Adding Nanotechnology to the Metastasis Treatment Arsenal

Nanomaterial-Based Strategies for Preventing Tumor Metastasis by Interrupting the Metastatic Biological Processes

Tumor metastasis is the primary cause of cancer-related deaths. The prevention of tumor metastasis has garnered notable interest and interrupting metastatic biological processes is considered a potential strategy for preventing tumor metastasis. The tumor microenvironment (TME), circulating tumor cells (CTCs), and premetastatic niche (PMN) play crucial roles in metastatic biological processes. These processes can be interrupted using nanomaterials due to their excellent physicochemical properties. However, most studies have focused on only one aspect of tumor metastasis. Here, the hypothesis that nanomaterials can be used to target metastatic biological processes and explore strategies to prevent tumor metastasis is highlighted. First, the metastatic biological processes and strategies involving nanomaterials acting on the TME, CTCs, and PMN to prevent tumor metastasis are briefly summarized. Further, the current challenges and prospects of nanomaterials in preventing tumor metastasis by interrupting metastatic biological processes are discussed. Nanomaterial-and multifunctional nanomaterial-based strategies for preventing tumor metastasis are advantageous for the long-term fight against tumor metastasis and their continued exploration will facilitate rapid progress in the prevention, diagnosis, and treatment of tumor metastasis. Novel perspectives are outlined for developing more effective strategies to prevent tumor metastasis, thereby improving the outcomes of patients with cancer.

NIR-IIb fluorescence antiangiogenesis copper nano-reaper for enhanced synergistic cancer therapy

The formation of blood vessel system under a relatively higher Cu2+ ion level is an indispensable precondition for tumor proliferation and migration, which was assisted in forming the tumor immune microenvironment. Herein, a copper ions nano-reaper (LMDFP) is rationally designed not only for chelating copper ions in tumors, but also for combination with photothermal therapy (PTT) to improve antitumor efficiency. Under 808 nm laser irradiation, the fabricated nano-reaper converts light energy into thermal energy to kill tumor cells and promotes the release of D-penicillamine (DPA) in LMDFP. Photothermal properties of LMDFP can cause tumor ablation in situ, which further induces immunogenic cell death (ICD) to promote systematic antitumor immunity. The released DPA exerts an anti-angiogenesis effect on the tumor through chelating copper ions, and inhibits the expression of programmed death ligand 1 (PD-L1), which synergizes with PTT to enhance antitumor immunity and inhibit tumor metastasis. Meanwhile, the nanoplatform can emit near-infrared-IIb (NIR-IIb) fluorescence under 980 nm excitation, which can be used to track the nano-reaper and determine the optimal time point for PTT. Thus, the fabricated nano-reaper shows powerful potential in inhibiting tumor growth and metastasis, and holds great promise for the application of copper nanochelator in precise tumor treatment.

The Pharmacological Implications of Flavopiridol: An Updated Overview

Flavopiridol is a flavone synthesized from the natural product rohitukine, which is derived from an Indian medicinal plant, namely Dysoxylum binectariferum Hiern. A deeper understanding of the biological mechanisms by which such molecules act may allow scientists to develop effective therapeutic strategies against a variety of life-threatening diseases, such as cancer, viruses, fungal infections, parasites, and neurodegenerative diseases. Mechanistic insight of flavopiridol reveals its potential for kinase inhibitory activity of CDKs (cyclin-dependent kinases) and other kinases, leading to the inhibition of various processes, including cell cycle progression, apoptosis, tumor proliferation, angiogenesis, tumor metastasis, and the inflammation process. The synthetic derivatives of flavopiridol have overcome a few demerits of its parent compound. Moreover, these derivatives have much improved CDK-inhibitory activity and therapeutic abilities for treating severe human diseases. It appears that flavopiridol has potential as a candidate for the formulation of an integrated strategy to combat and alleviate human diseases. This review article aims to unravel the potential therapeutic effectiveness of flavopiridol and its possible mechanism of action.

