Layered double hydroxide-based nanomaterials for biomedical applications

Artificially tagging tumors with nano-aluminum adjuvant-tethered antigen mRNA recruits and activates antigen-specific cytotoxic T cells for enhanced cancer immunotherapy

T cell therapy for solid tumors faces significant challenges due to the immune off-target attack caused by the loss of tumor surface antigens and inactivation in acidic tumor microenvironment (TME). Herein, we developed a bifunctional immunomodulator (MO@NAL) by loading ovalbumin (OVA; model antigen) mRNA (mOVA) onto lysozyme-coated layered double hydroxide nano-aluminum adjuvant (NA). The NA's inherent alkalinity effectively neutralizes the excess acid within the TME and suppresses regulatory T cells, creating a favorable microenvironment to enhance cytotoxic T cell infiltration and activation in tumors. Particularly, once internalization by tumor cells, MO@NAL efficiently tags the tumor cell surface with OVA through the carried mOVA, providing targets for recruiting and directing the antigen-specific cytotoxic T cells to destroy tumor cells. In mice pre-vaccinated with the OVA vaccine, intratumoral administration of MO@NAL rapidly awakens OVA-specific immune memory, rapidly and effectively inhibiting the progression of colon tumors and melanoma at both early and advanced stages. In non-pre-vaccinated mice, combining MO@NAL with the OVA therapeutic vaccine or OVA-specific adoptive T cell transfusion similarly achieves robust solid tumor suppression. These findings thus underscore the potential of MO@NAL as an effective and safe immunomodulator for enhancing cytotoxic T cell responses and providing timely intervention in solid tumor progression.

Yellow light and ultrasound Dual-responsive strontium-doped zinc oxide composites for dental caries prevention and remineralization

Dental caries is one of the most prevalent chronic infectious diseases, mainly due to acid production by bacteria in the plaque biofilm, leading to enamel demineralization, tooth defects and pulpitis. Most of the current treatments are invasive and do not combine restoration of dental tissues, resolution of tooth staining or prevention of dental caries. In this study, a polydopamine (PDA)-encapsulated strontium-doped zinc oxide composite (Sr-ZnO@PDA, denoted as SZ@PDA) has been developed for caries prevention and remineralization. The PDA wrapping endows SZ@PDA with a narrow energy band gap (1.78 eV), which can simultaneously respond to yellow light (YL) with favorable biosafety and ultrasound (US) with high tissue penetration. The synergistic piezo-photocatalytic action of YL and US with the enhanced catalytic efficiency can generate an appropriate amount of reactive oxygen species (ROS), thus destroying the structure of bacterial cellular membranes and decomposing pigments for caries prevention and improvement of tooth staining, respectively. In addition, strontium ions (Sr2+) released by SZ@PDA, as an active element, can promote the remineralization of enamel and dentin, repairing defective dental tissues. Collectively, this versatile system (SZ@PDA) provides an effective strategy for the prevention and treatment of caries.

Progress on layered double hydroxides as green materials in sustainable agricultural production

As the global population continues to grow, there is increasing demand for high-quality and high-yield food. However, traditional agrochemicals such as fertilizers and pesticides suffer from low utilization rates and can be hazardous to non-target organisms and the soil environment. Two-dimensional layered double hydroxides (LDHs) have attracted considerable attention in the agricultural sector owing to their excellent properties. To alleviate the general concern about the use of LDH materials in combination with agrochemicals, this paper presents a comprehensive overview of the structure, properties, preparation methods, and cytotoxicity of LDHs, with a focus on the advantages and disadvantages of different synthesis methods. In addition, the current research status of the application of LDHs as green materials in modern agricultural production is presented, and the applications of nano fertilizers for promoting crop growth, nano pesticides for efficient herbicide and insecticide, efficient adsorption of pollutants and soil heavy metal ions to maintain soil stability, and applications in genetic modification and enhancement of plant photosynthesis are discussed in detail. Finally, future research directions for LDH are envisioned. We hope that this study will promote the use of LDH materials in agricultural practices.

Bioactive Inorganic Materials for Innervated Multi-Tissue Regeneration

Tissue engineering aims to repair damaged tissues with physiological functions recovery. Although several therapeutic strategies are there for tissue regeneration, the functional recovery of regenerated tissues still poses significant challenges due to the lack of concerns of tissue innervation. Design rationale of multifunctional biomaterials with both tissue-induction and neural induction activities shows great potential for functional tissue regeneration. Recently, the research and application of inorganic biomaterials attracts increasing attention in innervated multi-tissue regeneration, such as central nerves, bone, and skin, because of its superior tunable chemical composition, topographical structures, and physiochemical properties. More importantly, inorganic biomaterials are easily combined with other organic materials, biological factors, and external stimuli to enhance their therapeutic effects. This review presents a comprehensive overview of recent advancements of inorganic biomaterials for innervated multi-tissue regeneration. It begins with introducing classification and properties of typical inorganic biomaterials and design rationale of inorganic-based material composites. Then, recent progresses of inorganic biomaterials in regenerating various nerves and nerve-innervated tissues with functional recovery are systematically reviewed. Finally, the existing challenges and future perspectives are proposed. This review may pave the way for the direction of inorganic biomaterials and offers a new strategy for tissue regeneration in combination of innervation.

Recent progress on transition metal dichalcogenide-based composites for cancer therapy

Cancer remains a global health challenge, driving the need for advanced treatments. While transition metal dichalcogenides (TMDs) show promise in cancer therapy, their stability and efficacy require improvement. This study explores TMD-based composites as a solution to enhance their therapeutic potential. This review begins by providing an overview of TMDs and emphasizing their preparation techniques and fundamental properties. The focus is then shifted to categorizing TMD-based composites based on their constituent materials, delving into various types, such as TMD-organic, TMD-carbon, TMD-metal chalcogenide, TMD-metal, and TMD-oxide composites, as well as more complex ternary and multinary systems. We further explore key fabrication strategies, including hydrothermal/solvothermal methods and surface deposition/coating techniques. Subsequently, the focus shifted to their applications in cancer treatment, including chemotherapy, photothermal therapy, phototherapy, and integrated combination therapies. Finally, critical challenges in the field and perspectives on potential directions for future research are presented.

Interfering with proton and electron transfer enables antibacterial starvation therapy

Implant-associated infections are urgently addressed; however, existing materials are difficult to kill bacteria without damaging cells. Here, we propose an innovative concept of selective antibacterial starvation therapy based on interfering with proton and electron transfer on the bacterial membrane. As a proof-of-principle demonstration, a special Schottky heterojunction film composed of gold and alkaline magnesium-iron mixed metal oxides (Au/MgFe-MMO) was constructed on the titanium implant. Once bacteria contacted this implant, the Au/MgFe-MMO film continuously captured the proton and electron participated in respiratory chain of bacteria to impede their energy metabolism, leading to the deficit of adenosine 5'-triphosphate. Prolonged exposure to this starvation state inhibited numerous biosynthesis processes and triggered severe oxidative stress in bacteria, ultimately leading to their death due to DNA and membrane damage. In addition, this heterojunction film was comfortable for mammalian cells, without inhibiting mitochondrial function. This proposed starvation antibacterial therapy gives a notable perspective in designing biosafe smart antibacterial biomaterials.

Copper-doped layered double hydroxides co-deliver proteins/drugs for cascaded chemodynamic/immunotherapy via dual regulation of tumor metabolism

We report here a Cu2+-doped layered double hydroxide (LDH) nanoplatform to load both monocarboxylate transporter inhibitor diclofenac (DC) and lactate oxidase (LOX) for dual modulation of tumor lactate and redox metabolisms to activate immunotherapy through enhanced Cu-mediated chemodynamic therapy (CDT) of tumors. The formed LDH-DC-LOX nanoparticles with a diameter of 55 nm are stable, can be effectively taken up by cancer cells to regulate lactate through both LOX-mediated catalytic conversion and DC-enabled inhibition of extracellular efflux of lactate, and can exert redox metabolism through CDT via Cu2+-mediated glutathione (GSH) depletion and Fenton-like reaction with hydrogen peroxide (H2O2) that can be further accumulated via LOX-mediated catalysis. The major advantage of the developed LDH-DC-LOX nanoparticles lies in the therapeutic synergy and cascade that can be achieved through the loaded DC and LOX for enhanced tumor lactate metabolism regulation, for enhanced Cu-mediated CDT and redox metabolism regulation, and for activation of immunotherapy that can further enhances the Cu2+-mediated CDT effect. The developed LDH nanoplatform demonstrated here for effective murine breast tumor treatment provides a new paradigm for dual regulation of lactate and redox metabolisms that may enable synergistic and cascaded combination therapy of different cancer types. STATEMENT OF SIGNIFICANCE: Targeting the tumor microenvironment (TME) to alter tumor metabolic pathways represents a promising strategy for next-generation cancer therapy. Herein, a copper-doped layered double hydroxide (LDH) nanoplatform is developed to co-deliver both diclofenac (DC) and lactate oxidase (LOX) to tumor cells for efficient dual regulation of tumor lactate and redox metabolisms, resulting in synergistic and cascaded chemodynamic therapy/immunotherapy of breast tumors. The developed LDH-DC-LOX nanoparticles can release Cu2+ and DC under an acidic TME, and can act in synergy to reduce TME lactate and generate H2O2, thus modulating redox metabolism and activating anticancer immunotherapy. The secreted cytokine IFN-γ after activation of antitumor immune responses can further mediate enhanced chemodynamic therapy effect through downregulation of cystine/glutamate transporter SLC7A11 to suppress GSH synthesis.

