Protein Corona-Mediated Inhibition of Nanozyme Activity: Impact of Protein Shape

Porphyrinic metal-organic framework PCN-224 supported Prussian blue enables selective detection of casein and phytic acid

Monitoring casein and phytic acid content is of great significance for food safety and human health. In this paper, porphyrinic metal-organic framework PCN-224 supported Prussian blue (PCN-224@PB) nanoprobe was constructed by in-situ growth of PB on PCN-224 layer. The supported PCN-224 not only reduces the size and improves the dispersity of PB, but also provides specific affinity for casein and phytic acid. Based on the formation of Zr-OP structure, the peroxidase (POD)-like activity of PCN-224@PB is inhibited when encountering casein. In the presence of phytic acid, the deposited PB is decomposed, thus recovering the fluorescence of PCN-224 quenched by PB. The constructed nanoprobe exhibits high sensitivity with a limit of detection of 0.25 μg/mL for casein and 0.18 μM for phytic acid detection, respectively. In addition, PCN-224@PB shows excellent sensing performance in milk, beverage, corn and cells samples, with casein and phytic acid recoveries ranging from 94.30 % to 103.20 %, further demonstrating its feasibility in real sample analysis.

ZnO Nanoparticle Exposure Disrupted Iron-Sulfur Protein Functions to Increase Macrophage Erythrophagocytosis and Disturb Systemic Iron Recycling

Although anemia is a common systemic toxicological manifestation of zinc product overload, the underlying mechanisms remain elusive. Therefore, we explored the mechanisms underlying the anemia caused by exposure to zinc oxide nanoparticles (ZnO NPs), which are a widely utilized Zn product. We observed that ZnO NP-exposed mice developed evident anemia due to disrupted spleen iron metabolism. Since spleen iron metabolism relies on macrophages, we further investigated how ZnO NP exposure affected macrophage function. Results indicated that ZnO NP exposure triggered macrophage metabolic reprogramming to facilitate erythrophagocytosis and blunted the response of iron exporter ferroportin to enhanced erythrophagocytosis, thereby causing iron retention and ultimately impeding macrophage iron recycling. Mechanistically, Zn2+ released from ZnO NPs occupied the cluster-binding cysteines of iron-sulfur proteins, regulating glucose metabolism and ferroportin expression to suppress their activity, thereby inducing metabolic reprogramming and suppressing iron export. Our research unveils a category of nanobio interactions underlying ZnO NPs biotoxicity.

Boosting Cancer Cell Uptake of Gold Nanoparticles by Light-Modulated Protein Corona Reorganization for Tumor Ablation

Nanoparticles (NPs) administered into the human body are spontaneously modified by forming a protein corona, which is crucial for their biological activity. While NP-based photothermal therapy is an established noninvasive modality for tumor ablation, the impact of light irradiation on protein corona formation and clinical outcomes is unclear. This study unveils the promotive role of light irradiation in cancer cell uptake of gold nanoparticles (GNPs) by modulating the GNP-protein and protein-protein interactions within the corona. Specifically, infrared light irradiation increases the local temperature around GNPs to induce partial unfolding of corona proteins, increasing the availability of binding sites and enhancing adsorption. Additionally, light intensifies competition among different proteins for adsorption, resulting in a 25% increase in the abundance of higher molecular weight proteins, such as human serum albumin (HSA), on the GNP surface after irradiation. Notably, GNPs with positively charged surfaces, compared to GNPs with other modifications, exhibit more significant changes in the protein corona due to stronger electrostatic interactions with proteins (1.32 ± 0.17 × 103 kJ/mol). These variations in the amount, structure, and composition of associated proteins result in a 14.26% increase in GNP uptake by cancer cells, likely due to modifications at the GNP-cell membrane interface. Our findings highlight the critical role of light irradiation in influencing protein corona dynamics and cellular interactions, suggesting its potential as a valuable engineering tool in nanomedicine.

