Time-Dependent Internalization of Polymer-Coated Silica Nanoparticles in Brain Endothelial Cells and Morphological and Functional Effects on the Blood-Brain Barrier (original) (raw)
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Nanomedicine : nanotechnology, biology, and medicine, 2017
Nanomedicine offers a promising tool for therapies of brain diseases, but they may be associated with potential adverse effects. The aim of this study was to investigate the uptake of silica-nanoparticles engineered for laser-tissue soldering in the brain using SH-SY5Y cells, dissociated and organotypic slice cultures from rat hippocampus. Nanoparticles were predominantly taken up by microglial cells in the hippocampal cultures but nanoparticles were also found in differentiated SH-SY5Y cells. The uptake was time- and concentration-dependent in primary hippocampal cells. Transmission electron microscopy experiments demonstrated nanoparticle aggregates and single particles in the cytoplasm. Nanoparticles were found in the endoplasmic reticulum, but not in other cellular compartments. Nanoparticle exposure did not impair cell viability and neuroinflammation in primary hippocampal cultures at all times investigated. Neurite outgrowth was not significantly altered in SH-SY5Y cells, but ...
Journal of Nanoparticle Research, 2014
Silica nanoparticles could be promising delivery vehicles for drug targeting or gene therapy. However, few studies have been undertaken to determine the biological behavior effects of silica nanoparticles on primary endothelial cells. Here we investigated uptake, cytotoxicity and angiogenic properties of silica nanoparticle with positive and negative surface charge and sizes ranging from 25 to 115 nm in primary human umbilical vein endothelial cells. Dynamic light scattering measurements and nanoparticle tracking analysis were used to estimate the dispersion status of nanoparticles in cell culture media, which was a key aspect to understand the results of the in vitro cellular uptake experiments. Nanoparticles were taken up by primary endothelial cells in a sizedependent manner according to their degree of agglomeration occurring after transfer in cell culture media. Functionalization of the particle surface with positively charged groups enhanced the in vitro cellular uptake, compared to negatively charged nanoparticles. However, this effect was contrasted by the tendency of particles to form agglomerates, leading to lower internalization efficiency. Silica nanoparticle uptake did not affect cell viability and cell membrane integrity. More interestingly, positively and negatively charged 25 nm nanoparticles did not influence capillary-like tube formation and angiogenic sprouting, compared to controls. Considering the increasing interest in nanomaterials for several biomedical applications, a careful study of nanoparticle-endothelial cells interactions is of high relevance to assess possible risks associated to silica nanoparticle exposure and their possible applications in nanomedicine as safe and effective nanocarriers for vascular transport of therapeutic agents.
Materials
Silica nanoparticles (SiO2 NPs) represent environmentally born nanomaterials that are used in multiple biomedical applications. Our aim was to study the amorphous SiO2 NP-induced inflammatory response in MRC-5 human lung fibroblasts up to 72 hours of exposure. The intracellular distribution of SiO2 NPs was measured by transmission electron microscopy (TEM). The lactate dehydrogenase (LDH) test was used for cellular viability evaluation. We have also investigated the lysosomes formation, protein expression of interleukins (IL-1β, IL-2, IL-6, IL-8, and IL-18), COX-2, Nrf2, TNF-α, and nitric oxide (NO) production. Our results showed that the level of lysosomes increased in time after exposure to the SiO2 NPs. The expressions of interleukins and COX-2 were upregulated, whereas the expressions and activities of MMP-2 and MMP-9 decreased in a time-dependent manner. Our findings demonstrated that the exposure of MRC-5 cells to 62.5 µg/mL of SiO2 NPs induced an inflammatory response.