A new β-amylase detection strategy based on encapsulated enzyme in magnetic layered double hydroxide with high sensitivity and simplified workflow

β-Amylase (BMY) is a linchpin in food production and the pharmaceutical industry because the enzyme efficiently controls the ratio of diverse saccharides in fermentation and the manufacture of high-quality maltose. However, existing BMY detection tactics suffer from inadequate selectivity/sensitivity and cumbersome operation and do not meet the needs of precise quantification. Consequently, there is an urgent need to develop an ultrasensitive sensing platform to achieve precise BMY analysis with a low detection limit and simpler workflow. In this work, we establish an encapsulated-enzyme-based BMY biosensing platform in which α-glucosidase is embedded in magnetic layered double hydroxide using a self-sacrificing template. The encapsulated enzyme has increased activity, robustness, and recyclability and was utilized for BMY detection via a cascade chromatic process. We found a detection limit for the quantification of BMY activity of 2.67 U/L with a broad range (5-400 U/L), fast response speed (10 min), and satisfactory specificity. We applied the biosensing platform to liquor starters to verify the capability of the assay in complicated fermentation samples. The proposed platform holds great promise as an efficient and simple method for enzymatic bioactivity monitoring in food manufacturing, biopharmaceutical processing, and clinical laboratory tests.

Hydrotalcites-Induced Pyroptosis Combined with Toll-Like Receptor Activation Elicited Dual Stimulation of Innate and Adaptive Immunity

Increasing evidence illustrates the significance of promoting tumor immunogenicity and an efficient immune response in immunotherapy, but the immunosuppressive tumor microenvironment (TME) remains an obstacle. Herein, AlZn hydrotalcite (AZOH) was synthesized as a pyroptosis inducer and further loaded with R848 to formulate R@AZOH. R@AZOH efficiently triggered CT26 cell pyroptosis through Zn2+ overload-evoked mitochondrial dysfunction and its downstream caspase-1/GSDMD pathway, resulting in the release of inflammatory cytokines, membrane fracture, and immunogenic cell death (ICD). Moreover, R@AZOH served as antigen traps to facilitate antigen presentation, thereby cooperating with TLR activation to dually stimulate dendritic cells (DCs). The combination of R@AZOH rapidly initiated innate immunity and prolonged the adaptive immune response, resulting in the suppression of tumor growth, immune cell activation and a "hot" tumor niche. The potent antitumor immunity was further enhanced by combination with an immune checkpoint inhibitor (αCTLA-4), which inhibited both primary and distant tumors, as well as systemic immune activation. Astonishingly, we also explored the potential application of R@AZOH as a tumor vaccine adjuvant and demonstrated its ability to elicit immunological memory to prevent tumor growth in an orthotopic melanoma model. Overall, our work emphasized the potential application of combining pyroptosis and TLR activation to stimulate both innate and adaptive immunity to overcome the immunosuppressive TME and presented a good adjuvant candidate.

Tumor Microenvironment-Driven Structural Transformation of Vanadium-Based MXenzymes to Amplify Oxidative Stress for Multimodal Tumor Therapy

MXenzymes, a promising class of catalytic therapeutic material, offer great potential for tumor treatment, but they encounter significant obstacles due to suboptimal catalytic efficiency and kinetics in the tumor microenvironment (TME). Herein, this study draws inspiration from the electronic structure of transition metal vanadium, proposing the leverage of TME specific-features to induce structural transformations in sheet-like vanadium carbide MXenzymes (TVMz). These transformations trigger cascading catalytic reactions that amplify oxidative stress, thereby significantly enhancing multimodal tumor therapy. Specifically, the engineered HTVMz, coated with hyaluronic acid, exhibits good stability and generates a thermal effect under NIR-II laser irradiation. The thermal effect, combined with TME characteristics, facilities a structural transformation into ultra-small vanadium oxide nanozymes (VOx). The enlarged surface area of VOx substantially enhances ROS regeneration and amplifies oxidative stress, which promotes lysosomal permeability and induces endoplasmic reticulum stress. The high-valent vanadium in VOx interacts with intracellular glutathione, disrupting redox homeostasis and intensifying oxidative stress further. These amplifications accelerate tumor apoptosis, induce ferroptosis, and suppress HSP90 expression. Consequently, the heightened thermal sensitivity of HTVMz synergistically promotes tumor cell death via multimodal therapeutic pathways. This study presents an innovative strategy for tumor catalytic therapy by manipulating MXenzymes structures, advancing the field of catalytic therapy.

Ultrathin high-entropy hydrotalcites-based injectable hydrogel with programmed bactericidal and anti-inflammatory effects to accelerate drug-resistant bacterial infected wound healing

Drug-resistant bacteria infected wounds often bring high risks of delayed healing process and even death. Sonodynamic therapy (SDT) can efficiently kill drug-resistant bacteria. However, superabundant reactive oxygen species (ROS) generated during SDT inevitably trigger significant inflammatory responses, hindering tissue remodeling. Herein, we develop intelligent ultrathin high-entropy hydrotalcites (UHE-HTs)-based injectable thermal-responsive hydrogel loaded with nicotinamide mononucleotide (UHE-HTs/PFN), aiming to achieve programmed antibacterial and anti-inflammatory effects. In the early infection stage, sonosensitive UHE-HTs/PFN hydrogel simultaneously can trigger rapid production of singlet oxygen (1O2) under ultrasound and efficient MDR bacterial sterilization. After halting ultrasonic irradiation, oxidoreductase-mimicking catalysis and nicotinamide mononucleotide release of UHE-HTs/PFN hydrogel effectively reduce ROS levels at wound sites, dampening the NF-κB inflammatory pathway. Such inhibited NF-κB expression can not only reduce the production of pro-inflammatory cytokines and inflammatory responses, but also significantly down-regulate the pyroptosis pathways (NLRP3/ASC/Casp-1) and inhibit pyroptosis that leads to inflammation. Moreover, significantly reduced ROS levels and synergistic release of Mg2+ reverse pro-inflammatory immune microenvironment. Both in vitro and in vivo assays demonstrate that UHE-HTs/PFN hydrogel can transform the adverse infected wound environment into a regenerative one by eradicating drug-resistant bacteria, scavenging ROS, and synergistic anti-inflammation. Therefore, this work develop an intelligent UHE-HTs/PFN hydrogel act as a "lever" that effectively achieve a balance between ROS generation and annihilation, rebuilding harmonious bactericidal and anti-inflammatory effects to remedy drug-resistant bacteria infected wound.

Sensitive colorimetric sensing of dopamine and TYR based on enhanced HRP-like activity of CuNi/Fe LDHs nanozymes

CuNi/Fe LDHs with HRP-like activity (nanozyme) have been prepared. Contrary to the expected design, free dopamine (DA) was found to greatly enhance the catalytic performances of CuNi/Fe LDHs nanozyme. As far as we know, this is the first report that free DA boosts the catalytic performances of LDHs. Given the superior HRP-like enzyme activity of DA-CuNi/Fe LDHs, a colorimetric method for DA and tyrosinase (TYR) assay with high sensitivity and specificity was established, and it was successfully applied to quantify DA in artificial cerebrospinal fluid and TYR in newborn calf serum. The acquired insights in DA-CuNi/Fe LDHs will contribute to future rational design of other high-performance nanozymes. In addition, the novel DA and TYR assay pave a way for designing further nanozymes-based colorimetric chemo/biosensors.

