Organ-on-a-chip technology has gained great interest in recent years given its ability to control the spatio-temporal microenvironments of cells and tissues precisely. While physical parameters of the respective niche such as microchannel network sizes, geometric features, flow rates, and shear forces, as well as oxygen tension and concentration gradients, have been optimized for stem cell cultures, little has been done to improve cell-matrix interactions in microphysiological systems. Specifically, detailed research on the effect of matrix elasticity and extracellular matrix (ECM) nanotopography on stem cell differentiation are still in its infancy, an aspect that is known to alter a stem cell’s fate. Although a wide range of hydrogels s

The β42 amyloid peptides (Aβ) are identified as a candidate target for Alzheimer’s drugs. Phenolic compounds can bind to the Aβ and inhibit amyloid formation. However, the inhibitory mechanism of phenolic compounds remains unclear. In this study, the molecular dynamic simulation and docking program were used to characterize the molecular details of inhibitory mechanism of the phenolic compounds. Our Results show that the phenolic compounds can bind to hydrophobic region in Aβ42 monomer and alter hydrophobic interactions network at Aβ42 which play a key role in β-sheet formation. The cluster analysis and interactions network analysis were used to probe conformational changes in Aβ42. In most populated clusters of Aβ42-phenolic comp

Microfluidics cell-based assays require strong cell-substrate adhesion for cell viability, proliferation, and differentiation. The intrinsic properties of PDMS, a commonly used polymer in microfluidics systems, regarding cell-substrate interactions have limited its application for microfluidics cell-based assays. Various attempts by previous researchers, such as chemical modification, plasma-treatment, and protein-coating of PDMS revealed some improvements. These strategies are often reversible, time-consuming, short-lived with either cell aggregates formation, not cost-effective as well as not user-and eco-friendly too. To address these challenges, cell-surface interaction has been tuned by the modification of PDMS doped with different bio

The low membrane permeability of lipophilic drugs was resolved using liposomes as a solubilizing agent and the precise size control of them is a significant parameter in drug carrier technology. Here, we have established a microfluidic octanol-assisted liposome assembly method to produce a surfactant-assisted liposome which has merged by the cytoskeleton drug (Taxotere) encapsulation in a single process step, then a complete microfluidic cellular analysis was performed in trapping cell device with an optofluidic assay for quantifying drug permeability. The optimization of process variables resulted in the formation of liposomes with particle size 6.75?0.5 ?m and monodispersity 6.2%, representing encapsulation efficiency and loading capacity

: Lung cancer is the most killer cancer in both men and female, as the lung cancer mortality rate is higher than death by the next two breast and prostate cancers. Lung cancer treatment compared to breast cancer is almost unsatisfied, since the most of lung cancer cases are diagnosed at a stage of the disease where metastasis has occurred. The cause of late diagnosis in lung cancer is the similarity of signs and symptoms of cancer with pulmonary symptoms and lack of confidence approaches to identify it at early stage. Nowadays, much attempt is paid to biomarkers such micro RNAs, exosomes, and tetraspanins that can give us information about intracellular events. Microfluidic as science is the study of fluid behavior, and as technology is t

In view of the constant increase of nanotechnology and nanomaterials applications in our daily life, to determine whether they are safe,“in vitro” and “in vivo” screening methods are needed. Obviously, application of models that are similar to the physiological tissues process of the human body could be a better candidate. The three-dimensional spheroid method, spheroid were generated using commercial microplates, has many benefits (in comparison with traditional methods or monolayer cell culture) such as the growth of the cells in 3D, similar to the body's physiological tissue, an alternative for animal models, cell-to-cell interactions, and better cell signaling. In this study, the toxicity of silver nanoparticles by using three f

This paper presents experimental and numerical investigations of a novel passive micromixer based on the lamination of fluid layers. Lamination-based mixers benefit from increasing the contact surface between two fluid phases by enhancing molecular diffusion to achieve a faster mixing. Novel three-dimensional split and recombine (SAR) structures are proposed to generate fluid laminations. Numerical simulations were conducted to model the mixer performance. Furthermore, experiments were conducted using dyes to observe fluid laminations and evaluate the proposed mixer’s characteristics. Mixing quality was experimentally obtained by means of image-based mixing index (MI) measurement. The multi-layer device was fabricated utilizing the Xurogr

Lack of perfect insulin signaling can lead to the insulin resistance, which is the hallmark of diabetes mellitus. Activation of insulin and its binding to the receptor for signaling process initiates via B-chain C-terminal hinge conformational change through an open structure to “wide-open” conformation. Observational studies and basic scientific evidence suggest that vitamin D and E directly and/or indirectly prevent diabetes through improving glucose secretion and tolerance, activating calcium dependent endopeptidases and thus improving insulin exocytosis, antioxidant effect and reducing insulin resistance. On the contrary, clinical trials have yielded inconsistent results about the efficacy of vitamin D supplementations for the contr

Circulating miRNAs have also been proposed as novel biomarkers for early diagnosis and even prognosis of cancer. Due to the non-invasive access, in addition to before metastase early detection, the use of these molecules can reduced injuries of patients. In this study, the biosensor was designed to isolate circulating mi RNAs by microfluidic system. The design was based on the isolation of two miRNAs (miR-21 and miR-486), which have been described in papers as miRNAs with potential to diagnosis of lung cancer. In this system, miRNA isolation is performed using a capture probe (single-strand DNA), immobilized by GPTMS linker on PDMS surface. By attaching of microRNA to this probe, the second probe that was biotinilated DNA complement to uppe

The cell migration and movement is a critical step in metastasis processes and moved from initial tumor to secondary through capillaries of lymphatic systems. Conventional methods for cell migration studies have significant limitation in study of cell heterogeneity and simulated the limited step in metastasis process which is moved cell through capillaries of lymphatic systems. Moreover, all of these systems are endpoint assays. In our study, we designed a microfluidic chip to study of cell migration, metastasis properties of cells and cell heterogeneity of cancer cells. In our designed pattern, there are several trapping shapes in main channel which the cells trapped in these positions. In addition, the narrow channels were designed in fro

Recently, we reported that the histone methyltransferase, EZH2, controls leukocyte migration through interaction with the cytoskeleton remodeling effector, VAV, and direct methylation of the cytoskeletal regulatory protein, Talin. However, it is unclear whether this extranuclear, epigenetic-independent function of EZH2 has a profound impact on the initiation of cellular transformation and metastasis. Here, we show that EZH2 increases Talin1 methylation and cleavage, thereby enhancing adhesion turnover and promoting accelerated tumorigenesis. This transforming capacity is abolished by targeted disruption of EZH2 interaction with VAV. Furthermore, our studies demonstrate that EZH2 in the cytoplasm is closely associated with cancer stem cell p

The eukaryotic genome is highly compacted into a protein-DNA complex called chromatin. The cell controls access of transcriptional regulators to chromosomal DNA via several mechanisms that act on chromatin-associated proteins and provide a rich spectrum of epigenetic regulation. Elucidating the mechanisms that fold chromatin fibers into higher-order structures is therefore key to understanding the epigenetic regulation of DNA accessibility. Here, using histone H4-V21C and histone H2A-E64C mutations, we employed single-molecule force spectroscopy to measure the unfolding of individual chromatin fibers that are reversibly cross-linked through the histone H4 tail. Fibers with covalently linked nucleosomes featured the same folding characterist