A Multifunctional Cascade Bioreactor Based on a Layered Double Oxides Composite Hydrogel for Synergetic Tumor Chemodynamic/Starvation/Photothermal Therapy

Injectable nanocomposite hydrogels for targeted intervention in cancer, wound healing, and bone and myocardial tissue engineering

Despite current medicine's fast-paced advances, many acute and chronic illnesses still lack truly effective and safe therapies. Cancer treatments often lead to off-target healthy tissue damage and poor therapeutic outcomes, wound standard treatments generally demonstrate poor healing efficacy and increased susceptibility to infection, and bone tissue engineering and myocardial tissue engineering can result in immunological rejection and limited availability. To tackle these issues, injectable hydrogels have emerged, and through the incorporation of nanoparticles, nanocomposite hydrogels have appeared as versatile platforms, offering improved biocompatibility, mechanical strength, stability, and precise controlled drug release, as well as targeted delivery with increased drug retention at the site of action, reducing systemic drug distribution to non-target sites. With the ability to deliver a diverse range of therapeutic entities, including low molecular weight drugs, proteins, antibodies, and even isolated cells, injectable nanocomposite hydrogels have revolutionized current therapies, working as multifunctional platforms capable of improving efficacy and safety in cancer treatment, including in chemotherapy, immunotherapy, photothermal therapy, magnetic hyperthermia, photodynamic therapy, chemodynamic therapy, radiotherapy, molecularly targeted therapy, and after tumor surgical removal, and in general, chronic diabetic or tumor-induced wound healing, as well as in bone tissue engineering and myocardial tissue engineering. This review provides a thorough summary and critical insight of current advances on injectable nanocomposite hydrogels as an innovative approach that could bring substantial contributions to biomedical research and clinical practice, with a focus on their applications in cancer therapy, wound healing management, and tissue engineering.

Nanomaterials in cancer starvation therapy: pioneering advances, therapeutic potential, and clinical challenges

Gaining significant attention in recent years, starvation therapy based on the blocking nutrients supply to cancer cells via blood occlusion and metabolic interventions is a promisingly novel approach in cancer treatment. However, there are many crucial obstacles to overcome to achieve effective treatment, for example, poor-targeting delivery, cellular hypoxia, adverse effects, and ineffective monotherapy. The starvation-based multitherapy based on multifunctional nanomaterials can narrow these gaps and pave a promising way for future clinical translation. This review focuses on the progression in nanomaterials-mediated muti-therapeutic modalities based on starvation therapy in recent years and therapeutic limitations that prevent their clinical applications. Moreover, unlike previous reviews that focused on a single aspect of the field, this comprehensive review presents a broader perspective on starvation therapy by summarising advancements across its various therapeutic strategies.

Emerging glucose oxidase-delivering nanomedicines for enhanced tumor therapy

Abnormalities in glucose metabolism have been shown to characterize malignant tumors. Glucose depletion by glucose oxidase (GOD) has shown great potential in tumor therapy by causing tumor starvation. Since 2017, nanomedicines have been designed and utilized to deliver GOD for more precise and effective glucose modulation, which can overcome intrinsic limitations of different cancer therapeutic modalities by remodeling the tumor microenvironment to enhance antitumor therapy. To date, the topic of GOD-delivering nanomedicines for enhancing tumor therapy has not been comprehensively summarized. Herein, this review aims to provide an overview and discuss in detail recent advances in GOD delivery and directly involved starvation therapy strategies, GOD-sensitized various tumor therapy strategies, and GOD-mediated multimodal antitumor strategies. Finally, the challenges and outlooks for the future progress of the emerging tumor therapeutic nanomedicines are discussed. This review provides intuitive and specific insights to a broad audience in the fields of nanomedicines, biomaterials, and cancer therapy.

