ROS-responsive charge reversal mesoporous silica nanoparticles as promising drug delivery system for neovascular retinal diseases.

Intravitreal injection of biodegradable implant drug carriers shows promise in reducing the injection frequency for neovascular retinal diseases. However, current intravitreal ocular devices have limitations in adjusting drug release rates for individual patients, thereby affecting treatment effectiveness. Accordingly, we developed mesoporous silica nanoparticles (MSNs) featuring a surface that reverse its charge in response to reactive oxygen species (ROS) for efficient delivery of humanin peptide (HN) to retinal epithelial cells (ARPE-19). The MSN core, designed with a pore size of 2.8 nm, ensures a high HN loading capacity 64.4% (w/w). We fine-tuned the external surface of the MSNs by incorporating 20% Acetyl-L-arginine (Ar) to create a partial positive charge, while 80% conjugated thioketal (TK) methoxy polyethylene glycol (mPEG) act as ROS gatekeeper. Ex vivo experiments using bovine eyes revealed the immobilization of Ar-MSNs-TK-PEG (mean zeta potential: 2 mV) in the negatively charged vitreous. However, oxidative stress reversed the surface charge to -25 mV by mPEG loss, facilitating the diffusion of the nanoparticles impeded with HN. In vitro studies showed that ARPE-19 cells effectively internalize HN-loaded Ar-MSNs-TK, subsequently releasing the peptide, which offered protection against oxidative stress-induced apoptosis, as evidenced by reduced TUNEL and caspase3 activation. The inhibition of retinal neovascularization was further validated in an in vivo oxygen-induced retinopathy (OIR) mouse model.

Role of Chalcogenides in Sensitive Therapeutic Drug Monitoring Using Laser Desorption and Ionization.

This study investigates the applicability of six transition metal dichalcogenides to efficient therapeutic drug monitoring of ten antiepileptic drugs using laser desorption/ionization-mass spectrometry. We found that molybdenum ditelluride and tungsten ditelluride are suitable for the sensitive quantification of therapeutic drugs. The contribution of tellurium to the enhanced efficiency of laser desorption ionization was validated through theoretical calculations utilizing an integrated model that incorporates transition-metal dichalcogenides and antiepileptic drugs. The results of our theoretical calculations suggest that the relatively low surface electron density for the tellurium-containing transition metal dichalcogenides induces stronger Coulombic interactions, which results in enhanced laser desorption and ionization efficiency. To demonstrate applicability, up to 120 patient samples were analyzed to determine drug concentrations, and the results were compared with those of immunoassay and liquid chromatography-tandem mass spectrometry. Agreements among these methods were statistically evaluated using the Passing-Bablok regression and Bland-Altman analysis. Furthermore, our method has been shown to be applicable to the simultaneous detection and multiplexed quantification of antiepileptic drugs.

Visualization Materials Using Silicon-Based Optical Nanodisks (ViSiON) for Enhanced NIR Imaging in Ophthalmology.

ViSiON (visualization materials composed of silicon-based optical nanodisks) is presented, which offers a unique optical combination of near-infrared (NIR) optical properties and biodegradability. Initially, numerical simulations are conducted to calculate the total extinction and scattering effects of ViSiON by the diameter-to-thickness ratio, predicting precise control over its scattering properties in the NIR region. A top-down patterning technique is employed to synthesize ViSiON with accurate diameter and thickness control. ViSiON with a 50 nm thickness exhibits scattering properties over 400 times higher than that of 30 nm, rendering it suitable as a contrast agent for optical coherence tomography (OCT), especially in ophthalmic applications. Furthermore, ViSiON possesses inherent biodegradability in media, with ≈95% degradation occurring after 48 h, and the degradation rate can be finely tuned based on the quantity of protein coating applied to the surface. Subsequently, the OCT imaging capability is validated even within vessels smaller than 300 µm, simulating retinal vasculature using a retinal phantom. Then, using an ex ovo chick embryo model, it is demonstrated that ViSiON enhances the strength of protein membranes by 6.17 times, thereby presenting the potential for ViSiON as an OCT imaging probe capable of diagnosing retinal diseases.

Dual-Function Janus Nanozymes for Performance Evaluation and Application in a Surrogate Virus Neutralization Test with Vaccinated Samples.