Copper indium selenium nanomaterials for photo-amplified immunotherapy through simultaneously enhancing cytotoxic T lymphocyte recruitment and M1 polarization of macrophages

Photoactivated immunotherapy has promising therapeutic efficacy for treating malignancies, especially metastatic tumors. In this study, an erythrocyte membrane-encapsulated copper indium selenium (RCIS) semiconductor nanomaterial was developed to eliminate primary and metastatic tumors, in which copper ions can induce chemodynamic performance, and the narrow band gap endows RCIS with the properties of near-infrared (NIR) light-activated photothermal and photodynamic amplified immunotherapy. Furthermore, RCIS can be used as a nanocarrier to form RNCIS nanoparticles (NPs) by loading NLG919, which blocks the indoleamine 2,3-dioxygenase-1. Under NIR light irradiation, RNCIS NPs release NLG919 at tumor sites via photothermal properties, thereby promoting the recruitment of cytotoxic T lymphocytes and M1 polarization of macrophages, targeting the activation and amplification of immune responses. Herein, in vitro and in vivo studies showed that RNCIS NPs effectively kill cancer cells and eliminate primary and metastatic tumors. Therefore, this study suggests that semiconductor nanomaterials with narrow bandgaps have great potential as photoimmunotherapy agents and NIR light-responsive nanocarriers for controlled release, providing a great paradigm for synergetic tumor photoimmunotherapy. STATEMENT OF SIGNIFICANCE: The Erythrocyte membrane-coated, NLG919-loaded copper indium selenium (RNCIS) semiconductor was designed for eliminating primary and metastatic tumors. RNCIS exhibits chemodynamic, photodynamic, and photothermal activated immunotherapy by inhibiting indoleamine 2,3-dioxygenase-1. This can enhance the recruitment of cytotoxic T lymphocyte and M1 polarization of macrophage, leading to higher synergetic photo-immune therapeutic efficacy.

The Progress in the Application of Dissolving Microneedles in Biomedicine

In recent years, microneedle technology has been widely used for the transdermal delivery of substances, showing improvements in drug delivery effects with the advantages of minimally invasive, painless, and convenient operation. With the development of nano- and electrochemical technology, different types of microneedles are increasingly being used in other biomedical fields. Recent research progress shows that dissolving microneedles have achieved remarkable results in the fields of dermatological treatment, disease diagnosis and monitoring, and vaccine delivery, and they have a wide range of application prospects in various biomedical fields, showing their great potential as a form of clinical treatment. This review mainly focuses on dissolving microneedles, summarizing the latest research progress in various biomedical fields, providing inspiration for the subsequent intelligent and commercial development of dissolving microneedles, and providing better solutions for clinical treatment.

Nanotechnology-integrated ovarian cancer metastasis therapy: Insights from the metastatic mechanisms into administration routes and therapy strategies

Ovarian cancer is a kind of malignant tumour which locates in the pelvic cavity without typical clinical symptoms in the early stages. Most patients are diagnosed in the late stage while about 60 % of them have suffered from the cancer cells spreading in the abdominal cavity. The high recurrence rate and mortality seriously damage the reproductive needs and health of women. Although recent advances in therapeutic regimes and other adjuvant therapies improved the overall survival of ovarian cancer, overcoming metastasis has still been a challenge and is necessary for achieving cure of ovarian cancer. To present potential targets and new strategies for curbing the occurrence of ovarian metastasis and the treatment of ovarian cancer after metastasis, the first section of this paper explained the metastatic mechanisms of ovarian cancer comprehensively. Nanomedicine, not limited to drug delivery, offers opportunities for metastatic ovarian cancer therapy. The second section of this paper emphasized the advantages of various administration routes of nanodrugs in metastatic ovarian cancer therapy. Furthermore, the third section of this paper focused on advances in nanotechnology-integrated strategies for targeting metastatic ovarian cancer based on the metastatic mechanisms of ovarian cancer. Finally, the challenges and prospects of nanotherapeutics for ovarian cancer metastasis therapy were evaluated. In general, the greatest emphasis on using nanotechnology-based strategies provides avenues for improving metastatic ovarian cancer outcomes in the future.

Recent progress in nanocarrier-based drug delivery systems for antitumour metastasis

Tumour metastasis is one of the major factors leading to poor prognosis as well as lower survival among cancer patients. A number of studies investigating the inhibition of tumour metastasis have been conducted. It is difficult to achieve satisfactory results with surgery alone for distant metastatic tumours, and chemotherapy can boost the healing rate and prognosis of patients. However, the poor therapeutic efficacy of chemotherapy drugs due to their low solubility, lack of tumour targeting, instability in vivo, high toxicity and multidrug resistance hinder their application. Immunotherapy is beneficial to the treatment of metastatic cancers, but it also has disadvantages such as adverse reactions and acquired resistance. Fortunately, delivery of chemotherapeutic drugs with nanocarriers can reduce systemic reactions caused by chemotherapeutic agents and inhibit metastasis. This review discusses the underlying mechanisms of metastasis, therapeutic approaches for antitumour metastasis, the advantages of nanodrug delivery systems and their application in reducing metastasis.