Mesoporous polydopamine composite nanoparticles for multimodal therapy based on disrupting the redox homeostasis within tumor cells

Developing multimodal combination therapy strategies to disrupt the redox homeostasis within tumor cells is currently an important approach in cancer treatment. In this study, we designed and prepared multifunctional composite nanoparticles MPDA-PEG@MnO2@2-DG (MPPMD NPs) utilizing mesoporous polydopamine nanoparticles (MPDA NPs) as carriers. These carriers were coated with polyethylene glycol (PEG), and manganese dioxide (MnO2) and loaded with 2-deoxy-d-glucose (2-DG). Studies on mechanism revealed that upon accumulation in tumor cells via in situ injection, MnO2 can react with overexpressed H2O2 to generate Mn2+, O2, and toxic OH. Additionally, MnO2 undergoes an oxidation-reduction reaction (redox) with glutathione (GSH), consuming GSH and generating Mn2+. The resulting Mn2+ further participates in Fenton-like reactions with overexpressed H2O2 within the tumor. Furthermore, under 808 nm laser, MPPMD NPs facilitate photothermal therapy (PTT), promoting the generation of reactive oxygen species (ROS), inducing oxidative stress, and reducing the adenosine triphosphate (ATP) level. Concurrently, the 2-DG loaded by MPPMD NPs disguised as glucose disrupts the glycolysis process, inhibiting ATP production, and effectively inducing tumor starvation therapy (ST). By leveraging the multifunctionality of MPPMD NPs, this work realized the disruption of redox homeostasis within tumor cells, providing potential strategies for multimodal tumor treatment.

Nanozymes meet hydrogels: Fabrication, progressive applications, and perspectives

Nanozyme, a class of emerging enzyme mimics, is the nanomaterials with enzyme-mimicking activity, which has obtained significant and widespread applications in various fields. However, they still face many challenges in practical applications (e.g., instability and low biocompatibility in the physiological environments), which affect their widespread applications to a certain extent. Hydrogels with superior performances (e.g., the controllable degradability, good biocompatibility, hydrophilic properties, and adjustable physical properties) may provide a promising strategy to make up the existing deficiencies of nanozymes in practical applications. Thus, the sapiential combination of nanozymes with hydrogels endows nanozyme hydrogels with both characteristics of nanozymes and properties of hydrogels, making nanozyme hydrogels become novel multifunctional materials. In this review, we comprehensively summarizes the preparation, properties, and progressive applications of nanozyme hydrogels. First of all, the main design and preparation strategies of nanozyme hydrogels are considerately summarized. Then, the properties of different nanozyme hydrogels are introduced. In addition, sophisticated applications of nanozyme hydrogels in the fields of biosensing, biomedicine applications, and environmental are comprehensively summarized. Most importantly, future obstacles and chances in this emerging field are profoundly proposed. This review will provide a new horizon for the development and future applications of novel nanozyme hydrogels.

Natural polysaccharide hydrogel delivery system remodeling tumor microenvironment to promote postoperative tumor therapy

In recent years, postoperative tumor therapy with a suitable approach has been an important issue. Remodeling the tumor microenvironment and accelerating tissue repair can accelerate patients' surgical site recovery, reduce patient pain as well as prevent postoperative tumor recurrence. The shape non-adaptability, cytotoxicity, and non-degradability of some hydrogels still hinder the application of hydrogel-based drug delivery systems in postoperative recovery. Natural polysaccharides (e.g., chitosan, sodium alginate, and hyaluronic acid) are multifunctional compounds with biomimetic advantages to meet the growing demand for nontoxic, targeted therapeutic, and restorative preventive therapies. In this paper, we comprehensively and systematically investigated the synthesis methods, properties, and applications of natural polysaccharide hydrogel (NPH) delivery systems, as well as the mechanisms of remodeling the tumor microenvironment. We aim to provide insights into the design of NPH delivery systems. On this basis, future research directions for NPH delivery systems and their role in remodeling the tumor microenvironment and accelerating postoperative tumor therapy are proposed, and strategies for remodeling the tumor microenvironment using hydrogel delivery systems are discussed, as well as the latest research methods.