The need exists for biosensing technologies capable of sensitively and accurately detecting various biomarkers. In response, the development of nanozymes is actively underway; they have advantages in stability, cost, performance, and functionalization over natural enzymes commonly used for signal amplification in sensing technologies. However, the performance of nanozymes is interdependent with factors such as shape, size, and surface functional moiety, making it challenging to perform quantitative performance comparisons based on the nanozyme material. In this study, we propose a physical synthetic approach to fabricate double-layered bimetallic nanozymes with identical shapes, sizes, and surfaces but different material compositions. These Janus nanozymes consist of a nanozymatic layer responsible for catalytic activity and a gold layer responsible for quantification and efficient surface modification. Based on their identical physicochemical properties, the synthesized double-layered bimetallic nanozymes allow, for the first time, a quantitative comparison of nanozymatic activities in terms of various kinetic parameters. We compared several candidates and found that the Ir-Au nanozyme exhibited the best performance. Subsequently, we applied this nanozyme to detect neutralizing antibodies against SARS-CoV-2 based on a surrogate virus neutralization test. The results demonstrated a limit of detection as low as 2 pg/mL and selectivity specifically toward MERS-CoV. The performance of this assay was further validated using vaccinated samples, demonstrating the potential of our approach as a cost-effective, rapid, and sensitive diagnostic tool for neutralizing antibody detection against viruses such as SARS-CoV-2.

Dual-Emissive Mn-Doped Lead Halide Perovskite Nanocrystals as Background-Suppressed Latent Fingerprint Detection Probes.

Diverse strategies have been developed to visualize latent fingerprints (LFPs) that are undetectable by the naked eye. Among them, fluorescence-based approaches have emerged as an attractive method for enabling high-resolution LFP imaging. However, the use of fluorescent probes for LFP detection remains challenging due to cumbersome processing, low selectivity, and high background interference. Here, we demonstrate highly efficient, sensitive, and background-free LFP detection with dual-color emission arising from manganese (Mn)-doped lead halide perovskite (CsPb(Cl1-yBry)3) nanocrystals (NCs). The resulting bright, fluorescent, solid-state nanopowder (NP) permits the visualization of LFP ridge structures and the resolution of level 1-3 LFP features. The dual-color emission of the Mn-doped perovskite NP provides a simple, robust, and effective route to overcome background interference, thereby increasing the resolution and sensitivity of the LFP detection. The combination of the high quantum efficiency and dual emission of Mn-doped perovskite NP offers great potential for forensic science.

Highly Effective and Efficient Self-Assembled Multilayer-Based Electrode Passivation for Operationally Stable and Reproducible Electrolyte-Gated Transistor Biosensors.

To ensure the operational stability of transistor-based biosensors in aqueous electrolytes during multiple measurements, effective electrode passivation is crucially important for reliable and reproducible device performances. This paper presents a highly effective and efficient electrode passivation method using a facile solution-processed self-assembled multilayer (SAML) with excellent insulation property to achieve operational stability and reproducibility of electrolyte-gated transistor (EGT) biosensors. The SAML is created by the consecutive self-assembly of three different molecular layers of 1,10-decanedithiol, vinyl-polyhedral oligomeric silsesquioxane, and 1-octadecanethiol. This passivation enables EGT to operate stably in phosphate-buffered saline (PBS) during repeated measurements over multiple cycles without short-circuiting. The SAML-passivated EGT biosensor is fabricated with a solution-processed In2O3 thin film as an amorphous oxide semiconductor working both as a semiconducting channel in the transistor and as a functionalizable biological interface for a bioreceptor. The SAML-passivated EGT including In2O3 thin film is demonstrated for the detection of Tau protein as a biomarker of Alzheimer's disease while employing a Tau-specific DNA aptamer as a bioreceptor and a PBS solution with a low ionic strength to diminish the charge-screening (Debye length) effect. The SAML-passivated EGT biosensor functionalized with the Tau-specific DNA aptamer exhibits ultrasensitive, quantitative, and reliable detection of Tau protein from 1 × 10-15 to 1 × 10-10 M, covering a much larger range than clinical needs, via changes in different transistor parameters. Therefore, the SAML-based passivation method can be effectively and efficiently utilized for operationally stable and reproducible transistor-based biosensors. Furthermore, this presented strategy can be extensively adapted for advanced biomedical devices and bioelectronics in aqueous or physiological environments.

Disease-microenvironment modulation by bare- or engineered-exosome for rheumatoid arthritis treatment.

