2D Cu-Bipyridine MOF Nanosheet as an Agent for Colon Cancer Therapy: A Three-in-One Approach for Enhancing Chemodynamic Therapy

Tumor microenvironment activation amplify oxidative stress promoting tumor energy remodeling for mild photothermal therapy and cuproptosis

Tumor metabolic reprogramming requires high levels of adenosine triphosphate (ATP) to maintain treatment resistance, which poses major challenges to chemotherapy and photothermal therapy. Especially, high levels of ATP promote copper ion efflux for limiting the curative effect of cuproptosis. Here, an H2S-responsive mesoporous Cu2Cl(OH)3-loading chemotherapeutic cisplatin (CDDP) was synthesized, and the final nanoparticle, CDDP@Cu2Cl(OH)3-CDs (CDCuCDs), was encapsulated by electrostatic action with carbon dots (CDs). CDCuCDs reacted with overproduction H2S in colon tumor to produce photothermic copper sulfide for photothermal therapy. CDDP was released by lysis to achieve chemotherapeutic effects. Importantly, CDDP elevated H2O2 levels in cells through a cascade reaction and continuously transforms H2O2 into highly cytotoxic •OH through chemodynamic therapy between H2O2 and Cu+, which enables nanoparticles to generate •OH and improve the chemotherapeutic efficacy. Highly toxic •OH disrupts mitochondrial homeostasis, prohibiting it from performing normal energy-supplying functions. Down-regulated ATP inhibits heat shock protein expression, which promotes the therapeutic effect of mild photothermal therapy and reduces the efflux of intracellular copper ions, thus improving the therapeutic effect of cuproptosis. Our research provides a potential therapeutic strategy using overproduction H2S responses in tumors, allowing tumor microenvironment-activated •OH nanogenerators to promote tumor energy remodeling for cancer treatment.

Engineering polyvinyl alcohol microspheres with capability for use in photothermal/chemodynamic therapy for enhanced transarterial chemoembolization

Transarterial chemoembolization (TACE) is widely recognized as a non-surgical treatment approach for advanced liver cancer, combining chemotherapy with the blockage of blood vessels supplying the tumor. To enhance the efficacy of TACE and address chemotherapy resistance, there is growing interest in the development of multifunctional embolic microspheres. In this study, multifunctional PVA microspheres, which encapsulate MIT as a chemotherapeutic drug, PPY as a photothermal agent, and Fe3O4 as a chemodynamic therapy agent, were prepared successfully. The results demonstrated that the developed multifunctional PVA microspheres not only exhibit favorable drug release, photothermal therapy, and chemodynamic therapy performance, but also show a promising synergistic therapeutic effect both in vitro and in vivo. Consequently, the engineered multifunctional PVA microspheres hold tremendous promise for enhancing TACE effectiveness and have the potential to overcome limitations associated with traditional liver cancer treatments.

Two-dimensional metal organic frameworks in cancer treatment

With large specific surface area, controllable pore size, increased active sites, and structural stability, two-dimensional metal organic frameworks (2D MOFs) have emerged as promising nanomedicines in cancer therapy. These distinctive features make 2D MOFs particularly advantageous in cancer treatment and the corresponding application has gained considerable popularity, signifying significant application potential. Herein, recent advances in various applications including drug delivery and chemotherapy, photodynamic therapy, sonodynamic therapy, chemodynamic therapy, catalytic therapy, and combined therapy were summarized, with emphasis on the latest progress of new materials and mechanisms for these processes. Moreover, the current challenges, potential solutions, and possible future directions are discussed as well.

Metal-Organic Framework Nanomaterials as a Medicine for Catalytic Tumor Therapy: Recent Advances

Nanomaterials, with unique physical, chemical, and biocompatible properties, have attracted significant attention as an emerging active platform in cancer diagnosis and treatment. Amongst them, metal-organic framework (MOF) nanostructures are particularly promising as a nanomedicine due to their exceptional surface functionalities, adsorption properties, and organo-inorganic hybrid characteristics. Furthermore, when bioactive substances are integrated into the structure of MOFs, these materials can be used as anti-tumor agents with superior performance compared to traditional nanomaterials. In this review, we highlight the most recent advances in MOFs-based materials for tumor therapy, including their application in cancer treatment and the underlying mechanisms.

