALL cells (CD34 + /CD19 +) but no other cell populations in BM (CD34 + /CD19-; CD34-/CD19 + ; CD34-/CD19-) independent of age, diagnosis status (de novo or refractory), sex, karyotype, or immunophenotype. Understanding TPEN-induced cell death in leukemia cells provides insight into more effective therapeutic oxidation-inducing anticancer agents.