Regulating Acidosis and Relieving Hypoxia by Platelet Membrane-Coated Nanoparticle for Enhancing Tumor Chemotherapy

Photothermally reinforced chemodynamic therapy in the treatment of osteosarcoma by polydopamine-modified, copper peroxide loaded ZIF8 nanoparticles

Chemodynamic therapy (CDT) has played an important role in osteosarcoma (OS) treatment. However, the insufficient content of endogenous H2O2 and high expression of glutathione (GSH) in tumor tissues limit the antitumor efficacy of CDT. In this work, we developed polydopamine (PDA) coated and CuO2 NPs loaded ZIF8 nanoparticles (CuO2@ZIF8@PDA NPs) for thermally reinforced CDT treatment of OS. The CuO2@ZIF8@PDA NPs exhibited excellent stability in neutral solutions while degraded in weakly acidic environments to generate hydrogen peroxide (H2O2) and Cu2+. Cu2+ consumes GSH in tumor tissues to generate Cu+. Both Cu2+ and Cu+ catalyzed the decomposition of H2O2, triggering a Fenton-like reaction to produce hydroxyl radicals (•OH). The PDA coating endowed the nanosystem with photothermal conversion capabilities under near-infrared laser irradiation, further promoting the generation of •OH, and inducing tumor cell death. In vitro experiments demonstrated that CuO2@ZIF8@PDA NPs exhibited significant toxicity towards K7M2 cells while remaining non-toxic to normal cells. In vivo studies revealed that under 808 nm laser irradiation, CuO2@ZIF8@PDA NPs exhibited stronger killing ability against K7M2 cells than CuO2@ZIF8@PDA NPs alone. This system, which combines GSH depletion, intratumoral H2O2 self-generation, and photothermally enhanced CDT, holds great promise for playing a pivotal role in the treatment of osteosarcoma.

Advancements in precision nanomedicine design targeting the anoikis-platelet interface of circulating tumor cells

Tumor metastasis, the apex of cancer progression, poses a formidable challenge in therapeutic endeavors. Circulating tumor cells (CTCs), resilient entities originating from primary tumors or their metastases, significantly contribute to this process by demonstrating remarkable adaptability. They survive shear stress, resist anoikis, evade immune surveillance, and thwart chemotherapy. This comprehensive review aims to elucidate the intricate landscape of CTC formation, metastatic mechanisms, and the myriad factors influencing their behavior. Integral signaling pathways, such as integrin-related signaling, cellular autophagy, epithelial-mesenchymal transition, and interactions with platelets, are examined in detail. Furthermore, we explore the realm of precision nanomedicine design, with a specific emphasis on the anoikis‒platelet interface. This innovative approach strategically targets CTC survival mechanisms, offering promising avenues for combatting metastatic cancer with unprecedented precision and efficacy. The review underscores the indispensable role of the rational design of platelet-based nanomedicine in the pursuit of restraining CTC-driven metastasis.

Recent progress in lactate oxidase-based drug delivery systems for enhanced cancer therapy

Lactate oxidase (LOX) is a natural enzyme that efficiently consumes lactate. In the presence of oxygen, LOX can catalyse the formation of pyruvate and hydrogen peroxide (H2O2) from lactate. This process led to acidity alleviation, hypoxia, and a further increase in oxidative stress, alleviating the immunosuppressive state of the tumour microenvironment (TME). However, the high cost of LOX preparation and purification, poor stability, and systemic toxicity limited its application in tumour therapy. Therefore, the rational application of drug delivery systems can protect LOX from the organism's environment and maintain its catalytic activity. This paper reviews various LOX-based drug-carrying systems, including inorganic nanocarriers, organic nanocarriers, and inorganic-organic hybrid nanocarriers, as well as other non-nanocarriers, which have been used for tumour therapy in recent years. In addition, this area's challenges and potential for the future are highlighted.

Convergence of nanomedicine and neutrophils for drug delivery

Neutrophils have recently emerged as promising carriers for drug delivery due to their unique properties including rapid response toward inflammation, chemotaxis, and transmigration. When integrated with nanotechnology that has enormous advantages in improving treatment efficacy and reducing side effects, neutrophil-based nano-drug delivery systems have expanded the repertoire of nanoparticles employed in precise therapeutic interventions by either coating nanoparticles with their membranes, loading nanoparticles inside living cells, or engineering chimeric antigen receptor (CAR)-neutrophils. These neutrophil-inspired therapies have shown superior biocompatibility, targeting ability, and therapeutic robustness. In this review, we summarized the benefits of combining neutrophils and nanotechnologies, the design principles and underlying mechanisms, and various applications in disease treatments. The challenges and prospects for neutrophil-based drug delivery systems were also discussed.

Biomaterial-Based Responsive Nanomedicines for Targeting Solid Tumor Microenvironments

Solid tumors are composed of a highly complex and heterogenic microenvironment, with increasing metabolic status. This environment plays a crucial role in the clinical therapeutic outcome of conventional treatments and innovative antitumor nanomedicines. Scientists have devoted great efforts to conquering the challenges of the tumor microenvironment (TME), in respect of effective drug accumulation and activity at the tumor site. The main focus is to overcome the obstacles of abnormal vasculature, dense stroma, extracellular matrix, hypoxia, and pH gradient acidosis. In this endeavor, nanomedicines that are targeting distinct features of TME have flourished; these aim to increase site specificity and achieve deep tumor penetration. Recently, research efforts have focused on the immune reprograming of TME in order to promote suppression of cancer stem cells and prevention of metastasis. Thereby, several nanomedicine therapeutics which have shown promise in preclinical studies have entered clinical trials or are already in clinical practice. Various novel strategies were employed in preclinical studies and clinical trials. Among them, nanomedicines based on biomaterials show great promise in improving the therapeutic efficacy, reducing side effects, and promoting synergistic activity for TME responsive targeting. In this review, we focused on the targeting mechanisms of nanomedicines in response to the microenvironment of solid tumors. We describe responsive nanomedicines which take advantage of biomaterials' properties to exploit the features of TME or overcome the obstacles posed by TME. The development of such systems has significantly advanced the application of biomaterials in combinational therapies and in immunotherapies for improved anticancer effectiveness.

