Engineering Exosomes for Therapeutic Applications: Decoding Biogenesis, Content Modification, and Cargo Loading Strategies.

Exosomes emerge from endosomal invagination and range in size from 30 to 200 nm. Exosomes contain diverse proteins, lipids, and nucleic acids, which can indicate the state of various physiological and pathological processes. Studies have revealed the remarkable clinical potential of exosomes in diagnosing and prognosing multiple diseases, including cancer, cardiovascular disorders, and neurodegenerative conditions. Exosomes also have the potential to be engineered and deliver their cargo to a specific target. However, further advancements are imperative to optimize exosomes' diagnostic and therapeutic capabilities for practical implementation in clinical settings. This review highlights exosomes' diagnostic and therapeutic applications, emphasizing their engineering through simple incubation, biological, and click chemistry techniques. Additionally, the loading of therapeutic agents onto exosomes, utilizing passive and active strategies, and exploring hybrid and artificial exosomes are discussed.

Defects and Defect Engineering of Two-Dimensional Transition Metal Dichalcogenide (2D TMDC) Materials.

As layered materials, transition metal dichalcogenides (TMDCs) are promising two-dimensional (2D) materials. Interestingly, the characteristics of these materials are transformed from bulk to monolayer. The atomically thin TMDC materials can be a good alternative to group III-V and graphene because of their emerging tunable electrical, optical, and magnetic properties. Although 2D monolayers from natural TMDC materials exhibit the purest form, they have intrinsic defects that limit their application. However, the synthesis of TMDC materials using the existing fabrication tools and techniques is also not immune to defects. Additionally, it is difficult to synthesize wafer-scale TMDC materials for a multitude of factors influencing grain growth mechanisms. While defect engineering techniques may reduce the percentage of defects, the available methods have constraints for healing defects at the desired level. Thus, this holistic review of 2D TMDC materials encapsulates the fundamental structure of TMDC materials, including different types of defects, named zero-dimensional (0D), one-dimensional (1D), and two-dimensional (2D). Moreover, the existing defect engineering methods that relate to both formation of and reduction in defects have been discussed. Finally, an attempt has been made to correlate the impact of defects and the properties of these TMDC materials.

Cellular and Exosomal MicroRNAs: Emerging Clinical Relevance as Targets for Breast Cancer Diagnosis and Prognosis.

Breast cancer accounts for the highest cancer cases globally, with 12% of occurrences progressing to metastatic breast cancer with a low survival rate and limited effective early intervention strategies augmented by late diagnosis. Moreover, a low concentration of prognostic and predictive markers hinders disease monitoring. Circulating and exosomal microRNAs (miRNAs) have recently shown a considerable interplay in breast cancer, standing out as effective diagnostic and prognostic markers. The primary functions are as gene regulatory agents at the genetic and epigenetic levels. An array of dysregulated miRNAs stimulates cancer-promoting mechanisms, activating oncogenes and controlling tumor-suppressing genes and mechanisms. Exosomes are vastly studied extracellular vesicles, carrying, and transporting cargo, including noncoding RNAs with premier roles in oncogenesis. Translocation of miRNAs from the circulation to exosomes, with RNA-binding proteins in stress-induced conditions, has shown significant cooperation in function to promote breast cancer. This review examines cellular and exosomal miRNA biogenesis and loading, the clinical implications of their dysregulation, their function in diagnosis, prognosis, and prediction of breast cancer, and in regulating cancer signaling pathways. The influence of cellular and exosomal miRNAs presents clinical significance on breast cancer diagnosis, subtyping, staging, prediction, and disease monitoring during treatment, hence a potent marker for breast cancer.

Improving DNA nanostructure stability: A review of the biomedical applications and approaches.

