Multifunctional Nanoplatform for Mild Microwave-Enhanced Thermal, Antioxidative, and Chemotherapeutic Treatment of Rheumatoid Arthritis

Thermosensitive Light-Driven Smart Platform Induces Apoptosis of Fibroblast-like Synovial Cells and Macrophages for Enhanced Rheumatoid Arthritis Therapy

Macrophage activation induces rapid proliferation and division of fibroblast-like synovial cells (FLSs), resulting in the degradation of cartilage matrix and bone destruction, which are the main pathological characteristics of rheumatoid arthritis (RA). Inducing apoptosis in these inflammatory cells to mitigate the inflammatory response and alleviate bone damage is a potential therapeutic strategy for RA. In this study, we developed a smart platform for synergistic photothermal therapy (PTT) and chemotherapy by utilizing hyaluronic acid (HA)-modified thermally sensitive liposomes loaded with celastrol (CEL) and gold nanorods (GNRs), termed HA/Lipo-CEL-GNRs, for application in a rat RA model. Under laser irradiation, GNRs exhibited excellent photothermal effects due to localized surface plasmon resonance. The resulting increase in temperature not only effectively eliminated hyperproliferative inflammatory cells in the joints but also triggered CEL release from the thermosensitive liposomes, significantly increasing its concentration in the synovium. The synergistic effect of PTT and chemotherapy significantly promoted the apoptosis of FLSs and macrophages and effectively suppressed the inflammatory response in the RA microenvironment. In summary, multifunctional thermosensitive HA/Lipo-CEL-GNRs represent promising nanotherapeutic platforms capable of achieving light-driven enrichment of heat and therapeutic agents, significantly preventing the progression of RA.

Overcoming hypoxia-induced breast cancer drug resistance: a novel strategy using hollow gold-platinum bimetallic nanoshells

Breast cancer (BC) is a significant cause of cancer-related deaths among women worldwide. Hypoxia, a common feature of solid tumor, is associated with drug resistance and a poor prognosis in BC. In this study, we present a strategy to overcome hypoxia-induced chemotherapy tolerance in BC. Specifically, we synthesized a hollow gold (Au)-platinum (Pt) bimetallic nanoshell for the first time, which acted as a drug delivery system (DDS) for doxorubicin (DOX). The photothermal effect, induced by the surface plasmon resonance (SPR) from the Au-Pt shell under near infrared-II (NIR-II) laser irradiation, not only directly causes tumor cell death through photothermal therapy (PTT), but also significantly enhances the catalase-like activity between Pt nanoparticles and endogenous H2O2. This, subsequently, results in a heightened yield of O2, which further facilitates the release of DOX. This process alleviates tumor hypoxia and down-regulating hypoxia-inducible factor-1α (HIF-1α), multidrug resistance gene 1 (MDR1), and P-glycoprotein (P-gp), which can reverse drug resistance and achieve more effective DOX chemotherapy effects. Significantly, the increased availability of oxygen further re-polarizes immunosuppressive M2 macrophages into antitumor M1 macrophages. This study presents a novel strategy to tackle tumor proliferation and enhance tumor response to chemotherapy, offering hope for reversing in drug resistance in cancerous lesions.

Self-Cascade of ROS/Glucose-Scavenging Immunomodulatory Hydrogels for Programmed Therapeutics of Infected Diabetic Ulcers via Nrf2/NF-κB Pathway

