An Endogenous H2S-Activated Nanoplatform for Triple Synergistic Therapy of Colorectal Cancer

Autophagic cell death induced by pH modulation for enhanced iron-based chemodynamic therapy

Iron-based chemodynamic therapy (CDT) exhibits commendable biocompatibility and selectivity, but its efficacy is constrained by the intracellular pH of tumors. To overcome this obstacle, we constructed a silica delivery platform loaded with autophagy-inducing reagents (rapamycin, RAPA) and iron-based Fenton reagents (Fe3O4). This platform was utilized to explore a novel strategy that leverages autophagy to decrease tumor acidity, consequently boosting the effectiveness of CDT. Both in vitro and in vivo experiments revealed that RAPA prompted the generation of acidic organelles (e.g., autophagic vacuoles and autophagosomes), effectively changing the intracellular pH in the tumor microenvironment. Furthermore, RAPA-induced tumor acidification significantly amplified the efficacy of Fe3O4-based Fenton reactions, consequently increasing the effectiveness of Fe3O4-based CDT. This innovative approach, which leverages the interplay between autophagy induction and iron-based CDT, shows promise in overcoming the limitations posed by tumor pH, thus offering a more efficient approach to tumor treatments.

Research progress on the synthesis, performance regulation, and applications of Prussian blue nanozymes

Nanocatalytic medicine offers a novel solution to address the issues of low efficacy, potential side effects, and the development of drug resistance associated with traditional therapies. Therefore, developing highly efficient and durable nanozymes is of great significance for treating diseases related to oxidative stress. In recent years, prussian blue nanoparticles (PBNPs) have been demonstrated to possess multiple enzyme-like catalytic activities and are thus referred to as prussian blue nanozymes (PBNZs). Their excellent biocompatibility and biodegradability make PBNZs promising candidates as biomedical materials. Due to their remarkable catalytic activities, PBNZs have shown great potential in various biomedical applications, such as heavy metal detoxification, antioxidative damage, and anticancer therapies. This paper systematically summarizes the Synthetic strategies of PBNZs, analyzes the regulatory factors of their catalytic performance, and highlights the corresponding modulation methods. Furthermore, the biomedical applications of PBNZs are also reviewed. This study aims to provide researchers with insights and inspirations for the design and preparation of high-performance PBNZs.

Modulation of β secretase and neuroinflammation by biomimetic nanodelivery system for Alzheimer's disease therapy

Alzheimer's disease (AD) is an irreversible and progressive neurodegenerative disorder. The vicious circle between amyloid-β peptide (Aβ) overgeneration and microglial dysfunction is an important pathological event that promotes AD progression. However, therapeutic strategies toward only Aβ or microglial modulation still have many problems. Herein, inspired by the Aβ transportation, an Aβ-derived peptide (CKLVFFAED) engineered biomimetic nanodelivery system (MK@PC-R NPs) is reported for realizing BBB penetration and reprogram neuron and microglia in AD lesion sites. This hollow mesoporous Prussian blue-based MK@PC-R NPs carrying curcumin and miRNA-124 can down-regulate β secretase expression, thereby inhibiting Aβ production and reducing Aβ-induced neurotoxicity. Meanwhile, MK@PC-R NPs with excellent antioxidant and anti-inflammatory properties could normalize the microglial phenotype and promote Aβ degradation, providing neuroprotection. As expected, after treatment with MK@PC-R NPs, the Aβ burdens, neuron damages, neuroinflammation, and memory deficits of transgenic AD mice (APP/PS1 mice) are significantly attenuated. Overall, this biomimetic nanodelivery system with anti-Aβ and anti-inflammatory properties provides a promising strategy for the multi-target therapy of early AD.

Nanoenzymes-Integrated and Microenvironment Self-Adaptive Hydrogel for the Healing of Burn Injury and Post-Burn Depression

Burn injuries often cause prolonged oxidative stress and inflammatory pain due to an initial increase in inflammatory responses, consequently exacerbating depressive disorders and severely impairing patients' quality of life. The primary function of traditional burn dressings is to prevent infection and facilitate tissue repair. However, these dressings are not intended for the inflammatory pain and depression that often occur during recovery. This study describes a self-healing hydrogel H@EFCP, which is designed to alleviate inflammatory pain and post-burn depression in burn injuries. This hydrogel is synthesized through the cross-linking of carboxymethyl chitosan with borate ester chelates formed from epigallocatechin gallate and 4-formylphenylboronic acid. The incorporated Prussian blue nanoparticles increase the ability of H@EFCP to regulate the inflammatory process. H@EFCP is effective in the treatment of skin burns by reducing oxidative stress and improving the microenvironment of peripheral inflammation in mice. This modulation consists of a reduction of central nervous system inflammation and the risk of post-burn depression. Behavioral assays indicate that the hydrogel significantly reduces feelings of despair and anxiety after burns. Consequently, H@EFCP provides a dual-effect solution for the care and recovery of burn patients, including both burn repair and the associated psychological effects.