Mechanistic insights into the formation of hydroxides with unconventional coordination environments to achieve their cost-effective synthesis

Transition metal hydroxides, comprising metal-centered polyhedra, are abundant in nature and have a broad range of applications. Although the intercalation/deintercalation of polyhedra with unconventional coordination numbers (UCN) plays a pivotal role in their formation process and influences their chemical behavior, the detailed mechanism remains obscure. Here, taking the kinetically controlled growth of Co(OH)2 as a model system (where polyhedra with UCN refers to 4-coordinated tetrahedra), by combining in situ pH measurement and in situ ultraviolet-visible (UV-vis) spectroscopy, we tracked Co2+ tetrahedral intercalation/deintercalation with varying OH- concentrations, discovering that the initial Co2+ tetrahedral intercalation into the Co(OH)2 lattice is inevitable and its retention is influenced by the effective OH- concentration, challenging previous beliefs about the formation of Co(OH)2 and potentially other hydroxides. More importantly, an understanding of the intercalation mechanism would significantly contribute to optimization of the synthesis conditions of hydroxides with tunable coordination environments, which hold significant application potential, as evidenced by a proof-of-concept application in the oxygen evolution reaction.

Anchoring Ru single-atoms on MXene achieves dual-enzyme activities for mild photothermal augmented nanocatalytic therapy

Single-atom catalysts with abnormally high catalytic activity have garnered extensive attention and interest for their application in tumor therapy. Despite the advancements made with current nanotherapeutic agents, developing efficient systems for cancer treatment remains challenging due to low activity, uncontrollable behavior, and nonselective interactions. Herein, we have constructed Ru single-atom-anchored MXene nanozymes (Ru-Ti3C2Tx-PEG) with a mild photothermal effect and multi-enzyme catalytic activity for synergistic tumor therapy. Ru single atoms anchored on the surface of MXene nanosheets not only facilitate multi-enzyme catalytic activity but also amplify the photothermal performance owing to the localized surface plasmon resonance effect. The Ru single atoms could decompose H2O2 into toxic hydroxyl radicals (•OH) in response to the tumor microenvironment (TME) for enzyme catalytic therapy, and the heat produced by the nanozyme under near-infrared laser excitation enhanced the •OH generation yield. Moreover, the nanozyme exhibited oxygen formation and glutathione depletion capability in cancer cells, thereby regulating the TME and accelerating the •OH levels. The in vitro and in vivo studies in this work confirm that the two-dimensional Ru single-atom-anchored MXene nanozyme has an extraordinary tumor growth inhibition effect, thus presenting a rational therapeutic strategy for tumor ablation through the synergistic effect of photothermal activity and heat-promoted enzymatic catalysis.

Layered Double Hydroxide LDH-Loaded miR-141-3p Targets RAB10 Suppressing Cellular Autophagy to Reverse Paclitaxel Resistance in Breast Cancer

Autophagy is a cellular protective mechanism. As tumor cells are stimulated by drugs, autophagy is activated to increase their resistance to drugs. In gene regulation, microRNA (miRNA) plays a vital role. The diagnostic and prognostic potential of various miRNAs in cancer has been recognized, and for several years, miRNA-based therapeutic approaches have garnered significant interest in the oncology field. RAB10, a member of the RAB guanosine triphosphatase family, has been reported that it contributes to tumor resistance to chemotherapy. The bionanomaterial layered double hydroxide (LDH) is considered as an ideal gene delivery vehicle because of its nontoxicity, good biocompatibility, and slow drug release. According to our findings, we proved that miR-141-3p mediated breast cancer resistance to paclitaxel (PTX) by inhibiting autophagy through downregulation of RAB10, and LDH@miR-141-3p increased breast cancer cell sensitivity to PTX treatment, which provided a new idea for antitumor therapy.

Periodic Table of Immunomodulatory Elements and Derived Two-Dimensional Biomaterials

Periodic table of chemical elements serves as the foundation of material chemistry, impacting human health in many different ways. It contributes to the creation, growth, and manipulation of functional metallic, ceramic, metalloid, polymeric, and carbon-based materials on and near an atomic scale. Recent nanotechnology advancements have revolutionized the field of biomedical engineering to tackle longstanding clinical challenges. The use of nano-biomaterials has gained traction in medicine, specifically in the areas of nano-immunoengineering to treat inflammatory and infectious diseases. Two-dimensional (2D) nanomaterials have been found to possess high bioactive surface area and compatibility with human and mammalian cells at controlled doses. Furthermore, these biomaterials have intrinsic immunomodulatory properties, which is crucial for their application in immuno-nanomedicine. While significant progress has been made in understanding their bioactivity and biocompatibility, the exact immunomodulatory responses and mechanisms of these materials are still being explored. Current work outlines an innovative "immunomodulatory periodic table of elements" beyond the periodic table of life, medicine, and microbial genomics and comprehensively reviews the role of each element in designing immunoengineered 2D biomaterials in a group-wise manner. It recapitulates the most recent advances in immunomodulatory nanomaterials, paving the way for the development of new mono, hybrid, composite, and hetero-structured biomaterials.

Recent advances of anti-tumor nano-strategies via overturning pH gradient: alkalization and acidification

The acidic tumor microenvironment, a hallmark of many solid tumors, is primarily induced by the high glycolytic rate of tumor cells. To avoid acidosis, tumor cells ingeniously maintain an acidic extracellular pH while keeping a relatively alkaline intracellular pH. Overturning the unique pH gradient of tumor cells has exhibited to be a viable approach for cancer therapy. In this review, the formation and regulatory mechanisms of the acidic microenvironment in solid tumors will be firstly outlined. Subsequently, we will comprehensively summarize the latest advancements in anti-tumor therapy via using nanomedicines to manipulate the tumor pH gradient, including acidifying intracellular environment and alkalizing extracellular environment. Following this, we will discuss the future potential of strategies employing nanomedicines to reverse tumor pH gradient. This review aims to foster research on therapeutic approaches targeting the pH regulation of solid tumors and holds an optimistic outlook for the future development of this field.

Wearable Biodevices Based on Two-Dimensional Materials: From Flexible Sensors to Smart Integrated Systems

The proliferation of wearable biodevices has boosted the development of soft, innovative, and multifunctional materials for human health monitoring. The integration of wearable sensors with intelligent systems is an overwhelming tendency, providing powerful tools for remote health monitoring and personal health management. Among many candidates, two-dimensional (2D) materials stand out due to several exotic mechanical, electrical, optical, and chemical properties that can be efficiently integrated into atomic-thin films. While previous reviews on 2D materials for biodevices primarily focus on conventional configurations and materials like graphene, the rapid development of new 2D materials with exotic properties has opened up novel applications, particularly in smart interaction and integrated functionalities. This review aims to consolidate recent progress, highlight the unique advantages of 2D materials, and guide future research by discussing existing challenges and opportunities in applying 2D materials for smart wearable biodevices. We begin with an in-depth analysis of the advantages, sensing mechanisms, and potential applications of 2D materials in wearable biodevice fabrication. Following this, we systematically discuss state-of-the-art biodevices based on 2D materials for monitoring various physiological signals within the human body. Special attention is given to showcasing the integration of multi-functionality in 2D smart devices, mainly including self-power supply, integrated diagnosis/treatment, and human-machine interaction. Finally, the review concludes with a concise summary of existing challenges and prospective solutions concerning the utilization of 2D materials for advanced biodevices.

A Smart Nanomedicine Unleashes a Dual Assault of Glucose Starvation and Cuproptosis to Supercharge αPD-L1 Therapy

Combination therapy has become a promising strategy for promoting the outcomes of anti-programmed death ligand-1 (αPD-L1) therapy in lung cancer. Among all, emerging strategies targeting cancer metabolism have shown great potency in treating cancers with immunotherapy. Here, alteration in glucose and copper metabolisms is found to synergistically regulate PD-L1 expression in lung cancer cells. Thus, an intelligent biomimetic nano-delivery system is synthesized by camouflaging lung cancer cell membranes onto glucose oxidase-loaded Cu-LDHs (CMGCL) for cancer metabolism targeted interference. Such novel nanomedicine is able to induce lung cancer cell cuproptosis and PD-L1 upregulation significantly via self-amplified cascade reactions. Meanwhile, with a decent cancer cell membrane coating, CMGCL exhibited great biosafety, tumor-targeted efficiency and anti-tumor effects in LLC lung tumor-bearing mice models. Additionally, a combination of CMGCL can sensitize the therapeutic effects of αPD-L1, substantially promoting tumor inhibition in both subcutaneous and lung metastasis LLC-bearing mice models. Overall, these findings highlight the potential connections between glucose metabolism and cell cuproptosis, offering a promising approach for treating lung cancer by integrating starvation, cuproptosis, and immunotherapy.