The Analyst, 2014
Nanoparticle properties, such as small size relative to large highly modifiable surface area, offer great promise for neuro-therapeutics and nanodiagnostics. A fundamental understanding and control of how nanoparticles interact with the blood-brain barrier (BBB) could enable major developments in nanomedical treatment of previously intractable neurological disorders, and help ensure that nanoparticles not intended to reach the brain do not cause adverse effects. Nanosafety is of utmost importance to this field. However, a distinct lack of knowledge exists regarding nanoparticle accumulation within the BBB and the biological effects this may induce on neighbouring cells of the Central Nervous System (CNS), particularly in the long-term. This study focussed on the exposure of an in vitro BBB model to model carboxylated polystyrene nanoparticles (PS COOH NPs), as these nanoparticles are well characterised for in vitro experimentation and have been reported as non-toxic in many biological settings. TEM imaging showed accumulation but not degradation of 100 nm PS COOH NPs within the lysosomes of the in vitro BBB over time. Cytokine secretion analysis from the in vitro BBB post 24 h 100 nm PS COOH NP exposure showed a low level of pro-inflammatory RANTES protein secretion compared to control. In contrast, 24 h exposure of the in vitro BBB endothelium to 100 nm PS COOH NPs in the presence of underlying astrocytes caused a significant increase in pro-survival signalling. In conclusion, the tantalising possibilities of nanomedicine must be balanced by cautious studies into the possible long-term toxicity caused by accumulation of known 'toxic' and 'non-toxic' nanoparticles, as general toxicity assays may be disguising significant signalling regulation during longterm accumulation.
Amorphous silica nanoparticles impair vascular homeostasis and induce systemic inflammation
International journal of nanomedicine, 2014
Amorphous silica nanoparticles (SiNPs) are being used in biomedical, pharmaceutical, and many other industrial applications entailing human exposure. However, their potential vascular and systemic pathophysiologic effects are not fully understood. Here, we investigated the acute (24 hours) systemic toxicity of intraperitoneally administered 50 nm and 500 nm SiNPs in mice (0.5 mg/kg). Both sizes of SiNPs induced a platelet proaggregatory effect in pial venules and increased plasma concentration of plasminogen activator inhibitor-1. Elevated plasma levels of von Willebrand factor and fibrinogen and a decrease in the number of circulating platelets were only seen following the administration of 50 nm SiNPs. The direct addition of SiNPs to untreated mouse blood significantly induced in vitro platelet aggregation in a dose-dependent fashion, and these effects were more pronounced with 50 nm SiNPs. Both sizes of SiNPs increased lactate dehydrogenase activity and interleukin 1β concentrati...
Progress in Neurobiology, 2017
Highlights The blood brain barrier (BBB) protects the central nervous system (CNS) from harmful substances, including therapeutic agents. The cell-cell communications at BBB occur mostly between astrocytes, pericytes and endothelial cells. Alternative ways to deliver drugs to the CNS, overcoming the BBB are required, to improve the efficacy of brain target drugs. Nanoparticles have demonstrate ability to increase the bioavailability of drugs in the CNS. The influence of non-endothelial may have on the BBB translocation of nanoparticles is discussed in this review. The influence of macrophages and/or monocytes as nanoparticle delivery carriers to the CNS are also approached. The temporarily disruption of the BBB to promote the penetration of nanoparticles to the CNS is described.
Nanomedicine, 2013
Catastrophic inflammatory death of monocytes and macrophages by overtaking of a critical dose of endocytosed synthetic amorphous silica nanoparticles/serum protein complexes Aims: We tested whether phagocytic monocytes/macrophages are more susceptible than nonphagocytes to nanoparticle (NP) toxicity. Materials & methods: We compared in vitro cell death and proinflammatory cytokine production in human monocytes, macrophages, lymphocytes and HeLa cells due to synthetic amorphous silica (SiO 2 )-NPs in different serum concentrations and correlated them with cellular uptake and distribution. Results: Phagocytes were approximately ten-times more sensitive than nonphagocytes to SiO 2 -NPs and more effectively endocytosed SiO 2 -NP-serum protein nanoagglomerates, so determining their accumulation in acidic endocytic compartments well beyond a critical/cytotoxic threshold. Monocyte/macrophage death was paralleled by cytokine secretion. Conclusion: The physiological specialization of monocytes/macrophages to effectively capture NPs may expose them to the risk of catastrophic inflammatory death upon saturation of their maximal storage capacity.
