Nanoenabled Tumor Energy Metabolism Disorder via Sonodynamic Therapy for Multidrug Resistance Reversal and Metastasis Inhibition

Design, Synthesis, and Biological Evaluation of Marchantin C-NO Donor Hybrids for Overcoming Pgp-Mediated Drug Resistance by Targeting Lysosome

A series of marchantin C-NO donor hybrids were designed, synthesized, and evaluated for their antitumor activity in vitro and in vivo. Notably, MC-furoxan hybrid 14 exhibited the best selective inhibitory activity against MCF-7/ADR (IC50 = 0.024 μM) with 883 times potency compared with MCF-7 cells (IC50 = 21.20 μM), and the cytotoxicity toward A549/Taxol (IC50 = 1.43 μM) increased 17-fold compared with that in A549 cells (IC50 = 23.75 μM). Preliminary pharmacological studies revealed that 14 could "hijack" the lysosomal Pgp and release NO to produce reactive oxygen species (ROS) in lysosomes, resulting in lysosomal membrane permeabilization (LMP) and potentiated cytotoxicity. Additionally, compound 14 achieved stronger antitumor activity and superior biosafety at relatively low doses than paclitaxel in the A549/Taxol xenograft model. In summary, this study provides a promising strategy for the design of such MC-furoxan hybrids like 14 to overcome MDR via the utilization of lysosomal Pgp transport activity.

Recent advances in chemodynamic nanotherapeutics to overcome multidrug resistance in cancers

Multidrug resistance (MDR) has become a major challenge in cancer therapy, it results in the failure of chemotherapy and anticancer drug development. Chemodynamic therapy (CDT), an emerging cancer treatment strategy, has been reported as a novel approach for cancer treatment characterized by low toxicity and minimal side effects. By generating robust cytotoxic hydroxyl radicals (·OH) via Fenton/Fenton-like reaction, CDT may cause cellular damage and oxidative stress-induced cell death. In recent years, many therapies based on CDT and/or combined with other treatment modalities are reported and exhibit exciting treatment efficacy in cancer treatment, such as photothermal therapy, photodynamic therapy, sonodynamic therapy, chemotherapy, starvation therapy and gas therapy etc. These combination therapies exhibit synergistic effects, significantly improving anticancer outcomes compared to CDT alone. Herein, we provide a comprehensive overview of CDT-based strategies in cancer treatment, highlighting developments of CDT and CDT-based combination strategies in tumor therapy, especially in overcoming MDR challenges. Finally, the opportunities and challenges of CDT and CDT-combination therapy in the clinical application are also addressed.

Cell-membrane targeting sonodynamic therapy combination with FSP1 inhibition for ferroptosis-boosted immunotherapy

Cell membrane targeting sonodynamic therapy could induce the accumulation of lipid peroxidation (LPO), drive ferroptosis, and further enhances immunogenic cell death (ICD) effects. However, ferroptosis is restrained by the ferroptosis suppressor protein 1 (FSP1) at the plasma membrane, which can catalyze the regeneration of ubiquinone (CoQ10) by using NAD(P)H to suppress the LPO accumulation. This work describes the construction of US-active nanoparticles (TiF NPs), which combinate cell-membrane targeting sonosensitizer TBT-CQi with FSP1 inhibitor (iFSP1), facilitating cell-membrane targeting sonodynamic-triggered ferroptosis. TiF NPs could induce a sonodynamic effect, which promotes lipid peroxidation and drives apoptosis. Furthermore, TiF NPs could suppress FSP1, induce CoQ10 depletion, down-regulate the NADH, enhance LPO accumulation, and finally induce ferroptosis. In vitro results demonstrated that synergetic cell membrane targeting SDT/FSP1 inhibition triggered immunogenic cell death (ICD). Moreover, the as-synthesized TiF NPs-mediated cell membrane targeting SDT/FSP1 inhibition thoroughly inhibited the tumor growth and simultaneously activated antitumor immunity to suppress lung metastasis. This work represents a promising tumor therapeutic strategy combining cell membrane targeting SDT and FSP1 inhibition, potentially inspiring further research in developing logical and effective cancer therapies based on synergistic SDT/ferroptosis.

aPD-L1-facilitated theranostic and tumor microenvironment remodeling of pancreatic cancer via docetaxel-loaded phase-transformation nanoparticles triggered by low-intensity pulsed ultrasound