Diabetic ulcers (DUs) are characterized by a microenvironment with high oxidative stress, high blood glucose levels, and recalcitrant bacterial infections. This microenvironment is accompanied by long-term suppression of endogenous antioxidant systems, which makes their clinical management extremely challenging. To address this issue, a hybridized novel gold-palladium (AuPd) nanoshell of the injectable/injectable hydrogel system UiO/AuPdshells/BNN6/PEG@Gel (UAPsBP@Gel) is developed. The system is capable of acting as a nitric oxide (NO) reactor utilizing synergistic therapy that harnesses NIR-II light-triggered photothermal effects and controlled release of NO gas for synergistic treatment to eradicate biofilm infections at different depths. The AuPd nanoshells exhibits superoxide dismutase (SOD)-, glucose oxidase (GOx)-, and catalase (CAT)-like activities, enabling self-cascade process for scavenging both reactive oxygen species (ROS) and glucose. This activity reshapes the DUs microenvironment, switches on the endogenous antioxidant Nrf2/HO-1 pathway and inhibits the NF-κB pathway, promotes macrophage polarization toward the anti-inflammatory M2 phenotype, and reduces oxidative stress, resulting in efficient immunomodulation. In vitro/in vivo results demonstrate that the UAPsBP@Gel can multifacetedly enhance the epithelial rejuvenation process through wound hemostasis, pro-cellular migration and vascularization. These results highlight that a programmed therapeutic based on UBAPsP@Gel tailored to the different stages of infected DUs can meet complex clinical needs.

Nanozyme-based therapeutic strategies for rheumatoid arthritis

Rheumatoid arthritis (RA) is a prevalent chronic autoimmune disease that leads to severe joint damage and disability. Conventional treatment options are limited by their efficacy and side effect profiles. Nanozymes, nanomaterials with enzyme-like activities, offer a novel therapeutic approach for RA. This review summarizes recent advances in nanozyme-based treatments, focusing on their antioxidant and immunomodulatory roles in mitigating RA. We discuss various nanozymes, including those based on cerium, iron, manganese, silver, copper, platinum, rhodium, and multi-metallic nanozymes, which mimic natural enzymes such as superoxide dismutase, catalase, and peroxidase to reduce oxidative stress. Additionally, we explore nanozyme-based combination therapies that integrate with other strategies, such as vesicles and phototherapy, to achieve synergistic effects and enhance efficacy. This review highlights the significant potential of nanozymes in improving RA treatment, offering a new perspective for future research and clinical applications.

Contribution of macrophage polarization in bone metabolism: A literature review

Macrophage polarization divides macrophages into two main cell subpopulations, classically and alternatively activated macrophages (M1 and M2, respectively). M1 polarization promotes osteoclastogenesis, while M2 polarization promotes osteogenesis. The physiological homeostasis of bone metabolism involves a high dynamic balance between osteoclastic-mediated bone resorption and formation. Reportedly, M1/M2 imbalance causes the onset and persistence of inflammation-related bone diseases. Therefore, understanding the research advances in functions and roles of macrophages in such diseases will provide substantial guidance for improved treatment of bone diseases. In this review, we underscore and summarize the research advances in macrophage polarization, and bone-related diseases, such as rheumatoid arthritis, osteoarthritis, and osteoporosis, over the last 5 years. Our findings showed that targeting macrophages and balancing macrophage polarization can effectively reduce inflammation and decrease bone destruction while promoting bone formation and vascular repair. These results indicate that regulating macrophage and macrophage polarization to restore homeostasis is a prospective approach for curing bone-related diseases.

Target-Engineered Liposomes Decorated with Nanozymes Alleviate Liver Fibrosis by Remodeling the Liver Microenvironment

Liver fibrosis is a pathological repair response that occurs after sustained liver damage, and prompt intervention is necessary to prevent liver fibrosis from developing into a potentially life-threatening condition. In long-term liver injury, damaged hepatocytes produce excessive amounts of reactive oxygen species (ROS), which activate hepatic stellate cells (HSCs). This activation leads to excessive accumulation of extracellular matrix proteins in liver tissue. Additionally, liver macrophages contribute to the inflammatory microenvironment in the hepatic fibrotic process, exacerbating liver fibrosis through ROS production and the secretion of pro-inflammatory factors. To address the dysregulation of the hepatic microenvironment associated with liver fibrosis, we developed cerium oxide nanozymes using hyaluronic acid (HA) as a template and decorated them on the surface of liposomes loaded with oleanolic acid (OA). We named this prepared and obtained target-engineered liposome HCOL. The inherent superoxide dismutase (SOD) and catalase (CAT) activities of HCOL enabled it to effectively scavenge ROS in HSCs and alleviate the hypoxic conditions characteristic of fibrotic livers. Furthermore, HCOL reduced the concentrations of ROS in macrophages, promoting a shift in macrophage polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. This transition increased the production of the anti-inflammatory cytokine interleukin 10 (IL-10), which contributed to the mitigation of the inflammatory microenvironment. Consequently, this therapeutic approach proves effective in decelerating the advancement of liver fibrosis.