BACKGROUND: Exosomes are extracellular vesicles secreted by eukaryotic cells and have been extensively studied for their surface markers and internal cargo with unique functions. A deeper understanding of exosomes has allowed their application in various research areas, particularly in diagnostics and therapy. MAIN BODY: Exosomes have great potential as biomarkers and delivery vehicles for encapsulating therapeutic cargo. However, the limitations of bare exosomes, such as rapid phagocytic clearance and non-specific biodistribution after injection, pose significant challenges to their application as drug delivery systems. This review focuses on exosome-based drug delivery for treating rheumatoid arthritis, emphasizing pre/post-engineering approaches to overcome these challenges. CONCLUSION: This review will serve as an essential resource for future studies to develop novel exosome-based therapeutic approaches for rheumatoid arthritis. Overall, the review highlights the potential of exosomes as a promising therapeutic approach for rheumatoid arthritis treatment.

Theoretical and experimental comparison of the performance of gold, titanium, and platinum nanodiscs as contrast agents for photoacoustic imaging.

Exogenous contrast agents in photoacoustic imaging help improve spatial resolution and penetration depth and enable targeted molecular imaging. To screen efficient photoacoustic signaling materials as contrast agents, we propose a light absorption-weighted figure of merit (FOM) that can be calculated using material data from the literature and numerically simulated light absorption cross-sections. The calculated light absorption-weighted FOM shows that a Ti nanodisc has a photoacoustic conversion performance similar to that of an Au nanodisc and better than that of a Pt nanodisc. The photoacoustic imaging results of Ti, Au, and Pt nanodiscs, which are physically synthesized with identical shapes and dimensions, experimentally demonstrated that the Ti nanodisc could be a highly efficient contrast agent.

CRISPR/Cas-Assisted Colorimetric Biosensor for Point-of-Use Testing for African Swine Fever Virus.

African swine fever virus (ASFV) causes a highly contagious and fatal disease affecting both domesticated and wild pigs. Substandard therapies and inadequate vaccinations cause severe economic damages from pig culling and removal of infected carcasses. Therefore, there is an urgent need to develop a rapid point-of-use approach that assists in avoiding the spread of ASFV and reducing economic loss. In this study, we developed a colorimetric sensing platform based on dual enzymatic amplification that combined the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 12a (Cas12a) system and the enzyme urease for accurate and sensitive detection of ASFV. The mechanism of the sensing platform involves a magnetic bead-anchored urease-conjugated single-stranded oligodeoxynucleotide (MB@urODN), which in the presence of ASFV dsDNA is cleaved by activated CRISPR/Cas12a. After magnetically separating the free urease, the presence of virus can be confirmed by measuring the colorimetric change in the solution. The advantage of this method is that it can detect the presence of virus without undergoing a complex target gene duplication process. The established method detected ASFV from three clinical specimens collected from porcine clinical tissue samples. The proposed platform is designed to provide an adequate, simple, robust, highly sensitive and selective analytical technique for rapid zoonotic disease diagnosis while eliminating the need for vast or specialized tools.

Simultaneous Multiplexed Imaging of Biomolecules in Transgenic Mouse Brain Tissues Using Mass Spectrometry Imaging: A Multi-omic Approach.

The importance of multi-omic-based approaches to better understand diverse pathological mechanisms including neurodegenerative diseases has emerged. Spatial information can be of great help in understanding how biomolecules interact pathologically and in elucidating target biomarkers for developing therapeutics. While various analytical methods have been attempted for imaging-based biomolecule analysis, a multi-omic approach to imaging remains challenging due to the different characteristics of biomolecules. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a powerful tool due to its sensitivity, chemical specificity, and high spatial resolution in visualizing chemical information in cells and tissues. In this paper, we suggest a new strategy to simultaneously obtain the spatial information of various kinds of biomolecules that includes both labeled and label-free approaches using ToF-SIMS. The enzyme-assisted labeling strategy for the targets of interest enables the sensitive and specific imaging of large molecules such as peptides, proteins, and mRNA, a task that has been, to date, difficult for any MS analysis. Together with the strength of the analytical performance of ToF-SIMS in the label-free tissue imaging of small biomolecules, the proposed strategy allows one to simultaneously obtain integrated information of spatial distribution of metabolites, lipids, peptides, proteins, and mRNA at a high resolution in a single measurement. As part of the suggested strategy, we present a sample preparation method suitable for MS imaging. Because a comprehensive method to examine the spatial distribution of multiple biomolecules in tissues has remained elusive, our strategy can be a useful tool to support the understanding of the interactions of biomolecules in tissues as well as pathological mechanisms.