DNA's programmable, predictable, and precise self-assembly properties enable structural DNA nanotechnology. DNA nanostructures have a wide range of applications in drug delivery, bioimaging, biosensing, and theranostics. However, physiological conditions, including low cationic ions and the presence of nucleases in biological systems, can limit the efficacy of DNA nanostructures. Several strategies for stabilizing DNA nanostructures have been developed, including i) coating them with biomolecules or polymers, ii) chemical cross-linking of the DNA strands, and iii) modifications of the nucleotides and nucleic acids backbone. These methods significantly enhance the structural stability of DNA nanostructures and thus enable in vivo and in vitro applications. This study reviews the present perspective on the distinctive properties of the DNA molecule and explains various DNA nanostructures, their advantages, and their disadvantages. We provide a brief overview of the biomedical applications of DNA nanostructures and comprehensively discuss possible approaches to improve their biostability. Finally, the shortcomings and challenges of the current biostability approaches are examined.

Towards Low-Temperature CVD Synthesis and Characterization of Mono- or Few-Layer Molybdenum Disulfide.

Molybdenum disulfide (MoS2) transistors are a promising alternative for the semiconductor industry due to their large on/off current ratio (>1010), immunity to short-channel effects, and unique switching characteristics. MoS2 has drawn considerable interest due to its intriguing electrical, optical, sensing, and catalytic properties. Monolayer MoS2 is a semiconducting material with a direct band gap of ~1.9 eV, which can be tuned. Commercially, the aim of synthesizing a novel material is to grow high-quality samples over a large area and at a low cost. Although chemical vapor deposition (CVD) growth techniques are associated with a low-cost pathway and large-area material growth, a drawback concerns meeting the high crystalline quality required for nanoelectronic and optoelectronic applications. This research presents a lower-temperature CVD for the repeatable synthesis of large-size mono- or few-layer MoS2 using the direct vapor phase sulfurization of MoO3. The samples grown on Si/SiO2 substrates demonstrate a uniform single-crystalline quality in Raman spectroscopy, photoluminescence (PL), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy. These characterization techniques were targeted to confirm the uniform thickness, stoichiometry, and lattice spacing of the MoS2 layers. The MoS2 crystals were deposited over the entire surface of the sample substrate. With a detailed discussion of the CVD setup and an explanation of the process parameters that influence nucleation and growth, this work opens a new platform for the repeatable synthesis of highly crystalline mono- or few-layer MoS2 suitable for optoelectronic application.

An outlook on the current challenges and opportunities in DNA data storage.

Silicon is the gold standard for information storage systems. The exponential generation of digital information will exhaust the global supply of refined silicon. Therefore, investing in alternative information storage materials such as DNA has gained momentum. DNA as a memory material possesses several advantages over silicon-based data storage, including higher storage capacity, data retention, and lower operational energy. Routine DNA data storage approaches encode data into chemically synthesized nucleotide sequences. The scalability of DNA data storage depends on factors such as the cost and the generation of hazardous waste during DNA synthesis, latency of writing and reading, and limited rewriting capacity. Here, we review the current status of DNA data storage encoding, writing, storing, retrieving and reading, and discuss the technology's challenges and opportunities.

Modulation of Structural, Electronic, and Optical Properties of Titanium Nitride Thin Films by Regulated In Situ Oxidation.