NO- and H2S- releasing nanomaterials: A crosstalk signaling pathway in cancer

The gasotransmitters nitric oxide (NO) and hydrogen sulfide (H2S) play important roles not only in maintaining physiological functions, but also in pathological conditions and events. Importantly, these molecules show a complex interplay in cancer biology, demonstrating both tumor-promoting and anti-tumor activities depending on their concentration, flux, and the environmental redox state. Additionally, various cell types respond differently to NO and H2S. These gasotransmitters can be synergistically combined with traditional anticancer treatments such as radiotherapy, immunotherapy, chemotherapy, and phototherapy. Notably, NO, and more recently H2S, have been shown to reverse multidrug resistance. Nanomaterials to deliver NO donors and, to a lesser extent, H2S donors, have emerged as a promising approach for targeted delivery of these gasotransmitters. Nanotechnology has advanced the delivery of anticancer drugs, enhancing efficiency and reducing side effects on non-cancerous cells. This review highlights recent progress in the design of NO and H2S-releasing nanomaterials for anticancer effects. It also explores the interactions between NO and H2S, which are crucial for developing combined therapies and nanomedicines with minimal side effects.

Hydrogen Sulfide Delivery System Based on Salting-Out Effect for Enhancing Synergistic Photothermal and Photodynamic Cancer Therapies

The simultaneous application of photothermal therapy (PTT) and photodynamic therapy (PDT) offers substantial advantages in cancer treatment. However, their synergistic anticancer efficacy is often limited by tumor hypoxia, and thermotolerance induced by high expression of heat shock proteins (HSP). Fortunately, hydrogen sulfide (H2S), known for its direct cytotoxic effect on tumor cells, has been recognized for its ability to enhance PTT and PDT. The effectiveness of H2S in these therapies is challenged by its low loading efficiency, poor stability, and short diffusion distance. To address these issues, a nanoscale emulsion drop template created through the salting-out effect is employed to construct a robust H2S delivery system. Polydopamine (PDA), chosen for its interfacial polymerization tendency and excellent photothermal conversion rate, is utilized as a carrier for the H2S donor (ADT) and Zinc phthalocyanine (ZnPc) to fabricate a novel nanomedicine termed APZ NPs. The temperature-responsive APZ NPs are designed to release H2S during the PTT process. Elevated H2S levels promoted vasodilation, thereby enhancing the enhanced permeability and retention effect (EPR) of APZ NPs within solid tumors. This strategy effectively alleviated tumor hypoxia by disrupting the mitochondrial respiratory chain and mitigated tumor cell heat tolerance by inhibiting HSP expression.

Emerging Chemodynamic Nanotherapeutics for Cancer Treatment

Chemodynamic therapy (CDT) has emerged as a transformative paradigm in the realm of reactive oxygen species -mediated cancer therapies, exhibiting its potential as a sophisticated strategy for precise and effective tumor treatment. CDT primarily relies on metal ions and hydrogen peroxide to initiate Fenton or Fenton-like reactions, generating cytotoxic hydroxyl radicals. Its notable advantages in cancer treatment are demonstrated, including tumor specificity, autonomy from external triggers, and a favorable side-effect profile. Recent advancements in nanomedicine are devoted to enhancing CDT, promising a comprehensive optimization of CDT efficacy. This review systematically elucidates cutting-edge achievements in chemodynamic nanotherapeutics, exploring strategies for enhanced Fenton or Fenton-like reactions, improved tumor microenvironment modulation, and precise regulation in energy metabolism. Moreover, a detailed analysis of diverse CDT-mediated combination therapies is provided. Finally, the review concludes with a comprehensive discussion of the prospects and intrinsic challenges to the application of chemodynamic nanotherapeutics in the domain of cancer treatment.

Curcumin-shellac nanoparticle-loaded GelMA/SilMA hydrogel for colorectal cancer therapy

In this study, a novel approach was employed to develop a therapeutic system for colorectal cancer treatment. Specifically, a GelMA/SilMA hydrogel loaded with curcumin-shellac nanoparticles (Cur@Lac NPs) was created. A microfluidic swirl mixer was utilized to formulate stable Cur@Lac NPs, ensuring their consistent and effective encapsulation. The pH-specific release of curcumin from the NPs demonstrated their potential for colon cancer treatment. By carefully regulating the ratio of GelMA (gelatin methacrylate) and SilMA (silk fibroin methacrylate), a GelMA/SilMA dual network hydrogel was generated, offering controlled release and degradation capabilities. The incorporation of SilMA notably enhanced the mechanical properties of the dual network matrix, improving compression resistance and mitigating deformation. This mechanical improvement is crucial for maintaining the structural integrity of the hydrogel during in vivo applications. In comparison to the direct incubation of curcumin, the strategy of encapsulating curcumin into NPs and embedding them within the GelMA/SilMA hydrogel resulted in more controlled release mechanisms. This controlled release was achieved through the disintegration of the NPs and the swelling and degradation of the hydrogel matrix. The encapsulating strategy also demonstrated enhanced cellular uptake of curcumin, leveraging the advantages of both NPs and in-situ hydrogel injection. This combination ensures a more efficient and sustained delivery of the therapeutic agent directly to the tumor site. Overall, this approach holds significant promise as a smart drug delivery system, potentially improving the efficacy of colorectal cancer treatments by providing targeted, controlled, and sustained drug release with enhanced mechanical stability and biocompatibility.

