Neurovascular unit on a chip: the relevance and maturity as an advanced in vitro model

[No abstract available

Biosensors Integration in blood-brain barrier-on-a-chip: emerging platform for monitoring neurodegenerative diseases

Over the most recent decades, the development of new biological platforms to study disease progression and drug efficacy has been of great interest due to the high increase in the rate of neurodegenerative diseases (NDDs). Therefore, blood–brain barrier (BBB) as an organ-on-a-chip (OoC) platform to mimic brain-barrier performance could offer a deeper understanding of NDDs as well as a very valuable tool for drug permeability testing for new treatments. A very attractive improvement of BBB-oC technology is the integration of detection systems to provide continuous monitoring of biomarkers in real time and a fully automated analysis of drug permeably, rendering more efficient platforms for commercialization. In this Perspective, an overview of the main BBB-oC configurations is introduced and a critical vision of the BBB-oC platforms integrating electronic read out systems is detailed, indicating the strengths and weaknesses of current devices, proposing the great potential for biosensors integration in BBB-oC. In this direction, we name potential biomarkers to monitor the evolution of NDDs related to the BBB and/or drug cytotoxicity using biosensor technology in BBB-oC

Ferulic acid-loaded polymeric nanoparticles prepared from nano-emulsion templates facilitate internalisation across the blood?brain barrier in model membranes

Ferulic acid-loaded PLGA NPs were synthesised via low-energy emulsification methods utilising nano-emulsion templating including permeabilisation efficiency assessed using an in vitro organ-on-a-chip system that simulates the blood-brain barrier

Aislamiento de exosomas con nanopartículas de oro funcionalizadas obtenidos desde la línea celular B16F10

Memoria para optar al título de Químico FarmacéuticoLos exosomas son vesículas extracelulares de tamaño nanométrico involucradas en la comunicación celular. El desarrollo de “nanovehículos”, como los exosomas, es una innovadora estrategia para optimizar la entrega de fármacos a un determinado sitio de acción. Por otro lado, las nanopartículas de oro (AuNPs) son candidatos interesantes para su aplicación en biomedicina debido a sus múltiples propiedades fisicoquímicas que le permiten ser empleadas para terapia y diagnóstico. En estudios anteriores se ha observado que los exosomas provenientes de las células B16F10 presentan una acumulación preferente a nivel pulmonar. A partir de esto, estas nanovesículas podrían utilizarse para direccionar de manera selectiva compuestos bioactivos tales como las nanopartículas de oro (AuNPs). Por lo tanto, la hipótesis de este trabajo plantea que es posible aislar exosomas que contienen nanopartículas de oro funcionalizadas a partir del sobrenadante de la línea celular B16F10. Para llevar a cabo lo anterior, el objetivo de este trabajo fue desarrollar una estrategia para incorporar las AuNPs al interior de los exosomas, y con esto mejorar la entrega terapéutica de éstas. Para esto, se desarrollaron AuNPs conjugadas con ácido fólico o el péptido R7CLPFFD y luego éstas se incubaron con el cultivo celular de B16F10. Posteriormente, se aislaron las nanovesículas por dos métodos: ultracentrifugación y utilizando el kit comercial Exospin®. Ambas muestras obtenidas se caracterizaron por dynamic light scattering, potencial zeta, microscopía electrónica de transmisión y western blotting. Posteriormente, se evaluó la presencia de oro en las muestras de exosomas aislados a través de espectrofotometría UV-visible y activación neutrónica. Como resultado de la estrategia propuesta se obtuvieron exosomas que contienen nanopartículas de oro desde el sobrenadante de la línea celular B16F10. Finalmente, se espera que este nanosistema pueda ser utilizado para la entrega selectiva de principios activos hacia el pulmónExosomes are nanometric extracellular vesicles involved in cell communication. The development of “nanovehicles”, such as the exosomes, is an innovative strategy to optimize the drug delivery to specific action sites. On another hand, gold nanoparticles (AuNPs) are interesting candidate for biomedical applications due to its physicochemical properties that allow them to be used for therapy and diagnosis. Previous studies have shown that isolated exosomes from B16F10 cells are accumulated preferentially in the lungs. Consequently, this nanovesicles could be used for the selective delivery of bioactive compounds such as the gold nanoparticles (AuNPs). Therefore, the hypothesis of this work suggests that it is possible to isolate exosomes containing functionalized gold nanoparticles from the supernatant of the B16F10 cell line. From the above, the goal of this project was developed a strategy for the incorporation of gold nanoparticles (AuNPs) into exosomes that permitting improve the drug delivery of them. For this, we developed functionalized AuNPs with folic acid or R7CLPFFD peptide and later those AuNPs were incubated with B16F10 cell culture. Then, we isolated the nanovesicles by two methods: ultracentrifugation and using the Exospin® kit. Both samples were characterized by dynamic light scattering, zeta potential, transmission electronic microscopy and western blotting. Later, we evaluated the presence of gold in the isolated exosomes samples by UV-visible spectrophotometry and neutronic activation. As result of the proposed strategy, we isolated exosomes containing gold nanoparticles from the B16F10 culture supernatants. Finally, we expect that this nanosystem could be used for the selective delivery of active compounds to the lung