Epitaxial titanium nitride (TiN) and titanium oxynitride (TiON) thin films have been grown on sapphire substrates using a pulsed laser deposition (PLD) method in high-vacuum conditions (base pressure <3 × 10-6 T). This vacuum contains enough residual oxygen to allow a time-independent gas phase oxidation of the ablated species as well as a time-dependent regulated surface oxidation of TiN to TiON films. The time-dependent surface oxidation is controlled by means of film deposition time that, in turn, is controlled by changing the number of laser pulses impinging on the polycrystalline TiN target at a constant repetition rate. By changing the number of laser pulses from 150 to 5000, unoxidized (or negligibly oxidized) and oxidized TiN films have been obtained with the thickness in the range of four unit cells to 70 unit cells of TiN/TiON. X-ray photoelectron spectroscopy (XPS) investigations reveal higher oxygen content in TiON films prepared with a larger number of laser pulses. The oxidation of TiN films is achieved by precisely controlling the time of deposition, which affects the surface diffusion of oxygen to the TiN film lattice. The lattice constants of the TiON films obtained by x-ray diffraction (XRD) increase with the oxygen content in the film, as predicted by molecular dynamics (MD) simulations. The lattice constant increase is explained based on a larger electrostatic repulsive force due to unbalanced local charges in the vicinity of Ti vacancies and substitutional O. The bandgap of TiN and TiON films, measured using UV-visible spectroscopy, has an asymmetric V-shaped variation as a function of the number of pulses. The bandgap variation following the lower number of laser pulses (150-750) of the V-shaped curve is explained using the quantum confinement effect, while the bandgap variation following the higher number of laser pulses (1000-5000) is associated with the modification in the band structure due to hybridization of O2p and N2p energy levels.

Fabrication of Nylon-6 and Nylon-11 Nanoplastics and Evaluation in Mammalian Cells.

Microplastics (MPs) and nanoplastics (NPs) exist in certain environments, beverages, and food products. However, the ultimate risk and consequences of MPs and NPs on human health remain largely unknown. Studies involving the biological effects of small-scale plastics have predominantly used commercially available polystyrene beads, which cannot represent the breadth of globally dominant plastics. Nylon is a commodity plastic that is used across various industry sectors with substantial global production. Here, a series of well-characterized nylon-11 and nylon-6 NPs were successfully fabricated with size distributions of approximately 100 nm and 500 nm, respectively. The facile fabrication steps enabled the incorporation of fluorescent tracers in these NPs to aid the intracellular tracking of particles. RAW 264.7 macrophages were exposed to nylon NPs in a dose-dependent manner and cytotoxic concentrations and cellular uptake were determined. These well-characterized nylon NPs support future steps to assess how the composition and physicochemical properties may affect complex biological systems and ultimately human health.

Atomic Layer Deposition of Cobalt Catalyst for Fischer-Tropsch Synthesis in Silicon Microchannel Microreactor.

In recent years, rising environmental concerns have led to the focus on some of the innovative alternative technologies to produce clean burning fuels. Fischer-Tropsch (FT) synthesis is one of the alternative chemical processes to produce synthetic fuels, which has a current research focus on reactor and catalyst improvements. In this work, a cobalt nanofilm (~4.5 nm), deposited by the atomic layer deposition (ALD) technique in a silicon microchannel microreactor (2.4 cm long × 50 µm wide × 100 µm deep), was used as a catalyst for atmospheric Fischer-Tropsch (FT) synthesis. The catalyst film was characterized by XPS, TEM-EDX, and AFM studies. The data from AFM and TEM clearly showed the presence of polygranular cobalt species on the silicon wafer. The XPS studies of as-deposited and reduced cobalt nanofilm in silicon microchannels showed a shift on the binding energies of Co 2p spin splits and confirmed the presence of cobalt in the Co0 chemical state for FT synthesis. The FT studies using the microchannel microreactor were carried out at two different temperatures, 240 °C and 220 °C, with a syngas (H2:CO) molar ratio of 2:1. The highest CO conversion of 74% was observed at 220 °C with the distribution of C1-C4 hydrocarbons. The results showed no significant selectivity towards butane at the higher temperature, 240 °C. The deactivation studies were performed at 220 °C for 60 h. The catalyst exhibited long-term stability, with only ~13% drop in the CO conversion at the end of 60 h. The deactivated cobalt film in the microchannels was investigated by XPS, showing a weak carbon peak in the XPS spectra.

Investigation of eight cellulose nanomaterials' impact on Differentiated Caco-2 monolayer integrity and cytotoxicity.

