scholarly journals Development of Scaffolds with Adjusted Stiffness for Mimicking Disease-Related Alterations of Liver Rigidity

2020 ◽  
Vol 11 (1) ◽  
pp. 17 ◽  
Author(s):  
Marc Ruoß ◽  
Silas Rebholz ◽  
Marina Weimer ◽  
Carl Grom-Baumgarten ◽  
Kiriaki Athanasopulu ◽  
...  
Keyword(s):  
Drug Metabolism ◽  
Liver Toxicity ◽  
Calf Serum ◽  
Liver Stiffness ◽  
In Vivo Studies ◽  
Drug Induced ◽  
Fibrotic Liver ◽  
Vitro Model

Drug-induced liver toxicity is one of the most common reasons for the failure of drugs in clinical trials and frequent withdrawal from the market. Reasons for such failures include the low predictive power of in vivo studies, that is mainly caused by metabolic differences between humans and animals, and intraspecific variances. In addition to factors such as age and genetic background, changes in drug metabolism can also be caused by disease-related changes in the liver. Such metabolic changes have also been observed in clinical settings, for example, in association with a change in liver stiffness, a major characteristic of an altered fibrotic liver. For mimicking these changes in an in vitro model, this study aimed to develop scaffolds that represent the rigidity of healthy and fibrotic liver tissue. We observed that liver cells plated on scaffolds representing the stiffness of healthy livers showed a higher metabolic activity compared to cells plated on stiffer scaffolds. Additionally, we detected a positive effect of a scaffold pre-coated with fetal calf serum (FCS)-containing media. This pre-incubation resulted in increased cell adherence during cell seeding onto the scaffolds. In summary, we developed a scaffold-based 3D model that mimics liver stiffness-dependent changes in drug metabolism that may more easily predict drug interaction in diseased livers.

Advancements in Cancer Therapeutics

2021 ◽  
pp. 89-115
Author(s):  
Serda Kecel Gunduz ◽  
Bilge Bicak ◽  
Aysen E. Ozel
Keyword(s):  
Protein Design ◽  
Complex Structure ◽  
Cancer Therapeutics ◽  
New Drugs ◽  
In Vivo Studies ◽  
Drug Induced ◽  
Dimensional Simulation ◽  
Dynamics And Function

In this chapter, computational approaches for the discovery of new drugs that are useful for diagnosis and treatment of disease will be described in three parts. MD technique uniquely supports protein design attempts by giving information about protein dynamics associated with atomic-level descriptions of the relationship between dynamics and function. The purpose of molecular docking is to provide an estimate of the ligand-receptor complex structure using computational methods. By this estimation, the mechanism of drug binding and action are described by determining the three-dimensional simulation of drug and drug-induced macrostructure. ADME characteristics are physicochemically significant descriptors and pharmacokinetically relevant properties used to design more effective drugs and new analogs. As a result, in-silico calculations can provide robust preliminary information as to drug activity and mechanism in the drug production process, as well as in vitro and in vivo studies.

Hypoxia induces capillary network formation in cultured bovine pulmonary microvessel endothelial cells

1995 ◽  
Vol 268 (5) ◽  
pp. L789-L800 ◽  
Author(s):  
P. G. Phillips ◽  
L. M. Birnby ◽  
A. Narendran
Keyword(s):  
In Vitro Model ◽  
Network Formation ◽  
Collagen Gel ◽  
Coronary Artery Occlusion ◽  
In Vivo Studies ◽  
Hypoxic Exposure ◽  
Vitro Model ◽  
Vessel Networks

The development of new vessels (angiogenesis) is essential to wound healing. The center of a wound space is hypoxic, a condition that has been shown to stimulate angiogenesis in animal models of coronary artery occlusion. Because the mechanisms involved in this complex process are difficult to study in situ, an in vitro model would provide a useful complement to in vivo studies. This laboratory has developed and characterized calf pulmonary microvessel endothelial cell (PMVEC) cultures and an in vitro model system of angiogenesis using collagen three-dimensional gels that permit migration of cells into vessel networks. This system was used to study the direct effect of normoxia (20% O2) or hypoxia (5% O2) on PMVEC ability to undergo angiogenesis in vitro. Major changes leading to formation of capillary-like networks occurred during the first 3 days of hypoxic exposure only and included restructuring of actin filament networks, focal changes in distribution of basic fibroblast growth factor, and orientation and migration of cell tracts into a collagen gel matrix to form vessel networks.

scholarly journals Porcine hepatocytes culture on biofunctionalized 3D inverted colloidal crystal scaffolds as an in vitro model for predicting drug hepatotoxicity

