Engineered nanodrug targeting oxidative stress for treatment of acute kidney injury

Biocompatible and size-dependent melanin-like nanocapsules for efficient therapy in hyperoxia-induced acute lung injury

Hyperoxia-induced acute lung injury (HALI) is a serious pulmonary disease, and its therapeutic effect is greatly limited by disordered oxidative stress microenvironment. Safe and efficient antioxidant-immunomodulatory therapy may be a promising strategy to maintain redox homeostasis in HALI. Herein, a novel therapeutic strategy (PCT) composed size-dependent melanin-like polydopamine nanocapsules (PC) and IKK-2 inhibitor TPCA-1 is developed to alleviate HALI. By flexibly tuning the size of nanocapsules, the lung-to-liver ratio could be finely optimized, which facilitates to delivery adequate dose of TPCA-1 to pulmonary lesions and improve the bioavailability. Notably, these nanocapsules exhibit superior biosafety in vitro and in vivo. The selected PCT sharply scavenges intracellular reactive oxygen species (ROS) and protects mitochondrial function, subsequently reprogramming the repolarization of macrophages. Moreover, injection of PCT eliminates elevated ROS and oxidative stress products against the redox imbalance in HALI mice. Mechanistically, benefiting from much ROS depletion, PCT plays a positive role in inhibiting immune cell infiltration, down-regulating multiple inflammatory factors, and promoting macrophage polarization toward anti-inflammatory M2 phenotype through activating the Keap-1/Nrf2 pathway, thus remarkably breaking the vicious cycle of inflammation and oxidative stress in HALI. Overall, these findings provide a secure and effective therapy combining antioxidation and immunoregulation for HALI and other pulmonary diseases.

Signal "Off-On Model'' for Colorimetric Sensing Proanthocyanidin B2 Achieved by the Organic Solvent-Processed Amorphous BiVO4 Nanozyme

Here, we report a "off-on model"-based colorimetric sensor without the assistance of H2O2, achieved by organic solvent-processed amorphous BiVO4 nanoparticles favorable for large-scale manufacturing. The amorphous material beyond traditional crystalline nanozymes has both vanadium vacancy (Vv) and oxygen vacancy (Ov), as well as single oxidase-like activity with both hydroxyl radical (•OH) and superoxide anion (O2•-) as electron acceptors. Despite the high enzymatic performance, the dual-defect-rich amorphous BiVO4 preserves good long-term activity in either buffer solution or the solid state. The specially designed BiVO4 is capable of accelerating TMB oxidation in the presence of polyphenols, thus leading to an interesting signal-intensified colorimetric response. This is probably due to the coordination of the ortho dihydroxyl group in polyphenols with the catalyst by replacing the surface-adsorbed NO3-, which results in faster charge transfer between BiVO4 and substrate and, thus, more rapid depletion of radicals for TMB oxidation. Based on these findings, a sensor platform for proanthocyanidin (PAC) B2 is established with a limit of detection (LOD) as low as 65 nM and good specificity. The sensor shows higher sensitivity than the standard Porter method (LOD: 0.29 μM) and comparable accuracy when analyzing PAC B2 in commercially available grape seed capsules, with quantitative recoveries varying from 104.0 to 108.3% and relative standard deviations ranging from 1.7 to 5.7%. To date, this is the only nanozyme-based chemical sensor that is active for the signal "off-on model" for the detection of reducing polyphenols. Also, this method seems quite general, and it can be used for sensing of a series of specific polyphenols in addition to PAC B2.

Metal-phenolic nanozyme as a ferroptosis inhibitor for alleviating cisplatin-induced acute kidney injury

Introduction

Cisplatin-induced acute kidney injury (AKI) is primarily caused by oxidative stress from reactive oxygen species (ROS) accumulation. Developing ROS scavengers presents promising opportunities for preventing and treating this condition by targeting oxidative stress mechanisms.

Methods

This study involves the fabrication of a metal-polyphenol self-assembled nanozyme (Fe@Ba) designed to inhibit ferroptosis through synergistic catalytic actions and antioxidant properties. The nanozyme is constructed using metal-polyphenol coordination-driven nanoprecipitation techniques. Its performance is evaluated in vitro using MTEC cells and in vivo within an AKI model, with assessments of catalytic activities, ROS depletion efficacy, antioxidant effects, and anti-ferroptotic mechanisms.