Nanoparticles in the diagnosis and treatment of cancer metastases: Current and future perspectives

Metastasis accounts for greater than 90% of cancer-related deaths. Despite recent advancements in conventional chemotherapy, immunotherapy, targeted therapy, and their rational combinations, metastatic cancers remain essentially untreatable. The distinct obstacles to treat metastases include their small size, high multiplicity, redundancy, therapeutic resistance, and dissemination to multiple organs. Recent advancements in nanotechnology provide the numerous applications in the diagnosis and prophylaxis of metastatic diseases, including the small particle size to penetrate cell membrane and blood vessels and their capacity to transport complex molecular 'cargo' particles to various metastatic regions such as bones, brain, liver, lungs, and lymph nodes. Indeed, nanoparticles (NPs) have demonstrated a significant ability to target specific cells within these organs. In this regard, the purpose of this review is to summarize the present state of nanotechnology in terms of its application in the diagnosis and treatment of metastatic cancer. We intensively reviewed applications of NPs in fluorescent imaging, PET scanning, MRI, and photoacoustic imaging to detect metastasis in various cancer models. The use of targeted NPs for cancer ablation in conjunction with chemotherapy, photothermal treatment, immuno therapy, and combination therapy is thoroughly discussed. The current review also highlights the research opportunities and challenges of leveraging engineering technologies with cancer cell biology and pharmacology to fabricate nanoscience-based tools for treating metastases.

Essential oil of Ruta chalepensis L. from Djibouti: Chemical Analysis and Modeling of In Vitro Anticancer Profiling

Ruta chalepensis L. (Rutaceae) is a tropical medicinal plant traditionally used in the Republic of Djibouti to treat several diseases, including tumors. In this study, the anticancer activities of this plant from Djibouti were investigated according to an in vitro evaluation method and statistical modeling. The results obtained will make it possible to complete the previous work already published on this genus of plant, in particular by using untested cancer cell lines, such as U87-MG, U2OS, RT4, PC3, NCI-N87, MRC-5, MIA-Paca2, K562, JIMT-T1, HEK293, HCT116, A549, and A2780. The main volatile compound turned out to be 2-undecanone (51.3%). Correlation modeling was performed from the principal component analysis (PCA) of IC50 of the essential oil and four active substances (vinblastine, doxorubicin, combrestatin A4, and monomethyl auristatin E) versus the cancer cell lines tested, which confirmed the effectiveness of the oil against 6 lines: U2OS, NCI-N87, MRC-5, MIA-Paca2, JIMT-T1, and HEK293. These data reveal promising prospects for good biomass management through the future exploitation of the R. chalepensis L. essential oil as a potential source of natural anticancer agents for targeted investigations.

Polymeric microneedles for enhanced drug delivery in cancer therapy

Microneedles (MNs) have attracted the interest of researchers. Polymeric MNs offer tremendous promise as drug delivery vehicles for bio-applications because of their high loading capacity, strong patient adherence, excellent biodegradability and biocompatibility, low toxicity, and extremely cheap cost. Incorporating enhanced-property nanomaterials into polymeric MNs matrix increases their features such as better mechanical strength, sustained drug delivery, lower toxicity, and higher therapeutic effects, therefore considerably increasing their biomedical application. This paper discusses polymeric MN fabrication techniques and the present status of polymeric MNs as a delivery method for enhanced drug delivery in cancer therapeutic applications. Furthermore, the opportunities and challenges of polymeric MNs for improved drug delivery in cancer therapy are highlighted.

Alpha radionuclide-chelated radioimmunotherapy promoters enable local radiotherapy/chemodynamic therapy to discourage cancer progression

BACKGROUND

Astatine-211 is an α-emitter with high-energy α-ray and high cytotoxicity for cancer cells. However, the targeted alpha therapy (TAT) also suffers from insufficient systematic immune activation, resulting in tumor metastasis and relapse. Combined immune checkpoint blockade (ICB) with chemodynamic therapy (CDT) could boost antitumor immunity, which may magnify the immune responses of TAT. This study aims to discourage tumor metastasis and relapse by tri-model TAT-CDT-ICB strategy.