Amino-Acid-Engineered Bionanozyme Selectivity for Colorimetric Detection of Human Serum Albumin

Nanozymes are emerging nanomaterials owing to their superior stability and enzyme-mimicking catalytic functions. However, unlike natural enzymes with inherent amino-acid-based recognition motifs for target interactions, manipulating nanozyme selectivity toward specific targets remains a major challenge. In this study, we introduce the de novo strategy using the supramolecular assembly of l-tryptophan (l-Trp) as the recognition amino acid with copper (Cu) ions for creating a human serum albumin (HSA)-responsive bionanozyme. This amino-acid-engineered bionanozyme enables selective colorimetric detection of HSA, a critical urinary biomarker for kidney diseases, overcoming the challenge that HSA is neither a typical substrate nor an inhibitor for most nanozymes. Kinetic studies and competitive tests reveal that HSA subdomain IIIA binding to l-Trp sites limits the electron-transfer-induced structural changes of l-Trp-Cu chelate rings, resulting in noncompetitive inhibition. This inhibition effect is significantly stronger than that observed for canonical amino acids, common proteins, and urinary interference species. Colorimetric monitoring of bionanozyme activity enables sensitive HSA detection with a detection limit of 1.3 nM and a quantification range of 2 nM to 10 μM. This approach is exceptionally more sensitive and offers a broader detection range compared to conventional colorimetric and fluorescent methods, suitable for diagnostics across various clinical stages of disease. This innovative rational strategy to designing and manipulating selective nanozyme-target interactions not only addresses the limitations of nanozymes but also expands their precise applications in complex biological systems.

Second coordination sphere regulates nanozyme inhibition to assist early drug discovery

Early drug discovery is a time- and cost-consuming task requiring enzymes. Although nanozymes with metal sites akin to metallocofactors display similar activities, the lack of proximal amino acids hinders them from more adequately mimicking enzymes for drug discovery purposes. Hence, the rational design of the nanozyme second coordination sphere is desirable yet remains challenging. Herein, we report a nanozyme featuring atomically dispersed Cu-N4 sites with proximal hydroxyl groups (CuNC-OH). Experimental and theoretical results reveal that Cu-N4 site and hydroxyl respectively behave as cofactor and amino acid of the enzymatic pocket to interact with adsorbates, regulating nanozyme activity and inhibition. This mechanism involving dual sites is similar to that of thyroid peroxidases, which enables specific inhibition of CuNC-OH by antithyroid drugs. Based on these findings, a nanozyme-assisted drug discovery kit is established to analyze inhibition features of thyroid peroxidase inhibitors and screen out promising antithyroid drugs with a significant cost reduction compared with traditional enzyme kits.

Tailored protein corona behavior in titanium dioxide nanosheet fluorescence biosensor for protein quantification assays

The spontaneous adsorption of proteins onto nanoparticles, known as the protein corona, provides a unique perspective for designing protein-sensing biosensors. This study proposes a tailored protein corona method mediated by Tween-20 and develops a reverse-capture approach for protein quantification assays. The protein-coated microplate captures titanium dioxide nanosheets (TiO2-NS) in a phosphate buffer containing Tween-20 and generates fluorescence signals via the photocatalytic reduction of resazurin to resorufin, thereby indicating the amount of protein. The linear range of the current assay was 0.5-5 ng/mL, and the limit of detection (LOD) was 0.28 ng/mL, which is 100-1000 times more sensitive than the classical colorimetric methods. This method is suitable for the determination of proteins in artificial urine and has broad potential for practical applications.

Multiple recognition-powered abiotic bimetallic oxide nanozyme-based colorimetric platform for the selective detection of allergen β-lactoglobulin

β-lactoglobulin (β-lg) is the major allergen in dairy products, and poses a significant threat to special people including infants and young children. Therefore, a convenient, cost-efficient, and aptamer-free colorimetric sensing platform is developed for β-lg assay based on a germanium/zinc bimetallic oxide nanozyme (GeO2/ZnO). The CTAB-assisted intercalation growth of ZnO nanoparticles between GeO2 layers endows GeO2/ZnO with enhanced peroxidase-mimicking activity and β-lg affinity. By virtue of multiple recognition-meditated specific protein corona formation, the catalytic activity of GeO2/ZnO is greatly deteriorated in the presence of β-lg. The selective discrimination and accurate detection of β-lg in dairy samples is achieved with a detection limit of 14.1 nM, and a portable kit is further established for point-of-care testing and visual colorimetric analysis. This study not only provides a promising strategy for allergen assay, but paves an avenue for engineering the abiotic protein affinity sensors for food safety analysis.