Results

The Fe@Ba nanozyme demonstrates significant catalase (CAT) and superoxide dismutase (SOD)-like activities upon internalization by MTEC cells, effectively reducing high ROS levels in the AKI model. Baicalein (Ba), a traditional Chinese medicine component in the nanozyme, exhibits strong antioxidant properties, inhibits lipid peroxidation (LPO), upregulates reductive glutathione (GSH), and promotes glutathione peroxidase 4 (GPX4) expression, thereby inhibiting ferroptosis. Fluorescence imaging confirms effective renal accumulation of Cy5.5-labeled Fe@Ba nanozyme. In vivo experiments show the nanozyme reduces inflammation and significantly enhances survival rates in AKI models.

Discussion

This study validates the concept of self-assembling nanozymes for AKI treatment and offers new insights into nanomedicine applications. The Fe@Ba nanozyme's ability to counteract inflammation-related damage and inhibit ferroptosis through multiple mechanisms highlights its therapeutic potential. The successful integration of traditional Chinese medicine components with nanotechnology represents an innovative approach to addressing cisplatin-induced AKI, suggesting broader applications for metal-polyphenol nanozymes in oxidative stress-related kidney diseases.

Carbon Dot Nanozymes with Ferrous Ion-Chelating and Antioxidative Activity Inhibiting Ferroptosis to Alleviate Renal Ischemia-Reperfusion Injury

Renal ischemia-reperfusion (I/R) significantly contributes to acute kidney injury (AKI), causing substantial oxidative stress and metabolic disruptions. Ferroptosis, a Fe2+-dependent form of regulated cell death characterized by lipid peroxide accumulation, is the predominant cause of renal I/R injury (RIRI). Here, carbon dot (C-dot) nanozymes that inhibit ferroptosis by regulating Fe2⁺ levels and scavenging reactive oxygen species, offering a potential treatment for RIRI are reported. C-dots chelate Fe2⁺ via surface carbonyl, hydroxyl, and carboxyl groups to reduce free Fe2⁺ levels, suppress the Fenton reaction, and limit hydroxyl radical generation. Additionally, C-dots scavenge superoxide anions and hydroxyl radicals to restore redox balance. By targeting the kidneys, C-dots effectively reduce renal iron overload and lipid peroxidation to prevent ferroptotic cell death in the renal I/R male mice model. RNA sequencing (RNA-seq) analysis further confirms the crucial roles of C-dots in mitigating oxidative stress, preserving iron homeostasis, and downregulating acyl-CoA synthetase long-chain family member 4 (ACSL4) after I/R. This work emphasizes the perfect alignment between the multifunctional roles of C-dots and the conditions required for inhibiting ferroptosis and offers an innovative strategy to treat RIRI effectively.

Research and Application Prospect of Nanomedicine in Kidney Disease: A Bibliometric Analysis From 2003 to 2024

Kidney disease is a major public health concern that has a significant effect on a patient's life span and quality of life. However, effective treatment for most kidney diseases is lacking. Nanotechnology mainly explores the design, characterization, production, and applications of objects in the nanoscale range and has been widely used in the medical field. To date, there has been an increasing amount of research on the application of nanotechnology in kidney disease. However, systematic bibliometric studies remain rare. In this review, data collected from the Web of Science Core Collection database until December 31, 2024, were subjected to a bibliometric analysis. A total of 1179 articles and reviews were included. The publication trends, countries, institutions, authors, co-authorship, co-citations, journals, keywords, and references pertaining to this topic were examined. The results showed that nanotechnology research in kidney disease is increasing. The leading country, organization, and author were China, Sichuan University, and Professor Peng Huang, respectively. ACS APPLIED MATERIALS & INTERFACES was the top journal among the 464 journals in which articles on nanotechnology in kidney disease were published. KIDNEY INTERNATIONAL was the most cited journal in the field. The most significant increases were shown for "acute kidney disease", "drug delivery", "oxidative stress", "diabetic nephropathy", and "chronic kidney disease", indicating the current research hotspots. Furthermore, the development prospects and challenges of nanotechnology in kidney disease were discussed in this review. How to achieve precise drug delivery to render kidney-targeting therapy a reality may be problematic in future studies.