Metal Doping Enabling Defective CoMo-Layered Double Hydroxide Nanosheets as Highly Efficient Photosensitizers for NIR-II Photodynamic Cancer Therapy

Photodynamic therapy (PDT) is attracting widespread attention as a promising strategy for tumor treatment. However, the efficacy of PDT is severely limited by the insufficient tissue penetration depth of the light source and low reactive oxygen species (ROS) generation efficiency. Herein, the metal doping strategy is reported to construct a series of defect-rich M-doped amorphous CoMo-layered double hydroxide (a-M-CoMo-LDH, M = Mn, Cu, Al, Ni, Mg, Zn) photosensitizers (PSs) for NIR-II PDT. Especially, M-doped CoMo-LDH nanosheets are synthesized through a simple hydrothermal method and then etched by acid treatment to prepare defect-rich a-M-CoMo-LDH nanosheets. Under NIR-II 1270 nm laser irradiation, the defect-rich a-Zn-CoMo-LDH nanosheets exhibit the optimal PDT performance compared with other a-M-CoMo-LDH nanosheets, and also possess much higher ROS production activity (3.9 times) than that of the pristine a-CoMo-LDH, with a singlet oxygen quantum yield up to 1.86, which is the highest among all the reported PSs. After polyethylene glycol (PEG) modification, the a-Zn-CoMo-LDH-PEG nanosheets can function as an effective inorganic PS for PDT, effectively inducing cell apoptosis in vitro and eradicating tumors in vivo. Notably, transcriptome sequencing analysis and further molecular validation highlight the critical role of the apoptotic/p53/AMPK/oxidative phosphorylation signaling pathways in a-Zn-CoMo-LDH-PEG-induced cancer cell apoptosis.

Coupling Probiotics with CaO2 Nanoparticle-Loaded CoFeCe-LDH Nanosheets to Remodel the Tumor Microenvironment for Precise Chemodynamic Therapy

Chemodynamic therapy (CDT) has become an emerging cancer treatment strategy with advantages of tumor-specificity, high selectivity, and low systemic toxicity. However, it usually suffers from low therapeutic efficacy. This is caused by low hydroxyl radical (·OH) yield arising because of the relatively high pH, overexpressed glutathione, and low H2O2 concentration in the tumor microenvironment (TME). Herein, a probiotic metabolism-initiated pH reduction and H2O2 supply-enhanced CDT strategy is reported to eradicate tumors by generating ·OH, in which Lactobacillus acidophilus is coupled with CoFeCe-layered double hydroxide nanosheets loaded with CaO2 nanoparticles (NPs) as a chemodynamic platform for high-efficiency CDT (CaO2/LDH@L. acidophilus). Owing to the hypoxia tropism of L. acidophilus, CaO2/LDH@L. acidophilus exhibits increased accumulation at tumor sites compared with the CaO2/LDH. The CaO2 NPs loaded on CoFeCe-LDH nanosheets are decomposed into H2O2 in the TME. L. acidophilus metabolite-induced pH reduction (<5.5) and CaO2-mediated in situ H2O2 generation synergistically boost ·OH generation activity of the CoFeCe-LDH nanosheets, effectively damaging cancer cells and ablating tumors with a tumor inhibition rate of 96.4%, 2.32-fold higher than that of CaO2/LDH. This work demonstrates that probiotics can function as a tumor-targeting platform to remodel the TME and amplify ROS generation for highly efficient and precise CDT.

Gold Nanoparticles Decorated CoAl LDH Monolayer: A Peroxidase-Like Nanozyme for Sensitive Colorimetric Detection of Acetylcholinesterase and Inhibitors

Monitoring acetylcholinesterase (AChE) activity and its inhibitor is crucial yet challenging for the early diagnosis and treatment of neurological diseases. In this study, we present Au nanoparticle decorated CoAl layered double hydroxide monolayer (Au@CoAl-LDH-m) as a peroxidase-like (POD) nanozyme for the sensitive colorimetric detection of AChE and its inhibitor, thiamine pyrophosphate (TPP). Remarkably, the Au@CoAl-LDH-m nanozyme can catalyze the oxidation of chromogenic substrates through its POD-like activity, which is effectively inhibited by thiocholine (TCh, a catalytic product of AChE), thereby enabling detection of AChE and TPP through a visible colorimetric readout. The approach provides a highly sensitive and specificity assay with a broader linear response range (1-100 mU mL-1 for AChE and 1-1000 ng mL-1 for TPP) and a low detection limit (0.092 mU mL-1 for AChE and 0.201 ng mL-1 for TPP), respectively. These results highlight the significant potential of Au@CoAl-LDH-m for advancing colorimetric sensors in detecting small molecules across various biological applications.

Recent advances in two-dimensional materials for drug delivery

Two-dimensional (2D) materials exhibit significant potential in biomedical applications, particularly as drug carriers. Thus, 2D materials, including graphene, black phosphorus, transition metal dichalcogenides, transition metal carbides/nitrides, and hexagonal boron nitride, have been extensively studied. Their large specific surface area, abundant surface active sites, and excellent biocompatibility and biodegradability make them ideal platforms for drug loading and delivery. By optimizing the physicochemical properties and methods for the surface modification of 2D materials, improved drug release mechanisms and enhanced combination therapy effects can be achieved, providing a reliable foundation for efficient cancer treatment. This review provides a comprehensive analysis of the recent advances in the utilization of 2D materials for drug delivery. It systematically categorizes and summarizes the preparation methodologies, surface modification strategies, application domains, primary advantages and potential drawbacks of various 2D materials in the biomedical field. Furthermore, it provides an extensive overview of current challenges in this field and outlines potential future research directions for 2D materials in drug delivery based on existing issues.

Tailored Engineering of Layered Double Hydroxide Catalysts for Biomass Valorization: A Way Towards Waste to Wealth

Layered double hydroxides (LDH) have significant attention in recent times due to their unique characteristic properties, including layered structure, variable compositions, tunable acidity and basicity, memory effect, and their ability to transform into various kinds of catalysts, which make them desirable for various types of catalytic applications, such as electrocatalysis, photocatalysis, and thermocatalysis. In addition, the upcycling of lignocellulose biomass and its derived compounds has emerged as a promising strategy for the synthesis of valuable products and fine chemicals. The current review focuses on recent advancements in LDH-based catalysts for biomass conversion reactions. Specifically, this review highlights the structural features and advantages of LDH and LDH-derived catalysts for biomass conversion reactions, followed by a detailed summary of the different synthesis methods and different strategies used to tailor their properties. Subsequently, LDH-based catalysts for hydrogenation, oxidation, coupling, and isomerization reactions of biomass-derived molecules are critically summarized in a very detailed manner. The review concludes with a discussion on future research directions in this field which anticipates that further exploration of LDH-based catalysts and integration of cutting-edge technologies into biomass conversion reactions hold promise for addressing future energy challenges, potentially leading to a carbon-neutral or carbon-positive future.

Nanotechnology used for siRNA delivery for the treatment of neurodegenerative diseases: Focusing on Alzheimer's disease and Parkinson's disease

Neurodegenerative diseases (ND) are often accompanied by dementia, motor dysfunction, or disability. Caring for these patients imposes a significant psychological and financial burden on families. Until now, there are no effective methods for the treatment of NDs. Among them, Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common. Recently, studies have revealed that the overexpression of certain genes may be linked to the occurrence of AD and PD. Small interfering RNAs (siRNAs) are a powerful tool for gene silencing because they can specifically bind to and cleave target mRNA. However, the intrinsic properties of naked siRNA and various physiological barriers limit the application of siRNA in the brain. Nanotechnology is a promising option for addressing these issues. Nanoparticles are not only able to protect siRNA from degradation but also have the advantage of crossing various physiological barriers to reach the brain target of siRNA. In this review, we aim to introduce diverse nanotechnology used for delivering siRNA to treat AD and PD. Finally, we will briefly discuss our perspectives on this promising field.