Early diagnosis of pancreatic ductal adenocarcinoma (PDAC) is challenging because of its depth, which often leads to misdiagnosis during ultrasound examinations. The unique PDAC tumor microenvironment (TME) is characterized by significant fibrous tissue growth, and high interstitial pressure hinders drug penetration into tumors. Additionally, hypoxia and immune suppression within the tumor contribute to poor responses to radiotherapy and chemotherapy, ultimately leading to an unfavorable prognosis. In this study, aPD-L1-modified docetaxel and perfluoropentane-loaded liquid‒vapor phase-transformation lipid nanoparticles (aPDL1-DTX/PFP@Lipid) were synthesized and had an average diameter of 61.63 nm with 84.3% antibody modification. We demonstrated that the nanoparticles (NPs) exhibited excellent PDAC-targeting capabilities both in vitro and in vivo. Upon exposure to low-intensity pulsed ultrasound (LIPUS) stimulation, the NPs underwent a phase transformation to form microbubbles with substantial molecular ultrasound diagnostic effects, and combined treatment resulted in a tumor growth inhibition rate of 88.91%. This treatment strategy also led to the infiltration of CD8+ T cells, the downregulation of Treg cells, the promotion of M1 macrophage polarization, the inhibition of fibrosis to reduce tumor stromal pressure, and the facilitation of perfluoropentane (PFP) gasification to release O2 and improve tumor hypoxia. In conclusion, aPD-L1-modified liquid‒vapor phase-transformation nanoparticles loaded with docetaxel (DTX) and PFP were successfully combined with ultrasound for the molecular diagnosis and targeted treatment of PDAC. aPDL1-DTX/PFP@Lipid could reshape the PDAC TME, offering a new approach for ultrasound-mediated diagnosis and treatment with promising clinical applications.

Wheat germ agglutinin modified mixed micelles overcome the dual barrier of mucus/enterocytes for effective oral absorption of shikonin and gefitinib

The combination of shikonin (SKN) and gefitinib (GFB) can reverse the drug resistance of lung cancer cells by affecting energy metabolism. However, the poor solubility of SKN and GFB limits their clinical application because of low bioavailability. Wheat germ agglutinin (WGA) can selectively bind to sialic acid and N-acetylglucosamine on the surfaces of microfold cells and enterocytes, and is a targeted biocompatible material. Therefore, we created a co-delivery micelle system called SKN/GFB@WGA-micelles with the intestinal targeting functions to enhance the oral absorption of SKN and GFB by promoting mucus penetration for nanoparticles via oral administration. In this study, Caco-2/HT29-MTX-E12 co-cultured cells were used to simulate a mucus/enterocyte dual-barrier environment, and HCC827/GR cells were used as a model of drug-resistant lung cancer. We aimed to evaluate the oral bioavailability and anti-tumor effect of SKN and GFB using the SKN/GFB@WGA-micelles system. In vitro and in vivo experimental results showed that WGA promoted the mucus penetration ability of micelles, significantly enhanced the uptake efficiency of enterocytes, improved the oral bioavailability of SKN and GFB, and exhibited good anti-tumor effects by reversing drug resistance. The SKN/GFB@WGA-micelles were stable in the gastrointestinal tract and provided a novel safe and effective drug delivery strategy.

Sensitize Tumor Immunotherapy: Immunogenic Cell Death Inducing Nanosystems

Low immunogenicity of tumors poses a challenge in the development of effective tumor immunotherapy. However, emerging evidence suggests that certain therapeutic approaches, such as chemotherapy, radiotherapy, and phototherapy, can induce varying degrees of immunogenic cell death (ICD). This ICD phenomenon leads to the release of tumor antigens and the maturation of dendritic cells (DCs), thereby enhancing tumor immunogenicity and promoting immune responses. However, the use of a single conventional ICD inducer often fails to achieve in situ tumor ablation and establish long-term anti-tumor immune responses. Furthermore, the induction of ICD induction varies among different approaches, and the distribution of the therapeutic agent within the body influences the level of ICD and the occurrence of toxic side effects. To address these challenges and further boost tumor immunity, researchers have explored nanosystems as inducers of ICD in combination with tumor immunotherapy. This review examines the mechanisms of ICD and different induction methods, with a specific focus on the relationship between ICD and tumor immunity. The aim is to explore the research advancements utilizing various nanomaterials to enhance the body's anti-tumor effects by inducing ICD. This paper aims to contribute to the development and clinical application of nanomaterial-based ICD inducers in the field of cancer immunotherapy by providing important theoretical guidance and practical references.

Co-delivery of Paclitaxel/Atovaquone/Quercetin to regulate energy metabolism to reverse multidrug resistance in ovarian cancer by PLGA-PEG nanoparticles