H2S-driven chemotherapy and mild photothermal therapy induced mitochondrial reprogramming to promote cuproptosis

The elevated level of hydrogen sulfide (H2S) in colon cancer hinders complete cure with a single therapy. However, excessive H2S also offers a treatment target. A multifunctional cascade bioreactor based on the H2S-responsive mesoporous Cu2Cl(OH)3-loaded hypoxic prodrug tirapazamine (TPZ), in which the outer layer was coated with hyaluronic acid (HA) to form TPZ@Cu2Cl(OH)3-HA (TCuH) nanoparticles (NPs), demonstrated a synergistic antitumor effect through combining the H2S-driven cuproptosis and mild photothermal therapy. The HA coating endowed the NPs with targeting delivery to enhance drug accumulation in the tumor tissue. The presence of both the high level of H2S and the near-infrared II (NIR II) irradiation achieved the in situ generation of photothermic agent copper sulfide (Cu9S8) from the TCuH, followed with the release of TPZ. The depletion of H2S stimulated consumption of oxygen, resulting in hypoxic state and mitochondrial reprogramming. The hypoxic state activated prodrug TPZ to activated TPZ (TPZ-ed) for chemotherapy in turn. Furthermore, the exacerbated hypoxia inhibited the synthesis of adenosine triphosphate, decreasing expression of heat shock proteins and subsequently improving the photothermal therapy. The enriched Cu2+ induced not only cuproptosis by promoting lipoacylated dihydrolipoamide S-acetyltransferase (DLAT) heteromerization but also performed chemodynamic therapy though catalyzing H2O2 to produce highly toxic hydroxyl radicals ·OH. Therefore, the nanoparticles TCuH offer a versatile platform to exert copper-related synergistic antitumor therapy.

A chemo/chemodynamic nanoparticle based on hyaluronic acid induces ferroptosis and apoptosis for triple-negative breast cancer therapy

Triple-negative breast cancer (TNBC) poses a serious threat to women's life and health due to its high malignancy, strong invasiveness, and propensity for early recurrence and metastasis. Therefore, there is an urgent need to develop a highly effective and low-toxic TNBC treatment scheme to enhance the anti-cancer efficacy and prolong the survival of patients. In this work, we designed and synthesized a chemodynamic therapy (CDT) agent (HA-Fc-Mal). The chemo/chemodynamic (CT/CDT) nanoparticle (HCM@DOX) based on hyaluronic acid induces ferroptosis and apoptotic for TNBC therapy was constructed via self-assembled of HA-Fc-Mal and doxorubicin (DOX). HCM@DOX orderly realized the TNBC targeting, controlled DOX release, GSH depletion and induce ROS erupt. In vivo and in vitro experiments confirmed that HCM@DOX inhibited the growth of 4 T1 tumors through ferroptosis and apoptosis, and the tumor inhibition rate was as high as 81.87 %. In addition, HCM@DOX significantly inhibited lung metastasis and exhibited excellent biosafety. Overall, our findings offer a new strategy for TNBC therapy using a CT/CDT nanoparticle that induces ferroptosis and apoptosis.