PAD4 Inhibitor-Loaded Layered Double Hydroxide Nanosheets as a Multifunctional Nanoplatform for Photodynamic Therapy-Mediated Tumor Metastasis Treatment

Photodynamic therapy (PDT) is demonstrated to be effective in inducing antitumor immune responses for tumor metastasis treatment. However, tumor hypoxia, inferior tissue penetration of light, and low singlet oxygen (1O2) quantum yield significantly hamper the efficacy of PDT, thus weakening its immune function. Moreover, PDT-mediated neutrophil extracellular traps (NETs) formation can further reduce the therapeutic effectiveness. Herein, the use of defect-rich CoMo-layered double hydroxide (DR-CoMo-LDH) nanosheets as a carrier to load a typical peptidyl arginine deiminase 4 inhibitor, i.e., YW4-03, to construct a multifunctional nanoagent (403@DR-LDH) for PDT/immunotherapy, is reported. Specifically, 403@DR-LDH inherits excellent 1O2 generation activity under 1550 nm laser irradiation and improves the half-life of YW4-03. Meanwhile, 403@DR-LDH plus 1550 nm laser irradiation can stimulate immunogenic cell death to promote the maturation of dendric cells and activation/infiltration of T cells and significantly downregulate H3cit protein expression to inhibit NETs formation, synergistically promoting the antitumor metastasis effect. Taken together, 403@DR-LDH can kill cancer cells and inhibit tumor growth/metastasis under 1550 nm laser irradiation. Single-cell analysis indicates that 403@DR-LDH can regulate the ratio of immune cells and immune-related proteins to improve the tumor immune microenvironment, showing strong efficacy to inhibit the tumor growth, metastasis, and recurrence.

Composites formed by layered double hydroxides with inorganic compounds: An overview of the synthesis methods and characteristics

Nowadays, layered double hydroxides (LDH), sometimes referred as hydrotalcite-like compounds, have gained great attention since their composition and structure can be easily modified, so that they can be implemented in multiple fields. LDH-based composite materials based on LDH exhibit tremendously improved properties such as high specific surface area, which promotes the accessibility to a greater number of LDH active sites, considerably improving their catalytic, adsorbent and biological activities. Therefore, this review summarizes and discusses the synthesis methods of composites constituted by LDH with other inorganic compounds such as zeolites, cationic clays, hydroxyapatites, among many others, and describe the resulting characteristics of the resulting composites, emphasizing the morphology. Brief descriptions of their properties and applications are also included.

Multiple-Effect Combined Hydrogels: "Temporal Regulation" Treatment of Osteosarcoma-Associated Bone Defects with Switchable Hyperthermia and Bioactive Agents

Achieving the clinically staged treatment of osteosarcoma-associated bone defects encounters the multiple challenges of promptly removing postoperative residual tumor cells and bacterial infection, followed by bone reconstruction. Herein, a core/shell hydrogel with multiple-effect combination is designed to first exert antitumor and antibacterial activities and then promote osteogenesis. Specifically, doxorubicin (DOX) is loaded by magnesium-iron-based layered double hydroxide (LDH) to prepare LDOX, which is introduced into a thermo-sensitive hydrogel to serve as an outer shell of the core/shell hydrogel, meanwhile, LDH-contained liquid crystal hydrogel, abbreviated as LCgel-L, is served as an inner core. At the early stage of treatment, the dissociation of the outer shell triggered by moderate hyperthermia led to the thermo-sensitive release of LDOX, which can be targeted for the release of DOX within tumor cells, thereby promptly removing postoperative residual tumor cells based on the synergistic effect of photothermal therapy (PTT) and DOX, and postoperative bacterial infection can also be effectively prevented by PTT simultaneously. More importantly, the dissociation of the outer shell prompted the full exposure of the inner core, which will exert osteogenic activity based on the synergy of liquid crystal hydrogel as well as LDH-induced mild hyperthermia and ion effects, thereby enabling "temporal regulation" treatment of osteosarcoma-associated bone defects. This study provides a valuable insight for the development of osteosarcoma-associated bone repair materials.

Honeycomb Bionic Graphene Oxide Quantum Dot/Layered Double Hydroxide Composite Nanocoating Promotes Osteoporotic Bone Regeneration via Activating Mitophagy

Abnormal osteogenic and remodeling microenvironment due to osteoblast apoptosis are the primary causes of delayed fracture healing in osteoporotic patients. Magnesium (Mg) alloys exhibit biodegradability and appropriate elastic moduli for bone defects in osteoporosis, but the effect on the local bone remodeling disorder is still insufficient. Inspired by the "honeycomb," layered double hydroxide (LDH) with regular traps with graphene oxide quantum dots (GOQDs) inlayed is constructed by pulsed electrodeposition to generate GOQD/LDH composite nanocoatings on the surfaces of Mg alloy substrates. The honeycomb bionic multi-layer stereoscopic structure shows good regulation of the degradation of Mg alloy for the support of healing time required for osteoporotic bone defect. Within its lattice, the local microenvironment conducive to osteogenesis is provided by both the rescue effect of GOQD and LDH. The osteoblast apoptosis is rescued due to the activation of mitophagy to clear dysfunctional mitochondria, where the upregulation of BNIP3 phosphorylation played a key role. The osteoporotic rat model of femoral defects confirmed the improvement of bone regeneration and osseointegration of GOQD/LDH coating. In summary, honeycomb bionic composite nanocoatings with controllable degradation and excellent pro-osteogenic performance demonstrated a promising design strategy on Mg alloy implants in the therapy of osteoporotic bone defects.

Surface modification strategies to reinforce the soft tissue seal at transmucosal region of dental implants

Soft tissue seal around the transmucosal region of dental implants is crucial for shielding oral bacterial invasion and guaranteeing the long-term functioning of implants. Compared with the robust periodontal tissue barrier around a natural tooth, the peri-implant mucosa presents a lower bonding efficiency to the transmucosal region of dental implants, due to physiological structural differences. As such, the weaker soft tissue seal around the transmucosal region can be easily broken by oral pathogens, which may stimulate serious inflammatory responses and lead to the development of peri-implant mucositis. Without timely treatment, the curable peri-implant mucositis would evolve into irreversible peri-implantitis, finally causing the failure of implantation. Herein, this review has summarized current surface modification strategies for the transmucosal region of dental implants with improved soft tissue bonding capacities (e.g., improving surface wettability, fabricating micro/nano topographies, altering the surface chemical composition and constructing bioactive coatings). Furthermore, the surfaces with advanced soft tissue bonding abilities can be incorporated with antibacterial properties to prevent infections, and/or with immunomodulatory designs to facilitate the establishment of soft tissue seal. Finally, we proposed future research orientations for developing multifunctional surfaces, thus establishing a firm soft tissue seal at the transmucosal region and achieving the long-term predictability of dental implants.

Thermally Stable High-Entropy Layered Double Hydroxides for Advanced Catalysis

Layered double hydroxides (LDHs), especially high-entropy LDHs (HE-LDHs), have gained increasing attention. However, HE-LDHs often possess poor thermal stability, restricting their applications in thermo-catalysis. Herein, a novel complexing nucleation method is proposed for engineering HE-LDHs with enhanced thermal stability. This approach precisely controls the nucleation of metal ions with different solubility products, achieving homogeneous nucleation and effectively mitigating phase segregation and transformation at elevated temperatures. The prepared HE-LDH sample demonstrated exceptional thermal stability at temperatures up to 300 °C, outperforming all previously reported LDHs. Importantly, these HE-LDHs preserve both Lewis and Brønsted acidic sites, enabling the 100% removal of aromatic sulfides and alkaline nitrogen compounds from fuel oils in thermo-catalytic oxidation reactions. Experimental and characterization findings reveal that the metal-hydroxide bonds in the prepared HE-LDHs are strengthened by associated hydroxyl groups, inducing negative thermal expansion and augmenting the presence of acidic sites, thereby ensuring structural stability and enhancing catalytic activity. This study not only proposes a strategy for engineering HE-LDHs with remarkable thermal stability but also highlights potential applications of LDHs in thermo-catalysis.