METHODS

We successfully designed Mn-based radioimmunotherapy promoters (²¹¹At-ATE-MnO₂-BSA), which are consisting of ²¹¹At, MnO₂ and bovine serum albumin (BSA). The efficacy of ²¹¹At-ATE-MnO₂-BSA was studied as monotherapy or in combination with anti-PD-L1 in both metastatic and relapse models. The immune effects of radioimmunotherapy promoters on cytotoxic T lymphocytes and dendritic cells (DCs) were analyzed by flow cytometry. Enzyme-linked immunosorbent assay and immunofluorescence were used to explore the underlying mechanism.

RESULTS

Such radioimmunotherapy promoters could not only enhance the therapeutic outcomes of TAT and CDT, but also induce robust anti-cancer immune activity by activating dendritic cells. More intriguingly, ²¹¹At-ATE-MnO₂-BSA could effectively suppress the growths of primary tumors and distant tumors when combined with immune checkpoint inhibitors.

CONCLUSIONS

The tri-model TAT-CDT-ICB strategy provides a long-term immunological memory, which can protect against tumor rechallenge after eliminating original tumors. Therefore, this work presents a novel approach for TAT-CDT-ICB tri-modal cancer therapy with repressed metastasis and relapse in clinics.

Biocompatible tumor-targeted GQDs nanocatalyst for chemodynamic tumor therapy

To deal with the complex tumor microenvironment (TME), chemodynamic therapy (CDT) has been developed, which uses nanocatalysts simulating peroxidase to convert high concentration hydrogen peroxide (H₂O₂) into highly toxic hydroxyl radicals (˙OH) in situ and effectively kills tumor cells. Due to the low catalytic activity of traditional nanocatalysts, the present CDT treatment has to be combined with other anti-tumor therapies, which increases the complexity and uncertainty of the treatment. Thus, developing new nanocatalysts with stable and high enzymatic activity is the key point to CDT treatment. Graphene quantum dots (GQDs) are important metal-free catalysts with intrinsic peroxidase-like activity due to their excellent electron transport performance. Here, we prepare a nitrogen-doped GQD (NGOD) nanocatalyst, which displays much higher peroxidase activity than known metal nanocatalysts. The NGQD nanocatalyst is further grafted with RGDS peptide-modified polyethylene glycol (PEG), which guides the nanocatalyst to the tumor area and increases its circulation time in blood. The as-produced RGDS-PEG@NG nanocatalyst displays stable and high peroxidase activity, which achieves the conversion of H₂O₂ → ˙OH in the TME. Through an in vivo study it has been observed that RGDS-PEG@NGs obviously inhibit tumor growth without combining with other treatment methods and show excellent biocompatibility, which provides a unique idea for the application of GQDs in CDT.

Multifunctional DNAzyme-Anchored Metal-Organic Framework for Efficient Suppression of Tumor Metastasis

High mortality and rapid development of metastasis requires the development of more effective antimetastasis strategies. However, conventional therapeutic methods, including surgery, radiation therapy, and chemotherapy, show less effectiveness in curbing the metastatic spread of cancer cells and the formation of metastases. A therapeutic platform, targeting the early stage of metastasis cascade, could effectively prevent metastasis dissemination. Herein, Fe/Mn-based metal-organic frameworks (FMM) were constructed for the delivery of a specific DNAzyme with high catalytic cleavage activity on the metastasis-involved Twist mRNA, thus efficiently inhibiting the invasion of cancer cells through DNAzyme-catalyzed gene silencing. Highly potent combined gene/chemodynamic therapy is achieved from the self-supplied DNAzyme cofactors and efficient glutathione depletion. Importantly, by virtue of the intrinsic photo-to-thermal conversion of the FMM nanocarriers, our combined therapeutic strategy could be further promoted under photothermal stimuli to speed up the Fenton reaction and to accelerate the release of the Twist DNAzyme with efficient gene therapy. Consequently, the effective elimination of tumors and the blockage of metastasis are simultaneously achieved under photothermal/magnetic resonance imaging guidance. This work aims at developing versatile theranostic agents to combat metastatic tumors.