The potential applications of cellulose nanomaterials (CNMs) as food additives or in food packaging, present a possible source of human ingestion. While micron- and macro-scale cellulose products are classified as Generally Regarded As Safe, the safety of ingested nano-scale cellulose is largely unknown. Using fully differentiated Caco-2 cells, the perturbation of intestinal barrier function and cytotoxicity was investigated for four nanocellulose crystals (CNCs) and four nanocellulose fibrils (CNFs) following 24 h of exposure at 50 µg/mL. Scanning electron microscope showed some aggregation of both CNCs and CNFs. X-ray photoelectron spectroscopy analyses showed that carbon and oxygen were the main elements. The zeta-potential for CNMs formulated in cell culture medium showed a negative surface charge. Two CNMs increased cell membrane permeability and three CNMs decreased the cell metabolic activity. While three CNMs lead to cytotoxic responses, no changes in apparent permeability coefficient (Papp) for dextran or tight junction integrity were found. Our results show that three CNMs induce cytotoxicity in differentiated Caco-2 cells, demonstrating the need to understand the role of size and shape. The interaction between CNMs and the intestinal epithelium needs to be evaluated to understand potential intestinal barrier dysfunction and resulting health implications following CNM ingestion.

Oral administration of TiO2 nanoparticles during early life impacts cardiac and neurobehavioral performance and metabolite profile in an age- and sex-related manner.

BACKGROUND: Nanoparticles (NPs) are increasingly incorporated in everyday products. To investigate the effects of early life exposure to orally ingested TiO2 NP, male and female Sprague-Dawley rat pups received four consecutive daily doses of 10 mg/kg body weight TiO2 NP (diameter: 21 ± 5 nm) or vehicle control (water) by gavage at three different pre-weaning ages: postnatal day (PND) 2-5, PND 7-10, or PND 17-20. Cardiac assessment and basic neurobehavioral tests (locomotor activity, rotarod, and acoustic startle) were conducted on PND 20. Pups were sacrificed at PND 21. Select tissues were collected, weighed, processed for neurotransmitter and metabolomics analyses. RESULTS: Heart rate was found to be significantly decreased in female pups when dosed between PND 7-10 and PND 17-20. Females dosed between PND 2-5 showed decrease acoustic startle response and when dosed between PND 7-10 showed decreased performance in the rotarod test and increased locomotor activity. Male pups dosed between PND 17-20 showed decreased locomotor activity. The concentrations of neurotransmitters and related metabolites in brain tissue and the metabolomic profile of plasma were impacted by TiO2 NP administration for all dose groups. Metabolomic pathways perturbed by TiO2 NP administration included pathways involved in amino acid and lipid metabolism. CONCLUSION: Oral administration of TiO2 NP to rat pups impacted basic cardiac and neurobehavioral performance, neurotransmitters and related metabolites concentrations in brain tissue, and the biochemical profiles of plasma. The findings suggested that female pups were more likely to experience adverse outcome following early life exposure to oral TiO2 NP than male pups. Collectively the data from this exploratory study suggest oral administration of TiO2 NP cause adverse biological effects in an age- and sex-related manner, emphasizing the need to understand the short- and long-term effects of early life exposure to TiO2 NP.

Multidimensional Imaging Reveals Mechanisms Controlling Multimodal Label-Free Biosensing in Vertical 2DM-Heterostructures.

Two-dimensional materials and their van der Waals heterostructures enable a large range of applications, including label-free biosensing. Lattice mismatch and work function difference in the heterostructure material result in strain and charge transfer, often varying at a nanometer scale, that influence device performance. In this work, a multidimensional optical imaging technique is developed in order to map subdiffractional distributions for doping and strain and understand the role of those for modulation of the electronic properties of the material. As an example, vertical heterostructures comprised of monolayer graphene and single-layer flakes of transition metal dichalcogenide MoS2 were fabricated and used for biosensing. Herein, the optical label-free detection of doxorubicin, a common cancer drug, is reported via three independent optical detection channels (photoluminescence shift, Raman shift, and graphene enhanced Raman scattering). Non-uniform broadening of components of multimodal signal correlates with the statistical distribution of local optical properties of the heterostructure. Multidimensional nanoscale imaging allows one to reveal the physical origin for such a local response and propose the best strategy for the mitigation of materials variability and future device fabrication, enabling multiplexed biosensing.