"Three-in-one" Analysis of Proteinuria for Disease Diagnosis through Multifunctional Nanoparticles and Machine Learning

Urinalysis is one of the predominant tools for clinical testing owing to the abundant composition, sufficient volume, and non-invasive acquisition of urine. As a critical component of routine urinalysis, urine protein testing measures the levels and types of proteins, enabling the early diagnosis of diseases. Traditional methods require three separate steps including strip testing, protein/creatinine ratio measurement, and electrophoresis respectively to achieve qualitative, quantitative, and classification analyses of proteins in urine with long time and cumbersome operations. Herein, this work demonstrates a "three-in-one" protocol to analyze the urine composition by combining multifunctional nanoparticles with machine learning. This work constructs a sensor array to analyze proteinuria by employing nanoparticles with unique optical properties, outstanding catalytic activity, diverse composition, and tunable structure as probes. Different proteins interacted with nanoprobes differently and are classified by this sensor array based on their physicochemical heterogeneities. With the aid of machine learning, the urine composition is precisely detected for the diagnosis of bladder cancer. This protocol enables quantification and classification of 5 proteinuria in 10 min without any tedious pretreatment, showing proimise for the comprehensive analysis of body fluid for early disease diagnosis.

Unraveling the mechanism: How does β-phosphoglucomutase from the haloacid dehalogenase superfamily catalyze the interconversion of β-d-glucose 1-phosphate and β-d-glucose 6-phosphate? A chemical perspective

The catalytic mechanisms of enzymes can be phylogenetically mapped corresponding to their catalytic structures. This mapping effectively elucidates the diversity of enzyme catalytic mechanisms and the emergence of new enzymatic activities within enzyme superfamilies. The haloacid dehalogenase (HAD) superfamily serves as an exemplary model system for comprehending the co-evolution of catalytic structures and mechanisms. This study delves into the mechanism underlying the functional divergence of β-phosphoglucomutase (β-PGM) from the phosphatase branch of the HAD superfamily, employing a chemical perspective. Through the construction and calculation of three models of varying scales using the Density Functional Theory method with B3LYP function, we aim to investigate the chemical mechanism driving this functional divergence of β-PGM from the HAD family. The computational results indicate that residues His20 and Lys76 in the second shell stabilize substrates and enhance the acid-base catalytic ability of Asp10. Additionally, residues Arg49, Ser116 and Asn118 facilitate substrate binding by engaging in close hydrogen bonding interactions with the substrates. Through cooperative action, these residues enable β-PGM to function as an efficient phosphoglucomutase. Through computational modeling and a chemical perspective, we unravel the mechanisms enabling β-PGM to convert β-d-glucose 1-phosphate to β-d-glucose 6-phosphate. Finally, based on the analysis of the evolutionary tree, we discussed and summarized the evolutionary relationships among different forms of metal cores of hydrolases.

Stealth Nanoparticles with a "Self-Consuming" Shell for Long-Term Blood Vessel Imaging

The development of lanthanide-doped upconversion nanoparticle (UCNP)-based imaging with minimal autofluorescence and improved penetration depth is important in medical applications. Exogenous nanocarriers readily adsorb plasma proteins following intravenous administration (<0.5 min), resulting in the formation of a protein corona on the fixed surface. The protein corona facilitates UCNP interception by the immune system, preventing targeted delivery to disease sites. In this study, we report a novel surface-camouflaging strategy using lanthanide hydroxyl carbonate that is slowly dissolved by physiological phosphate in serum. The "self-consuming" inorganic-shell-modified UCNPs (denoted as UCSP-PEG) effectively reduce protein corona adhesion by more than 90% through a dissociation effect associated with the amphiphilic poly(ethylene glycol) (PEG)-modified UCNPs as determined in an ex vivo assay. The UCSP-PEG exhibits a prolonged blood circulation time (t1/2 = 73.9 ± 9.5 min), 185 times that of camouflage materials without the "stealth" feature, and can employ upconverted luminescence (UCL) imaging to monitor tumor-related blood vessels for at least 120 min. Based on the superior optical properties of UCSP-PEG, the application of a UCL dual-channel stereoscope magnification imaging system has enabled the observation of capillaries with high resolution, offering a powerful tool for monitoring biological activities at the fine tissue level. This work provides a novel "stealth" nanovehicle, resisting blood protein adhesion based on a "self-consuming" effect that can significantly advance tissue imaging and target-specific cancer diagnosis.