Near-infrared-responsive Prussian blue nanocages loaded with 5-fluorouracil for combined chemotherapy and photothermal therapy in tumor treatment

Nanodrug delivery systems (NDDS) have been proposed to improve the targeting and bioavailability of chemotherapy drugs. The approach of drug loading via physical adsorption is facile to operate; however, there exists a risk of premature leakage. Coupling the drug molecules with the carrier through chemical reactions can guarantee the stability of the drug delivery process, yet the preparation procedure is relatively intricate. In this research, a kind of Prussian blue nanocage (PB Cage) was fabricated, and the phase change material, 1-pentadecanol, was used as the gating material to solidify 5-fluorouracil (5-FU) inside the nanocage. Upon irradiation with near-infrared (NIR) light, the temperature of the PB Cage can rise rapidly. When the temperature exceeds 43 °C, 1-pentadecanol undergoes a solid-liquid phase transition and subsequently releases 5-FU to inhibit DNA synthesis. Meanwhile, the photothermal therapy (PTT) mediated by the PB Cage is also capable of ablating tumor cells. The NDDS constructed based on PB has achieved the precise release of 5-FU triggered by NIR light, which may avoid side effects on normal tissues. Moreover, the combination of chemotherapy and photothermal therapy can efficaciously suppress the proliferation of tumor cells.

A "Ferroptosis-Amplifier" Hydrogel for Eliminating Refractory Cancer Stem Cells Post-lumpectomy

The unique "Iron Addiction" feature of cancer stem cells (CSCs) with tumorigenicity and plasticity generally contributes to the tumor recurrence and metastasis after a lumpectomy. Herein, a novel "Ferroptosis Amplification" strategy is developed based on integrating gallic acid-modified FeOOH (GFP) and gallocyanine into Pluronic F-127 (F127) and carboxylated chitosan (CC)-based hydrogel for CSCs eradication. This "Ferroptosis Amplifier" hydrogel is thermally sensitive and achieves rapid gelation at the postsurgical wound in a breast tumor model. Specifically, gallocyanine, as the Dickkopf-1 (DKK1) inhibitor, can decrease the expression of SLC7A11 and GPX4 and synergistically induce ferroptosis of CSCs with GFP. Encouragingly, it is found that this combination suppresses the migratory and invasive capability of cancer cells via the downregulation of matrix metalloproteinase 7 (MMP7). The in vivo results further confirm that this "Ferroptosis Amplification" strategy is efficient in preventing tumor relapse and lung metastasis, manifesting an effective and promising postsurgical treatment for breast cancer.

Cobalt doped Prussian blue modified hollow polydopamine for enhanced antibacterial therapy

Give the emergence of drug resistance in bacteria resulting from antibiotic misuse, there is an urgent need for research and application of novel antibacterial approaches. In recent years, nanoparticles (NPs) have garnered significant attention due to their potential to disrupt bacteria cellular structure through loading drugs and special mechanisms, thus rendering them inactive. In this study, the surface of hollow polydopamine (HPDA) NPs was utilized for the growth of Prussian blue (PB), resulting in the formation of HPDA-PB NPs. Incorporation of Co element during the preparation process led to partial doping of PB with Co2+ions. The performance test results demonstrated that the HPDA-PB NPs exhibited superior photothermal conversion efficiency and peroxidase-like activity compared to PB NPs. HPDA-PB NPs have the ability to catalyze the formation of hydroxyl radicals from H2O2in a weakly acidic environment. Due to the tiny PB particles on the surface and the presence of Co2+doping, they have strong broad-spectrum antibacterial properties. Bothin vitroandin vivoevaluations confirm their efficacy against various bacterial strains, particularlyStaphylococcus aureus, and their potential to promote wound healing, making them a promising candidate for advanced wound care and antimicrobial applications.

