Oxygenator assisted dynamic microphysiological culture elucidates the impact of hypoxia on valvular interstitial cell calcification.

Introduction: Microphysiological systems (MPS) offer simulation of (patho)physiological parameters. Investigation includes items which lead to fibrosis and calcification in development and progress of calcific aortic valve disease, based e.g.

Direct competitive assay for HER2 detection in human plasma using Bloch surface wave-based biosensors.

The overexpression and/or amplification of the HER2/neu oncogene has been proposed as a prognostic marker in breast cancer. The detection of the related peptide HER2 remains a grand challenge in cancer diagnosis and for therapeutic decision-making. Here, we used a biosensing device based on Bloch Surface Waves excited on a one-dimensional photonic crystal (1DPC) as valid alternative to standard techniques.

Challenges of aortic valve tissue culture - maintenance of viability and extracellular matrix in the pulsatile dynamic microphysiological system.

Background: Calcific aortic valve disease (CAVD) causes an increasing health burden in the 21 century due to aging population. The complex pathophysiology remains to be understood to develop novel prevention and treatment strategies. Microphysiological systems (MPSs), also known as organ-on-chip or lab-on-a-chip systems, proved promising in bridging in vitro and in vivo approaches by applying integer AV tissue and modelling biomechanical microenvironment.

Expression of toxic genes in Methylorubrum extorquens with a tightly repressed, cumate-inducible promoter.

Methylorubrum extorquens is an important model methylotroph and has enormous potential for the development of C1-based microbial cell factories. During strain construction, regulated promoters with a low background expression level are important genetic tools for expression of potentially toxic genes. Here we present an accordingly optimised promoter, which can be used for that purpose.

Microphysiological Conditions Do Not Affect MDR1-Mediated Transport of Rhodamine 123 above an Artificial Proximal Tubule.

Despite disadvantages, such as high cost and their poor predictive value, animal experiments are still the state of the art for pharmaceutical substance testing. One reason for this problem is the inability of standard cell culture methods to emulate the physiological environment necessary to recapitulate in vivo processes. Microphysiological systems offer the opportunity to close this gap.

A New In Vitro Blood Flow Model for the Realistic Evaluation of Antimicrobial Surfaces.

Device-associated bloodstream infections can cause serious medical problems and cost-intensive postinfection management, defining a need for more effective antimicrobial coatings. Newly developed coatings often show reduced bacterial colonization and high hemocompatibility in established in vitro tests, but fail in animal studies or clinical trials. The poor predictive power of these models is attributed to inadequate representation of in vivo conditions.

Human endothelial cells form an endothelium in freestanding collagen hollow filaments fabricated by direct extrusion printing.

Fiber-shaped materials have great potential for tissue engineering applications as they provide structural support and spatial patterns within a three-dimensional construct. Here we demonstrate the fabrication of mechanically stable, meter-long collagen hollow filaments by a direct extrusion printing process. The fibres are permeable for oxygen and proteins and allow cultivation of primary human endothelial cells (ECs) at the inner surface under perfused conditions.

Enhanced structural maturation of human induced pluripotent stem cell-derived cardiomyocytes under a controlled microenvironment in a microfluidic system.

The lack of a fully developed human cardiac model in vitro hampers the progress of many biomedical research fields including pharmacology, developmental biology, and disease modeling. Currently, available methods may only differentiate human induced pluripotent stem cells (iPSCs) into immature cardiomyocytes. To achieve cardiomyocyte maturation, appropriate modulation of cellular microenvironment is needed.

Label-Free Monitoring of Human IgG/Anti-IgG Recognition Using Bloch Surface Waves on 1D Photonic Crystals.

Optical biosensors based on one-dimensional photonic crystals sustaining Bloch surface waves are proposed to study antibody interactions and perform affinity studies. The presented approach utilizes two types of different antibodies anchored at the sensitive area of a photonic crystal-based biosensor. Such a strategy allows for creating two or more on-chip regions with different biochemical features as well as studying the binding kinetics of biomolecules in real time.

Bloch surface wave enhanced biosensor for the direct detection of Angiopoietin-2 tumor biomarker in human plasma.