Bidirectional Drive Reverse-Phase Enhanced Fluorescence Lateral Flow Immunoassay with Spectral Overlap and Quantitative Balance for the Analysis of Deoxynivalenol

The capacity of the reverse-phase enhanced fluorescence (turn-on mode) to sensitively alter fluorescence intensity from "zero" to "one" has drawn increasing interest and investigation in competitive lateral flow immunoassay (LFIA). During this process, three important considerations must be made: designing an effective quenching agent, choosing a suitable fluorescence donor, and building a suitable quenching mode. In this work, we employed Au@MnO2 nanoparticles as highly effective quenchers and AuNCs as fluorescence donors to achieve the overlap of absorption and emission spectra. Furthermore, we have effectively created an immunological network-based competitive LFIA to balance the quantitative relationship for the quick and accurate detection of the deoxynivalenol (DON) toxin (Au@MnO2-GAB-CFLFIA). Notably, our proposed fluorescent turn-on mode demonstrated 11.65-fold sensitivity enhancement (0.0509 ng/mL) compared to the colorimetric mode (0.593 ng/mL). Furthermore, the immunological network mode shows 5.08-fold sensitivity enhancement compared to the non-network mode (0.259 ng/mL). Moreover, satisfactory recoveries of 93.33-109.02% are obtained in real samples (maize, wheat, and oat). In this DON detection, spectral overlap and quantitative balance offer more novel and efficient strategies for reverse-phase enhanced fluorescence LFIA.

Protein corona formation on different-shaped CdSe/CdS semiconductor nanocrystals

Nanoparticles (NPs) have been widely studied and applied in medical and pharmaceutical fields. When NPs enter the in vivo environment, they are covered with protein molecules to form the so-called "protein corona". Because NPs and proteins are comparable in size, the shape of NPs has a significant impact on NP-protein interactions. Although NPs of various shapes have been synthesized, how the shape of NPs affects the protein corona is poorly understood, and little is known about the underlying molecular mechanism. In the present study, we synthesized spherical, football-shaped, and rod-shaped semiconductor nanocrystals (SNCs) as model NPs and compared their interaction with human serum albumin (HSA) using fluorescence correlation spectroscopy, fluorescence quenching, Fourier-transform infrared spectroscopy, and thermodynamic analysis. Based on the binding enthalpy and entropy and secondary structural changes of HSA, with the help of hydrodynamic diameter changes of SNCs, we concluded that HSA adopts a conformation or orientation that is appropriate for the local curvature of SNCs. This study demonstrates the effect of NP shape on their interaction with proteins and provides a mechanistic perspective.

Efficient Cytosolic Delivery of Single-Chain Polymeric Artificial Enzymes for Intracellular Catalysis and Chemo-Dynamic Therapy

Designing artificial enzymes for in vivo catalysis presents a great challenge due to biomacromolecule contamination, poor biodistribution, and insufficient substrate interaction. Herein, we developed single-chain polymeric nanoparticles with Cu/N-heterocyclic carbene active sites (SCNP-Cu) to function as peroxidase mimics for in vivo catalysis and chemo-dynamic therapy (CDT). Compared with the enzyme mimics based on unfolded linear polymer scaffold and multichain cross-linked scaffold, SCNP-Cu exhibits improved tumor accumulation and CDT efficiency both in vitro and in vivo. Protein-like size of the SCNP scaffold promotes passive diffusion, whereas positive surface charge allows its active transcytosis for deep tumor penetration and hence accumulation in the tumor site. The submolecular compartments of the SCNP scaffold effectively protect the active sites from protein bindings, thereby providing a "cleaner" microenvironment for catalysis within a living system. The folded structure of SCNP-Cu facilitates their cytosolic delivery of and free diffusion within cytosol, ensuring efficient contact with endogenous H2O2, in situ generation of toxic hydroxyl radicals (·OH), and effective damage of intracellular targets (i.e., lipids, nucleic acids). This work establishes versatile SCNP-based nanoplatforms for developing artificial enzymes for in vivo catalysis.