Biocompatible Copper-Based Nanocomposites for Combined Cancer Therapy

Copper (Cu) and Cu-based nanomaterials have received tremendous attention in recent years because of their unique physicochemical properties and good biocompatibility in the treatment of various diseases, especially cancer. To date, researchers have designed and fabricated a variety of integrated Cu-based nanocomplexes with distinctive nanostructures and applied them in cancer therapy, mainly including chemotherapy, radiotherapy (RT), photothermal therapy (PTT), chemodynamic therapy (CDT), photodynamic therapy (PDT), cuproptosis-mediated therapy, etc. Due to the limited effect of a single treatment method, the development of composite diagnostic nanosystems that integrate chemotherapy, PTT, CDT, PDT, and other treatments is of great significance and offers great potential for the development of the next generation of anticancer nanomedicines. In view of the rapid development of Cu-based nanocomplexes in the field of cancer therapy, this review focuses on the current state of research on Cu-based nanomaterials, followed by a discussion of Cu-based nanocomplexes for combined cancer therapy. Moreover, the current challenges and future prospects of Cu-based nanocomplexes in clinical translation are proposed to provide some insights into the design of integrated Cu-based nanotherapeutic platforms.

Endogenous H2S-activated Ag nanoparticles embedded in programmed DNA-cubes for specific visualization of colorectal cancer cells

To avoid the unexpected aggregation and reduce the cytotoxicity of nanomaterials as optical probes in cell imaging applications, we propose a programmed DNA-cube as a carrier for silver nanoparticles (Ag NPs) to construct a specific hydrogen sulfide (H2S) responsive platform (Ag NP@DNA-cube) for diagnosing colorectal cancer (CRC) in this study. The DNA-cube maintains good dispersion of Ag NPs while providing excellent biocompatibility. Based on the characteristic overexpression of endogenous H2S in CRC cells, the Ag NPs are etched by H2S within target cells into silver sulfide quantum dots, thereby selectively illuminating the target cells. The Ag NP@DNA-cube exhibits a specific fluorescence response to CRC cells and achieves satisfactory imaging.

Curcumin reduces myocardial ischemia-reperfusion injury, by increasing endogenous H2S levels and further modulating m6A

BACKGROUND

Our previous research shows that Curcumin (CUR) attenuates myocardial ischemia-reperfusion injury (MIRI) by reducing intracellular total RNA m6A levels. However, the mechanism remains unknown.

METHODS

For ischemia-reperfusion (IR), H9c2 cells were cultured for 6 h in serum-free low-glycemic (1 g/L) medium and a gas environment without oxygen, and then cultured for 6 h in high-glycemic (4.5 g/L) medium supplemented with 10% FBS and a 21% oxygen environment. The effects of different concentrations of CUR (5, 10, and 20 µM) treatments on signaling molecules in conventionally cultured and IR-treated H9c2 cells were examined.

RESULTS

CUR treatment significantly up-regulated the H2S levels, and the mRNA and protein expression of cystathionine γ-lyase (CSE), and down-regulated the mRNAs and proteins levels of thiosulfate sulfurtransferase (TST) and ethylmalonic encephalopathy 1 (ETHE1) in H9c2 cells conventionally cultured and subjected to IR. Exogenous H2S supply (NaHS and GYY4137) significantly reduced intracellular total RNA m6A levels, and the expression of RNA m6A "writers" METTL3 and METTL14, and increased the expression of RNA m6A "eraser" FTO in H9c2 cells conventionally cultured and subjected to IR. CSE knockdown counteracted the inhibitory effect of CUR treatment on ROS production, promotion on cell viability, and inhibition on apoptosis of H9c2 cells subjected to IR.

CONCLUSION

CUR attenuates MIRI by regulating the expression of H2S level-regulating enzymes and increasing the endogenous H2S levels. Increased H2S levels could regulate the m6A-related proteins expression and intracellular total RNA m6A levels.

Glutathione-Responsive and Hydrogen Sulfide Self-Generating Nanocages Based on Self-Weaving Technology To Optimize Cancer Immunotherapy

As an ideal drug carrier, it should possess high drug loading and encapsulation efficiency and precise drug targeting release. Herein, we utilized a template-guided self-weaving technology of phase-separated silk fibroin (SF) in reverse microemulsion (RME) to fabricate a kind of hyaluronic acid (HA) coated SF nanocage (HA-gNCs) for drug delivery of cancer immunotherapy. Due to the hollow structure, HA-gNCs were capable of simultaneous encapsulation of the anti-inflammatory drug betamethasone phosphate (BetP) and the immune checkpoint blockade (ICB) agent PD-L1 antibody (αPD-L1) efficiently. Another point worth noting was that the thiocarbonate cross-linkers used to strengthen the SF shell of HA-gNCs could be quickly broken by overexpressed glutathione (GSH) to reach responsive drug release inside tumor tissues accompanied by hydrogen sulfide (H2S) production in one step. The synergistic effect of released BetP and generated H2S guaranteed chronological modulation of the immunosuppressive tumor microenvironment (ITME) to amplify the therapeutic effect of αPD-L1 for the growth, metastasis, and recurrence of tumors. This study highlighted the exceptional prospect of HA-gNCs as a self-assistance platform for cancer drug delivery.