Adipose-derived stem cell exosomes loaded with icariin attenuated M1 polarization of macrophages via inhibiting the TLR4/Myd88/NF-κB signaling pathway

Abnormal macrophage polarization is one of the common pathological bases of various inflammatory diseases. The current research focus involves targeting macrophages to remodel their phenotype as a treatment approach for inflammatory diseases. Notably, exosomes can be delivered to specific types of cells or tissues or inflammatory area to realize targeted drug delivery. Although icariin (ICA) exhibits regulatory potential in macrophage polarization, the practical application of ICA is impeded by its water insolubility, poor permeability, and low bioavailability. Exploiting the inherent advantages of exosomes as natural drug carriers, we introduce a novel drug delivery system-adipose-derived stem cells-exosomes (ADSCs-EXO)-ICA. High-performance liquid chromatography analysis confirmed a loading rate of 92.7 ± 0.01 % for ADSCs-EXO-ICA, indicating the successful incorporation of ICA. As demonstrated by cell counting kit-8 assays, ADSCs-EXO exerted a significantly higher promotion effect on macrophage proliferation. The subsequent experimental results revealed the superior anti-inflammatory effect of ADSCs-EXO-ICA compared to individual treatments with EXO or ICA in the lipopolysaccharide + interferon-gamma-induced M1 inflammation model. Additionally, results from enzyme-linked immunosorbent assay, quantitative polymerase chain reaction, and western blot analyses revealed that ADSCs-EXO-ICA effectively inhibited macrophage polarization toward the M1-type and concurrently promoted polarization toward the M2-type. The underlying mechanism involved the modulation of macrophage polarization through inhibition of the Toll-like receptor 4/myeloid differentiation factor 88/nuclear transcription factor-kappa B signaling pathway, thereby mitigating inflammation. These findings underscore the potential therapeutic value of ADSCs-EXO-ICA as a novel intervention for inflammatory diseases.

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.

Nanotechnology-empowered combination therapy for rheumatoid arthritis: principles, strategies, and challenges

Rheumatoid arthritis (RA) is an autoimmune disease with multifactorial etiology and intricate pathogenesis. In RA, repeated monotherapy is frequently associated with inadequate efficacy, drug resistance, and severe side effects. Therefore, a shift has occurred in clinical practice toward combination therapy. However, conventional combination therapy encounters several hindrances, including low selectivity to arthritic joints, short half-lives, and varying pharmacokinetics among coupled drugs. Emerging nanotechnology offers an incomparable opportunity for developing advanced combination therapy against RA. First, it allows for co-delivering multiple drugs with augmented physicochemical properties, targeted delivery capabilities, and controlled release profiles. Second, it enables therapeutic nanomaterials development, thereby expanding combination regimens to include multifunctional nanomedicines. Lastly, it facilitates the construction of all-in-one nanoplatforms assembled with multiple modalities, such as phototherapy, sonodynamic therapy, and imaging. Thus, nanotechnology offers a promising solution to the current bottleneck in both RA treatment and diagnosis. This review summarizes the rationale, advantages, and recent advances in nano-empowered combination therapy for RA. It also discusses safety considerations, drug-drug interactions, and the potential for clinical translation. Additionally, it provides design tips and an outlook on future developments in nano-empowered combination therapy. The objective of this review is to achieve a comprehensive understanding of the mechanisms underlying combination therapy for RA and unlock the maximum potential of nanotechnology, thereby facilitating the smooth transition of research findings from the laboratory to clinical practice.