Upconverting Ultra-Thin Bi2O2CO3 Nanosheets for Synergistic Photodynamic Therapy and Radiotherapy

Synergistic therapy has become the major therapeutic method for malignant tumors in clinical. Photodynamic therapy (PDT) and radiotherapy (RT) always combine together because of their identical anti-tumor mechanisms, that is reactive oxygen species are generated by the use of radiosensitizers after irradiation by X-ray to efficiently kill cancer cells, PDT also follows similar mechanism. Full exposure of energy-absorbing species in nanomaterials to X-ray or near-infrared light irradiation makes the energy interchange between nanomaterials and surrounding H2O or dissolved oxygen easier, however, it remains challenging. Herein, an ultrathin two-dimensional (2D) nanosheet (NS) is developed, Bi2O2CO3, doped with lanthanide ions to give out upconversion luminescence, where the high Z elements Bi, Yb, and Er promote the radio-sensitizing effect. To the surprise, lanthanide activator ions gave out completely different luminescence properties compared with traditional upconversion nanoparticles. Less dopant of Er ions in nanosheets lattice resulted in brighter red emission, which provides more efficient PDT. Under RT/PDT combined treatment, NS shows a good tumor growth-inhibiting effect. In addition, synergistic therapy requires lower radiation dose than conventional radiotherapy and lower light power than single photodynamic therapy, thus greatly reducing radiation damage caused by RT and thermal damage caused by PDT.

Solubilization techniques used for poorly water-soluble drugs

About 40% of approved drugs and nearly 90% of drug candidates are poorly water-soluble drugs. Low solubility reduces the drugability. Effectively improving the solubility and bioavailability of poorly water-soluble drugs is a critical issue that needs to be urgently addressed in drug development and application. This review briefly introduces the conventional solubilization techniques such as solubilizers, hydrotropes, cosolvents, prodrugs, salt modification, micronization, cyclodextrin inclusion, solid dispersions, and details the crystallization strategies, ionic liquids, and polymer-based, lipid-based, and inorganic-based carriers in improving solubility and bioavailability. Some of the most commonly used approved carrier materials for solubilization techniques are presented. Several approved poorly water-soluble drugs using solubilization techniques are summarized. Furthermore, this review summarizes the solubilization mechanism of each solubilization technique, reviews the latest research advances and challenges, and evaluates the potential for clinical translation. This review could guide the selection of a solubilization approach, dosage form, and administration route for poorly water-soluble drugs. Moreover, we discuss several promising solubilization techniques attracting increasing attention worldwide.

Proton nanomodulators for enhanced Mn2+-mediated chemodynamic therapy of tumors via HCO3- regulation

BACKGROUND

Mn2+-mediated chemodynamic therapy (CDT) has been emerged as a promising cancer therapeutic modality that relies heavily on HCO3- level in the system. Although the physiological buffers (H2CO3/HCO3-) provide certain amounts of HCO3-, the acidity of the tumor microenvironment (TME) would seriously affect the HCO3- ionic equilibrium (H2CO3 ⇌ H+ + HCO3-). As a result, HCO3- level in the tumor region is actually insufficient to support effective Mn2+-mediated CDT.

RESULTS

In this study, a robust nanomodulator MnFe2O4@ZIF-8 (PrSMZ) with the capability of in situ self-regulation HCO3- is presented to enhance therapeutic efficacy of Mn2+-mediated CDT. Under an acidic tumor microenvironment, PrSMZ could act as a proton sponge to shift the HCO3- ionic equilibrium to the positive direction, significantly boosting the generation of the HCO3-. Most importantly, such HCO3- supply capacity of PrSMZ could be finely modulated by its ZIF-8 shell thickness, resulting in a 1000-fold increase in reactive oxygen species (ROS) generation. Enhanced ROS-dependent CDT efficacy is further amplified by a glutathione (GSH)-depletion ability and the photothermal effect inherited from the inner core MnFe2O4 of PrSMZ to exert the remarkable antitumor effect on mouse models.

CONCLUSIONS

This work addresses the challenge of insufficient HCO3- in the TME for Mn2+-mediated Fenton catalysts and could provide a promising strategy for designing high-performance Mn2+-mediated CDT agents to treat cancer effectively.

Next-generation aluminum adjuvants: Immunomodulatory layered double hydroxide NanoAlum reengineered from first-line drugs

Aluminum adjuvants (Alum), approved by the US Food and Drug Administration, have been extensively used in vaccines containing recombinant antigens, subunits of pathogens, or toxins for almost a century. While Alums typically elicit strong humoral immune responses, their ability to induce cellular and mucosal immunity is limited. As an alternative, layered double hydroxide (LDH), a widely used antacid, has emerged as a novel class of potent nano-aluminum adjuvants (NanoAlum), demonstrating advantageous physicochemical properties, biocompatibility and adjuvanticity in both humoral and cellular immune responses. In this review, we summarize and compare the advantages and disadvantages of Alum and NanoAlum in these properties and their performance as adjuvants. Moreover, we propose the key features for ideal adjuvants and demonstrate that LDH NanoAlum is a promising candidate by summarizing its current progress in immunotherapeutic cancer treatments. Finally, we conclude the review by offering our integrated perspectives about the remaining challenges and future directions for NanoAlum's application in preclinical/clinical settings.

Designed functions of oxide/hydroxide nanosheets via elemental replacement/doping

Partial replacement of one structural element in a solid with another of a similar size was conducted to impart functionality to the solids and modify their properties. This phenomenon is found in nature in coloured gemstones and clay minerals and is used in materials chemistry and physics, endowing materials with useful properties that can be controlled by incorporated heteroelements and their amounts. Depending on the area of research (or expected functions), the replacement is referred to as "isomorphous substitution", "doping", etc. Herein, elemental replacement in two-dimensional (2D) oxides and hydroxides (nanosheets or layered materials) is summarised with emphasis on the uniqueness of their preparation, characterisation and application compared with those of the corresponding bulk materials. Among the 2D materials (graphene, metallenes, transition metal chalcogenides, metal phosphate/phosphonates, MXenes, etc.), 2D oxides and hydroxides are characterised by their presence in nature, facile synthesis and storage under ambient conditions, and possible structural variation from atomic-level nanosheets to thicker nanosheets composed of multilayered structures. The heteroelements to be doped were selected depending on the target application objectively; however, there are structural and synthetic limitations in the doping of heteroelements. In the case of layered double hydroxides (single layer) and layered alkali silicates (from single layer to multiple layers), including layered clay minerals (2 : 1 layer), the replacement (commonly called isomorphous substitution) is discussed to understand/design characteristics such as catalytic, adsorptive (including ion exchange), and swelling properties. Due to the variation in their main components, the design of layered transition metal oxide/hydroxide materials via isomorphous substitution is more versatile; in this case, tuning their band structure, doping both holes and electrons, and creating impurity levels are examined by the elemental replacement of the main components. As typical examples, material design for the photocatalytic function of an ion-exchangeable layered titanate (lepidocrocite-type titanate) and a perovskite niobate (KCa2Nb3O10) is discussed, where elemental replacement is effective in designing their multiple functions.

Microorganism microneedle micro-engine depth drug delivery

As a transdermal drug delivery method, microneedles offer minimal invasiveness, painlessness, and precise in-situ treatment. However, current microneedles rely on passive diffusion, leading to uncontrollable drug penetration. To overcome this, we developed a pneumatic microneedle patch that uses live Enterobacter aerogenes as microengines to actively control drug delivery. These microbes generate gas, driving drugs into deeper tissues, with adjustable glucose concentration allowing precise control over the process. Our results showed that this microorganism-powered system increases drug delivery depth by over 200%, reaching up to 1000 μm below the skin. In a psoriasis animal model, the technology effectively delivered calcitriol into subcutaneous tissues, offering rapid symptom relief. This innovation addresses the limitations of conventional microneedles, enhancing drug efficiency, transdermal permeability, and introducing a creative paradigm for on-demand controlled drug delivery.

2D nanomaterials-based delivery systems and their potentials in anticancer synergistic photo-immunotherapy

As the field of cancer therapeutics evolves, integrating two-dimensional (2D) nanomaterials with photo-immunotherapy has emerged as a promising approach with significant potential to augment cancer treatment efficacy. These 2D nanomaterials include graphene-based 2D nanomaterials, 2D MXenes, 2D layered double hydroxides, black phosphorus nanosheets, 2D metal-organic frameworks, and 2D transition metal dichalcogenides. They exhibit high load capacities, multiple functionalization pathways, optimal biocompatibility, and physiological stability. Predominantly, they function as anti-tumor delivery systems, amalgamating diverse therapeutic modalities, most notably phototherapy and immunotherapy, and the former is a recognized non-invasive treatment modality, and the latter represents the most promising anti-cancer strategy presently accessible. Thus, integrating phototherapy and immunotherapy founded on 2D nanomaterials unveils a novel paradigm in the war against cancer. This review delineates the latest developments in 2D nanomaterials as delivery systems for synergistic photo-immunotherapy in cancer treatment. We elaborate on the burgeoning realm of photo-immunotherapy, exploring the interplay between phototherapy and enhanced immune cells, immune response modulation, or immunosuppressive tumor microenvironments. Notably, the strategies to augment photo-immunotherapy have also been discussed. Finally, we discuss the challenges and future perspectives of these 2D nanomaterials in photo-immunotherapy.