PloS one, 2016
Drug delivery into the brain is impeded by the blood-brain-barrier (BBB) that filters out the vast majority of drugs after systemic administration. In this work, we assessed the transport, uptake and cytotoxicity of promising drug nanocarriers, mesoporous silica nanoparticles (MSNs), in in vitro models of the BBB. RBE4 rat brain endothelial cells and Madin-Darby canine kidney epithelial cells, strain II, were used as BBB models. We studied spherical and rod-shaped MSNs with the following modifications: bare MSNs and MSNs coated with a poly(ethylene glycol)-poly(ethylene imine) (PEG-PEI) block copolymer. In transport studies, MSNs showed low permeability, whereas the results of the cellular uptake studies suggest robust uptake of PEG-PEI-coated MSNs. None of the MSNs showed significant toxic effects in the cell viability studies. While the shape effect was detectable but small, especially in the real-time surface plasmon resonance measurements, coating with PEG-PEI copolymers clearly...
Nanotoxicology, 2013
Engineered amorphous silica nanoparticles (SiO 2 NPs), due to simple and low cost production, are increasingly used in commercial products and produced on an industrial scale. Despite the potential benefits, there is a concern that exposure to certain types of SiO 2 NPs may lead to adverse health effects. As some NPs can cross the blood-brain barrier and may, in addition, reach the central nervous system through the nasal epithelium, this study addresses the responses of different neural tissue-type cells including neural stem cells, neurons, astrocytes and microglia cells to increasing doses of 50 nm fluorescent core/shell SiO 2 NPs with different [-NH 2 , -SH and polyvinylpyrrolidone (PVP)] surface chemistry. The SiO 2 NPs are characterized using a variety of physicochemical methods. Assays of cytotoxicity and cellular metabolism indicates that SiO 2 NPs cause cell death only at high particle doses, except PVP-coated SiO 2 NPs which do not harm cells even at very high concentrations. All SiO 2 NPs, except those coated with PVP, form large agglomerates in physiological solutions and adsorb a variety of proteins. Except PVP-NPs, all SiO 2 NPs adhere strongly to cell surfaces, but internalization differs depending on neural cell type. Neural stem cells and astrocytes internalize plain SiO 2 , SiO 2 -NH 2 and SiO 2 -SH NPs, while neurons do not take up any NPs. The data indicates that the PVP coat, by lowering the particle-biomolecular component interactions, reduces the biological effects of SiO 2 NPs on the investigated neural cells.
Cell Stress and Chaperones, 2014
In the present study, the effects of 10-or 100-nm silica oxide (SiO 2 ) NPs on human peripheral blood mononuclear cells (PBMC) were examined. Cytotoxic effects and oxidative stress effects, including glutathione (GSH) depletion, the formation of protein radical species, and proinflammatory cytokine responses, were measured. PBMC exposed to 10-nm NP concentrations from 50 to 4,000 ppm showed concentration-response increases in cell death; whereas, for 100-nm NPs, PBMC viability was not lost at <500 ppm. Interestingly, 10-nm NPs were more cytotoxic and induced more oxidative stress than 100-nm NPs. Immunoelectron micrographs show the cellular distribution of GSH and NPs. As expected based on the viability data, the 10-nm NPs disturbed cell morphology to a greater extent than did the 100-nm NPs. Antibody to the radical scavenger, 5, 5-dimethyl-1-pyrroline N-oxide (DMPO), was used for Western blot analysis of proteins with radicals; more DMPO proteins were found after exposure to 10-nm NPs than 100-nm NPs. Examination of cytokines (TNF-α, IL-1ra, IL-6, IL-8, IL-1β, and IFN-γ) indicated that different ratios of cytokines were expressed and released after exposure to 10-and 100-nm NPs. IL-1β production was enhanced by 10-and 100-nm NPs;, the cytotoxicity of the NPs was associated with an increase in the IL-1β/IL-6 ratio and 100-nm NPs at concentrations that did not induce loss of cell viability enhanced IL-1β and IL-6 to an extent similar to phytohemagglutinin (PHA), a T cell mitogen. In conclusion, our results indicate that SiO 2 NPs trigger a cytokine inflammatory response and induce oxidative stress in vitro, and NPs of the same chemistry, but of different sizes, demonstrate differences in their intracellular distribution and immunomodulatory properties, especially with regard to IL-1β and IL-6 expression.