scholarly journals Sorption of neuropsychopharmaca in microfluidic materials for in-vitro studies

2021 ◽  
Author(s):  
Thomas E Winkler ◽  
Anna Herland
Keyword(s):  
Small Molecule ◽  
Biological Fluids ◽  
Type System ◽  
Sorption Behavior ◽  
Shear Stresses ◽  
Surface Areas ◽  
Biological Studies ◽  
On Chip

Sorption (i.e., ad- & ab-sorption) of small-molecule compounds to polydimethylsiloxane (PDMS) is widely acknowledged. However, studies to date have largely been conducted under atypical conditions for microfluidic applications (lack of perfusion, lack of biological fluids); especially considering the biological studies such as Organs-on-Chips where small-molecule sorption poses the largest concern. Here, we present the first study of small-molecule sorption under relevant conditions for microphysiological systems, focusing on a standard geometry for biological barrier studies that find application in pharmacokinetics. We specifically assess the sorption of a compound panel including 15 neuropsychopharmaca at in-vivo concentration levels. We consider devices constructed from PDMS as well as two material alternatives (off-stoichiometry thiol-ene-epoxy, or tape/polycarbonate laminates). Moreover, we study the much-neglected impact of peristaltic pump tubing, an essential component of the recirculating systems required to achieve in-vivo-like perfusion shear stresses. We find that choice of device material does not significantly impact sorption behavior in our barrier-on-chip-type system. Our PDMS observations in particular suggest that excessive compound sorption observed in prior studies is not sufficiently described by compound hydrophobicity or other suggested predictors. Critically, we show that sorption by peristaltic tubing, including the commonly-utilized PharMed BPT, dominates over device sorption even on an area-normalized basis, let alone at the typically much larger tubing surface areas. Our findings highlight the importance of validating compound dosages in Organ-on-Chip studies, as well as the need for considering tubing materials with equal or higher care than device materials.

scholarly journals Transcriptome comparisons of in vitro intestinal epithelia grown under static and microfluidic gut-on-chip conditions with in vivo human epithelia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kornphimol Kulthong ◽  
Guido J. E. J. Hooiveld ◽  
Loes Duivenvoorde ◽  
Ignacio Miro Estruch ◽  
Victor Marin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Culture Conditions ◽  
Gene Set Enrichment Analysis ◽  
Shear Stresses ◽  
Static Culture ◽  
Dynamic Culture ◽  
Intestinal Segments ◽  
On Chip

AbstractGut-on-chip devices enable exposure of cells to a continuous flow of culture medium, inducing shear stresses and could thus better recapitulate the in vivo human intestinal environment in an in vitro epithelial model compared to static culture methods. We aimed to study if dynamic culture conditions affect the gene expression of Caco-2 cells cultured statically or dynamically in a gut-on-chip device and how these gene expression patterns compared to that of intestinal segments in vivo. For this we applied whole genome transcriptomics. Dynamic culture conditions led to a total of 5927 differentially expressed genes (3280 upregulated and 2647 downregulated genes) compared to static culture conditions. Gene set enrichment analysis revealed upregulated pathways associated with the immune system, signal transduction and cell growth and death, and downregulated pathways associated with drug metabolism, compound digestion and absorption under dynamic culture conditions. Comparison of the in vitro gene expression data with transcriptome profiles of human in vivo duodenum, jejunum, ileum and colon tissue samples showed similarities in gene expression profiles with intestinal segments. It is concluded that both the static and the dynamic gut-on-chip model are suitable to study human intestinal epithelial responses as an alternative for animal models.

scholarly journals Luminal Flow Actuation Generates Coupled Shear and Strain in a Microvessel-on-Chip

2021 ◽  
Author(s):  
Claire A. Dessalles ◽  
Clara Ramón-Lozano ◽  
Avin Babataheri ◽  
Abdul I. Barakat
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Fluid Pressure ◽  
Shear Stresses ◽  
Collagen Hydrogel ◽  
Luminal Flow ◽  
Wall Shear ◽  
On Chip