Selenium-Based Catalytic Scavengers for Concurrent Scavenging of H2 S and Reactive Oxygen Species

Hydrogen sulfide (H2 S) is an endogenous gasotransmitter that plays important roles in redox signaling. H2 S overproduction has been linked to a variety of disease states and therefore, H2 S-depleting agents, such as scavengers, are needed to understand the significance of H2 S-based therapy. It is known that elevated H2 S can induce oxidative stress with elevated reactive oxygen species (ROS) formation, such as in H2 S acute intoxication. We explored the possibility of developing catalytic scavengers to simultaneously remove H2 S and ROS. Herein, we studied a series of selenium-based molecules as catalytic H2 S/H2 O2 scavengers. Inspired by the high reactivity of selenoxide compounds towards H2 S, 14 diselenide/monoselenide compounds were tested. Several promising candidates such as S6 were identified. Their activities in buffers, as well as in plasma- and cell lysate-containing solutions were evaluated. We also studied the reaction mechanism of this scavenging process. Finally, the combination of the diselenide catalyst and photosensitizers was used to achieve light-induced H2 S removal. These Se-based scavengers can be useful tools for understanding H2 S/ROS regulations.

Metal-organic framework-based advanced therapeutic tools for antimicrobial applications

The escalating concern over conventional antibiotic resistance has emphasized the urgency in developing innovative antimicrobial agents. In recent times, metal-organic frameworks (MOFs) have garnered significant attention within the realm of antimicrobial research due to their multifaceted antimicrobial attributes, including the sustained release of intrinsic or exogenous antimicrobial components, chemodynamically catalyzed generation of reactive oxygen species (ROS), and formation of photogenerated ROS. This comprehensive review provides a thorough overview of the synthetic approaches employed in the production of MOF-based materials, elucidating their underlying antimicrobial mechanisms in depth. The focal point lies in elucidating the research advancements across various antimicrobial modalities, encompassing intrinsic component release system, extraneous component release system, auto-catalytical system, and energy conversion system. Additionally, the progress of MOF-based antimicrobial materials in addressing wound infections, osteomyelitis, and periodontitis is meticulously elucidated, culminating in a summary of the challenges and potential opportunities inherent within the realm of antimicrobial applications for MOF-based materials. STATEMENT OF SIGNIFICANCE: Growing concerns about conventional antibiotic resistance emphasized the need for alternative antimicrobial solutions. Metal-organic frameworks (MOFs) have gained significant attention in antimicrobial research due to their diverse attributes like sustained antimicrobial components release, catalytic generation of reactive oxygen species (ROS), and photogenerated ROS. This review covers MOF synthesis and their antimicrobial mechanisms. It explores advancements in intrinsic and extraneous component release, auto-catalysis, and energy conversion systems. The paper also discusses MOF-based materials' progress in addressing wound infections, osteomyelitis, and periodontitis, along with existing challenges and opportunities. Given the lack of related reviews, our findings hold promise for future MOF applications in antibacterial research, making it relevant to your journal's readership.

Recent Advances of Emerging Metal-Containing Two-Dimensional Nanomaterials in Tumor Theranostics

In recent years, metal-containing two-dimensional (2D) nanomaterials, among various 2D nanomaterials have attracted widespread attention because of their unique physical and chemical properties, especially in the fields of biomedical applications. Firstly, the review provides a brief introduction to two types of metal-containing 2D nanomaterials, based on whether metal species take up the major skeleton of the 2D nanomaterials. After this, the synthetical approaches are summarized, focusing on two strategies similar to other 2D nanomaterials, top-down and bottom-up methods. Then, the performance and evaluation of these 2D nanomaterials when applied to cancer therapy are discussed in detail. The specificity of metal-containing 2D nanomaterials in physics and optics makes them capable of killing cancer cells in a variety of ways, such as photodynamic therapy, photothermal therapy, sonodynamic therapy, chemodynamic therapy and so on. Besides, the integrated platform of diagnosis and treatment and the clinical translatability through metal-containing 2D nanomaterials is also introduced in this review. In the summary and perspective section, advanced rational design, challenges and promising clinical contributions to cancer therapy of these emerging metal-containing 2D nanomaterials are discussed.