Carbon Dots in Biomedicine: A Review

Despite the rapid development of science and technology, the effective treatment of cancer still threatens human life and health. However, the success of cancer treatment is closely related to early diagnosis, identification, and effective treatment. In recent years, with the strengthening of the development and research of nanomaterials for cancer diagnosis and treatment, researchers have found that carbon dots (CDs) have the advantages of wide absorption, excellent biocompatibility, diverse imaging characteristics, and photostability and are widely used in various fields, such as sensing, imaging, and drug/gene transportation. Recently, researchers also discovered that CDs could be used as an effective photosensitizer to generate active oxygen or convert light energy into heat under the stimulation of the external lasers, making them have the effects of photothermal and photodynamic therapy for cancer. In this review, we first outline the single-modal and multimodal imaging analysis of CDs in cancer cells. After introducing diversified imaging functions, we focused on the design and the latest research progress of CDs in phototherapy and introduced in detail the strategies of CDs in phototherapy treatment and the challenges faced by clinical applications. We hope that this overview can provide important insights for researchers and accelerate the pace of research on CDs in imaging-guided phototherapy treatment.

Innate Immune Invisible Ultrasmall Gold Nanoparticles-Framework for Synthesis and Evaluation

Nanomedicine is seen as a potential central player in the delivery of personalized medicine. Biocompatibility issues of nanoparticles have largely been resolved over the past decade. Despite their tremendous progress, less than 1% of applied nanosystems can hit their intended target location, such as a solid tumor, and this remains an obstacle to their full ability and potential with a high translational value. Therefore, achieving immune-tolerable, blood-compatible, and biofriendly nanoparticles remains an unmet need. The translational success of nanoformulations from bench to bedside involves a thorough assessment of their design, compatibility beyond cytotoxicity such as immune toxicity, blood compatibility, and immune-mediated destruction/rejection/clearance profile. Here, we report a one-pot process-engineered synthesis of ultrasmall gold nanoparticles (uGNPs) suitable for better body and renal clearance delivery of their payloads. We have obtained uGNP sizes of as low as 3 nm and have engineered the synthesis to allow them to be accurately sized (almost nanometer by nanometer). The synthesized uGNPs are biocompatible and can easily be functionalized to carry drugs, peptides, antibodies, and other therapeutic molecules. We have performed in vitro cell viability assays, immunotoxicity assays, inflammatory cytokine analysis, a complement activation study, and blood coagulation studies with the uGNPs to confirm their safety. These can help to set up a long-term safety-benefit framework of experimentation to reveal whether any designed nanoparticles are immune-tolerable and can be used as payload carriers for next-generation vaccines, chemotherapeutic drugs, and theranostic agents with better body clearance ability and deep tissue penetration.

Smart transformable nanomedicines for cancer therapy

Despite that great progression has been made in nanoparticulate drug delivery systems (nano-DDS), multiple drug delivery dilemmas still impair the delivery efficiency of nanomedicines. Rational design of smart transformable nano-DDS based on the in vivo drug delivery process represents a promising strategy for overcoming delivery obstacle of nano-DDS. In recent years, tremendous efforts have been devoted to developing smart transformable anticancer nanomedicines. Herein, we provide a review to outline the advances in this emerging field. First, smart size-reducible nanoparticles (NPs) for deep tumor penetration are summarized, including carrier degradation-induced, protonation-triggered and photobleaching-induced size reduction. Second, emerging transformable nanostructures for various therapeutic applications are discussed, including prolonging tumor retention, reversing drug-resistance, inhibiting tumor metastasis, preventing tumor recurrence and non-pharmaceutical therapy. Third, shell-detachable nanocarriers are introduced, focusing on chemical bonds breaking-initiated, charge repulsion-mediated and exogenous stimuli-triggered shell detachment approaches. Finally, the future perspectives and challenges of transformable nanomedicines in clinical cancer therapy are highlighted.