MOF-818 Nanozyme Suppresses Calcium Oxalate Kidney Stones by Alleviating Oxidative Stress and Inflammatory Injury

There remains a lack of effective drugs to alleviate the kidney stones caused by oxidative stress and inflammatory damage. The MOF-818 nanozyme is utilized to lessen the generation of reactive oxygen species (ROS) effectively, restore the membrane potential of mitochondria, regulate the cell cycle, decrease cell death, hinder the recruitment of macrophages, and mitigate the release of inflammatory factors in macrophages. These effects are attributed to the nanozyme's ability to mimic the enzyme properties of catalase (CAT) and superoxide dismutase (SOD). It is demonstrated that this nanozyme can reduce kidney calcium oxalate crystal deposition by reducing the renal injury caused by high concentration oxalate, upregulate the expression levels of SOD and CAT in tissues, downregulate adhesion proteins and inflammatory factor IL-6 and TNF-α, and promote the polarization of macrophages from M1 to M2 phenotype in the rat model induced by ethylene glycol. Overall, MOF-818 has the potential to effectively suppress oxidative stress and inflammatory harm caused by high levels of oxalate, hence lowering the likelihood of stone formation. MOF-818 nanozyme is also expected to be used as an alternative drug for the treatment of calcium oxalate kidney stones and provide an experimental theoretical basis for the development of new nanomedicines.

Design and advances in antioxidant hydrogels for ROS-induced oxidative disease

Reactive oxygen species (ROS) play a crucial role in human physiological processes, but oxidative stress caused by excessive ROS may lead to a variety of acute and chronic diseases. Despite the development of various strategies and biomaterials, an efficiently and broadly applied method for treatment of ROS-induced oxidative disease remains a bottleneck. Aiming to improve the local oxidative stress environment, numerous bioactive hydrogels with antioxidant properties have emerged and are proven to quickly and continuously eliminate excessive ROS. To deeply understand the design principles and applications of antioxidant hydrogels is highly beneficial for designing antioxidant hydrogels for treatment of oxidative disease. This review provides a detailed summary of recent advances in design and applications of antioxidant hydrogels for various ROS-induced oxidative diseases. In this review, the kinds of antioxidant components in antioxidant hydrogels are outlined in detail. Additionally, the crosslinking methods and the biomedical applications of antioxidant hydrogels are widely summarized and discussed, especially focusing on their usage in different types of diseases and the attention given to the treatment of diseases such as skin wounds, myocardial infarction, and osteoarthritis. Finally, the future development direction of antioxidant hydrogel is further proposed. STATEMENT OF SIGNIFICANCE: Oxidative stress is a pivotal biochemical process that plays a critical role in cellular homeostasis. Excessive cellular oxidative stress triggers an inflammatory response, which is implicated in a spectrum of associated diseases. Given the critical need for managing oxidative stress, antioxidant therapies have become a vital focus in medical research. Hydrogels have garnered substantial interest among biomaterial scientists due to their hydrophilic nature and biocompatibility. The review delves into the realm of antioxidant hydrogels, encompassing the classification of antioxidant components, the synthesis and fabrication of hydrogels, and a comprehensive overview of the biological applications and challenges of these antioxidant hydrogels. Aiming to provide new perspectives for researchers in developing cutting-edge therapeutic approaches that leverage antioxidant hydrogels.

Biocompatible Metal-Organic Framework-Based Fabric Composite as an Efficient Personal Protective Equipment for Particulate Matter-Induced Pulmonary Injury

Efficient personal protection has emerged as a crucial approach for reducing pulmonary injury induced by particulate matter (PM). However, current personal protective equipments usually lack essential biosafety concerns and fail to own adsorbing/antioxidant/antibacterial function together, making it a challenge to develop an integrated platform with the above characteristics. Herein, a facile oxygen-free hydrothermal strategy is proposed to synthesize new copper-based metal-organic frameworks, Cu-HHTPs, (HHTP: 2,3,6,7,10,11-hexahydroxytriphenylene), with great adsorbing/antioxidant/antibacterial activity and high biosafety. The Cu-HHTPs can serve as an efficient additive incorporated with various fabrics including cellulose acetate (CA) membrane to achieve novel fabric composites, such as CA@Cu-HHTPs, with ideal scavenging outcome for the main components of PM. Evidenced by the animal experiments, CA@Cu-HHTPs can highly mitigate PM-induced adverse effects via adsorbing PM, scavenging ROS, and killing bacteria, leading to a significant reduction in lung permeability, inflammation and oxidative stress, and pulmonary infection. Last but not least, a two-week exposure of CA@Cu-HHTPs exhibits no obvious damage toward the animals by examining their long-term toxicity. Collectively, this study not only highlights the potential of Cu-HHTPs as attractive additives for the preparation of fabric composites, but also lays out a new concept toward the development of new-generation multifunctional personal protective equipment against PM.