Recent advances in metal-organic frameworks: Synthesis, application and toxicity

Metal-organic frameworks (MOFs) are a new class of crystalline porous hybrid materials with high porosity, large specific surface area and adjustable channel structure and biocompatibility, which are being investigated with increasing interest for energy storage and conversion, gas adsorption/separation, catalysis, sensing and biomedicine. However, the practical applications of MOFs make them release into the environment inevitable, posing a threat to humans and organisms. In this article, we cover advances in the currently available MOFs synthesis methods and the emerging applications of MOFs, especially in the biomedical field (therapeutic agents and bioimaging). Additionally, after evaluating the current status of main exposure routes and affecting factors in the field of MOFs-toxicity, the molecular mechanism is also clarified and identified. Knowledge gaps are identified from such a summarization and frontier development are explored for MOFs. Afterwards, we also present the limitations, challenges, and future perspectives in the study of the entire life cycle of MOFs. This review emphasizes the need for a more targeted discussion of the latest, widely used and effective versatile material class in order to exploit the full potential of high-performance and non-toxicity MOFs in the future.

Copper(II)-MOFs for bio-applications

The recent development and implementation of copper-based metal-organic frameworks in biological applications are reviewed. The advantages of the presence of copper in MOFs for relevant applications such as drug delivery, cancer treatment, sensing, and antimicrobial are highlighted. Advanced composites such as MOF-polymers are playing critical roles in developing materials for specific applications.

Photothermal-Responsive Intelligent Hybrid of Hierarchical Carbon Nanocages Encapsulated by Metal-Organic Hydrogels for Sensitized Photothermal Therapy

Hierarchical carbon nanocages as emerging nanomaterials have a great potential for photothermal therapy due to their unique porous structure, high specific surface area, and excellent photothermal property. Herein, a hierarchical nitrogen-doped carbon nanocage (hNCNC) is introduced as a second near-infrared photothermal agent, and then functionalizes it with metal-organic hydrogel (MOG) to form a thermal-responsive switch for sensitized photothermal therapy. Upon 1064 nm light irradiation, the hNCNCs exhibit a remarkable photothermal conversion efficiency of 65.9% owing to a high near-infrared extinction coefficient. Meanwhile, due to the hierarchical structure, hNCNCs show 60.2% (wt./wt.) loading efficiency of quercetin, a heat shock protein (Hsp70) inhibitor. Through thermal-driven dry-gel transformation, the coating MOGs intelligently release the encapsulated quercetin for sensitizing cancer cells to heat. Based on the synergistic effect of hyperthermia elevation and thermal-driven drug release, the dual thermal utilization platform achieves effective photothermal tumor ablation in vivo under low concentration of hNCNCs and mild irradiation, which provides a new diagram of intelligent responsive photothermal agents for enhanced photothermal therapy.

Nano-enabled colorectal cancer therapy

Colorectal cancer (CRC), one of the most common and deadliest diseases worldwide, poses a great health threat and social burden. The clinical treatments of CRC encompassing surgery, chemotherapy, and radiotherapy are challenged with toxicity, therapy resistance, and recurrence. In the past two decades, targeted therapy and immunotherapy have greatly improved the therapeutic benefits of CRC patients but they still suffer from drug resistance and low response rates. Very recently, gut microbiota regulation has exhibited a great potential in preventing and treating CRC, as well as in modulating the efficacy and toxicity of chemotherapy and immunotherapy. In this review, we provide a cutting-edge summary of nanomedicine-based treatment in colorectal cancer, highlighting the recent progress of oral and systemic tumor-targeting and/or tumor-activatable drug delivery systems as well as novel therapeutic strategies against CRC, including nano-sensitizing immunotherapy, anti-inflammation, gut microbiota modulation therapy, etc. Finally, the recent endeavors to address therapy resistance, metastasis, and recurrence in CRC were discussed. We hope this review could offer insight into the design and development of nanomedicines for CRC and beyond.