Quantitative detection of angiogenic biomarkers provides a powerful tool to diagnose cancers in early stages and to follow its progression during therapy. Conventional tests require trained personnel, dedicated laboratory equipment and are generally time-consuming. Herein, we propose our developed biosensing platform as a useful tool for a rapid determination of Angiopoietin-2 biomarker directly from patient plasma within 30 minutes, without any sample preparation or dilution.

Detection and identification of using magnetic particle enhanced surface plasmon spectroscopy.

In this work, an approach for SPR spectroscopy using the SPR system is examined that combines signal amplification by PCR and magnetic nanoparticles in one injection step. Therefore, the synthesis of PCR products was performed on the beads similar to a solid-phase PCR, termed PCR-on-a-bead. The functionality of this PCR was proven using an enzymatic assay.

Replacing the Ethylmalonyl-CoA Pathway with the Glyoxylate Shunt Provides Metabolic Flexibility in the Central Carbon Metabolism of Methylobacterium extorquens AM1.

The ethylmalonyl-CoA pathway (EMCP) is an anaplerotic reaction sequence in the central carbon metabolism of numerous Proteo- and Actinobacteria. The pathway features several CoA-bound mono- and dicarboxylic acids that are of interest as platform chemicals for the chemical industry. The EMCP, however, is essential for growth on C1 and C2 carbon substrates and therefore cannot be simply interrupted to drain these intermediates.

Ultrasensitive SPR detection of miRNA-93 using antibody-enhanced and enzymatic signal amplification.

MiRNAs are endogenous noncoding RNA molecules. They play important gene-regulatory roles by binding to the mRNA of target genes thereby leading to either transcript degradation or translational repression. In virtually all diseases, distinct alterations of miRNA expression profiles have been found thus suggesting miRNAs as interesting biomarkers.

Bloch Surface Waves Biosensors for High Sensitivity Detection of Soluble ERBB2 in a Complex Biological Environment.

We report on the use of one-dimensional photonic crystals to detect clinically relevant concentrations of the cancer biomarker ERBB2 in cell lysates. Overexpression of the ERBB2 protein is associated with aggressive breast cancer subtypes. To detect soluble ERBB2, we developed an optical set-up which operates in both label-free and fluorescence modes.

Universal Micromachining Platform and Basic Technologies for the Manufacture and Marking of Microphysiological Systems.

Micro Physiological Systems (MPS), also known as Multi-Organ-Chip, Organ-on-a-Chip, or Body-on-a-Chip, are advanced microfluidic systems that allow the cultivation of different types of cells and tissue in just one common circuit. Furthermore, they thus can also adjust the interaction of these different tissues. Perspectival MPS will replace animal testing.

Detection of soluble ERBB2 in breast cancer cell lysates using a combined label-free/fluorescence platform based on Bloch surface waves.

We report on the use of one-dimensional photonic crystals to detect clinically relevant concentrations of ERBB2/neu/Her2 in cell lysates. ERBB2 is a pivotal breast cancer biomarker and targetable oncogenic driver associated with aggressive breast cancer subtypes. To quantitate soluble ERBB2, we developed an optical platform that combines label-free and fluorescence detection modes.

Additive manufacturing of collagen scaffolds by three-dimensional plotting of highly viscous dispersions.

Additive manufacturing (AM) allows the free form fabrication of three-dimensional (3D) structures with distinct external geometry, fitting into a patient-specific defect, and defined internal pore architecture. However, fabrication of predesigned collagen scaffolds using AM-based technologies is challenging due to the low viscosity of collagen solutions, gels or dispersions commonly used for scaffold preparation. In the present study, we have developed a straightforward method which is based on 3D plotting of a highly viscous, high density collagen dispersion.

Better lipid target achievement for secondary prevention through disease management programs for diabetes mellitus and coronary heart disease in clinical practice in Germany.

Aims: Disease management programs (DMP) for diabetes mellitus (DM) or coronary heart disease (CHD) address the treatment of lipid disorders. The current registry aimed to compare drug utilization, lipid lowering effects and further outcomes of outpatients at high cardiovascular risk in DMP for DM or CHD compared to patients in routine care (no-DMP).