Adipose-derived stem cell exosomes loaded with icariin alleviates rheumatoid arthritis by modulating macrophage polarization in rats

Rheumatoid arthritis (RA) is a chronic autoimmune disease marked by synovitis and cartilage destruction. The active compound, icariin (ICA), derived from the herb Epimedium, exhibits potent anti-inflammatory properties. However, its clinical utility is limited by its water insolubility, poor permeability, and low bioavailability. To address these challenges, we developed a multifunctional drug delivery system-adipose-derived stem cells-exosomes (ADSCs-EXO)-ICA to target active macrophages in synovial tissue and modulate macrophage polarization from M1 to M2. High-performance liquid chromatography analysis confirmed a 92.4 ± 0.008% loading efficiency for ADSCs-EXO-ICA. In vitro studies utilizing cellular immunofluorescence (IF) and flow cytometry demonstrated significant inhibition of M1 macrophage proliferation by ADSCs-EXO-ICA. Enzyme-linked immunosorbent assay, cellular transcriptomics, and real-time quantitative PCR indicated that ADSCs-EXO-ICA promotes an M1-to-M2 phenotypic transition by reducing glycolysis through the inhibition of the ERK/HIF-1α/GLUT1 pathway. In vivo, ADSCs-EXO-ICA effectively accumulated in the joints. Pharmacodynamic assessments revealed that ADSCs-EXO-ICA decreased cytokine levels and mitigated arthritis symptoms in collagen-induced arthritis (CIA) rats. Histological analysis and micro computed tomography confirmed that ADSCs-EXO-ICA markedly ameliorated synovitis and preserved cartilage. Further in vivo studies indicated that ADSCs-EXO-ICA suppresses arthritis by promoting an M1-to-M2 switch and suppressing glycolysis. Western blotting supported the therapeutic efficacy of ADSCs-EXO-ICA in RA, confirming its role in modulating macrophage function through energy metabolism regulation. Thus, this study not only introduces a drug delivery system that significantly enhances the anti-RA efficacy of ADSCs-EXO-ICA but also elucidates its mechanism of action in macrophage function inhibition.

Integrating Pt nanoparticles with 3D Cu2- x Se/GO nanostructure to achieve nir-enhanced peroxidizing Nano-enzymes for dynamic monitoring the level of H2O2 during the inflammation

The treatment of wound inflammation is intricately linked to the concentration of reactive oxygen species (ROS) in the wound microenvironment. Among these ROS, H2O2 serves as a critical signaling molecule and second messenger, necessitating the urgent need for its rapid real-time quantitative detection, as well as effective clearance, in the pursuit of effective wound inflammation treatment. Here, we exploited a sophisticated 3D Cu2- x Se/GO nanostructure-based nanonzymatic H2O2 electrochemical sensor, which is further decorated with evenly distributed Pt nanoparticles (Pt NPs) through electrodeposition. The obtained Cu2- x Se/GO@Pt/SPCE sensing electrode possesses a remarkable increase in specific surface derived from the three-dimensional surface constructed by GO nanosheets. Moreover, the localized surface plasma effect of the Cu2- x Se nanospheres enhances the separation of photogenerated electron-hole pairs between the interface of the Cu2- x Se NPs and the Pt NPs. This innovation enables near-infrared light-enhanced catalysis, significantly reducing the detection limit of the Cu2- x Se/GO@Pt/SPCE sensing electrode for H2O2 (from 1.45 μM to 0.53μM) under NIR light. Furthermore, this biosensor electrode enables in-situ real-time monitoring of H2O2 released by cells. The NIR-enhanced Cu2- x Se/GO@Pt/SPCE sensing electrode provide a simple-yet-effective method to achieve a detection of ROS (H2O2、-OH) with high sensitivity and efficiency. This innovation promises to revolutionize the field of wound inflammation treatment by providing clinicians with a powerful tool for accurate and rapid assessment of ROS levels, ultimately leading to improved patient outcomes.