Advancing Gastrointestinal Health: Curcumin's Efficacy and Nanopreparations

Curcumin (CCM) is a polyphenol compound extracted from the turmeric rhizome. It has various biological activities, including antibacterial, anti-inflammatory, anti-cancer, and antioxidant. Due to its diverse activities, it is often used by researchers to study the therapeutic effects on various diseases. However, its poor solubility leads to poor bioavailability, and it is necessary to increase the water solubility with the help of carriers to improve the therapeutic effect. Gastrointestinal disease is a major global health problem that continues to affect human health. In this review, we have summarized the possible mechanism and therapeutic effect of CCM in various gastrointestinal diseases, and the improvement in the curative effect of CCM with nanopreparation. Finally, we concluded that there have been many clinical trials of CCM in combination with other drugs for the treatment of gastrointestinal disease, but so far, few have used CCM nanomaterials for treatment. Although in vitro and preclinical experiments have shown that nanopreparations can improve the efficacy of CCM, there are still insufficient studies on the safety of carriers.

Recent Progress on Tumor Microenvironment-Activated NIR-II Phototheranostic Agents with Simultaneous Activation for Diagnosis and Treatment

Malignant tumors seriously threaten human life and well-being. Emerging Near-infrared II (NIR-II, 1000-1700 nm) phototheranostic nanotechnology integrates diagnostic and treatment modalities, offering merits including improved tissue penetration and enhanced spatiotemporal resolution. This remarkable progress has opened promising avenues for advancing tumor theranostic research. The tumor microenvironment (TME) differs from normal tissues, exhibiting distinct attributes such as hypoxia, acidosis, overexpressed hydrogen peroxide, excess glutathione, and other factors. Capitalizing on these attributes, researchers have developed TME-activatable NIR-II phototheranostic agents with diagnostic and therapeutic attributes concurrently. Therefore, developing TME-activatable NIR-II phototheranostic agents with diagnostic and therapeutic activation holds significant research importance. Currently, research on TME-activatable NIR-II phototheranostic agents is still in its preliminary stages. This review examines the recent advances in developing dual-functional NIR-II activatable phototheranostic agents over the past years. It systematically presents NIR-II phototheranostic agents activated by various TME factors such as acidity (pH), hydrogen peroxide (H2 O2 ), glutathione (GSH), hydrogen sulfide (H2 S), enzymes, and their hybrid. This encompasses NIR-II fluorescence and photoacoustic imaging diagnostics, along with therapeutic modalities, including photothermal, photodynamic, chemodynamic, and gas therapies triggered by these TME factors. Lastly, the difficulties and opportunities confronting NIR-II activatable phototheranostic agents in the simultaneous diagnosis and treatment field are highlighted.

Hydrogen sulfide responsive nanoplatforms: Novel gas responsive drug delivery carriers for biomedical applications

Hydrogen sulfide (H2S) is a toxic, essential gas used in various biological and physical processes and has been the subject of many targeted studies on its role as a new gas transmitter. These studies have mainly focused on the production and pharmacological side effects caused by H2S. Therefore, effective strategies to remove H2S has become a key research topic. Furthermore, the development of novel nanoplatforms has provided new tools for the targeted removal of H2S. This paper was performed to review the association between H2S and disease, related H2S inhibitory drugs, as well as H2S responsive nanoplatforms (HRNs). This review first analyzed the role of H2S in multiple tissues and conditions. Second, common drugs used to eliminate H2S, as well as their potential for combination with anticancer agents, were summarized. Not only the existing studies on HRNs, but also the inhibition H2S combined with different therapeutic methods were both sorted out in this review. Furthermore, this review provided in-depth analysis of the potential of HRNs about treatment or detection in detail. Finally, potential challenges of HRNs were proposed. This study demonstrates the excellent potential of HRNs for biomedical applications.

Nanoplatform-Mediated Autophagy Regulation and Combined Anti-Tumor Therapy for Resistant Tumors

The overall cancer incidence and death toll have been increasing worldwide. However, the conventional therapies have some obvious limitations, such as non-specific targeting, systemic toxic effects, especially the multidrug resistance (MDR) of tumors, in which, autophagy plays a vital role. Therefore, there is an urgent need for new treatments to reduce adverse reactions, improve the treatment efficacy and expand their therapeutic indications more effectively and accurately. Combination therapy based on autophagy regulators is a very feasible and important method to overcome tumor resistance and sensitize anti-tumor drugs. However, the less improved efficacy, more systemic toxicity and other problems limit its clinical application. Nanotechnology provides a good way to overcome this limitation. Co-delivery of autophagy regulators combined with anti-tumor drugs through nanoplatforms provides a good therapeutic strategy for the treatment of tumors, especially drug-resistant tumors. Notably, the nanomaterials with autophagy regulatory properties have broad therapeutic prospects as carrier platforms, especially in adjuvant therapy. However, further research is still necessary to overcome the difficulties such as the safety, biocompatibility, and side effects of nanomedicine. In addition, clinical research is also indispensable to confirm its application in tumor treatment.