TME-Related Biomimetic Strategies Against Cancer

The tumor microenvironment (TME) plays an important role in various stages of tumor generation, metastasis, and evasion of immune monitoring and treatment. TME targeted therapy is based on TME components, related pathways or active molecules as therapeutic targets. Therefore, TME targeted therapy based on environmental differences between TME and normal cells has been widely studied. Biomimetic nanocarriers with low clearance, low immunogenicity, and high targeting have enormous potential in tumor treatment. This review introduces the composition and characteristics of TME, including cancer‑associated fibroblasts (CAFs), extracellular matrix (ECM), tumor blood vessels, non-tumor cells, and the latest research progress of biomimetic nanoparticles (NPs) based on TME. It also discusses the opportunities and challenges of clinical transformation of biomimetic nanoparticles.

Current Advances on Nanomaterials Interfering with Lactate Metabolism for Tumor Therapy

Increasing numbers of studies have shown that tumor cells prefer fermentative glycolysis over oxidative phosphorylation to provide a vast amount of energy for fast proliferation even under oxygen-sufficient conditions. This metabolic alteration not only favors tumor cell progression and metastasis but also increases lactate accumulation in solid tumors. In addition to serving as a byproduct of glycolytic tumor cells, lactate also plays a central role in the construction of acidic and immunosuppressive tumor microenvironment, resulting in therapeutic tolerance. Recently, targeted drug delivery and inherent therapeutic properties of nanomaterials have attracted great attention, and research on modulating lactate metabolism based on nanomaterials to enhance antitumor therapy has exploded. In this review, the advanced tumor therapy strategies based on nanomaterials that interfere with lactate metabolism are discussed, including inhibiting lactate anabolism, promoting lactate catabolism, and disrupting the "lactate shuttle". Furthermore, recent advances in combining lactate metabolism modulation with other therapies, including chemotherapy, immunotherapy, photothermal therapy, and reactive oxygen species-related therapies, etc., which have achieved cooperatively enhanced therapeutic outcomes, are summarized. Finally, foreseeable challenges and prospective developments are also reviewed for the future development of this field.

Immobilization of horseradish peroxidase on metal-organic framework to imporve enzyme activity for enhanced chemodynamic therapy

Bio-enzymes have the advantages of strong substrate specificity, high catalytic efficiency, and minimal toxic side effects, making them promising drugs in cancer therapy. However, the poor stability and cellular penetrability of uncoated protein in the physiological environment severely restricts the direct application of Bio-enzyme. To address it, we report a metal-organic framework (MOF), Hf-DBA (H2DBA, biphenyl carboxylic acid ligands). The morphology of the Hf-DBA was revealed by TEM and the diameter was in the range of 200 to 350 nm. Hf-DBA acted a carrier for intracellular delivery and protection of horseradish peroxidase (HRP). The prepared HRP@Hf-DBA can catalyze the excess H2O2 in the tumor cells to generation of •OH for chemodynamic therapy (CDT). Compared with free HRP, the catalytic activity of HRP@Hf-DBA is significantly improved, and the optimal catalytic conditions are explored. The catalytic stability of HRP@Hf-DBA remained above 70% after 12 cycles of catalysis. After treatment with HRP@Hf-DBA, the apoptosis rates of A549 and Hela cells was 71.64%, and 76.86%. The results in vitro show that HRP@Hf-DBA can effectively inhibit the growth of tumor cells through enhanced CDT.

Platelet-Based Nanoparticles with Stimuli-Responsive for Anti-Tumor Therapy

In addition to hemostasis and coagulation, years of studies have proved that platelets are involved in the whole process of tumor progression, including tumor invasion, intravasation, extravasation, and so on. It means that this property of platelets can be used in anti-tumor therapy. However, traditional platelet-based antitumor drugs often cause autologous platelet damage due to lack of targeting, resulting in serious side effects. Therefore, the researchers designed a variety of anti-tumor drug delivery systems based on platelets by targeting platelets or platelet membrane coating. The drug delivery systems have special response modes, which is crucial in the design of nanoparticles. These modes enhance the targeting and improve the anti-tumor effect. Here, we present a review of recent discoveries in the field of the crosstalk between platelets and tumors and the progress of platelet-based anti-tumor nanoparticles.

Lactate-Oxidase-Instructed Cancer Diagnosis and Therapy

Lactate oxidase (LOx) has attracted extensive interest in cancer diagnosis and therapy in recent years owing to its specific catalysis on l-lactate; its catalytic process consumes oxygen (O₂ ) and generates a large amount of hydrogen peroxide (H₂ O₂ ) and pyruvate. Given high levels of lactate in tumor tissues and its tight correlation with tumor growth, metastasis, and recurrence, LOx-based biosensors including H₂ O₂ -based, O₂ -based, pH-sensitive, and electrochemical have been designed for cancer diagnosis, and various LOx-based cancer therapy strategies including lactate-depletion-based metabolic cancer therapy/immunotherapy, hypoxia-activated chemotherapy, H₂ O₂ -based chemodynamic therapy, and multimodal synergistic cancer therapy have also been developed. In this review, the lactate-specific catalytic properties of LOx are introduced, and the recent advances on LOx-instructed cancer diagnostic or therapeutic platforms and corresponding biological applications are summarized. Additionally, the challenges and potential of LOx-based nanomedicines are highlighted.