Current advances in nanozyme-based nanodynamic therapies for cancer

Nanozymes are nano-catalysis materials with enzyme-like activities, which can repair the defects of natural enzyme such as harsh catalytic conditions, and harness their strengths to treat tumor. The emerging nanodynamic therapies improved drug selectivity and decreased drug tolerance, while causing efficient cell apoptosis through the generated reactive oxygen species (ROS). Nanodynamic therapies based on nanozymes can improve the complicated tumor microenvironment (TME) to reduce the defect rate of nanodynamic therapies, and provide more options for tumor treatment. This review summarized the characteristics and applications of nanozymes with different activities and the factors influencing the activity of nanozymes. We also focused on the application of nanozymes in nanodynamic therapies, including photodynamic therapy (PDT), chemodynamic therapy (CDT), and sonodynamic therapy (SDT). Moreover, we discussed the strategies for optimizing nanodynamic therapies based on nanozymes for tumor treatment in detail, and provided a systematic review of tactics for synergies with other tumor therapies. Ultimately, we analyzed the shortcomings of nanodynamic therapies based on nanozymes and the relevant research prospect, which would provide sufficient evidence and lay a foundation for further research. STATEMENT OF SIGNIFICANCE: 1. The novelty and significance of the work with respect to the existing literatures. (1) Recent advances in nanozyme-based nanodynamic therapies are comprehensively and systematically reviewed, and strategies to address the limitations and challenges of current therapies based on nanozymes are discussed firstly. (2) The mechanism of nanozymes in nanodynamic therapies is described for the first time. The synergistic therapies, prospects, and challenges of nanozyme-based nanodynamic therapies are innovatively discussed. 2. The scientific impact and interest to our readership. This review focuses on the recent progress of nanozyme-based nanodynamic therapies. This review indicates the way forward for the combined treatment of nanozymes and nanodynamic therapies, and lays a foundation for facilitating theoretical development in clinic.

The recent research progress in the application of the nanozyme-hydrogel composite system for drug delivery

Hydrogels, comprising 3D hydrophilic polymer networks, have emerged as promising biomaterial candidates for emulating the structure of biological tissues and delivering drugs through topical administration with good biocompatibility. Nanozymes can catalyze endogenous biomolecules, thereby initiating or inhibiting in vivo biological processes. A nanozyme-hydrogel composite inherits the biological functions of hydrogels and nanozymes, where the nanozyme serves as the catalytic core and the hydrogel forms the structural scaffold. Moreover, the composite can concentrate nanozymes in targeted lesions and catalyze the binding of a specific group of substrates, resulting in pathological microenvironment remodeling and drug-penetrating barrier impairment. The composite also shields nanozymes to prevent burst release during catalytic production and reduce related toxicity. Currently, the application of these composites has been extended to antibacterial, anti-inflammatory, anticancer, and tissue repair applications. In this review, we elucidate the preparation methods for nanozyme-hydrogel composites, provide compelling evidence of their advantages in drug delivery and provide a comprehensive overview of their biological application.

Self-Oxygenated Hydrogel Enhances Immune Cell Response and Infiltration Via Triggering Dual DNA Damage to Activate cGAS-STING and Inhibiting CAFs

Immune checkpoint inhibitors (ICIs) offer promise in breaking through the treatment and survival dilemma of triple-negative breast cancer (TNBC), yet only immunomodulatory subtype and ≈5% TNBC patients respond as monotherapy due to lack of effector immune cells (internal problem) and physical barrier (external limitation) formed by cancer-associated fibroblasts (CAFs). A hydrogel drug-delivery platform, ALG@TBP-2/Pt(0)/nintedanib (ALG@TPN), is designed to induce strong immune functions and the dual elimination of the internal and external tumor microenvironment (TME). Activated by white light, through type I and II photodynamic therapy (PDT), TBP-2 generates large amounts of reactive oxygen species (ROS) intracellularly, oxidizing mitochondrial DNA (mtDNA). The unique catalase activity of Pt(0) converts endogenous H2O2 to O2, reducing the anoxia-limiting PDT and enhancing ROS generation efficacy. Abundant ROS can oxidize Pt(0) to cytotoxic Pt(II), damaging the nuclear DNA (nDNA). Dual damage to mtDNA and nDNA might bi-directionally activate the cGAS/STING pathway and enhance the immune cell response. Besides, nintedanib demonstrates a significant inhibitory effect on CAFs, weakening the immune barrier and deepening immune cell infiltration. Overall, the study provides a self-oxygenating hydrogel with the "PDT/chemotherapy/anti-CAFs" effect, triggering the cGAS/STING pathway to reshape the TME. Both internal and external interventions increase anti-TNBC immune responses.