AbstractIn the microvasculature, blood flow-derived forces are key regulators of vascular structure and function. Consequently, the development of hydrogel-based microvessel-on-chip systems that strive to mimic the in vivo cellular organization and mechanical environment has received great attention in recent years. However, despite intensive efforts, current microvessel- on-chip systems suffer from several limitations, most notably failure to produce physiologically relevant wall strain levels. In this study, a novel microvessel-on-chip based on the templating technique and using luminal flow actuation to generate physiologically relevant levels of wall shear stress and circumferential stretch is presented. Normal forces induced by the luminal pressure compress the surrounding soft collagen hydrogel, dilate the channel, and create large circumferential strain. The fluid pressure gradient in the system drives flow forward and generates realistic pulsatile wall shear stresses. Rigorous characterization of the system reveals the crucial role played by the poroelastic behavior of the hydrogel in determining the magnitudes of the wall shear stress and strain. The experimental measurements are combined with an analytical model of flow in both the lumen and the porous hydrogel to provide an exceptionally versatile user manual for an application-based choice of parameters in microvessels-on-chip. This unique strategy of flow actuation adds a dimension to the capabilities of microvessel-on-chip systems and provides a more general framework for improving hydrogel-based in vitro engineered platforms.Abstract Figure

scholarly journals The Capability of O-Acetyl-ADP-Ribose, an Epigenetic Metabolic Small Molecule, on Promoting the Further Spreading of Sir3 along the Telomeric Chromatin

Genes ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 577
Author(s):  
Tung ◽  
Wang ◽  
Lee ◽  
Tsai ◽  
Su ◽  
...  
Keyword(s):  
Small Molecule ◽  
Histone Deacetylases ◽  
Affinity Purification ◽  
Direct Interaction ◽  
Structural Rearrangement ◽  
Histone Deacetylation ◽  
Titration Calorimetry ◽  
On Chip

O-acetyl-ADP-ribose (AAR) is a metabolic small molecule relevant in epigenetics that is generated by NAD-dependent histone deacetylases, such as Sir2. The formation of silent heterochromatin in yeast requires histone deacetylation by Sir2, structural rearrangement of SIR complexes, spreading of SIR complexes along the chromatin, and additional maturation processing. AAR affects the interactions of the SIR-nucleosome in vitro and enhances the chromatin epigenetic silencing effect in vivo. In this study, using isothermal titration calorimetry (ITC) and dot blotting methods, we showed the direct interaction of AAR with Sir3. Furthermore, through chromatin immunoprecipitation (ChIP)-on-chip and chromatin affinity purification (ChAP)-on chip assays, we discovered that AAR is capable of increasing the extended spreading of Sir3 along telomeres, but not Sir2. In addition, the findings of a quantitative real-time polymerase chain reaction (qRT-PCR) and examinations of an in vitro assembly system of SIR-nucleosome heterochromatin filament were consistent with these results. This study provides evidence indicating another important effect of AAR in vivo. AAR may play a specific modulating role in the formation of silent SIR-nucleosome heterochromatin in yeast.

scholarly journals A small molecule HIF-1α stabilizer that accelerates diabetic wound healing

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guodong Li ◽  
Chung-Nga Ko ◽  
Dan Li ◽  
Chao Yang ◽  
Wanhe Wang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Small Molecule ◽  
Hypoxia Inducible Factor ◽  
Diabetic Patients ◽  
Diabetic Mice ◽  
Impaired Wound Healing ◽  
Von Hippel Lindau ◽  
Design And Synthesis

AbstractImpaired wound healing and ulcer complications are a leading cause of death in diabetic patients. In this study, we report the design and synthesis of a cyclometalated iridium(III) metal complex 1a as a stabilizer of hypoxia-inducible factor-1α (HIF-1α). In vitro biophysical and cellular analyses demonstrate that this compound binds to Von Hippel-Lindau (VHL) and inhibits the VHL–HIF-1α interaction. Furthermore, the compound accumulates HIF-1α levels in cellulo and activates HIF-1α mediated gene expression, including VEGF, GLUT1, and EPO. In in vivo mouse models, the compound significantly accelerates wound closure in both normal and diabetic mice, with a greater effect being observed in the diabetic group. We also demonstrate that HIF-1α driven genes related to wound healing (i.e. HSP-90, VEGFR-1, SDF-1, SCF, and Tie-2) are increased in the wound tissue of 1a-treated diabetic mice (including, db/db, HFD/STZ and STZ models). Our study demonstrates a small molecule stabilizer of HIF-1α as a promising therapeutic agent for wound healing, and, more importantly, validates the feasibility of treating diabetic wounds by blocking the VHL and HIF-1α interaction.