Fabrication of targeted and pH responsive lysozyme-hyaluronan nanoparticles for 5-fluorouracil and curcumin co-delivery in colorectal cancer therapy

Green nanotechnology is considered a promising method to construct functional materials with significant anticancer activity, while overcoming the shortcomings of traditional synthesis process complexity and high organic solvents consumption. Thus, in this study, we report for the first time the rational design and green synthesis of functionalized 5-fluorouracil and curcumin co-loaded lysozyme-hyaluronan composite colloidal nanoparticles (5-Fu/Cur@LHNPs) for better targeted colorectal cancer therapy with minimized side effects. The functionalized 5-Fu/Cur@LHNPs exhibit stabilized particle size (126.1 nm) with excellent homogeneity (PDI = 0.1), favorable colloidal stabilities, and excellent re-dispersibility. In vitro cell experiments illustrate that the cellular uptake of 5-Fu/Cur@LHNPs was significantly improved and further promoted a higher apoptosis ratio of HCT-116 cells. Compared with the control group, the 5-Fu/Cur@LHNPs formulation group achieved effective inhibition (60.1 %) of colorectal tumor growth. The alcohol-free self-assembly method to construct 5-Fu/Cur@LHNPs is simple and safe for a translational chemotherapy drug, also to promote more robust delivery systems for treating colorectal cancer.

Bufotalin-loaded biomimetic Prussian blue nanoparticles for colorectal cancer chemo-photothermal ferroptosis therapy

Purpose: We constructed biomimetic nanoparticles with biocompatible, tumor-targeting, laser-responsive properties for ferroptosis-induced colorectal cancer chemo-photothermal therapy, with the aim to realize double-hit ferroptosis treatment for colorectal cancer. Methods: The nanoparticles were prepared by first loading the chemotherapy drug bufotalin (CS-5) with Prussian blue (PB), then combining a hybridized erythrocyte-tumor membrane (M) with PB@CS-5 to produce PB@CS-5@M. The chemo-photothermal therapy efficiency of PB@CS-5@M was tested by in vitro and in vivo experiments. Results and conclusion: The combined PB and CS-5 act as promising ferroptosis inducers to enhance ferroptosis efficacy. The hyperthermia induced by laser stimulation can trigger PB to release CS-5 and iron and ferrous ions, which further promotes ferroptosis.

Metal-Organic Frameworks Meet Polymers: From Synthesis Strategies to Healthcare Applications

Metal-organic frameworks (MOFs) have been at the forefront of nanotechnological research for the past decade owing to their high porosity, high surface area, diverse configurations, and controllable chemical structures. They are a rapidly developing class of nanomaterials that are predominantly applied in batteries, supercapacitors, electrocatalysis, photocatalysis, sensors, drug delivery, gas separation, adsorption, and storage. However, the limited functions and unsatisfactory performance of MOFs resulting from their low chemical and mechanical stability hamper further development. Hybridizing MOFs with polymers is an excellent solution to these problems, because polymers-which are soft, flexible, malleable, and processable-can induce unique properties in the hybrids based on those of the two disparate components while retaining their individuality. This review highlights recent advances in the preparation of MOF-polymer nanomaterials. Furthermore, several applications wherein the incorporation of polymers enhances the MOF performance are discussed, such as anticancer therapy, bacterial elimination, imaging, therapeutics, protection from oxidative stress and inflammation, and environmental remediation. Finally, insights from the focus of existing research and design principles for mitigating future challenges are presented.

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 tumor microenvironment-activatable nanoplatform with phycocyanin-assisted in-situ nanoagent generation for synergistic treatment of colorectal cancer

The in-situ generation of therapeutic agents in targeted lesions is promising for revolutionizing oncotherapy but is limited by the low production efficiency. Given the specific tumor microenvironment (TME) of colorectal cancer (CRC), i.e., mild acidity, overexpressed H2O2, glutathione (GSH) and H2S, we develop phycocyanin (PC) encapsulated PZTC/SS/HA nanocapsules (NCs) for TME-responsive, protein-assisted "turn-on'' therapy of CRC. The NCs are prepared by sequentially assembling Cu2+-tannic acid (TA) coordination shell, disulfide bond-bearing cross-linker, and hyaluronic acid (HA) on the sacrificial template ZIF-8, thus achieving pH-, GSH-responsiveness, and tumor targeting capability, respectively. Once reaching the CRC sites, the NCs can quickly disintegrate and release Cu2+ and PC, accompanied by subsequent endogenous H2S-triggered generation of copper sulfide (CuS). Significantly, the intracellular sulfidation process can be accelerated by PC, thereby enabling efficient photothermal therapy (PTT) under NIR-Ⅱ laser. Besides, Cu2+-associated chemodynamic therapy (CDT) can be simultaneously activated and enhanced by PTT-induced local hyperthermia and disulfide bond-induced GSH consumption. This CRC-targeted and TME-activated synergistic PTT/CDT strategy displays high therapeutic efficacy both in vitro and in vivo, which can open up a new avenue for biomolecule-assisted in-situ nanoagent generation and effective TME-responsive synergistic treatment of CRC.