Safety Landscape of Therapeutic Nanozymes and Future Research Directions

Oxidative stress and inflammation are at the root of a multitude of diseases. Treatment of these conditions is often necessary but current standard therapies to fight excessive reactive oxygen species (ROS) and inflammation are often ineffective or complicated by substantial safety concerns. Nanozymes are emerging nanomaterials with intrinsic enzyme-like properties that hold great promise for effective cancer treatment, bacterial elimination, and anti-inflammatory/anti-oxidant therapy. While there is rapid progress in tailoring their catalytic activities as evidenced by the recent integration of single-atom catalysts (SACs) to create next-generation nanozymes with superior activity, selectivity, and stability, a better understanding and tuning of their safety profile is imperative for successful clinical translation. This review outlines the current applied safety assessment approaches and provides a comprehensive summary of the safety knowledge of therapeutic nanozymes. Overall, nanozymes so far show good in vitro and in vivo biocompatibility despite considerable differences in their composition and enzymatic activities. However, current safety investigations mostly cover a limited set of basic toxicological endpoints, which do not allow for a thorough and deep assessment. Ultimately, remaining research gaps that should be carefully addressed in future studies are highlighted, to optimize the safety profile of therapeutic nanozymes early in their pre-clinical development.

A cocatalytic nanozyme based on metal-organic framework-embedded iron porphyrin for the sensitive detection of Salmonella typhimurium in milk

The nanozyme, acting as the signal labeling reporter, is widely employed in colorimetric immunoassays due to its exceptional catalytic activity and reliable performance. Nonetheless, when immobilized on the nanozyme's surface, there is a decline in catalytic activity, which hinders its ability to meet the escalating demand for advanced colorimetric immunoassays. Herein, we introduce a novel MILL-88@TcP nanozyme, formed by encapsulating iron porphyrins (TcP) within metal-organic frameworks (MILL-88), where the catalytic activity of TcP is fully preserved through ethanol-induced release. Leveraging the superior encapsulation capacity and enzyme-mimicking characteristics of MILL-88, the MILL-88@TcP nanozyme demonstrates a remarkable colorimetric performance, 1430-fold higher than that of MILL-88 alone. Furthermore, we developed the MILL-88@TcP nanozyme-based Enzyme-Linked Immunosorbent Assay (N-ELISA) for enhanced sensitivity in detecting Salmonella typhimurium, achieving a detection limit of 1.68 × 102 CFU/mL, approximately 500-fold enhancement compared to the traditional HRP-based ELISA (8.35 × 104 CFU/mL). Notably, the average recoveries ranged from 91.50 % to 108.50 % with a variation of 3.53 %-10.41 %, indicating high accuracy and precision. Collectively, this study highlights that the MILL-88@TcP nanozyme, with its superior catalytic performance and anti-interference capabilities, holds promise as a colorimetric labeling reporter to enhance the detection efficacy of colorimetric immunoassays and has the potential to establish a more stable and sensitive colorimetric assay platform.

Influence of albumin concentration on surface characteristics and cellular responses in the pre-incubation of multi-walled carbon nanotubes

Reliable characterization of protein coronas (PCs) that form when nanomaterials are introduced into biological fluids is a critical step in the development of safe and efficient nanomedicine. We observed that bovine serum albumin (BSA)-coated multi-walled carbon nanotubes (MWCNTs) do not induce cytotoxicity, but have different cellular uptake rates depending on the BSA pretreatment concentration. To determine how these slight differences affect A549 cell responses and intracellular changes, we conducted spectroscopic (circular dichroism and Fourier-transform infrared) and spectrometric (nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry) analyses. The various characterization techniques conducted in this study reveal the following. (i) The composition ratio of PCs on MWCNTs differs depending on the BSA concentration. (ii) Analysis of the secondary structure of the proteins revealed that the α-helix structure increased with increasing BSA concentration. (iii) Proteomic analysis showed that different biological pathways were activated at levels higher and lower than 5 mg mL-1. Such combined spectroscopic and spectrometric approaches provide an integrated understanding of PC composition as well as how nano/bio-interface states are linked to cellular-level responses. Our results can support reliable and practical applications of nanomedicine development.