Polyoxometalate-Decorated Gold Nanoparticles Inhibit β-Amyloid Aggregation and Cross the Blood–Brain Barrier in a µphysiological Model

Alzheimer’s disease is characterized by a combination of several neuropathological hallmarks, such as extracellular aggregates of beta amyloid (Aβ). Numerous alternatives have been studied for inhibiting Aβ aggregation but, at this time, there are no effective treatments available. Here, we developed the tri-component nanohybrid system AuNPs@POM@PEG based on gold nanoparticles (AuNPs) covered with polyoxometalates (POMs) and polyethylene glycol (PEG). In this work, AuNPs@POM@PEG demonstrated the inhibition of the formation of amyloid fibrils, showing a 75% decrease in Aβ aggregation in vitro. As it is a potential candidate for the treatment of Alzheimer’s disease, we evaluated the cytotoxicity of AuNPs@POM@PEG and its ability to cross the blood–brain barrier (BBB). We achieved a stable nanosystem that is non-cytotoxic below 2.5 nM to human neurovascular cells. The brain permeability of AuNPs@POM@PEG was analyzed in an in vitro microphysiological model of the BBB (BBB-on-a-chip), containing 3D human neurovascular cell co-cultures and microfluidics. The results show that AuNPs@POM@PEG was able to cross the brain endothelial barrier in the chip and demonstrated that POM does not affect the barrier integrity, giving the green light to further studies into this system as a nanotherapeutic

Tuneable hydrogel patterns in pillarless microfluidic devices

Organ-on-chip (OOC) technology has recently emerged as a powerful tool to mimic physiological or pathophysiological conditions through cell culture in microfluidic devices. One of its main goals is bypassing animal testing and encouraging more personalized medicine. The recent incorporation of hydrogels as 3D scaffolds into microfluidic devices has changed biomedical research since they provide a biomimetic extracellular matrix to recreate tissue architectures. However, this technology presents some drawbacks such as the necessity for physical structures as pillars to confine these hydrogels, as well as the difficulty in reaching different shapes and patterns to create convoluted gradients or more realistic biological structures. In addition, pillars can also interfere with the fluid flow, altering the local shear forces and, therefore, modifying the mechanical environment in the OOC model. In this work, we present a methodology based on a plasma surface treatment that allows building cell culture chambers with abutment-free patterns capable of producing precise shear stress distributions. Therefore, pillarless devices with arbitrary geometries are needed to obtain more versatile, reliable, and biomimetic experimental models. Through computational simulation studies, these shear stress changes are demonstrated in different designed and fabricated geometries. To prove the versatility of this new technique, a blood–brain barrier model has been recreated, achieving an uninterrupted endothelial barrier that emulates part of the neurovascular network of the brain. Finally, we developed a new technology that could avoid the limitations mentioned above, allowing the development of biomimetic OOC models with complex and adaptable geometries, with cell-to-cell contact if required, and where fluid flow and shear stress conditions could be controlled

Gold nanoparticle based double‑labeling of melanoma extracellular vesicles to determine the specificity of uptake by cells and preferential accumulation in small metastatic lung tumors

Background Extracellular vesicles (EVs) have shown great potential for targeted therapy, as they have a natural ability to pass through biological barriers and, depending on their origin, can preferentially accumulate at defined sites, including tumors. Analyzing the potential of EVs to target specific cells remains challenging, considering the unspecific binding of lipophilic tracers to other proteins, the limitations of fluorescence for deep tissue imaging and the effect of external labeling strategies on their natural tropism. In this work, we determined the cell-type specific tropism of B16F10-EVs towards cancer cell and metastatic tumors by using fluorescence analysis and quantitative gold labeling measurements. Surface functionalization of plasmonic gold nanoparticles was used to promote indirect labeling of EVs without affecting size distribution, polydispersity, surface charge, protein markers, cell uptake or in vivo biodistribution. Double-labeled EVs with gold and fluorescent dyes were injected into animals developing metastatic lung nodules and analyzed by fluorescence/computer tomography imaging, quantitative neutron activation analysis and gold-enhanced optical microscopy. Results We determined that B16F10 cells preferentially take up their own EVs, when compared with colon adenocarcinoma, macrophage and kidney cell-derived EVs. In addition, we were able to detect the preferential accumulation of B16F10 EVs in small metastatic tumors located in lungs when compared with the rest of the organs, as well as their precise distribution between tumor vessels, alveolus and tumor nodules by histological analysis. Finally, we observed that tumor EVs can be used as effective vectors to increase gold nanoparticle delivery towards metastatic nodules. Conclusions Our findings provide a valuable tool to study the distribution and interaction of EVs in mice and a novel strategy to improve the targeting of gold nanoparticles to cancer cells and metastatic nodules by using the natural properties of malignant EVsComisión Nacional de Investigación Científica y Tecnológica (CONICYT) 21140353 3140463 Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) CONICYT FONDAP 15130011 Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) CONICYT FONDECYT 1130250 1170925 11181330 119092