Reactive Oxygen Species: A Crosslink between Plant and Human Eukaryotic Cell Systems

Reactive oxygen species (ROS) are important regulating factors that play a dual role in plant and human cells. As the first messenger response in organisms, ROS coordinate signals in growth, development, and metabolic activity pathways. They also can act as an alarm mechanism, triggering cellular responses to harmful stimuli. However, excess ROS cause oxidative stress-related damage and oxidize organic substances, leading to cellular malfunctions. This review summarizes the current research status and mechanisms of ROS in plant and human eukaryotic cells, highlighting the differences and similarities between the two and elucidating their interactions with other reactive substances and ROS. Based on the similar regulatory and metabolic ROS pathways in the two kingdoms, this review proposes future developments that can provide opportunities to develop novel strategies for treating human diseases or creating greater agricultural value.

Recent advances in Prussian blue-based photothermal therapy in cancer treatment

Malignant tumours are a serious threat to human health. Traditional chemotherapy has achieved breakthrough improvements but also has significant detrimental effects, such as the development of drug resistance, immunosuppression, and even systemic toxicity. Photothermal therapy (PTT) is an emerging cancer therapy. Under light irradiation, the phototherapeutic agent converts optical energy into thermal energy and induces the hyperthermic death of target cells. To date, numerous photothermal agents have been developed. Prussian blue (PB) nanoparticles are among the most promising photothermal agents due to their excellent physicochemical properties, including photoacoustic and magnetic resonance imaging properties, photothermal conversion performance, and enzyme-like activity. By the construction of suitably designed PB-based nanotherapeutics, enhanced photothermal performance, targeting ability, multimodal therapy, and imaging-guided cancer therapy can be effectively and feasibly achieved. In this review, the recent advances in PB-based photothermal combinatorial therapy and imaging-guided cancer therapy are comprehensively summarized. Finally, the potential obstacles of future research and clinical translation are discussed.

Continuous Spatiotemporal Therapy of A Full-API Nanodrug via Multi-Step Tandem Endogenous Biosynthesis

Nanomedicine holds great promise to enhance cancer therapy. However, low active pharmaceutical ingredient (API) loading content, unpredictable drug release, and potential toxicity from excipients limit their translational capability. We herein report a full-API nanodrug composed of FDA-approved 5-aminolevulinic acid (ALA), human essential element Fe3+, and natural bioactive compound curcumin with an ideal API content and pH-responsive release profile for continuous spatiotemporal cancer therapy achieved by multi-step tandem endogenous biosynthesis. First, ALA enzymatically converts into photosensitizer protoporphyrin IX (PpIX). Afterward, multiple downstream products including carbon monoxide (CO), Fe2+, biliverdin (BV), and bilirubin (BR) are individually biosynthesized through the PpIX-heme-CO/Fe2+/BV-BR metabolic pathway, further cooperating with released Fe3+ and curcumin, ultimately eliciting mitochondria damage, membrane disruption, and intracytoplasmic injury. This work not only provides a paradigm for exploiting diversified metabolites for tumor suppression, but also presents a safe and efficient full-API nanodrug, facilitating the practical translation of nanodrugs.

Progress in the preparation of Prussian blue-based nanomaterials for biomedical applications

Prussian blue (PB) is composed of the coordination network of Fe²⁺-CN-Fe³⁺ mixed valence state as a classic metal complex, which includes a C atom and Fe²⁺ (low spin), N atom and Fe³⁺ (high spin). PB and its analogues (PBA) have excellent biosafety, good magnetic properties, outstanding photothermal properties and the ability to mimic enzymatic behaviors due to their stable structure, tunable size, controllable morphology, abundant modification methods and excellent physicochemical properties. They have received increasing research interest and have shown promising applications in the biomedical field. Here, progress in the preparation of PB-based nanomaterials for biomedical applications is summarized and discussed. The preparation strategies, traditional synthesis and emerging preparation methods of PB are summarized systematically in this review. The design and preparation of PBA, PB(PBA)-based hollow structures and PB(PBA)-based composites are also included. While introducing the preparation status, some PB-based nanomaterials that have performed well in specific biomedical fields are emphasized. More importantly, the key factors and future development of PB for the clinical translation as multifunctional nanomaterials are also discussed. This review provides a reference for the design and biomedical application of PB-based nanomaterials.