Targeting RECQL5 Functions, by a Small Molecule, Selectively Kills Breast Cancer in Vitro and in Vivo

2021 ◽  
Vol 64 (3) ◽  
pp. 1524-1544
Author(s):  
Saikat Chakraborty ◽  
Kartik Dutta ◽  
Pooja Gupta ◽  
Anubrata Das ◽  
Amit Das ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Small Molecule

scholarly journals Distribution of the Transcription Factors Sox9, AP-2, and [Delta]EF1 in Adult Murine Articular and Meniscal Cartilage and Growth Plate

2002 ◽  
Vol 50 (8) ◽  
pp. 1059-1065 ◽  
Author(s):  
Sherri R. Davies ◽  
Shinji Sakano ◽  
Yong Zhu ◽  
Linda J. Sandell
Keyword(s):  
Transcription Factors ◽  
Growth Plate ◽  
Type Ii Collagen ◽  
Nuclear Staining ◽  
Lower Growth ◽  
Biological Studies ◽  
Transcription In Vitro ◽  
Sox9 Protein

The control of extracellular matrix (ECM) production is important for the development, maintenance, and repair of cartilage tissues. Matrix molecule synthesis is generally regulated by the rate of gene transcription determined by DNA transcription factors. We have shown that transcription factors Sox9, AP-2, and [delta]EF1 are able to alter the rate of CD-RAP transcription in vitro: Sox9 upregulates, AP-2 exhibits biphasic effects, and [delta]EF1 represses expression of the CD-RAP gene. To correlate these in vitro activities in vivo, transcription factors were co-immunolocalized with ECM proteins in three different cartilage tissues in which the rates of biosynthesis are quite different: articular, meniscal, and growth plate. Immunoreactivities of type II collagen and CD-RAP were higher in growth plate than in either the articular or meniscal cartilages and correlated positively with Sox9 protein. Sox9 staining decreased with hypertrophy and was low in articular and meniscal cartilages. In contrast, AP-2 and [delta]EF1 were low in proliferating chondrocytes but high in lower growth plate, articular, and meniscal cartilages. This increase was also accompanied by intense nuclear staining. These immunohistochemical results are the first to localize both [delta]EF1 and AP-2 to adult articular, meniscal, and growth plate cartilages and provide in vivo correlation of previous molecular biological studies.

The Role of microRNAs in Osteoporosis Diagnostics

2021 ◽  
Vol 30 (03) ◽  
pp. 222-229
Author(s):  
Matthias Hackl ◽  
Elisabeth Semmelrock ◽  
Johannes Grillari
Keyword(s):  
Bone Mass ◽  
Bone Metabolism ◽  
Messenger Rna ◽  
Biological Fluids ◽  
Clinical Diagnostics ◽  
Bone Architecture ◽  
Estrogen Metabolism ◽  
Age Related

AbstractMicroRNAs (miRNAs) are short (18–24 nucleotides) non-coding RNA sequences that regulate gene expression via binding of messenger RNA. It is estimated that miRNAs co-regulate the expression of more than 70% of all human genes, many of which fulfil important roles in bone metabolism and muscle function. In-vitro and in-vivo experiments have shown that the targeted loss of miRNAs in distinct bone cell types (osteoblasts and osteoclasts) results in altered bone mass and bone architecture. These results emphasize the biological relevance of miRNAs for bone health.MiRNAs are not only considered as novel bone biomarkers because of their biological importance to bone metabolism, but also on the basis of other favorable properties: 1) Secretion of miRNAs from cells enables “minimally invasive” detection in biological fluids such as serum. 2) High stability of miRNAs in serum enables the retrospective analysis of frozen blood specimens. 3) Quantification of miRNAs in the serum is based on the RT-PCR - a robust method that is considered as the gold standard for the analysis of nucleic acids in clinical diagnostics.With regard to osteoporosis, it has been shown that many of the known risk factors are characterized by distinct miRNA profiles in the affected tissues: i) age-related loss of bone mass, ii) sarcopenia, iii) changes in estrogen metabolism and related changes Loss of bone mass, and iv) diabetes. Therefore, numerous studies in recent years have dealt with the characterization of miRNAs in the serum of osteoporosis patients and healthy controls, and were able to identify recurring miRNA patterns that are characteristic of osteoporosis. These novel biomarkers have great potential for the diagnosis and prognosis of osteoporosis and its clinical outcomes.The aim of this article is to give a summary of the current state of knowledge on the research and application of miRNA biomarkers in osteoporosis.