Enhanced detection sensitivity through enzyme-induced precipitate accumulation in LSPR-active nano-valleys.

Biomolecule detection based on the localized surface plasmon resonance (LSPR) phenomenon has advantages in label-free detection, good sensitivity, and measurement simplicity and reproducibility. However, in order to ultimately be used for actual diagnosis, the ability to detect trace amounts of biomarkers is necessary, which requires the development of signal enhancement strategies that enable ultrasensitive detection. In this paper, we provide a straightforward and efficient route to boost LSPR sensitivity based on multiple sample washings. We found that repeated washing and drying cycles lead to a shift in the LSPR peak in a concentration-dependent manner, where this process drives the accumulation of a precipitate, formed by an enzyme reaction with target specificity, in the sample's LSPR active plasmonic nano-valley structure. Results show that the washing and drying process leads to a signal enhancement of more 200 times compared to a sensor with only enzyme-based amplification. To maximize this effect, optimization of the plasmonic nanostructure was also carried out to finally achieve atto-molar detection of miRNA with a distinguishable LSPR peak shift.

Advanced graphene oxide-based paper sensor for colorimetric detection of miRNA.

MicroRNAs (miRNAs), found in blood and body fluids, have emerged as potential non-invasive biomarkers for disease and injury. miRNAs are quantitatively evaluated using typical RNA analysis methods such as the quantitative reverse transcription polymerase chain reaction, microarrays, and Northern blot, all of which require complex procedures and expensive reagents. To utilize miRNAs as practical biomarkers, it will be helpful to develop simple and user-friendly sensors. In this study, a paper-based miRNA sensor was developed by combining two methods: (1) target-recycled DNAzyme (Dz) amplification and (2) graphene oxide-assisted Dz blotting on paper. The Dz spots on paper caused a miRNA-dependent color change in presence of colorimetric reagents and facilitated the quantification of absolute amount of the target miRNA, irrespective of the volume, with high reproducibility. This approach is technologically straightforward and enables quantification of as low as 7.75 fmol miRNA using a portable smartphone.

Analyte-Induced Desert Rose-like Ag Nanostructures for Surface-Enhanced Raman Scattering-Based Biomolecule Detection and Imaging.

Biomolecule detection based on surface-enhanced Raman scattering (SERS) for application to biosensors and bio-imaging requires the fabrication of SERS nanoprobes that can generate strong Raman signals as well as surface modifications for analyte-specific recognition and binding. Such requirements lead to disadvantages in terms of reproducibility and practicality, and thus, it has been difficult to apply biomolecule detection utilizing the advantages of the SERS phenomenon to actual clinically relevant analysis. To achieve reproducible and practical SERS signal generation in a biomolecule-specific manner without requiring the synthesis of nanostructures and their related surface modification to introduce molecules for specific recognition, we developed a new type of SERS probe formed by enzyme reactions in the presence of Raman reporters. By forming unique plasmonic structures, our method achieves the detection of biomolecules on chips with uniform and stable signals over long periods. To test the proposed approach, we applied it to a SERS-based immunohistochemistry assay and found successful multiplexed protein detection in brain tissue from transgenic mice.

Quantitative Analysis of Immunosuppressive Drugs Using Tungsten Disulfide Nanosheet-Assisted Laser Desorption Ionization Mass Spectrometry.

For organ transplantation patients, the therapeutic drug monitoring (TDM) of immunosuppressive drugs is essential to prevent the toxicity or rejection of the organ. Currently, TDM is done by immunoassays or liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods; however, these methods lack specificity or are expensive, require high levels of skill, and offer limited sample throughput. Although matrix-assisted (MA) laser desorption ionization (LDI) mass spectrometry (MS) can provide enhanced throughput and cost-effectiveness, its application in TDM is limited due to the limitations of the matrixes such as a lack of sensitivity and reproducibility. Here, we present an alternative quantification method for the TDM of the immunosuppressive drugs in the blood of organ transplant patients by utilizing laser desorption ionization mass spectrometry (LDI-MS) based on a tungsten disulfide nanosheet, which is well-known for its excellent physicochemical properties such as a strong UV absorbance and high electron mobility. By adopting a microliquid inkjet printing system, a high-throughput analysis of the blood samples with enhanced sensitivity and reproducibility was achieved. Furthermore, up to 80 cases of patient samples were analyzed and the results were compared with those of LC-MS/MS by using Passing-Bablok regression and Bland-Altman analysis to demonstrate that our LDI-MS platform is suitable to replace current TDM techniques. Our approach will facilitate the rapid and accurate analysis of blood samples from a large number of patients for immunosuppressive drug prescriptions.