Piezoelectric Bilayer Nickel-Iron Layered Double Hydroxide Nanosheets with Tumor Microenvironment Responsiveness for Intensive Piezocatalytic Therapy

Piezocatalytic therapy (PCT) based on 2D layered materials has emerged as a promising non-invasive tumor treatment modality, offering superior advantages. However, a systematic investigation of PCT, particularly the mechanisms underlying the reactive oxygen species (ROS) generation by 2D nanomaterials, is still in its infancy. Here, for the first time, biodegradable piezoelectric 2D bilayer nickel-iron layered double hydroxide (NiFe-LDH) nanosheets (thickness of ≈1.86 nm) are reported for enhanced PCT and ferroptosis. Under ultrasound irradiation, the piezoelectric semiconducting NiFe-LDH exhibits a remarkable ability to generate superoxide anion radicals, due to the formation of a built-in electric field that facilitates the separation of electrons and holes. Notably, the significant excitonic effect in the ultrathin NiFe-LDH system enables long-lived excited triplet excitons (lifetime of ≈5.04 µs) to effectively convert triplet O2 molecules into singlet oxygen. Moreover, NiFe-LDH exhibited tumor microenvironment (TME)-responsive peroxidase (POD)-like and glutathione (GSH)-depleting capabilities, further enhancing oxidative stress in tumor cells and inducing ferroptosis. To the best of knowledge, this is the first report on piezoelectric semiconducting sonosensitizers based on LDHs for PCT and ferroptosis, providing a comprehensive understanding of the piezocatalysis mechanism and valuable references for the application of LDHs and other 2D materials in cancer therapy.

A LDH-Derived Metal Sulfide Nanosheet-Functionalized Bioactive Glass Scaffold for Vascularized Osteogenesis and Periprosthetic Infection Prevention/Treatment

Periprosthetic infection and prosthetic loosing stand out as prevalent yet formidable complications following orthopedic implant surgeries. Synchronously addressing the two complications is long-time challenging. Herein, a bioactive glass scaffold (BGS) functionalized with MgCuFe-layered double hydroxide (LDH)-derived sulfide nanosheets (BGS/MCFS) is developed for vascularized osteogenesis and periprosthetic infection prevention/treatment. Apart from the antibacterial cations inhibiting bacterial energy and material metabolism, the exceptional near-infrared-II (NIR-II) photothermal performance empowers BGS/MCFS to eliminate periprosthetic infections, outperforming previously reported functionalized BGS. The rough surface topography and the presence of multi-bioactive metal ions bestow BGS/MCFS with exceptional osteogenic and angiogenic properties, with 8.5-fold and 2.3-fold enhancement in bone mass and neovascularization compared with BGS. Transcriptome sequencing highlights the involvement of the TGF-β signaling pathway in these processes, while single-cell sequencing reveals a significant increase in osteoblasts and endothelial cells around BGS/MCFS compared to BGS.

Plant exosomes‐like nano‐vesicles: Characterization, functional food potential, and emerging therapeutic applications as a nano medicine

Plant cells release exosome‐like nanovesicles (PENVs), which are small, membrane‐bound vesicles secreted by cells for intercellular interactions. These vesicles, rich in biologically active substances, are crucial for information transmission, intercellular interaction, and organism homeostasis conservation. They can also be used for treating diseases as large‐scale drug carriers due to their vesicular architecture. This study explores the isolation, potential of nanovesicles in creating bio‐therapeutic and drug‐delivery nano‐platforms to address clinical challenges. The bio‐therapeutic roles of PENVs, include immunomodulation, antitumor, regenerative impacts, wound healing, anti‐fibrosis, whitening effects, and treatment of intestinal flora disorders. This study also deliberates the potential for designing these nanovesicles into effective, safe, and non‐immunogenic nano‐vectors to carry drugs. PENVs may offer a cutting‐edge platform for the creation of functional foods and nutraceuticals. They might be employed to encapsulate certain bioactive substances produced from plants, offering tailored health privileges. It also elucidates the potential for the development of therapeutic and provision nano‐platforms based on PENVs in clinical applications.

Sustained antibacterial release of zwitterionic globular hyperbranched polymer dots intercalated into layered double hydroxides

This study introduces zwitterionic hyperbranched polymer (HBP) dots intercalated into layered double hydroxides (LDHs) for sustained antibacterial release. The proposed zwitterionic HBPs possess a three-dimensional spherical structure; unconventional blue fluorescent luminescence; water solubility; abundant COOH, amine, and amide functional groups; anionic exchangeability for intercalating into LDH interlayers; and sustained-release antibacterial activity. The intercalation for the layered nanomaterials was determined by adding different weight ratios of HBPs to Mg-Al LDHs to investigate the changes in the interlayer distance. X-ray diffraction revealed that the LDH layer spacing increased from 8.6 to 25.5 Å, effectively expanding the interlayer spacing with increasing HBP intercalation. Additionally, Fourier-transform infrared spectroscopy revealed the functional groups of the intercalated nanohybrids. Because the peripheral functional groups of HBPs are amino (-NH2) groups, preliminary evaluations revealed that pristine HBPs exhibited antibacterial properties. We further examined the antibacterial properties of the HBP/LDH nanohybrids. The results showed that HBPs combined with LDHs' controllable release properties can effectively achieve long-term sustained antibacterial release.

Lithiation: Advancing Material Synthesis and Structural Engineering for Emerging Applications

Lithiation, a process of inserting lithium ions into a host material, is revolutionizing nanomaterials synthesis and structural engineering as well as enhancing their performance across emerging applications, particularly valuable for large-scale synthesis of high-quality low-dimensional nanomaterials. Through a systematic investigation of the synthetic strategies and structural changes induced by lithiation, this review aims to offer a comprehensive understanding of the development, potential, and challenges associated with this promising approach. First, the basic principles of lithiation/delithiation processes will be introduced. Then, the recent advancements in the lithiation-induced structure changes of nanomaterials, such as morphology tuning, phase transition, defect generation, etc., will be stressed, emphasizing the importance of lithiation in structural modulation of nanomaterials. With the tunable structures induced by the lithiation, the properties and performance in electrochemical, photochemical, electronic devices, bioapplications, etc. will be discussed, followed by outlining the current challenges and perspectives in this research area.

A Se Nanoparticle/MgFe-LDH Composite Nanosheet as a Multifunctional Platform for Osteosarcoma Eradication, Antibacterial and Bone Reconstruction

Despite advances in treating osteosarcoma, postoperative tumor recurrence, periprosthetic infection, and critical bone defects remain critical concerns. Herein, the growth of selenium nanoparticles (SeNPs) onto MgFe-LDH nanosheets (LDH) is reported to develop a multifunctional nanocomposite (LDH/Se) and further modification of the nanocomposite on a bioactive glass scaffold (BGS) to obtain a versatile platform (BGS@LDH/Se) for comprehensive postoperative osteosarcoma management. The uniform dispersion of negatively charged SeNPs on the LDH surface restrains toxicity-inducing aggregation and inactivation, thus enhancing superoxide dismutase (SOD) activation and superoxide anion radical (·O2 -)-H2O2 conversion. Meanwhile, Fe3+ within the LDH nanosheets can be reduced to Fe2+ by depleting glutathione (GSH) in the tumor microenvironments (TME), which can catalyze H2O2 into highly toxic reactive oxygen species. More importantly, incorporating SeNPs significantly promotes the anti-bacterial and osteogenic properties of BGS@LDH/Se. Thus, the developed BGS@LDH/Se platform can simultaneously inhibit tumor recurrence and periprosthetic infection as well as promote bone regeneration, thus holding great potential for postoperative "one-stop-shop" management of patients who need osteosarcoma resection and scaffold implantation.