Hemoglobin Nanocrystals for Drugs Free, Synergistic Theranostics of Colon Tumor

The conventional approach in cancer nanomedicine involves advanced drug nanocarriers delivering preloaded therapeutics to targeted tumor sites to maximize drug efficiency. However, both cancer drugs and nanocarriers inevitably produce side effects and systemic toxicity. Herein, hemoglobin nanocrystals (HbC) as drug-free theranostic nanoformulations with the tumor microenvironment (TME) activated diagnostic and therapeutic abilities towards colon tumors are introduced. HbC can release Fe²⁺ oxidized to Fe³⁺ in the Fenton reaction with tumor endogenous H₂ O₂ , concurrently with the generation of cytotoxic hydroxyl radicals (•OH) that allow for chemodynamic therapy (CDT). Furthermore, in situ-produced Fe³⁺ reacts with colon tumor-abundant H₂ S, resulting in the production of Fe_{1- x} S, which provides magnetic resonance imaging (MRI) contrast and allows for NIR light-inducible photothermal therapy (PTT). In vitro and in vivo studies revealed that HbC produced CDT towards 4T1 tumors, and MRI-guided, synergistically enhanced combination of CDT and PTT against H₂ S abundant colon tumors (CT26), with negligible toxicity towards normal tissues, enlightening HbC as highly efficient and biocompatible TME activated theranostic nanoplatform specific against colon cancer without any traditional drugs and drug carriers.

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.

Inflammation-Regulated Nanodrug Sensitizes Hepatocellular Carcinoma to Checkpoint Blockade Therapy by Reprogramming the Tumor Microenvironment

Immune checkpoint blockade (ICB) utilizing programmed death ligand-1 (PD-L1) antibody is a promising treatment strategy in solid tumors. However, in fact, more than half of hepatocellular carcinoma (HCC) patients are unresponsive to PD-L1-based ICB treatment due to multiple immune evasion mechanisms such as the hyperactivation of inflammation pathway, excessive tumor-associated macrophages (TAMs) infiltration, and insufficient infiltration of T cells. Herein, an inflammation-regulated nanodrug was designed to codeliver NF-κB inhibitor curcumin and PD-L1 antibody to reprogram the tumor microenvironment (TME) and activate antitumor immunity. The nanodrug accumulated in TME by an enhanced permeability and retention effect, where it left antibody to block PD-L1 on the membrane of tumor cells and TAMs due to pH-responsiveness. Simultaneously, a new curcumin-encapsulated nanodrug was generated, which was easily absorbed by either tumor cells or TAMs to inhibit the nuclear factor kappa-B (NF-κB) signal and related immunosuppressive genes. The inflammation-regulated nanodrug possessed good biocompatibility. Simultaneously, it reprogrammed TME effectively and exhibited an effective anticancer effect in immunocompetent mice. Overall, this study provided a potent strategy to improve the efficiency of ICB-based treatment for HCC.

Modulation of Macrophages Using Nanoformulations with Curcumin to Treat Inflammatory Diseases: A Concise Review

Curcumin (Cur), a traditional Chinese medicine extracted from natural plant rhizomes, has become a candidate drug for the treatment of diseases due to its anti-inflammatory, anticancer, antioxidant, and antibacterial activities. However, the poor water solubility and low bioavailability of Cur limit its therapeutic effects for clinical applications. A variety of nanocarriers have been successfully developed to improve the water solubility, in vivo distribution, and pharmacokinetics of Cur, as well as to enhance the ability of Cur to polarize macrophages and relieve macrophage oxidative stress or anti-apoptosis, thus accelerating the therapeutic effects of Cur on inflammatory diseases. Herein, we review the design and development of diverse Cur nanoformulations in recent years and introduce the biomedical applications and potential therapeutic mechanisms of Cur nanoformulations in common inflammatory diseases, such as arthritis, neurodegenerative diseases, respiratory diseases, and ulcerative colitis, by regulating macrophage behaviors. Finally, the perspectives of the design and preparation of future nanocarriers aimed at efficiently exerting the biological activity of Cur are briefly discussed.

Hydrogen sulfide activatable metal-organic frameworks for Fluorescence Imaging-Guided Photodynamic Therapy of colorectal cancer

Photodynamic therapy (PDT) is a promising alternative and palliative therapeutic strategy for colorectal cancer (CRC). A novel photosensitizer with higher selectivity for CRC and fewer side effects is vital for clinical application. Given that the overexpression of hydrogen sulfide (H₂S) in CRC, it is expected to provide a selective stimulus for activatable photosensitizers that in respond to the specific microenvironment. Herein, we report a novel development of metal-organic frameworks (MOFs) composed of meso-Tetra (4-carboxyphenyl) porphine (TCPP) and ferric ion (Fe³⁺) through a facile one-pot process. Experiments both in vitro and in vivo reveal that the MOF is capable of depredating in response to the high content of H₂S in tumor microenvironment of CRC. Accompanying with the degradation and release of TCPP, the fluorescence and photosensitivity effect is switched from “off” to “on”, enabling the MOF to serve as a H₂S activatable nano-photosensitizer for real-time fluorescence imaging-guided and targeted PDT of CRC.