Microneedle-assisted dual delivery of PUMA gene and celastrol for synergistic therapy of rheumatoid arthritis through restoring synovial homeostasis

Abnormal proliferation of aggressive fibroblast-like synoviocytes (FLS) and perpetuate synovial inflammation can inevitably accelerate the progression of rheumatoid arthritis (RA). Herein, a strategy of simultaneously promoting FLS apoptosis and inhibiting inflammation as mediated by macrophages is proposed to restore synovial homeostasis for effective RA therapy. A hyaluronic acid-based dissolvable microneedle (MN) is fabricated for transdermal delivery of dual human serum albumin (HSA)-contained biomimetic nanocomplexes to regulate RA FLS and macrophages. Upon skin insertion, dual nanocomplexes are released rapidly from the MN and accumulate in RA joint microenvironment through both passive and active targeting as mediated by HSA. Thioketal-crosslinked fluorinated polyethyleneimine 1.8 K (TKPF) was constructed to bind the plasmid encoding pro-apoptotic gene PUMA with HSA coating layer (TKPF/pPUMA@HSA, TPH). TPH nanocomplexes can upregulate PUMA through RA FLS transfection to trigger efficient apoptosis. Also, HSA nanocomplexes encapsulating the classic anti-inflammatory natural product celastrol (Cel@HSA, CH) can inhibit inflammation of macrophages through blocking NF-κB pathway activation. TPH/CH MN can deplete RA FLS and inhibit M1 macrophage activation, suppress synovial hyperplasia as well as reduce bone and cartilage erosion in a collagen-induced arthritis (CIA) mouse model, demonstrating a promising strategy for efficient RA treatment.

Mild hyperthermia enhanced synergistic uric acid degradation and multiple ROS elimination for an effective acute gout therapy

BACKGROUND

Acute gouty is caused by the excessive accumulation of Monosodium Urate (MSU) crystals within various parts of the body, which leads to a deterioration of the local microenvironment. This degradation is marked by elevated levels of uric acid (UA), increased reactive oxygen species (ROS) production, hypoxic conditions, an upsurge in pro-inflammatory mediators, and mitochondrial dysfunction.

RESULTS

In this study, we developed a multifunctional nanoparticle of polydopamine-platinum (PDA@Pt) to combat acute gout by leveraging mild hyperthermia to synergistically enhance UA degradation and anti-inflammatory effect. Herein, PDA acts as a foundational template that facilitates the growth of a Pt shell on the surface of its nanospheres, leading to the formation of the PDA@Pt nanomedicine. Within this therapeutic agent, the Pt nanoparticle catalyzes the decomposition of UA and actively breaks down endogenous hydrogen peroxide (H2O2) to produce O2, which helps to alleviate hypoxic conditions. Concurrently, the PDA component possesses exceptional capacity for ROS scavenging. Most significantly, Both PDA and Pt shell exhibit absorption in the Near-Infrared-II (NIR-II) region, which not only endow PDA@Pt with superior photothermal conversion efficiency for effective photothermal therapy (PTT) but also substantially enhances the nanomedicine's capacity for UA degradation, O2 production and ROS scavenging enzymatic activities. This photothermally-enhanced approach effectively facilitates the repair of mitochondrial damage and downregulates the NF-κB signaling pathway to inhibit the expression of pro-inflammatory cytokines.

CONCLUSIONS

The multifunctional nanomedicine PDA@Pt exhibits exceptional efficacy in UA reduction and anti-inflammatory effects, presenting a promising potential therapeutic strategy for the management of acute gout.