Hierarchical Targeting Nanodrug with Holistic DNA Protection for Effective Treatment of Acute Kidney Injury

Acute kidney injury (AKI) manifests a hallmark pathological feature of extensive and severe DNA damage in renal tubules, primarily induced by the excessive of toxic reactive oxygen species (ROS) from the mitochondrial electron transport chain. The kidney's complex intricate physiological architecture and the heterogeneous intracellular environment pose significant challenges for effective sequential and high-resolution drug delivery-an urgent issue that remains unresolved. To address this, a hierarchical-targeting antioxidant nanodrug has been developed with a folic acid moiety (HAND) designed for high-resolution drug delivery in AKI treatment. For the first time, HAND enables sequential targeting from the kidney to the most severely damaged proximal tubular epithelial cells (PTECs), ultimately concentrating in the DNA-rich mitochondria and nucleus. As a result, HAND effectively scavenges ROS in situ, protecting both mitochondria and nuclei along with their vital genetic material. This action restores mitochondrial function, mitigates DNA oxidation and fragmentation, reduces apoptosis, and inhibits cGAS/STING-mediated sterile inflammation. Consequently, HAND demonstrates remarkable efficacy in safeguarding injured kidneys during AKI. Overall, this work pioneers a hierarchical, high-resolution antioxidant strategy, providing innovative guidance for the development of AKI therapies.

An enzyme-mimicking reactive oxygen species scavenger targeting oxidative stress-inflammation cycle ameliorates IR-AKI by inhibiting pyruvate dehydrogenase kinase 4

Rationale: Ischemia-reperfusion-induced acute kidney injury (IR-AKI), characterized by the abrupt decline in renal function, is distinguished by the intricate interplay between oxidative stress and inflammation. In this study, a reactive oxygen species (ROS) scavenger-CF@PDA was developed to effectively target antioxidant and anti-inflammatory pathways to disrupt the oxidative stress-inflammation cycle in IR-AKI. Methods: UV-vis absorption spectra, FTIR spectra, and TEM were employed to determine the successful construction of CF@P. ABTS, TMB, and NBT analyses were performed to detect the antioxidant ability and enzyme-mimicking ability of CF@P. In vitro and in vitro, the antioxidant/anti-inflammatory effect of CF@P was detected by MTT, qPCR, fluorescence, and flow cytometry. Multi-omics revealed the mechanism of CF@P in IR-AKI therapy, and molecular docking was further used to determine the mechanism. MRI and photoacoustic imaging were employed to explore the dual-mode imaging capacity of CF@P in IR-AKI management. Results: CF@P could disrupt the oxidative stress-inflammatory cascade by scavenging ROS, reducing pro-inflammatory cytokines, and modulation of macrophage polarization. Subsequent multi-omics indicated that the renal protective effects may be attributed to the inhibition of pyruvate dehydrogenase kinase 4 (PDK4). Metabolomics demonstrated that CF@P could improve the production of antioxidant compounds and reduce nephrotoxicity. Additionally, CF@P exhibited promising capabilities in T1-MRI and photoacoustic imaging for AKI management. Conclusions: Collectively, CF@P, possessing antioxidant/anti-inflammatory properties by inhibiting PDK4, as well as imaging capabilities and superior biocompatibility, holds promise as a therapeutic strategy for IR-AKI.

Two-Pronged Attack: Dual Activation of Fat Reduction Using Near-Infrared-Responsive Nanosandwich for Targeted Anti-Obesity Treatment

Excessive fat accumulation and chronic inflammation are two typical characteristics of obesity. AMP-activated protein kinase (AMPK), a master regulator of energy metabolism, is involved in adipogenesis, lipogenesis, and inflammation modulation in adipose tissue (AT). Thus, effective lipid reduction and anti-inflammation through AMPK regulation play vital roles in treating obesity. Herein, an anti-obesity nanosandwich is fabricated through attaching polymetformin (PolyMet) onto photothermal agent black phosphorus nanosheets (BP). PolyMet activates AMPK to inhibit adipogenesis, promote browning, and mitigate AT inflammation by decreasing macrophage infiltration, repolarizing macrophage phenotype, and downregulating pro-inflammatory cytokines. Additionally, BP induces lipolysis and apoptosis of adipocytes and macrophages through a photothermal effect. By further functionalization using hyaluronic acid (HA) and MMP2 substrate-linking P3 peptide-modified HA (P3-HA), an enhanced anti-obesity effect is obtained by dual-targeting of P3 and HA, and HA-mediated CD44 poly-clustering after MMP2 cleavage. Upon laser irradiation, the designed nanosandwich (P3-HA/PM@BP) effectively inhibits obesity development in obese mice, increases M2/M1 ratio in AT, reduces the serum levels of cholesterol/triglyceride and improves insulin sensitivity, exhibiting promising research potential to facilitate the clinical development of modern anti-obesity therapies.