RSC Advances ◽  
2019 ◽  
Vol 9 (31) ◽  
pp. 17995-18007 ◽  
Author(s):  
Lingyan Wu ◽  
Gaia Ferracci ◽  
Yan Wang ◽  
Teng Fei Fan ◽  
Nam-Joon Cho ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Colloidal Crystal ◽  
Three Dimensional ◽  
Drug Induced ◽  
Attrition Rates ◽  
Common Causes ◽  
Vitro Model ◽  
Colloidal Crystal Scaffolds

As drug-induced hepatotoxicity represents one of the most common causes of drug failure, three-dimensional in vitro liver platforms represent a fantastic toolbox to predict drug toxicity and reduce in vivo studies and drug attrition rates.

scholarly journals Acute drug transfer and particle release of drug coated balloons within a porcine in-vitro model

2017 ◽  
Vol 3 (2) ◽  
pp. 465-468
Author(s):  
Christoph Brandt-Wunderlich ◽  
Lucas Almstädt ◽  
Sebastian Kaule ◽  
Thomas Reske ◽  
Wolfram Schmidt ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Test Methods ◽  
In Vivo Studies ◽  
In Vitro Test ◽  
Drug Transfer ◽  
Particle Release ◽  
Artery Disease ◽  
Vitro Model

AbstractDrug coated balloons (DCB) are used in the therapy of coronary as well as peripheral artery disease. The success of drug transfer to the vessel wall depends on the excipient used in combination with paclitaxel as antiproliferative drug. Although in-vivo studies show very good results with this technology, there is a lack of in-vitro test methods for characterization of various DCB available on the market. This study describes a method to gain information about the drug transfer and the particle release of three different DCB based on cetylpyridinium salycate (Cetpyrsal), hyaluronic acid and iopromide within a porcine in-vitro model. The Cetpyrsal-based DCB showed promising results with the highest drug transfer while producing the lowest number of particles.

scholarly journals Increased oxidation of uroporphyrinogen by an inducible liver microsomal system. Possible relevance to drug-induced uroporphyria

1988 ◽  
Vol 250 (1) ◽  
pp. 161-169 ◽  
Author(s):  
F De Matteis ◽  
C Harvey ◽  
C Reed ◽  
R Hempenius
Keyword(s):  
Chick Embryo ◽  
Drug Metabolism ◽  
Microsomal Fraction ◽  
Marked Decrease ◽  
Rat Hepatocytes ◽  
Drug Induced ◽  
Dependent Mechanism ◽  
Stimulation Of

1. The hypothesis that uroporphyria-inducing drugs stimulate the oxidation of uroporphyrinogen by a microsomal NADPH-dependent mechanism was tested. 2. 3,4,3′,4′-Tetrachlorobiphenyl, a very effective inducer of uroporphyria in chick-embryo hepatocyte cultures, stimulates the NADPH-dependent oxidation of uroporphyrinogen by chick-embryo microsomal fraction in vitro. 3. Two different actions of 3,4,3′,4′-tetrachlorobiphenyl are apparently required for this effect: (a) induction of a microsomal system by treatment in vivo and (b) interaction with the induced microsomal fraction in vitro, producing an oxidizing species. 4. The analogue 2,4,2′,4′-tetrachlorobiphenyl is relatively ineffective in both the production of porphyria in culture and the stimulation of porphyrinogen oxidation in vitro. 5. Rat hepatocytes do not develop uroporphyria when treated with polychlorinated biphenyls in culture, yet they respond to these drugs with typical induction of cytochrome P-448-dependent drug metabolism. 6. These data provide support for the hypothesis of an increased oxidation of uroporphyrinogen in drug-induced uroporphyria, but also suggest that induction of cytochrome P-448 is not the only factor involved. 7. Both I and III isomers of uroporphyrin and heptacarboxylate porphyrin accumulate when chicken hepatocytes are made uroporphyric by drugs; treatment with desferrioxamine causes a marked decrease in both isomers, suggesting that iron may be involved in the accumulation of both.

scholarly journals In Vitro Studies of Synthesis and Release of Factor VIII Related Protein by Endothelial Cells

1977 ◽  
Author(s):  
E. G. D. Tuddenham ◽  
L. W. Hoyer
Keyword(s):  
Endothelial Cells ◽  
Factor Viii ◽  
Calf Serum ◽  
In Vivo Studies ◽  
Separate Experiment ◽  
Related Protein ◽  
Binding Studies ◽  
Radioactive Label