Advances in Smart-Response Hydrogels for Skin Wound Repair

Hydrogels have emerged as promising candidates for biomedical applications, especially in the treatment of skin wounds, as a result of their unique structural properties, highly tunable physicochemical properties, and excellent biocompatibility. The integration of smart-response features into hydrogels allows for dynamic responses to different external or internal stimuli. Therefore, this paper reviews the design of different smart-responsive hydrogels for different microenvironments in the field of skin wound therapy. First, the unique microenvironments of three typical chronic difficult-to-heal wounds and the key mechanisms affecting wound healing therapeutic measures are outlined. Strategies for the construction of internal stimulus-responsive hydrogels (e.g., pH, ROS, enzymes, and glucose) and external stimulus-responsive hydrogels (e.g., temperature, light, electricity, and magnetic fields) are highlighted from the perspective of the wound microenvironment and the in vitro environment, and the constitutive relationships between material design, intelligent response, and wound healing are revealed. Finally, this paper discusses the severe challenges faced by smart-responsive hydrogels during skin wound repair and provides an outlook on the combination of smart-responsive hydrogels and artificial intelligence to give scientific direction for creating and using hydrogel dressings that respond to stimuli in the clinic.

Nanozymes-Mediated Cascade Reaction System for Tumor-Specific Diagnosis and Targeted Therapy

Cascade reactions are described as efficient and versatile tools, and organized catalytic cascades can significantly improve the efficiency of chemical interworking between nanozymes. They have attracted great interest in many fields such as chromogenic detection, biosensing, tumor diagnosis, and therapy. However, how to selectively kill tumor cells by enzymatic reactions without harming normal cells, as well as exploring two or more enzyme-engineered nanoreactors for cascading catalytic reactions, remain great challenges in the field of targeted and specific cancer diagnostics and therapy. The latest research advances in nanozyme-catalyzed cascade processes for cancer diagnosis and therapy are described in this article. Here, various sensing strategies are summarized, for tumor-specific diagnostics. Targeting mechanisms for tumor treatment using cascade nanozymes are classified and analyzed, "elements" and "dimensions" of cascade nanozymes, types, designs of structure, and assembly modes of highly active and specific cascade nanozymes, as well as a variety of new strategies of tumor targeting based on the cascade reaction of nanozymes. Finally, the integrated application of the cascade nanozymes systems in tumor-targeted and specific diagnostic therapy is summarized, which will lay the foundation for the design of more rational, efficient, and specific tumor diagnostic and therapeutic modalities in the future.

Hybrid nano-stimulator for specific amplification of oxidative stress and precise tumour treatment

BACKGROUND

The use of reactive oxygen species (ROS) to target cancer cells has become a hot topic in tumor therapy.

PURPOSE

Although ROS has strong cytotoxicity against tumor cells, the key issue currently is how to generate a large amount of ROS within tumor cells.

METHODS

Organic/inorganic hybrid nanoreactor materials combine the advantages of organic and inorganic components and can amplify cancer treatment by increasing targeting and material self-action. The multifunctional organic / inorganic hybrid nanoreactor is helpful to overcome the shortcomings of current reactive oxygen species in cancer treatment. It can realize the combination of in situ dynamic therapy and immunotherapy strategies, and has a synergistic anti-tumor effect.