Simulated Gastric Digestion and In Vivo Intestinal Uptake of Orally Administered CuO Nanoparticles and TiO2 E171 in Male and Female Rat Pups.

Oral exposure to nanoparticles (NPs) during early life is an understudied area. The goals of this study were to evaluate the effect of pre-weaned rat gastric fluids on 50 nm CuO NPs and TiO2 E171 in vitro, and to evaluate uptake in vivo. The NP uptake was studied in vivo in male and female Sprague-Dawley rat pups following oral administration of four consecutive daily doses of 10 mg/kg CuO NPs, TiO2 E171, or vehicle control (water) between postnatal day (PND) 7-10. Rat pups were sacrificed on either PND10 or PND21. Simulated digestion led to dissolution of CuO NPs at the later ages tested (PND14 and PND21, but not PND7). In vivo intestinal uptake of CuO NPs and TiO2 E171 was observed by hyperspectral imaging of intestinal cross sections. Brightfield microscopy showed that the number of immune cells increased in the intestinal tissue following NP administration. Orally administered NPs led to low intestinal uptake of NPs and an increase in immune cells in the small and large intestine, suggesting that oral exposure to NPs during early life may lead to irritation or a low-grade inflammation. The long-term impact of increased immune cells in the intestinal tract during early life is unknown.

Bandgap recovery of monolayer MoS2 using defect engineering and chemical doping.

Two-dimensional transition metal dichalcogenide materials have created avenues for exciting physics with unique electronic and photonic applications. Among these materials, molybdenum disulfide is the most known due to extensive research in understanding its electronic and optical properties. In this paper, we report on the successful growth and modification of monolayer MoS2 (1L MoS2) by controlling carrier concentration and manipulating bandgap in order to improve the efficiency of light emission. Atomic size MoS2 vacancies were created using a Helium Ion Microscope, then the defect sites were doped with 2,3,5,6-tetrafluro7,7,8,8-tetracyanoquinodimethane (F4TCNQ). The carrier concentration in intrinsic (as-grown) and engineered 1L MoS2 was calculated using Mass Action model. The results are in a good agreement with Raman and photoluminescence spectroscopy as well as Kelvin probe force microscopy characterizations.

Fabrication of polyethylene terephthalate (PET) nanoparticles with fluorescent tracers for studies in mammalian cells.

Fluorescent nanoparticles (NPs) comprising polyethylene terephthalate (PET) with a hydrodynamic diameter of 158 ± 2 nm were synthesized in a bottom-up approach. Concentration-dependent uptake and cytotoxicity of PET NPs in macrophages are shown. The fabrication of well-characterized NPs, derived from high-commodity polymers, will support future studies to assess effects on biological systems.

Electrodynamic assisted self-assembled fibrous hydrogel microcapsules: a novel 3D in vitro platform for assessment of nanoparticle toxicity.

Nanoparticle (NP) toxicity assessment is a critical step in assessing the health impacts of NP exposure to both consumers and occupational workers. In vitro assessment models comprising cells cultured in a two-dimensional tissue culture plate (2D-TCP) are an efficient and cost-effective choice for estimating the safety risks of NPs. However, in vitro culture of cells in 2D-TCPs distorts cell-integrin and cell-cell interactions and is not able to replicate an in vivo phenotype. Three-dimensional (3D) in vitro platforms provide a unique alternative to bridge the gap between traditional 2D in vitro and in vivo models. In this study, novel microcapsules of alginate hydrogel incorporated with natural polymeric nanofibers (chitin nanofibrils) and synthetic polymeric nanofibers poly(lactide-co-glycolide) are designed as a 3D in vitro platform. This study demonstrates for the first time that electrodynamic assisted self-assembled fibrous 3D hydrogel (3D-SAF hydrogel) microcapsules with a size in the range of 300-500 µm in diameter with a Young's modulus of 12.7-42 kPa can be obtained by varying the amount of nanofibers in the hydrogel precursor solutions. The 3D-SAF microcapsules were found to mimic the in vivo cellular microenvironment for cells to grow, as evaluated using A549 cells. Higher cellular spreading and prolonged proliferation of A549 cells were observed in 3D-SAF microcapsules compared to control microcapsules without the nanofibers. The 3D-SAF microcapsule integrated well plate was used to assess the toxicity of model NPs, e.g., Al2O3 and ZnO. The toxicity levels of the model NPs were found to be dependent on the chemistry of the NPs and their physical agglomeration in the test media. Our results demonstrate that 3D-SAF microcapsules with an in vivo mimicking microenvironment can be developed as a physiologically relevant platform for high-throughput toxicity screening of NPs or pharmaceutical drugs.