Progress and perspective of microneedle system for anti-cancer drug delivery

Transdermal drug delivery exhibited encouraging prospects, especially through superficial drug administration routes. However, only a few limited lipophilic drug molecules could cross the skin barrier, those are with low molecular weight and rational Log P value. Microneedles (MNs) can overcome these limitations to deliver numerous drugs into the dermal layer by piercing the outermost skin layer of the body. In the case of superficial cancer treatments, topical drug administration faces severely low transfer efficiency, and systemic treatments are always associated with side effects and premature drug degradation. MN-based systems have achieved excellent technical capabilities and been tested for pre-clinical chemotherapy, photothermal therapy, photodynamic therapy, and immunotherapy. In this review, we will focus on the features, progress, and opportunities of MNs in the anticancer drug delivery system. Then, we will discuss the strategies and advantages in these works and summarize challenges, perspectives, and translational potential for future applications.

On/off switchable epicatechin-based ultra-sensitive MRI-visible nanotheranostics - see it and treat it

Nanotechnology has a remarkable impact on the preclinical development of future medicines. However, the complicated preparation and systemic toxicity to living systems prevent them from translation to clinical applications. In the present report, we developed a polyepicatechin-based on/off switchable ultra-sensitive magnetic resonance imaging (MRI) visible theranostic nanoparticle (PEMN) for image-guided photothermal therapy (PTT) using our strategy of integrating polymerization and biomineralization into the protein template. We have exploited natural polyphenols as the near infra-red (NIR) switchable photothermal source and MnO₂ for the MRI-guided theranostics. PEMN demonstrates excellent MRI contrast ability with a longitudinal relaxivity value up to 30.01 mM^-1 s^-1. PEMN has shown great tumor inhibition on orthotopic breast tumors and the treatment could be made switchable with an on/off interchangeable mode as needed. PEMN was found to be excretable mainly through the kidneys, avoiding potential systemic toxicity. Thus, PEMN could be extremely useful for developing on-demand therapeutics via'see it and treat it' means with distinguished MRI capability and on/off switchable photothermal properties.

Opportunities and obstacles of targeted therapy and immunotherapy in small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive malignant tumour which accounts for approximately 13-15% of all newly diagnosed lung cancer cases. To date, platinum-based chemotherapy are still the first-line treatments for SCLC. However, chemotherapy resistance and systemic toxicity limit the long-term clinical outcome of first-line treatment in SCLC. Recent years, targeted therapy and immunotherapy have made great breakthrough in cancer therapy, and researchers aim to exploit both as a single agent or in combination with chemotherapy to improve the survival of SCLC patients, but limited effectiveness and the adverse events remain the major obstacles in the treatment of SCLC. To overcome these challenges for SCLC therapies, prevention and early diagnosis for this refractory disease is very important. At the same time, we should reveal more information about the pathogenesis of SCLC and the mechanism of drug resistance. Finally, new treatment strategies should also be taken into considerations, such as repurposing drug, optimising of targets, combination therapy strategies or prognostic biomarkers to enhance therapeutic effects and decrease the adverse events rates in SCLC patients. This article will review the molecular biology characteristics of SCLC and discuss the opportunities and obstacles of the current therapy for SCLC patients.

Metastatic disease in head & neck oncology

The head and neck district represents one of the most frequent sites of cancer, and the percentage of metastases is very high in both loco-regional and distant areas. Prognosis refers to several factors: a) stage of disease; b) loco-regional relapses; c) distant metastasis. At diagnosis, distant metastases of head and neck cancers are present in about 10% of cases with an additional 20-30% developing metastases during the course of their disease. Diagnosis of distant metastases is associated with unfavorable prognosis, with a median survival of about 10 months. The aim of the present review is to provide an update on distant metastasis in head and neck oncology. Recent achievements in molecular profiling, interaction between neoplastic tissue and the tumor microenvironment, oligometastatic disease concepts, and the role of immunotherapy have all deeply changed the therapeutic approach and disease control. Firstly, we approach topics such as natural history, epidemiology of distant metastases and relevant pathological and radiological aspects. Focus is then placed on the most relevant clinical aspects; particular attention is reserved to tumours with distant metastasis and positive for EBV and HPV, and the oligometastatic concept. A substantial part of the review is dedicated to different therapeutic approaches. We highlight the role of immunotherapy and the potential effects of innovative technologies. Lastly, we present ethical and clinical perspectives related to frailty in oncological patients and emerging difficulties in sustainable socio-economical governance.