Lung-Targeting Perylenediimide Nanocomposites for Efficient Therapy of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis, an idiopathic interstitial lung disease with high mortality, remains challenging to treat due to the lack of clinically approved lung-targeting drugs. Herein, we present PDIC-DPC, a perylenediimide derivative that exhibits superior lung-selective enrichment. PDIC-DPC forms nanocomposites with plasma proteins, including fibrinogen beta chain and vitronectin, which bind to pulmonary endothelial receptors for lung-specific accumulation. Moreover, PDIC-DPC significantly suppresses transforming growth factor beta1 and activates adenosine monophosphate-activated protein kinase. As a result, compared to existing therapeutic drugs, PDIC-DPC achieves superior therapeutic outcomes, evidenced by the lowest Ashcroft score, significantly improved pulmonary function, and an extended survival rate in a bleomycin-induced pulmonary fibrosis model. This study elucidates the lung-selective enrichment of assembled prodrug from biological perspectives and affords a platform enabling therapeutic efficiency on idiopathic pulmonary fibrosis.

Exploring Nanozymes for Organic Substrates: Building Nano-organelles

Since the discovery of the first peroxidase nanozyme (Fe3O4), numerous nanomaterials have been reported to exhibit intrinsic enzyme-like activity toward inorganic oxygen species, such as H2O2, oxygen, and O2 -. However, the exploration of nanozymes targeting organic compounds holds transformative potential in the realm of industrial synthesis. This review provides a comprehensive overview of the diverse types of nanozymes that catalyze reactions involving organic substrates and discusses their catalytic mechanisms, structure-activity relationships, and methodological paradigms for discovering new nanozymes. Additionally, we propose a forward-looking perspective on designing nanozyme formulations to mimic subcellular organelles, such as chloroplasts, termed "nano-organelles". Finally, we analyze the challenges encountered in nanozyme synthesis, characterization, nano-organelle construction and applications while suggesting directions to overcome these obstacles and enhance nanozyme research in the future. Through this review, our goal is to inspire further research efforts and catalyze advancements in the field of nanozymes, fostering new insights and opportunities in chemical synthesis.

Computer-aided nanodrug discovery: recent progress and future prospects

Nanodrugs, which utilise nanomaterials in disease prevention and therapy, have attracted considerable interest since their initial conceptualisation in the 1990s. Substantial efforts have been made to develop nanodrugs for overcoming the limitations of conventional drugs, such as low targeting efficacy, high dosage and toxicity, and potential drug resistance. Despite the significant progress that has been made in nanodrug discovery, the precise design or screening of nanomaterials with desired biomedical functions prior to experimentation remains a significant challenge. This is particularly the case with regard to personalised precision nanodrugs, which require the simultaneous optimisation of the structures, compositions, and surface functionalities of nanodrugs. The development of powerful computer clusters and algorithms has made it possible to overcome this challenge through in silico methods, which provide a comprehensive understanding of the medical functions of nanodrugs in relation to their physicochemical properties. In addition, machine learning techniques have been widely employed in nanodrug research, significantly accelerating the understanding of bio-nano interactions and the development of nanodrugs. This review will present a summary of the computational advances in nanodrug discovery, focusing on the understanding of how the key interfacial interactions, namely, surface adsorption, supramolecular recognition, surface catalysis, and chemical conversion, affect the therapeutic efficacy of nanodrugs. Furthermore, this review will discuss the challenges and opportunities in computer-aided nanodrug discovery, with particular emphasis on the integrated "computation + machine learning + experimentation" strategy that can potentially accelerate the discovery of precision nanodrugs.

Protein Corona-Directed Cellular Recognition and Uptake of Polyethylene Nanoplastics by Macrophages

The widespread use of plastic products in daily life has raised concerns about the health hazards associated with nanoplastics (NPs). When exposed, NPs are likely to infiltrate the bloodstream, interact with plasma proteins, and trigger macrophage recognition and clearance. In this study, we focused on establishing a correlation between the unique protein coronal signatures of high-density (HDPE) and low-density (LDPE) polyethylene (PE) NPs with their ultimate impact on macrophage recognition and cytotoxicity. We observed that low-density and high-density lipoprotein receptors (LDLR and SR-B1), facilitated by apolipoproteins, played an essential role in PE-NP recognition. Consequently, PE-NPs activated the caspase-3/GSDME pathway and ultimately led to pyroptosis. Advanced imaging techniques, including label-free scattered light confocal imaging and cryo-soft X-ray transmission microscopy with 3D-tomographic reconstruction (nano-CT), provided powerful insights into visualizing NPs-cell interactions. These findings underscore the potential risks of NPs to macrophages and introduce analytical methods for studying the behavior of NPs in biological systems.