In vivo studies have shown that many stimuli such as epinephrine, exercise and pregnancy lead to a rise in factor VIII levels. However, the physiologic mechanisms controlling factor VIII levels are poorly, if at all, understood. Since endothelial cells synthesize factor VIII related protein (FVIII:RP) and can be grown in tissue culture, they provide a suitable in vitro model to study synthesis and release of FVIII:RP. Endothelial cells were harvested by collagenase digestion from human umbilical cords and grown in medium 199 supplemented with 20 to 30% pooled human serum. Confluent cultures were washed and then maintained in medium 199 supplemented with 20% fetal calf serum. Release of FVIII:RP into the medium was measured by immunoradiometric assay. Labeled amino acids were added to the medium for studies of FVIII:RP synthesis. Incorporation of radioactive label into FVIII:RP was measured in binding studies using a specific immunoadsorbent. Epinephrine in concentrations from 1 ng to 10 ug per ml had no effect on rate of release of FVIII:RP from cultured endothelial cells, suggesting that the in vivo effect of epinephrine is not due to a direct action on endothelial cells. In a separate experiment,exogenous FVIII:RP was added to the culture medium at a high concentration (2 units FVIII:RP per ml) along with 3H Leucine. A control without exogenous VIII:RP incorporated as much radioactivity into VIII:RP as did the culture with added FVIII:RP. This result suggests that there is no end product inhibition of FVIII:RP synthesis which operates on the endothelial cell.

scholarly journals Once-versus thrice-daily netilmicin combined with amoxicillin, penicillin, or vancomycin against Enterococcus faecalis in a pharmacodynamic in vitro model.

1996 ◽  
Vol 40 (10) ◽  
pp. 2258-2261 ◽  
Author(s):  
S Schwank ◽  
J Blaser
Keyword(s):  
Enterococcus Faecalis ◽  
Half Life ◽  
In Vitro Model ◽  
Bacterial Biofilm ◽  
In Vivo Studies ◽  
Bacterial Killing ◽  
Once Daily ◽  
Vitro Model

Several in vitro and in vivo studies as well as clinical trials have demonstrated that once-daily aminoglycoside regimens are as effective as or more effective than multiple daily dosings. However, the most favorable aminoglycoside dosing regimen for treating enterococcal endocarditis remains controversial. The same total dose of netilmicin was administered as once-daily (24-micrograms/ml peaks) and thrice-daily (8 micrograms/ml) regimens in a pharmacodynamic in vitro model simulating exposure of Enterococcus faecalis to human serum kinetics. Netilmicin was administered in combination with continuous infusions of amoxicillin, vancomycin, or penicillin against a bacterial biofilm adhering to glass beads. No significant differences in bacterial killing were found after 24 or 48 h between the once- and thrice-daily regimens. Additional experiments considering animal kinetics (half-life of netilmicin, 20 min) instead of human kinetics (half-life, 2.5 h) in the pharmacodynamic model also revealed similar results. The addition of netilmicin synergistically increased the activity of vancomycin (P < 0.05). In contrast, amoxicillin alone was as effective as the combination with netilmicin. Thus, it could not be established in this model that once-daily dosing of aminoglycosides is contraindicated for treating infections caused by E. faecalis.

An in vitro model of ischemia/reperfusion-induced microvascular injury

1990 ◽  
Vol 259 (1) ◽  
pp. G134-G139 ◽  
Author(s):  
W. Inauen ◽  
D. N. Granger ◽  
C. J. Meininger ◽  
M. E. Schelling ◽  
H. J. Granger ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
In Vitro Model ◽  
Cell Injury ◽  
Ischemia Reperfusion ◽  
In Vivo Studies ◽  
Cell Detachment ◽  
51Cr Release ◽  
Vitro Model

The major objective of this study was to develop an in vitro model of ischemia/reperfusion (I/R)-induced microvascular injury. Cultured venular endothelial cells were grown to confluency, labeled with 51Cr, and exposed to different durations of anoxia (0.5, 1, 2, 3, and 4 h). 51Cr release and cell detachment (indexes of cell injury) were determined at different times after reoxygenation (1, 2, 4, 6, 8, and 18 h). Because in vivo studies have implicated neutrophils in I/R injury, in some experiments human neutrophils were added to the endothelial cells upon reoxygenation. Periods of anoxia greater than or equal to 2 h resulted in 70-80% 51Cr release and 80-95% cell detachment upon reoxygenation. Under these conditions (near maximal injury), the addition of neutrophils produced negligible effects. Periods of anoxia less than or equal to 1 h resulted in 30-40% 51Cr release and 50-60% cell detachment. Under these conditions (moderate cell injury), addition of neutrophils enhanced endothelial cell injury. Using a 30-min period of anoxia, we also assessed the effects of superoxide dismutase (SOD; 300 U/ml) and allopurinol (20 microM) on anoxia/reoxygenation (A/R)-induced injury in the presence or absence of neutrophils. In the absence of neutrophils, SOD or allopurinol did not protect against A/R-induced injury. However, in the presence of neutrophils, both SOD and allopurinol attenuated the increases in 51Cr release. The results derived using this in vitro model of I/R injury are largely consistent with published in vivo studies. Thus this in vitro model may provide further insights regarding the mechanisms involved in I/R injury.