Biodistribution, cardiac and neurobehavioral assessments, and neurotransmitter quantification in juvenile rats following oral administration of aluminum oxide nanoparticles.

Little is known about the uptake, biodistribution, and biological responses of nanoparticles (NPs) and their toxicity in developing animals. Here, male and female juvenile Sprague-Dawley rats received four consecutive daily doses of 10 mg/kg Al2 O3 NP (diameter: 24 nm [transmission electron microscope], hydrodynamic diameter: 148 nm) or vehicle control (water) by gavage between postnatal days (PNDs) 17-20. Basic neurobehavioral and cardiac assessments were performed on PND 20. Animals were sacrificed on PND 21, and selected tissues were collected, weighed, and processed for histopathology or neurotransmitter analysis. The biodistribution of Al2 O3 NP in tissue sections of the intestine, liver, spleen, kidney, and lymph nodes were evaluated using enhanced dark-field microscopy (EDM) and hyperspectral imaging (HSI). Liver-to-body weight ratio was significantly increased for male pups administered Al2 O3 NP compared with control. HSI suggested that Al2 O3 NP was more abundant in the duodenum and ileum tissue of the female pups compared with the male pups, whereas the abundance of NP was similar for males and females in the other tissues. The abundance of NP was higher in the liver compared with spleen, lymph nodes, and kidney. Homovanillic acid and norepinephrine concentrations in brain were significantly decreased following Al2 O3 NP administration in female and male pups, whereas 5-hydroxyindoleacetic acid was significantly increased in male pups. EDM/HSI indicates intestinal uptake of Al2 O3 NP following oral administration. Al2 O3 NP altered neurotransmitter/metabolite concentrations in juvenile rats' brain tissues. Together, these data suggest that orally administered Al2 O3 NP interferes with the brain biochemistry in both female and male pups.

Nanonet-nano fiber electrospun mesh of PCL-chitosan for controlled and extended release of diclofenac sodium.

Electrospun nanofiber (EN) technology has been used in the past to generate electrostatically charged multilayer-nanofibers. This platform offers versatile applications including in tissue engineering, drug delivery, wound dressings, and high-efficiency particulate air filters. In this study, we synthesized for the first time nanonet-nanofiber electrospun meshes (NNEMs) of polycaprolactone (PCL)-chitosan (CH) using EN technology. The fabricated NNEMs were utilized for high payload delivery and controlled release of a water-soluble drug. Diclofenac Sodium (DS), a hydrophilic anti-inflammatory drug, was selected as a model drug because of its high aqueous solubility and poor compatibility with insoluble polymers. Various compositions of DS drug-loaded NNEMs (DS-NNEMs) were synthesized. The physicochemical properties such as structure, morphology, and aqueous stability and the chemical properties of DS-NNEMs were evaluated. High drug entrapment efficiency and concentration-dependent drug release patterns were investigated for up to 14 days. Furthermore, the biocompatibility of the DS-NNEMs was tested with NIH 3T3 cells. The physicochemical characterization results showed that the DS drug is a key contributing factor in the generation of nanonet-nanofiber networks during electrospinning. DS-NNEMs also enhanced 3T3 cell adhesion, viability, and proliferation in the nanonet-nano fiber network through the controlled release of DS. The presented EN technology-based biodegradable NNEM material is not only limited for the controlled release of hydrophilic anti-inflammatory drugs, but also can be a suitable platform for loading and release of antiviral drugs.