Utilization of chromogenic enzyme substrates for signal amplification in multiplexed detection of biomolecules using surface mass spectrometry.

MicroRNAs (miRNAs) are important post-transcriptional gene regulators and can serve as potential biomarkers for many diseases. Most of the current miRNA detection techniques require purification from biological samples, amplification, labeling, or tagging, which makes quantitative analysis of clinically relevant samples challenging. Here we present a new strategy for the detection of miRNAs with uniformity over a large area based on signal amplification using enzymatic reactions and measurements using time-of-flight secondary ion mass spectrometry (ToF-SIMS), a sensitive surface analysis tool. This technique has high sequence specificity through hybridization with a hairpin DNA probe and allows the identification of single-base mismatches that are difficult to distinguish by conventional mass spectrometry. We successfully detected target miRNAs in biological samples without purification, amplification, or labeling of target molecules. In addition, by adopting a well-known chromogenic enzymatic reaction from the field of biotechnology, we extended the use of enzyme-amplified signal enhancement ToF (EASE-ToF) to protein detection. Our strategy has advantages with respect to scope, quantification, and throughput over the currently available methods, and is amenable to multiplexing based on the outstanding molecular specificity of mass spectrometry (MS). Therefore, our technique not only has the potential for use in clinical diagnosis, but also provides evidence that MS can serve as a useful readout for biosensing to perform multiplexed analysis extending beyond the limitations of existing technology.

High-throughput chemical screening to discover new modulators of microRNA expression in living cells by using graphene-based biosensor.

MicroRNAs (miRNAs) are important regulatory RNAs that control gene expression in various biological processes. Therefore, control over the disease-related miRNA expression is important both for basic research and for a new class of therapeutic modality to treat serious diseases such as cancer. Here, we present a high-throughput screening strategy to identify small molecules that modulate miRNA expression in living cells. The screen enables simultaneous monitoring of the phenotypic cellular changes associated with the miRNA expression by measuring quantitative fluorescent signals corresponding to target miRNA level in living cells based on a novel biosensor composed of peptide nucleic acid and nano-sized graphene oxide. In this study, the biosensor based cellular screening of 967 compounds (including FDA-approved drugs, enzyme inhibitors, agonists, and antagonists) in cells identified four different classes of small molecules consisting of (i) 70 compounds that suppress both miRNA-21 (miR-21) expression and cell proliferation, (ii) 65 compounds that enhance miR-21 expression and reduce cell proliferation, (iii) 2 compounds that suppress miR-21 expression and increase cell proliferation, and (iv) 21 compounds that enhance both miR-21 expression and cell proliferation. We further investigated the hit compounds to correlate cell morphology changes and cell migration ability with decreased expression of miR-21.

Discrimination of single nucleotide mismatches using a scalable, flexible, and transparent three-dimensional nanostructure-based plasmonic miRNA sensor with high sensitivity.

Localized surface plasmon resonance (LSPR) biosensors have attracted much interest due to their capacity for multiplexing, miniaturization, and high performance, which offers the potential for their integration into lab-on-a-chip platforms for point-of-care (POC) diagnostics. The need for microRNA (miRNA)-sensing platforms is particularly urgent because miRNAs are key regulators and biomarkers in numerous pathological processes and diseases. Unfortunately, however, development of such miRNA-sensing platforms has not yet been achieved. In order to realize the detection of these important biomarkers, there has been an increasing demand for POC-sensing platforms that enable label-free quantification with low sample consumption, good sensitivity, real-time responsiveness, and high throughput. Here, we developed a highly specific, sensitive LSPR miRNA-sensing platform on a flexible, scalable plasmonic nanostructure to enable single-base mismatch discrimination and attomole detection of miRNAs in clinically relevant samples. The hairpin probe contained a locked nucleic acid (LNA) that enabled the discrimination of single base mismatches based on differences in melting temperatures of perfectly matched or single base mismatched miRNAs when they formed base pairs with probes. In addition, through hybridization induced signal amplification based on precipitate formation on the gold surface through the enzyme reaction, we observed a dramatic LSPR peak shift, which enabled attomole detection. Additionally, our LSPR miRNA sensor enabled the detection of miR-200a-3p in total RNA extracts from primary cancer cell lines without purification or labeling of the miRNA. This label-free and highly specific miRNA sensing platform may have applications in POC cancer diagnostics without the need for gene amplification.