Cu2 MoS4 /Au Heterostructures with Enhanced Catalase-Like Activity and Photoconversion Efficiency for Primary/Metastatic Tumors Eradication by Phototherapy-Induced Immunotherapy

Photoimmunotherapy can not only effectively ablate the primary tumor but also trigger strong antitumor immune responses against metastatic tumors by inducing immunogenic cell death. Herein, Cu₂ MoS₄ (CMS)/Au heterostructures are constructed by depositing plasmonic Au nanoparticles onto CMS nanosheets, which exhibit enhanced absorption in near-infrared (NIR) region due to the newly formed mid-gap state across the Fermi level based on the hybridization between Au 5d orbitals and S 3p orbitals, thus resulting in more excellent photothermal therapy and photodynamic therapy (PDT) effect than single CMS upon NIR laser irradiation. The CMS and CMS/Au can also serve as catalase to effectively relieve tumor hypoxia, which can enhance the therapeutic effect of O₂ -dependent PDT. Notably, the NIR laser-irradiated CMS/Au can elicit strong immune responses via promoting dendritic cells maturation, cytokine secretion, and activating antitumor effector T-cell responses for both primary and metastatic tumors eradication. Moreover, CMS/Au exhibits outstanding photoacoustic and computed tomography imaging performance owing to its excellent photothermal conversion and X-ray attenuation ability. Overall, the work provides an imaging-guided and phototherapy-induced immunotherapy based on constructing CMS/Au heterostructures for effectively tumor ablation and cancer metastasis inhibition.

Cascade reaction-mediated efficient ferroptosis synergizes with immunomodulation for high-performance cancer therapy

Graphical abstract of the cascade reaction-mediated efficient ferroptosis which synergizes with immunomodulation/immunotherapy for high-performance tumor ablation.

In vivo comparison of the biodistribution and long-term fate of colloids – gold nanoprisms and nanorods – with minimum surface modification

Aim: To study the difference in biodistribution of gold nanoprisms (NPr) and nanorods (NR), PEGylated to ensure colloidal stability. Materials & methods: Surface changes were studied for nanoparticles in different media, while the biodistribution was quantified and imaged in vivo. Results: Upon interaction with the mouse serum, NR showed more abrupt changes in surface properties than NPr. In the in vivo tests, while NPr accumulated similarly in the spleen and liver, NR showed much higher gold presence in the spleen than in liver; together with some accumulation in kidneys, which was nonexistent in NPr. NPr were cleared from the tissues 2 months after administration, while NR were more persistent. Conclusion: The results suggest that the differential biodistribution is caused by size-/shape-dependent interactions with the serum.

A Multifunctional Cascade Bioreactor Based on Hollow-Structured Cu2 MoS4 for Synergetic Cancer Chemo-Dynamic Therapy/Starvation Therapy/Phototherapy/Immunotherapy with Remarkably Enhanced Efficacy

The unique tumor microenvironment (TME) facilitates cancer proliferation and metastasis, and it is hard to cure cancer completely via monotherapy. Herein, a multifunctional cascade bioreactor based on hollow mesoporous Cu₂ MoS₄ (CMS) loaded with glucose oxidase (GOx) is constructed for synergetic cancer therapy by chemo-dynamic therapy (CDT)/starvation therapy/phototherapy/immunotherapy. The CMS harboring multivalent elements (Cu^1+/2+ , Mo^4+/6+ ) exhibit Fenton-like, glutathione (GSH) peroxidase-like and catalase-like activity. Once internalized into the tumor, CMS could generate ·OH for CDT via Fenton-like reaction and deplete overexpressed GSH in TME to alleviate antioxidant capability of the tumors. Moreover, under hypoxia TME, the catalase-like CMS could react with endogenous H₂ O₂ to generate O₂ for activating the catalyzed oxidation of glucose by GOx for starvation therapy accompanied with the regeneration of H₂ O₂ . The regenerated H₂ O₂ can devote to Fenton-like reaction for realizing GOx-catalysis-enhanced CDT. Meanwhile, the CMS under 1064 nm laser irradiation shows remarkable tumor-killing ability by phototherapy due to its excellent photothermal conversion efficiency (η = 63.3%) and cytotoxic superoxide anion (·O₂ ^- ) generation performance. More importantly, the PEGylated CMS@GOx-based synergistic therapy combined with checkpoint blockade therapy could elicit robust immune responses for both effectively ablating primary tumors and inhibiting cancer metastasis.