Antioxidant activities of metal single-atom nanozymes in biomedicine

Nanozymes are a class of nanomaterials with enzyme-like activity that can mimic the catalytic properties of natural enzymes. The small size, high catalytic activity, and strong stability of nanozymes compared to those of natural enzymes allow them to not only exist in a wide temperature and pH range but also maintain stability in complex environments. Recently developed single-atom nanozymes have metal active sites composed of a single metal atom fixed to a carrier. These metal atoms can act as independent catalytically active centers. Metal single-atom nanozymes have a homogeneous single-atom structure and a suitable coordination environment for stronger catalytic activity and specificity than traditional nanozymes. The antioxidant metal single-atom nanozymes with the ability of removing reactive oxygen species (ROS) can simulate superoxidase dismutase, catalase, and glutathione peroxidase to show different effects in vivo. Furthermore, due to the similar structure of antioxidant enzymes, a metal single-atom nanozyme often has multiple antioxidant activities, and this synergistic effect can more efficiently remove ROS related to oxidative stress. The versatility of single-atom nanozymes encompasses a broad spectrum of biomedical applications such as anti-oxidation, anti-infection, immunomodulatory, biosensing, bioimaging, and tumor therapy applications. Herein, the nervous, circulatory, digestive, motor, immune, and sensory systems are considered in order to demonstrate the role of metal single-atom nanozymes in biomedical antioxidants.

LRG1-Targeted Nintedanib Delivery for Enhanced Renal Fibrosis Mitigation

Renal fibrosis lacks effective nephroprotective drugs in clinical settings due to poor accumulation of therapeutic agents in damaged kidneys, underscoring the urgent need for advanced renal-targeted delivery systems. Herein, we exploited the significantly increased expression of the leucine-rich α-2 glycoprotein 1 (LRG1) protein during renal fibrosis to develop a novel drug delivery system. Our engineered nanocarrier, DENNM, preferentially targets fibrotic kidneys via the decorated ET peptide's high affinity for LRG1. Once internalized by damaged renal cells, DENNM releases its encapsulated nintedanib, triggered by the active caspase-3 protease, disrupting the nanomedicine's structural integrity. The released nintedanib effectively reduces the level of expression of the extracellular matrix and impedes the progression of renal fibrosis by inhibiting the transforming growth factor-β (TGF-β)-Smad2/3 pathway. Our comprehensive in vitro and in vivo studies validate DENNM's antifibrotic efficacy, emphasizing LRG1's potential in renal targeted drug delivery and introducing an innovative approach to nanomedicine for treating renal fibrosis.

Synergistic anti-oxidant and anti-inflammatory effects of ceria/resatorvid co-decorated nanoparticles for acute lung injury therapy

BACKGROUND

Acute lung injury (ALI) is a critical inflammatory response syndrome that rapidly develops into acute respiratory distress syndrome (ARDS). Currently, no effective therapeutic modalities are available for patients with ALI/ARDS. According to recent studies, inhibiting both the release of pro-inflammatory cytokines and the formation of reactive oxygen species (ROS) as early as possible may be a promising therapy for ALI.

RESULTS

In this study, a ROS-responsive nano-delivery system based on oxidation-sensitive chitosan (Ox-CS) was fabricated for the simultaneous delivery of Ce NPs and RT. The in vitro experiments have shown that the Ox-CS/Ceria-Resatorvid nanoparticles (Ox-CS/CeRT NPs) were rapidly and efficiently internalised by inflammatory endothelial cells. Biological evaluations validated the significant attenuation of ROS-induced oxidative stress and cell apoptosis by Ox-CS/CeRT NPs, while maintaining mitochondrial function. Additionally, Ox-CS/CeRT NPs effectively inhibited the release of pro-inflammatory factors. After intraperitoneal (i.p.) administration, Ox-CS/CeRT NPs passively targeted the lungs of LPS-induced inflamed mice and released the drug activated by the high ROS levels in inflammatory tissues. Finally, Ox-CS/CeRT NPs significantly alleviated LPS-induced lung injury through inhibiting both oxidative stress and pro-inflammatory cytokine expression.

CONCLUSIONS

The created Ox-CS/CeRT NPs could act as a prospective nano-delivery system for a combination of anti-inflammatory and anti-oxidant therapy of ALI.