Manganese-doped albumin-gelatin composite nanogel loaded with berberine applied to the treatment of gouty arthritis in rats via a SPARC-dependent mechanism

In this study, manganese-doped albumin-gelatin composite nanogels (MAGN) were prepared and used to load berberine (Ber) for the treatment of gouty arthritis (GA). The nanodrug delivery system (Ber-MAGN) can target inflammatory joints due to the intrinsic high affinity of albumin for SPARC, which is overexpressed at the inflammatory site of GA. Characterization of the pharmaceutical properties in vitro showed that Ber-MAGN had good dispersion, and the particle size was 121 ± 10.7 nm. The sustained release effect significantly improved the bioavailability of berberine. In vitro and in vivo experimental results showed that Ber-MAGN has better therapeutic effects in relieving oxidative stress and suppressing inflammation. Therefore, Ber-MAGN, as a potential pharmaceutical preparation for GA, provides a new reference for the clinical treatment plan of GA.

Manganese-Based Immunomodulatory Nanocomposite with Catalase-Like Activity and Microwave-Enhanced ROS Elimination Ability for Efficient Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is a chronic autoimmune disease commonly associated with the accumulation of hyperactive immune cells (HICs), particularly macrophages of pro-inflammatory (M1) phenotype, accompanied by the elevated level of reactive oxygen species (ROS), decreased pH and O2 content in joint synovium. In this work, an immunomodulatory nanosystem (IMN) is developed for RA therapy by modulating and restoring the function of HICs in inflamed tissues. Manganese tetraoxide nanoparticles (Mn3 O4 ) nanoparticles anchored on UiO-66-NH2 are designed, and then the hybrid is coated with Mn-EGCG film, further wrapped with HA to obtain the final nanocomposite of UiO-66-NH2 @Mn3 O4 /Mn-EGCG@HA (termed as UMnEH). When UMnEH diffuses to the inflammatory site of RA synovium, the stimulation of microwave (MW) irradiation and low pH trigger the slow dissociation of Mn-EGCG film. Then the endogenously overexpressed hydrogen peroxide (H2 O2 ) disintegrates the exposed Mn3 O4 NPs to promote ROS scavenging and O2 generation. Assisted by MW irradiation, the elevated O2 content in the RA microenvironment down-regulates the expression of hypoxia-inducible factor-1α (HIF-1α). Coupled with the clearance of ROS, it promotes the re-polarization of M1 phenotype macrophages into anti-inflammatory (M2) phenotype macrophages. Therefore, the multifunctional UMnEH nanoplatform, as the IMN, exhibits a promising potential to modulate and restore the function of HICs and has an exciting prospect in the treatment of RA.

Ce1-xZrxO2 nanoparticles in bacterial cellulose, bio-based composites with self-regenerating antioxidant capabilities

Bacterial cellulose (BC) is an emerging biopolymer with ever-widening uses in the biomedical field due to its purity, mechanical stability, conformability, moisture control, and biocompatibility. In the wet form, its highly porous nanofibrillar structure and abundant surface hydroxyl groups enable the functionalisation of BC with inorganic nanoparticles (NPs), granting the material additional purposive capabilities. As oxidative stress caused by reactive oxygen species (ROS) negatively affects various cellular structures, the functionalisation of BC with CeO2 NPs, known antioxidants, is pursued in this work to achieve composites capable of minimising inflammation and tissue damage. We report on low-temperature in situ syntheses of CeO2 NPs in BC enabling the formation of BC-CeO2 composites that exhibit self-regenerating antioxidant properties, as verified by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays and studies of the evolution in the CeO2 absorption edge (indicative of the Ce3+ and Ce4+ fractions). X-Ray photoelectron spectroscopy (XPS) further reveals that incorporation of zirconium into the CeO2 lattice leads to a four-fold increase in the Ce3+: Ce4+ ratio, thereby enhancing the composite antioxidant performance as exemplified by BC-Ce0.6Zr0.4O2 recording the highest %DPPH scavenging per unit mass of NPs among the BC-Ce1-xZrxO2 studied systems.