RESULTS

This paper reviews the research progress of organic/inorganic hybrid nanoreactor materials using tumor components to amplify reactive oxygen species for cancer treatment. The article reviews the tumor treatment strategies of nanohybrids from the perspectives of cancer cells, immune cells, tumor microenvironment, as well as 3D printing and electrospinning techniques, which are different from traditional nanomaterial technologies, and will arouse interest among scientists in tumor therapy and nanomedicine.

A Novel Nanozyme to Enhance Radiotherapy Effects by Lactic Acid Scavenging, ROS Generation, and Hypoxia Mitigation

Uveal melanoma (UM) is a leading intraocular malignancy with a high 5-year mortality rate, and radiotherapy is the primary approach for UM treatment. However, the elevated lactic acid, deficiency in ROS, and hypoxic tumor microenvironment have severely reduced the radiotherapy outcomes. Hence, this study devised a novel CoMnFe-layered double oxides (LDO) nanosheet with multienzyme activities for UM radiotherapy enhancement. On one hand, LDO nanozyme can catalyze hydrogen peroxide (H2O2) in the tumor microenvironment into oxygen and reactive oxygen species (ROS), significantly boosting ROS production during radiotherapy. Simultaneously, LDO efficiently scavenged lactic acid, thereby impeding the DNA and protein repair in tumor cells to synergistically enhance the effect of radiotherapy. Moreover, density functional theory (DFT) calculations decoded the transformation pathway from lactic to pyruvic acid, elucidating a previously unexplored facet of nanozyme activity. The introduction of this innovative nanomaterial paves the way for a novel, targeted, and highly effective therapeutic approach, offering new avenues for the management of UM and other cancer types.

Layered Double Hydroxides: Recent Progress and Promising Perspectives Toward Biomedical Applications

Layered double hydroxides (LDHs) have been widely studied for biomedical applications due to their excellent properties, such as good biocompatibility, degradability, interlayer ion exchangeability, high loading capacity, pH-responsive release, and large specific surface area. Furthermore, the flexibility in the structural composition and ease of surface modification of LDHs makes it possible to develop specifically functionalized LDHs to meet the needs of different applications. In this review, the recent advances of LDHs for biomedical applications, which include LDH-based drug delivery systems, LDHs for cancer diagnosis and therapy, tissue engineering, coatings, functional membranes, and biosensors, are comprehensively discussed. From these various biomedical research fields, it can be seen that there is great potential and possibility for the use of LDHs in biomedical applications. However, at the same time, it must be recognized that the actual clinical translation of LDHs is still very limited. Therefore, the current limitations of related research on LDHs are discussed by combining limited examples of actual clinical translation with requirements for clinical translation of biomaterials. Finally, an outlook on future research related to LDHs is provided.

Nanozymes with biomimetically designed properties for cancer treatment

Nanozymes, as a type of nanomaterials with enzymatic catalytic activity, have demonstrated tremendous potential in cancer treatment owing to their unique biomedical properties. However, the heterogeneity of tumors and the complex tumor microenvironment pose significant challenges to the in vivo catalytic efficacy of traditional nanozymes. Drawing inspiration from natural enzymes, scientists are now using biomimetic design to build nanozymes from the ground up. This approach aims to replicate the key characteristics of natural enzymes, including active structures, catalytic processes, and the ability to adapt to the tumor environment. This achieves selective optimization of nanozyme catalytic performance and therapeutic effects. This review takes a deep dive into the use of these biomimetically designed nanozymes in cancer treatment. It explores a range of biomimetic design strategies, from structural and process mimicry to advanced functional biomimicry. A significant focus is on tweaking the nanozyme structures to boost their catalytic performance, integrating them into complex enzyme networks similar to those in biological systems, and adjusting functions like altering tumor metabolism, reshaping the tumor environment, and enhancing drug delivery. The review also covers the applications of specially designed nanozymes in pan-cancer treatment, from catalytic therapy to improved traditional methods like chemotherapy, radiotherapy, and sonodynamic therapy, specifically analyzing the anti-tumor mechanisms of different therapeutic combination systems. Through rational design, these biomimetically designed nanozymes not only deepen the understanding of the regulatory mechanisms of nanozyme structure and performance but also adapt profoundly to tumor physiology, optimizing therapeutic effects and paving new pathways for innovative cancer treatment.