scholarly journals Antibodies to Tyvelose Exhibit Multiple Modes of Interference with the Epithelial Niche of Trichinella spiralis

2000 ◽  
Vol 68 (4) ◽  
pp. 1912-1918 ◽  
Author(s):  
Catherine S. McVay ◽  
Peter Bracken ◽  
Lucille F. Gagliardo ◽  
Judith Appleton
Keyword(s):  
Epithelial Cells ◽  
Trichinella Spiralis ◽  
In Vivo Studies ◽  
Parasite Development ◽  
Multiple Modes ◽  
Protective Antibodies ◽  
Sensory Reception ◽  
Vitro Model

ABSTRACT Infection with the parasitic nematode Trichinella spiralis is initiated when the L1 larva invades host intestinal epithelial cells. Monoclonal antibodies specific for glycans on the larval surface and secreted glycoproteins protect the intestine against infection. Protective antibodies recognize tyvelose which caps the target glycan. In this study, we used an in vitro model of invasion to further examine the mechanism(s) by which tyvelose-specific antibodies protect epithelial cells against T. spiralis. Using cell lines that vary in susceptibility to invasion, we confirmed and clarified the results of our in vivo studies by documenting three modes of interference: exclusion of larvae from cells, encumbrance of larvae as they migrated within epithelial monolayers, and inhibition of parasite development. Excluded larvae bear cephalic caps (C. S. McVay et al., Infect. Immun. 66:1941–1945, 1998) of immune complexes that may physically block invasion or may interfere with sensory reception. Monovalent Fab fragments prepared from a tyvelose-specific antibody also excluded larvae from cells, demonstrating that antibody binding can inhibit the parasite in the absence of antigen aggregation and cap formation. In contrast, encumbered larvae caused extensive damage to the monolayer yet were not successful in establishing a niche, as reflected by their failure to molt. These results show that antibodies to tyvelose exhibit multiple modes of inhibitory activity, further implicating tyvelose-bearing glycoproteins as mediators of invasion and niche establishment by T. spiralis.

scholarly journals Can We Panelize Seizure?

2020 ◽  
Author(s):  
Ruth Roberts ◽  
Simon Authier ◽  
R Daniel Mellon ◽  
Michael Morton ◽  
Ikuro Suzuki ◽  
...  
Keyword(s):  
Ion Channel ◽  
New Drugs ◽  
Detection Methods ◽  
In Vivo Studies ◽  
Design Stage ◽  
Early Screening ◽  
Drug Induced ◽  
Abnormal Movements

Abstract Seizure liability remains a significant cause of attrition in drug discovery and development, leading to loss of competitiveness, delays, and increased costs. Current detection methods rely on observations made in in vivo studies intended to support clinical trials, such as tremors or other abnormal movements. These signs could be missed or misinterpreted; thus, definitive confirmation of drug-induced seizure requires a follow-up electroencephalogram study. There has been progress in in vivo detection of seizure using automated video systems that record and analyze animal movements. Nonetheless, it would be preferable to have earlier prediction of seizurogenic risk that could be used to eliminate liabilities early in discovery while there are options for medicinal chemists making potential new drugs. Attrition due to cardiac adverse events has benefited from routine early screening; could we reduce attrition due to seizure using a similar approach? Specifically, microelectrode arrays could be used to detect potential seizurogenic signals in stem-cell-derived neurons. In addition, there is clear evidence implicating neuronal voltage-gated and ligand-gated ion channels, GPCRs and transporters in seizure. Interactions with surrounding glial cells during states of stress or inflammation can also modulate ion channel function in neurons, adding to the challenge of seizure prediction. It is timely to evaluate the opportunity to develop an in vitro assessment of seizure linked to a panel of ion channel assays that predict seizure, with the aim of influencing structure-activity relationship at the design stage and eliminating compounds predicted to be associated with pro-seizurogenic state.

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