CAAP48, a New Sepsis Biomarker, Induces Hepatic Dysfunction in an Liver-on-Chip Model.

Sepsis is a leading cause of mortality in the critically ill, characterized by life-threatening organ dysfunctions due to dysregulation of the host response to infection. Using mass spectrometry, we identified a C-terminal fragment of alpha-1-antitrypsin, designated CAAP48, as a new sepsis biomarker that actively participates in the pathophysiology of sepsis. It is well-known that liver dysfunction is an early event in sepsis-associated multi-organ failure, thus we analyzed the pathophysiological function of CAAP48 in a microfluidic-supported liver-on-chip model.

Corrigendum: Monocyte-induced recovery of inflammation-associated hepatocellular dysfunction in a biochip-based human liver model.

This corrects the article DOI: 10.1038/srep21868.

Preservation of Cell Structure, Metabolism, and Biotransformation Activity of Liver-On-Chip Organ Models by Hypothermic Storage.

The liver is a central organ in the metabolization of nutrition, endogenous and exogenous substances, and xenobiotic drugs. The emerging organ-on-chip technology has paved the way to model essential liver functions as well as certain aspects of liver disease in vitro in liver-on-chip models. However, a broader use of this technology in biomedical research is limited by a lack of protocols that enable the short-term preservation of preassembled liver-on-chip models for stocking or delivery to researchers outside the bioengineering community.

Monocyte-induced recovery of inflammation-associated hepatocellular dysfunction in a biochip-based human liver model.

Liver dysfunction is an early event in sepsis-related multi-organ failure. We here report the establishment and characterization of a microfluidically supported in vitro organoid model of the human liver sinusoid. The liver organoid is composed of vascular and hepatocyte cell layers integrating non-parenchymal cells closely reflecting tissue architecture and enables physiological cross-communication in a bio-inspired fashion.

Cytochrome P450 inhibition potential of new psychoactive substances of the tryptamine class.

New psychoactive substances (NPS) are not tested for their cytochrome P450 (CYP) inhibition potential before consumption. Therefore, this potential was explored for tryptamine-derived NPS (TDNPS) including alpha-methyl tryptamines (AMTs), dimethyl tryptamines (DMTs), diallyl tryptamines (DALTs), and diisopropyl tryptamines (DiPTs) using test substrates preferred by the Food and Drug Administration in a cocktail assay. All tested TDNPS with the exception of DMT inhibited CYP2D6 activity with IC50 values below 100μM.

A microfluidically perfused three dimensional human liver model.

Within the liver, non-parenchymal cells (NPCs) are critically involved in the regulation of hepatocyte polarization and maintenance of metabolic function. We here report the establishment of a liver organoid that integrates NPCs in a vascular layer composed of endothelial cells and tissue macrophages and a hepatic layer comprising stellate cells co-cultured with hepatocytes. The three-dimensional liver organoid is embedded in a microfluidically perfused biochip that enables sufficient nutrition supply and resembles morphological aspects of the human liver sinusoid.

In vitro cytochrome P450 inhibition potential of methylenedioxy-derived designer drugs studied with a two-cocktail approach.

In vitro cytochrome P450 (CYP) inhibition assays are common approaches for testing the inhibition potential of drugs for predicting potential interactions. In contrast to marketed medicaments, drugs of abuse, particularly the so-called novel psychoactive substances, were not tested before distribution and consumption. Therefore, the inhibition potential of methylenedioxy-derived designer drugs (MDD) of different drug classes such as aminoindanes, amphetamines, benzofurans, cathinones, piperazines, pyrrolidinophenones, and tryptamines should be elucidated.

Development of an in vitro cytochrome P450 cocktail inhibition assay for assessing the inhibition risk of drugs of abuse.

Drugs of abuse are not tested for cytochrome P450 (CYP) inhibition potential before distribution. Therefore, a cocktail assay should be developed for testing the inhibition potential for all relevant CYPs. The following CYP test substrates and selective inhibitors were incubated in pooled human liver microsomes: phenacetin (alpha-naphthoflavone for CYP1A2), coumarin (tranylcypromine, CYP2A6), bupropion (sertraline, CYP2B6), amodiaquine (trimethoprim, CYP2C8), diclofenac (sulfaphenazole, CYP2C9), omeprazole (fluconazole, CYP2C19), dextromethorphan (quinidine, CYP2D6), chlorzoxazone (clomethiazole, CYP2E1), testosterone (verapamil, CYP3A).

Development and validation of a liquid-chromatography high-resolution tandem mass spectrometry approach for quantification of nine cytochrome P450 (CYP) model substrate metabolites in an in vitro CYP inhibition cocktail.

Knowledge about the cytochrome P450 (CYP) inhibition potential of new drug candidates is important for drug development because of its risk of interactions. For novel psychoactive substances (NPS), corresponding data are not available. For developing a general drug inhibition cocktail assay, a liquid-chromatography high-resolution tandem mass spectrometry multi-analyte approach was developed and validated for quantifying low concentrations of O-diethyl phenacetin for CYP 1A2, 7-hydroxy coumarin for CYP 2A6, 4-hydroxy bupropion for CYP 2B6, N-diethyl amodiaquine for CYP 2C8, 4-hydroxy diclofenac for CYP 2C9, 5-hydroxy omeprazole for CYP 2C19, O-dimethyl dextromethorphan for CYP 2D6, 6-hydroxy chlorzoxazone for CYP 2E1, and 6-beta-hydroxy testosterone for CYP 3A in the incubation mixture in the presence of substrates and inhibitors.

The in vivo and in vitro metabolism and the detectability in urine of 3',4'-methylenedioxy-alpha-pyrrolidinobutyrophenone (MDPBP), a new pyrrolidinophenone-type designer drug, studied by GC-MS and LC-MS(n.).

3',4'-Methylenedioxy-alpha-pyrrolidinobutyrophenone (MDPBP), a designer drug of the pyrrolidinophenone-type, was first seized in Germany in 2009. It was also identified in 'legal high' samples investigated in the UK. Therefore, the aim of the presented work was to identify its in vivo and in vitro phase I and II metabolites using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-ion trap mass spectrometry (LC-MS(n) ).

Qualitative studies on the metabolism and the toxicological detection of the fentanyl-derived designer drugs 3-methylfentanyl and isofentanyl in rats using liquid chromatography-linear ion trap-mass spectrometry (LC-MS(n)).

The opioid 3-methylfentanyl, a designer drug of the fentanyl type, was scheduled by the Controlled Substance Act due to its high potency and abuse potential. To overcome this regulation, isofentanyl, another designer fentanyl, was synthesized in a clandestine laboratory and seized by the German police. The aims of the presented study were to identify the phase I and phase II metabolites of 3-methylfentanyl and isofentanyl in rat urine, to identify the cytochrome P450 (CYP) isoenzymes involved in their initial metabolic steps, and, finally, to test their detectability in urine.