A pH-responsive bi-MIL-88B MOF coated with folic acid-conjugated chitosan as a promising nanocarrier for targeted drug delivery of 5-Fluorouracil

Cancer has remained one of the leading causes of death worldwide, with a lack of effective treatment. The intrinsic shortcomings of conventional therapeutics regarding tumor specificity and non-specific toxicity prompt us to look for alternative therapeutics to mitigate these limitations. In this regard, we developed multifunctional bimetallic (FeCo) bi-MIL-88B-FC MOFs modified with folic acid-conjugated chitosan (FC) as drug delivery systems (DDS) for targeted delivery of 5-Fluorouracil (5-FU). The bi-MIL-88B nanocarriers were characterized through various techniques, including powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray, thermogravimetric analysis, and Fourier transform infrared spectroscopy. Interestingly, 5-FU@bi-MIL-88B-FC showed slower release of 5-FU due to a gated effect phenomenon endowed by FC surface coating compared to un-modified 5-FU@bi-MIL-88B. The pH-responsive drug release was observed, with 58% of the loaded 5-FU released in cancer cells mimicking pH (5.2) compared to only 24.9% released under physiological pH (5.4). The in vitro cytotoxicity and cellular internalization experiments revealed the superiority of 5-FU@bi-MIL-88B-FC as a highly potent targeted DDS against folate receptor (FR) positive SW480 cancer cells. Moreover, due to the presence of Fe and Co in the structure, bi-MIL-88B exhibited peroxidase-like activity for chemodynamic therapy. Based on the results, 5-FU@bi-MIL-88B-FC could serve as promising candidate for smart DDS by sustained drug release and selective targeting.

Porous Framework Materials for Bioimaging and Cancer Therapy

Cancer remains one of the most pressing diseases in the world. Traditional treatments, including surgery, chemotherapy, and radiotherapy still show certain limitations. Recently, numerous cancer treatments have been proposed in combination with novel materials, such as photothermal therapy, chemodynamic therapy, immunotherapy, and a combination of therapeutic approaches. These new methods have shown significant advantages in reducing side effects and synergistically enhancing anti-cancer efficacy. In addition to the above approaches, early diagnosis and in situ monitoring of lesion areas are also important for reducing side effects and improving the success rate of cancer therapy. This depends on the decent use of bioimaging technology. In this review, we mainly summarize the recent advances in porous framework materials for bioimaging and cancer therapy. In addition, we present future challenges relating to bioimaging and cancer therapy based on porous framework materials.

Nanomedicine-based multimodal therapies: Recent progress and perspectives in colon cancer

Colon cancer has attracted much attention due to its annually increasing incidence. Conventional chemotherapeutic drugs are unsatisfactory in clinical application because of their lack of targeting and severe toxic side effects. In the past decade, nanomedicines with multimodal therapeutic strategies have shown potential for colon cancer because of their enhanced permeability and retention, high accumulation at tumor sites, co-loading with different drugs, and comb-ination of various therapies. This review summarizes the advances in research on various nanomedicine-based therapeutic strategies including chemotherapy, radiotherapy, phototherapy (photothermal therapy and photodynamic therapy), chemodynamic therapy, gas therapy, and immunotherapy. Additionally, the therapeutic mechanisms, limitations, improvements, and future of the above therapies are discussed.

Implications of hydrogen sulfide in colorectal cancer: Mechanistic insights and diagnostic and therapeutic strategies

Hydrogen sulfide (H₂S) is an important signaling molecule in colorectal cancer (CRC). It is produced in the colon by the catalytic synthesis of the colonocytes' enzymatic systems and the release of intestinal microbes, and is oxidatively metabolized in the colonocytes' mitochondria. Both endogenous H₂S in colonic epithelial cells and exogenous H₂S in intestinal lumen contribute to the onset and progression of CRC. The up-regulation of endogenous synthetases is thought to be the cause of the elevated H₂S levels in CRC cells. Different diagnostic probes and combination therapies, as well as tumor treatment approaches through H₂S modulation, have been developed in recent years and have become active area of investigation for the diagnosis and treatment of CRC. In this review, we focus on the specific mechanisms of H₂S production and oxidative metabolism as well as the function of H₂S in the occurrence, progression, diagnosis, and treatment of CRC. We also discuss the present challenges and provide insights into the future research of this burgeoning field.