Methods: This was a prospective non-interventional registry with a 1 year follow-up which enrolled consecutive patients with known DM and/or any vascular disease on simvastatin 40 mg monotherapy, to document lipid target achievement in clinical practice in Germany according to existing guidelines.

Engineering Methylobacterium extorquens for de novo synthesis of the sesquiterpenoid α-humulene from methanol.

Over the last 10 to 15 years, metabolic engineering of microbes has become a versatile tool for high-level de novo synthesis of terpenoids, with the sesquiterpenoids armopha-1,4-diene, farnesene and artemisinic acid as prime examples. However, almost all cell factory approaches towards terpenoids to date have been based on sugar as the raw material, which is mainly used as a food resource and subject to high price volatilities. In this study we present de novo synthesis of the sesquiterpenoid α-humulene from the abundantly available non-food carbon source methanol by metabolically engineered Methylobacterium extorquens AM1.

A four-organ-chip for interconnected long-term co-culture of human intestine, liver, skin and kidney equivalents.

Systemic absorption and metabolism of drugs in the small intestine, metabolism by the liver as well as excretion by the kidney are key determinants of efficacy and safety for therapeutic candidates. However, these systemic responses of applied substances lack in most in vitro assays. In this study, a microphysiological system maintaining the functionality of four organs over 28 days in co-culture has been established at a minute but standardized microsystem scale.

The multi-organ chip--a microfluidic platform for long-term multi-tissue coculture.

The ever growing amount of new substances released onto the market and the limited predictability of current in vitro test systems has led to a high need for new solutions for substance testing. Many drugs that have been removed from the market due to drug-induced liver injury released their toxic potential only after several doses of chronic testing in humans. However, a controlled microenvironment is pivotal for long-term multiple dosing experiments, as even minor alterations in extracellular conditions may greatly influence the cell physiology.

Anaerobic microbial transformation of halogenated aromatics and fate prediction using electron density modeling.

Halogenated homo- and heterocyclic aromatics including disinfectants, pesticides and pharmaceuticals raise concern as persistent and toxic contaminants with often unknown fate. Remediation strategies and natural attenuation in anaerobic environments often build on microbial reductive dehalogenation. Here we describe the transformation of halogenated anilines, benzonitriles, phenols, methoxylated, or hydroxylated benzoic acids, pyridines, thiophenes, furoic acids, and benzenes by Dehalococcoides mccartyi strain CBDB1 and environmental fate modeling of the dehalogenation pathways.

Chip-based human liver-intestine and liver-skin co-cultures--A first step toward systemic repeated dose substance testing in vitro.

Systemic repeated dose safety assessment and systemic efficacy evaluation of substances are currently carried out on laboratory animals and in humans due to the lack of predictive alternatives. Relevant international regulations, such as OECD and ICH guidelines, demand long-term testing and oral, dermal, inhalation, and systemic exposure routes for such evaluations. So-called "human-on-a-chip" concepts are aiming to replace respective animals and humans in substance evaluation with miniaturized functional human organisms.

High-level production of ethylmalonyl-CoA pathway-derived dicarboxylic acids by Methylobacterium extorquens under cobalt-deficient conditions and by polyhydroxybutyrate negative strains.

Bio-based production of dicarboxylic acids is an emerging research field with remarkable progress during the last decades. The recently established synthesis of the ethylmalonyl-CoA pathway (EMCP)-derived dicarboxylic acids, mesaconic acid and (2S)-methylsuccinic acid, from the alternative carbon source methanol (Sonntag et al., Appl Microbiol Biotechnol 98:4533-4544, 2014) gave a proof of concept for the sustainable production of hitherto biotechnologically inaccessible monomers.

Purification and immunodetection of the complete recombinant HER-2[neu] receptor produced in yeast.

For the first time, the full length recombinant HER-2[neu] receptor has been produced in a yeast (Arxula adeninivorans). It is one of the most studied membrane receptors in oncology and is involved in aggressive tumor formation. A yeast integration rDNA cassette containing the human gene coding for the HER-2[neu] protein was constructed and a screening procedure was performed to select the most productive transformant.