Ovarian cancer is a malignant tumor that seriously endangers the lives of women, with chemotherapy being the primary clinical treatment. However, chemotherapy encounters the problem of generating multidrug resistance (MDR), mainly due to drug efflux induced by P-glycoprotein (P-gp), which decreases intracellular accumulation of chemotherapeutic drugs. The drugs efflux mediated by P-gp requires adenosine triphosphate (ATP) hydrolysis to provide energy. Therefore, modulating energy metabolism pathways and inhibiting ATP production may be a potential strategy to reverse MDR. Herein, we developed a PTX-ATO-QUE nanoparticle (PAQNPs) based on a PLGA-PEG nanoplatform capable of loading the mitochondrial oxidative phosphorylation (OXPHOS) inhibitor atovaquone (ATO), the glycolysis inhibitor quercetin (QUE), and the chemotherapeutic drug paclitaxel (PTX) to reverse MDR by inhibiting energy metabolism through multiple pathways. Mechanistically, PAQNPs could effectively inhibit the OXPHOS and glycolytic pathways of A2780/Taxol cells by suppressing the activities of mitochondrial complex III and hexokinase II (HK II), respectively, ultimately decreasing intracellular ATP levels in tumor cells. Energy depletion can effectively inhibit cell proliferation and reduce P-gp activity, increasing the chemotherapeutic drug PTX accumulation in the cells. Moreover, intracellular reactive oxygen species (ROS) is increased with PTX accumulation and leads to chemotherapy-resistant cell apoptosis. Furthermore, PAQNPs significantly inhibited tumor growth in the A2780/Taxol tumor-bearing NCG mice model. Immunohistochemical (IHC) analysis of tumor tissues revealed that P-gp expression was suppressed, demonstrating that PAQNPs are effective in reversing MDR in tumors by inducing energy depletion. In addition, the safety study results, including blood biochemical indices, major organ weights, and H&E staining images, showed that PAQNPs have a favorable in vivo safety profile. In summary, the results suggest that the combined inhibition of the two energy pathways, OXPHOS and glycolysis, can enhance chemotherapy efficacy and reverse MDR in ovarian cancer.

Personalized Cancer Therapeutics Using Photoacoustic Imaging-Guided Sonodynamic Therapy

Sonodynamic therapy (SDT) is a promising approach for cancer treatment that uses sonosensitizers (SNSs) to generate reactive oxygen species (ROS) in the presence of ultrasound (US). However, SDT is oxygen-dependent and requires an imaging tool to monitor the tumor microenvironment and guide treatment. Photoacoustic imaging (PAI) is a noninvasive and powerful imaging tool that offers high spatial resolution and deep tissue penetration. PAI can quantitatively assess tumor oxygen saturation (sO2) and guide SDT by monitoring time-dependent sO2 changes in the tumor microenvironment. Here, we discuss recent advances in PAI-guided SDT for cancer therapy. We discuss various exogenous contrast agents and nanomaterial-based SNSs developed for PAI-guided SDT. Additionally, combining SDT with other therapies, including photothermal (PTT) therapy, can enhance its therapeutic effect. However, the application of nanomaterial-based contrast agents in PAI-guided SDT for cancer therapy remains challenging due to the lack of simple designs, the need for extensive pharmacokinetic studies, and high production costs. Integrated efforts from researchers, clinicians, and industry consortia are necessary for the successful clinical translation of these agents and SDT for personalized cancer therapy. PAI-guided SDT shows the potential to revolutionize cancer therapy and improve patient outcomes, but further research is necessary to realize its full potential.

Tumor microenvironment diversity and plasticity in cancer multidrug resistance

Multidrug resistance (MDR) poses a significant obstacle to effective cancer treatment, and the tumor microenvironment (TME) is crucial for MDR development and reversal. The TME plays an active role in promoting MDR through several pathways. However, a promising therapeutic approach for battling MDR involves targeting specific elements within the TME. Therefore, this comprehensive review elaborates on the research developments regarding the dual role of the TME in promoting and reversing MDR in cancer. Understanding the complex role of the TME in promoting and reversing MDR is essential to developing effective cancer therapies. Utilizing the adaptability of the TME by targeting novel TME-specific factors, utilizing combination therapies, and employing innovative treatment strategies can potentially combat MDR and achieve personalized treatment outcomes for patients with cancer.

Glutathione and Esterase Dual-Responsive Smart Nano-drug Delivery System Capable of Breaking the Redox Balance for Enhanced Tumor Therapy

Conventional chemotherapy usually fails to achieve its intended effect because of the poor water solubility, poor tumor selectivity, and low tumor accumulation of chemotherapy drugs. The systemic toxicity of chemotherapy agents is also a problem that cannot be ignored. It is expected that smart nano-drug delivery systems that are able to respond to tumor microenvironments will provide better therapeutic outcomes with decreased side effects of chemotherapeutics. Nano-drug delivery systems capable of breaking the redox balance can also increase the sensitivity of tumor cells to chemotherapeutics. In this study, using polymer-containing disulfide bonds, ester bonds, and d-α-tocopherol polyethylene glycol succinate (TPGS), which can amplify reactive oxygen species (ROS) in tumor cells, we have successfully prepared a smart glutathione (GSH) and esterase dual-responsive nano-drug delivery system (DTX@PAMBE-SS-TPGS NPs) with the ability to deplete GSH as well as amplify ROS and effectively release an encapsulated chemotherapy drug (DTX) in tumor cells. The potential of DTX@PAMBE-SS-TPGS NPs for enhanced antitumor effects was thoroughly evaluated using in vitro as well as in vivo experiments. Our research offers a promising strategy for maximizing the efficacy of tumor therapy.