Activation and degranulation of CAR-T cells using engineered antigen-presenting cell surfaces.

Adoptive cell transfer of Chimeric Antigen Receptor (CAR)-T cells showed promising results in patients with B cell malignancies. However, the detailed mechanism of CAR-T cell interaction with the target tumor cells is still not well understood. This work provides a systematic method for analyzing the activation and degranulation of second-generation CAR-T cells utilizing antigen-presenting cell surfaces. Antigen-presenting cell surfaces composed of circular micropatterns of CAR-specific anti-idiotype antibodies have been developed to mimic the interaction of CAR-T cells with target tumor cells using micro-contact printing. The levels of activation and degranulation of fixed non-transduced T cells (NT), CD19.CAR-T cells, and GD2.CAR-T cells on the antigen-presenting cell surfaces were quantified and compared by measuring the intensity of the CD3ζ chain phosphorylation and the Lysosome-Associated Membrane Protein 1 (LAMP-1), respectively. The size and morphology of the cells were also measured. The intracellular Ca2+ flux of NT and CAR-T cells upon engagement with the antigen-presenting cell surface was reported. Results suggest that NT and CD19.CAR-T cells have comparable activation levels, while NT have higher degranulation levels than CD19.CAR-T cells and GD2.CAR-T cells. The findings show that antigen-presenting cell surfaces allow a quantitative analysis of the molecules involved in synapse formation in different CAR-T cells in a systematic, reproducible manner.

Investigation of Twenty Metal, Metal Oxide, and Metal Sulfide Nanoparticles' Impact on Differentiated Caco-2 Monolayer Integrity.

The use of engineered nanomaterials (ENMs) in foods and consumer products is rising, increasing the potential for unintentional ingestion. While the cytotoxicity of many ENMs has been investigated, less attention has been given to adverse impact on the intestinal barrier integrity. Chronical disruption of gastrointestinal integrity can have far reaching health implications. Using fully differentiated Caco-2 cells, the perturbation of intestinal barrier function and cytotoxicity were investigated for 20 metal, metal oxide, and metal sulfide ENMs. Caco-2 cells were exposed to 50 µg/mL ENMs for 24 hours. ENM formulations were characterized at 0 and 24 hours, and In Vitro Sedimentation, Diffusion and Dosimetry Modeling was applied to calculate the effective dose of exposure during 24 hours. The apparent permeability coefficient (Papp) was determined for fluorescent labeled dextran (3,000 Da) and tight junction integrity was evaluated by immunofluorescence microscopy. Cytotoxicity was investigated by determining lactate dehydrogenase release (LDH) and cell metabolic activity (tetrazolium based MTS) assays. Four ENMs led to significantly increased Papp, (15.8% w/w% Ag-SiO2 nanoparticle (NP), 60 nm CdS NP, 100 nm V2O5 flakes, and 50 nm ZnO NP), while one ENM (20 nm MgO NP) decreased Papp. With the exception of CdS NP, significantly increased Papp was not connected with cell cytotoxicity. The calculated effective dose concentration was not correlated with increased Papp. Our results illustrate that while many metal, metal oxide, and metal sulfide ENMs do not adversely affect monolayer integrity or induce cytotoxicity in differentiated Caco-2 cells, a subset of ENMs may compromise the intestinal integrity. This study demonstrated the use of differentiated Caco-2 monolayer and Papp as an endpoint to identify and prioritize ENMs that should be investigated further. The interaction between ENMs and the intestinal epithelium needs to be evaluated to understand potential intestinal barrier dysfunction and resulting health implications.