Folic Acid Functionalized Chlorin e6-Superparamagnetic Iron Oxide Nanocarriers as a Theranostic Agent for MRI-Guided Photodynamic Therapy

2021 ◽  
Vol 17 (2) ◽  
pp. 205-215
Author(s):  
Zhenbo Sun ◽  
Mingfang Luo ◽  
Jia Li ◽  
Ailing Wang ◽  
Xucheng Sun ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Folic Acid ◽  
Iron Oxide ◽  
Near Infrared ◽  
Biological Fluids ◽  
Superparamagnetic Iron Oxide ◽  
Chlorin E6 ◽  
Theranostic Agent

Imaging-guided cancer theranostic is a promising strategy for cancer diagnostic and therapeutic. Photodynamic therapy (PDT), as an approved treatment modality, is limited by the poor solubility and dispersion of photosensitizers (PS) in biological fluids. Herein, it is demonstrated that superparamagnetic iron oxide (SPIO)-based nanoparticles (SCFs), prepared by conjugated with Chlorin e6 (Ce6) and modified with folic acid (FA) on the surface, can be used as versatile drug delivery vehicles for effective PDT. The nanoparticles are great carriers for photosensitizer Ce6 with an extremely high loading efficiency. In vitro fluorescence imaging and in vivo magnetic resonance imaging (MRI) results indicated that SCFs selectively accumulated in tumor cells. Under near-infrared laser irradiation, SCFs were confirmed to be capable of inducing low cell viability of RM-1 cells In vitro and displaying efficient tumor ablation with negligible side effects in tumor-bearing mice models.

EPCO-18. A MESENCHYMAL CELL POPULATION MEDIATES RESISTANCE TO AURORA KINASE INHIBITORS IN GLIOBLASTOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi5-vi5
Author(s):  
Robert Suter ◽  
Vasileios Stathias ◽  
Anna Jermakowicz ◽  
Hari Pradhyumnan ◽  
Maurizio Affer ◽  
...  
Keyword(s):  
Single Cell ◽  
Small Molecule ◽  
Kinase Inhibitor ◽  
Patient Survival ◽  
Aurora Kinase ◽  
Adult Brain ◽  
Sequencing Data ◽  
Kinase Inhibition

Abstract Glioblastoma (GBM) remains the most common adult brain cancer, with a dismal average patient survival of less than two years. No new treatments have been approved for GBM since the introduction of the alkylating agent temozolomide in 2005. Even then, temozolomide treatment only increases the average survival of GBM patients by a few months. Thus, novel therapeutic options are direly needed. The aurora kinases A and B are targetable and overexpressed in GBM, and their expression is highly correlated with patient survival outcomes. Our lab has found that small molecule aurora kinase inhibition reduces GBM tumor growth in vitro and in vivo, however, eventually tumors still grow. Computational analysis integrating compound transcriptional response signatures from the LINCS L1000 dataset with the single-cell RNA-sequencing data of patient GBM tumors resected at the University of Miami predicts that aurora inhibition targets a subset of cells present within any GBM tumor. Results of in vivo single-cell perturbation experiments with the aurora kinase inhibitor alisertib coincide with our predictions and reveal a cellular transcriptional phenotype resistant to aurora kinase inhibition, characterized by a mesenchymal expression program. We find that small molecules that are predicted to target different cell populations from alisertib, including this resistant mesenchymal population, synergize with alisertib to kill GBM cells. As a whole, we have identified the cellular population resistant to aurora kinase inhibition and have developed an analytical framework that identifies synergistic small molecule combinations by identifying compounds that target transcriptionally distinct cellular populations within GBM tumors.

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