Bibliometric and visualization analysis of the application of inorganic nanomaterials to autoimmune diseases

Objective: To conduct bibliometric analysis of the application of inorganic nanomaterials to autoimmune diseases to characterize current research trends and to visualize past and emerging trends in this field in the past 15 years. Methods: The evolution and thematic trends of the application of inorganic nanomaterials to autoimmune diseases from January 1, 1985, to March 15, 2024, were analyzed by bibliometric analysis of data retrieved and extracted from the Web of Science Core Collection (WoSCC) database. A total of 734 relevant reports in the literature were evaluated according to specific characteristics such as year of publication, journal, institution, country/region, references, and keywords. VOSviewer was used to build co-authorship analysis, co-occurrence analysis, co-citation analysis, and network visualization. Some important subtopics identified by bibliometric characterization are further discussed and reviewed. Result: From 2009 to 2024, annual publications worldwide increased from 11 to 95, an increase of 764%. ACS Nano published the most papers (14) with the most citations (1372). China (230 papers, 4922 citations) and the Chinese Academy of Sciences (36 papers, 718 citations) are the most productive and influential country and institution, respectively. The first 100 keywords were co-clustered to form four clusters: (1) the application of inorganic nanomaterials in drug delivery, (2) the application of inorganic nano-biosensing to autoimmune diseases, (3) the use of inorganic nanomaterials for imaging applied to autoimmune diseases, and (4) the application of inorganic nanomaterials in the treatment of autoimmune diseases. Combination therapy, microvesicles, photothermal therapy (PTT), targeting, diagnostics, transdermal, microneedling, silver nanoparticles, psoriasis, and inflammatory cytokines are the latest high-frequency keywords, marking the emerging frontier of inorganic nanomaterials in the field of autoimmune diseases. Sub-topics were further discussed to help researchers determine the scope of research topics and plan research directions. Conclusion: Over the past 39 years, the application of inorganic nanotechnology to the field of autoimmune diseases shows extensive cooperation between countries and institutions, showing a continuous increase in the number of reports in the literature, and has clinical translation prospects. Future research should further improve the safety of inorganic nanomaterials, clarify the mechanism of action of nanomaterials, establish a standardized nanomaterial preparation and performance evaluation system, and ultimately achieve the goal of early detection and precise treatment of autoimmune diseases.

Three-dimensional Ni foam supported Pt/NiFe LDH catalyst with enhanced oxygen activation for room-temperature formaldehyde oxidation

Room-temperature catalytic oxidation of formaldehyde (HCHO) has been extensively investigated due to its high efficiency, convenience, and environmental friendliness. Herein, nickel-iron layered double hydroxide (NiFe LDH) nanosheets were synthesized in-situ on a nickel foil (NF) using a facile one-step hydrothermal method, followed by the deposition of ultra-low content (0.069 wt%) of Pt nanoparticles through NaBH4 reduction. The resulting three-dimensional (3D) hierarchical Pt/NiFe-NF catalyst exhibited exceptional activity for the complete decomposition of formaldehyde to carbon dioxide (CO2) at room temperature (∼95 % conversion within 1 h), as well as remarkable cycling stability. The 3D porous structure of Pt/NiFe-NF provides fast transport channels for the diffusion of gas molecules, making the active catalyst surfaces more accessible. Moreover, abundant hydroxyl groups in NiFe LDH serve as adsorption centers for HCHO molecules to form dioxymethylene (DOM) and formate intermediates. Furthermore, electronic interactions between NiFe LDH and Pt enhance the adsorption and activation of O2 on Pt surfaces, leading to the complete decomposition of intermediates into non-toxic products. This work presents new insights into the design and preparation of Pt-based 3D hierarchical catalysts with surface-rich hydroxyl groups for the efficient removal of indoor HCHO.

Boosting NIR Laser Marking Efficiency of a Transparent Epoxy Using a Layered Double Hydroxide

Efficient near-infrared (NIR) laser marking on transparent polymers like polypropylene, epoxy, and polyethylene has posed a big challenge due to their lack of absorption in the NIR. Currently, inorganic additives are used to improve NIR laser marking efficiency, but they come with issues such as toxicity, high loading requirement, adverse effects on color/opaqueness, and the need for low laser head speeds. Herein, we report a new strategy of incorporating a food-grade, Mg2Al-CO3 LDH as a boosting coadditive alongside the commercial NIR laser marking additive (Iriotech 8815) in an epoxy system. Our findings demonstrate that the incorporation of Mg2Al-CO3 LDH can significantly increase both the darkness and contrast of marking even at high laser head speed (5000 mm/s), while minimizing surface damage. Notably, by replacing 95% of Iriotech 8815 with Mg2Al-CO3 LDH, an epoxy plate can exhibit high transparency, while producing dark, sharply defined markings with excellent readable QR code markings at high laser speeds. This result offers a promising solution for enhancing high-speed NIR laser marking on transparent polymers with additional advantages of lower toxicity and cost and with minimal optical interference from high additive loadings.

2D Exfoliation Chemistry Towards Covalent Pseudo-Layered Phosphate Framework Derived by Radical/Strain-Synergistical Process

2D compounds exfoliated from weakly bonded bulk materials with van der Waals (vdW) interaction are easily accessible. However, the strong internal ionic/covalent bonding of most inorganic crystal frameworks greatly hinders 2D material exfoliation. Herein, we first proposed a radical/strain-synergistic strategy to exfoliate non-vdW interacting pseudo-layered phosphate framework. Specifically, hydroxyl radicals (⋅OH) distort the covalent bond irreversibly, meanwhile, H2O molecules as solvents, further accelerating interlayered ionic bond breakage but mechanical expansion. The innovative 2D laminar NASICON-type Na3V2(PO4)2O2F crystal, exfoliated by ⋅OH/H2O synergistic strategy, exhibits enhanced sodium-ion storage capacity, high-rate performance (85.7 mAh g-1 at 20 C), cyclic life (2300 cycles), and ion migration rates, compared with the bulk framework. Importantly, this chemical/physical dual driving technique realized the effective exfoliation for strongly coupled pseudo-layered frameworks, which accelerates 2D functional material development.

In vivo Fate of Targeted Drug Delivery Carriers

This review aimed to systematically investigate the intracellular and subcellular fate of various types of targeting carriers. Upon entering the body via intravenous injection or other routes, a targeting carrier that can deliver therapeutic agents initiates their journey. If administered intravenously, the carrier initially faces challenges presented by the blood circulation before reaching specific tissues and interacting with cells within the tissue. At the subcellular level, the car2rier undergoes processes, such as drug release, degradation, and metabolism, through specific pathways. While studies on the fate of 13 types of carriers have been relatively conclusive, these studies are incomplete and lack a comprehensive analysis. Furthermore, there are still carriers whose fate remains unclear, underscoring the need for continuous research. This study highlights the importance of comprehending the in vivo and intracellular fate of targeting carriers and provides valuable insights into the operational mechanisms of different carriers within the body. By doing so, researchers can effectively select appropriate carriers and enhance the successful clinical translation of new formulations.

PAD4 Inhibitor-Functionalized Layered Double Hydroxide Nanosheets for Synergistic Sonodynamic Therapy/Immunotherapy Of Tumor Metastasis

Sonodynamic therapy (SDT) is demonstrated to trigger the systemic immune response of the organism and facilitate the treatment of metastatic tumors. However, SDT-mediated neutrophil extracellular traps (NETs) formation can promote tumor cell spread, thus weakening the therapeutic effectiveness of metastatic tumors. Herein, the amorphous CoW-layered double hydroxide (a-CoW-LDH) nanosheets are functionalized with a peptidyl arginine deiminase 4 (PAD4) inhibitor, i.e., YW3-56, to construct a multifunctional nanoagent (a-LDH@356) for synergistic SDT/immunotherapy. Specifically, a-CoW-LDH nanosheets can act as a sonosensitizer to generate abundant reactive oxygen species (ROS) under US irradiation. After loading with YW3-56, a-LDH@356 plus US irradiation not only effectively induces ROS generation and immunogenic cell death, but also inhibits the elevation of citrullinated histone H3 (H3cit) and the release of NETs, enabling a synergistic enhancement of anti-tumor metastasis effect. Using 4T1 tumor model, it is demonstrated that combining a-CoW-LDH with YW3-56 stimulates an anti-tumor response by upregulating the proportion of immune-activated cells and inducing polarization of M1 macrophages, and inhibits immune escape by downregulating the expression of PD-1 on immune cells under US irradiation, which not only arrests primary tumor progression with a tumor inhibition rate of 69.5% but also prevents tumor metastasis with the least number of lung metastatic nodules.