TOF-SIMS analysis of an isocitrate dehydrogenase 1 mutation-associated oncometabolite in cancer cells.

The development of analytical tools for accurate and sensitive detection of intracellular metabolites associated with mutated metabolic enzymes is important in cancer diagnosis and staging. The gene encoding the metabolic enzyme isocitrate dehydrogenase 1 (IDH1) is mutated in various cancers, and mutant IDH1 could represent a good biomarker and potent target for cancer therapy. Owing to a mutation in an important arginine residue in the catalytic pocket, mutant IDH1 catalyzes the production of 2-hydroxyglutarate (2-HG) instead of its wild type product α-ketoglutarate (α-KG), which is involved in multiple cellular pathways involving the hydroxylation of proteins, ribonucleic acid, and deoxyribose nucleic acid (DNA). Since 2-HG is an α-KG antagonist, inhibiting normal α-KG-dependent metabolism, high intracellular levels of 2-HG result in abnormal histone and DNA methylation. Therefore, accurate and sensitive analytical tools for the direct detection of 2-HG in cancer cells expressing mutant IDH1 would benefit this field, as it would minimize the need both for complicated experimental procedures and for large amounts of biological samples. Here, the authors describe a useful analytical method for the direct detection of 2-HG in lysates from a mutant IDH1-expressing cell line by time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis, a powerful surface analysis tool. In addition, the authors verified the efficacy of the specific mutant IDH1 inhibitor AGI-5198 by tracking the intracellular 2-HG concentration, which decreased in a dose-dependent manner. Our results demonstrate the large potential of TOF-SIMS as an analytical tool for the simple, direct detection of oncometabolites during cancer diagnosis, and for verifying the efficiency of the targeted cancer drugs.

Highly robust, uniform and ultra-sensitive surface-enhanced Raman scattering substrates for microRNA detection fabricated by using silver nanostructures grown in gold nanobowls.

Highly sensitive and reproducible surface enhanced Raman spectroscopy (SERS) requires not only a nanometer-level structural control, but also superb uniformity across the SERS substrate for practical imaging and sensing applications. However, in the past, increased reproducibility of the SERS signal was incompatible with increased SERS sensitivity. This work presents multiple silver nanocrystals inside periodically arrayed gold nanobowls (SGBs) via an electrochemical reaction at an overpotential of -3.0 V (vs. Ag/AgCl). The gaps between the silver nanocrystals serve as hot spots for SERS enhancement, and the evenly distributed gold nanobowls lead to a high device-to-device signal uniformity. The SGBs on the large sample surface exhibit an excellent SERS enhancement factor of up to 4.80 × 109, with excellent signal uniformity (RSD < 8.0 ± 2.5%). Furthermore, the SGBs can detect specific microRNA (miR-34a), which plays a widely acknowledged role as biomarkers in diagnosis and treatment of diseases. Although the small size and low abundance of miR-34a in total RNA samples hinder their detection, by utilizing the advantages of SGBs in SERS sensing, reliable and direct detection of human gastric cancer cells has been successfully accomplished.

Real-time and label-free monitoring of nanoparticle cellular uptake using capacitance-based assays.

Nanoparticles have shown great potential as vehicles for the delivery of drugs, nucleic acids, and therapeutic proteins; an efficient, high-throughput screening method to analyze nanoparticle interaction with the cytomembrane would substantially improve the efficiency and accuracy of the delivery. Here, we developed a capacitance sensor array that monitored the capacitance values of nanoparticle-treated cells in a real-time manner, without the need for labeling. Upon cellular uptake of the nanoparticles, a capacitance peak was observed at a low frequency (e.g., 100 Hz) as a function of time based on zeta potential changes. In the high frequency region (e.g., 15-20 kHz), the rate of decreasing capacitance slowed as a function of time compared to the cell growth control group, due to increased cytoplasm resistance and decreased membrane capacitance and resistance. The information provided by our capacitance sensor array will be a powerful tool for scientists designing nanoparticles for specific purposes.