Photothermal Conversion of Hydrogel-Based Biomaterial

Traditional energy from fossil fuels like petroleum and coal is limited and contributes to global environmental pollution and climate change. Developing sustainable and eco-friendly energy is crucial for addressing significant challenges such as climate change, energy dilemma and achieving the long-term development of human society. Biomass hydrogels, which are easily synthesized and modified, have diverse sources and can be designed for different applications. They are being extensively researched for their applications in artificial intelligence, flexible sensing, biomedicine, and food packaging. The article summarizes recent advances in the preparation and applications of biomass-based photothermal conversion hydrogels, discussing the light source, photothermal agents, matrix, and preparation methods in detail. It also explores the use of these hydrogels in seawater desalination, photothermal therapy, antibacterial agents, and light-activated materials, offering new ideas for developing sustainable, efficient, and advanced photothermal conversion biomass hydrogel materials. The article concludes with suggestions for future research, highlighting the challenges and prospects in this field and paving the way for developing of long-lasting, efficient energy materials.

Nanorod/nanodisk-integrated liquid crystalline systems for starvation, chemodynamic, and photothermal therapy of cancer

Indocyanine green (ICG), glucose oxidase (GOx), and copper(II) sulfate (Cu)-installed hybrid gel based on organic nanorod (cellulose nanocrystal [CNC]) and inorganic nanodisk (Laponite [LAP]) was developed to perform a combination of starvation therapy (ST), chemodynamic therapy (CDT), and photothermal therapy (PTT) for localized cancers. A hybrid CNC/LAP network with a nematic phase was designed to enable instant gelation, controlled viscoelasticity, syringe injectability, and longer in vivo retention. Moreover, ICG was introduced into the CNC/LAP gel system to induce hyperthermia of tumor tissue, amplifying the CDT effect; GOx was used for glucose deprivation (related to the Warburg effect); and Cu was introduced for hydroxyl radical generation (based on Fenton-like chemistry) and cellular glutathione (GSH) degradation in cancer cells. The ICG/GOx/Cu-installed CNC/LAP gel in combination with near-infrared (NIR) laser realized improved antiproliferation, cellular reactive oxygen species (ROS) generation, cellular GSH degradation, and apoptosis induction in colorectal cancer (CT-26) cells. In addition, local injection of the CNC/ICG/GOx/Cu/LAP gel into the implanted CT-26 tumor while irradiating it with NIR laser provided strong tumor growth suppression effects. In conclusion, the designed hybrid nanorod/nanodisk gel network can be efficiently applied to the local PTT/ST/CDT of cancer cells.

Recent Advances in Hydrogel-Based Phototherapy for Tumor Treatment

Phototherapeutic agent-based phototherapies activated by light have proven to be safe modalities for the treatment of various malignant tumor indications. The two main modalities of phototherapies include photothermal therapy, which causes localized thermal damage to target lesions, and photodynamic therapy, which causes localized chemical damage by generated reactive oxygen species (ROS). Conventional phototherapies suffer a major shortcoming in their clinical application due to their phototoxicity, which primarily arises from the uncontrolled distribution of phototherapeutic agents in vivo. For successful antitumor phototherapy, it is essential to ensure the generation of heat or ROS specifically occurs at the tumor site. To minimize the reverse side effects of phototherapy while improving its therapeutic performance, extensive research has focused on developing hydrogel-based phototherapy for tumor treatment. The utilization of hydrogels as drug carriers allows for the sustained delivery of phototherapeutic agents to tumor sites, thereby limiting their adverse effects. Herein, we summarize the recent advancements in the design of hydrogels for antitumor phototherapy, offer a comprehensive overview of the latest advances in hydrogel-based phototherapy and its combination with other therapeutic modalities for tumor treatment, and discuss the current clinical status of hydrogel-based antitumor phototherapy.