Clinical Hemorheology and Microcirculation - Volume 79, issue 1

Authors: Maring, Janita A. | Becker, Matthias | Tung, Wing Tai | Stamm, Christof | Ma, Nan | Lendlein, Andreas

Article Type: Research Article

Abstract: BACKGROUND: Polymeric materials have been widely used as artificial grafts in cardiovascular applications. These polymeric implants can elicit a detrimental innate and adaptive immune response after interacting with peripheral blood. A surface modification with components from extracellular matrices (ECM) may minimize the activation of immune cells from peripheral blood. The aim of this study is to compare the cellular response of blood-born immune cells to the fiber meshes from polyesteretherurethane (PEEUm) and PEEUm with ECM coating (PEEUm + E). MATERIALS AND METHODS: Electrospun PEEUm were used as-is or coated with human cardiac ECM. Different immune cells were isolated form human …peripheral blood. Cytokine release profile from naïve and activated monocytes was assessed. Macrophage polarization and T cell proliferation, as indication of immune response were evaluated. RESULTS: There was no increase in cytokine release (IL-6, TNF-α, and IL-10) from activated monocytes, macrophages and mononuclear cells on PEEUm; neither upon culturing on PEEUm + E. Naïve monocytes showed increased levels of IL-6 and TNF-α, which were not present on PEEUm + E. There was no difference on monocyte derived macrophage polarization towards pro-inflammatory M1 or anti-inflammatory M2 on PEEUm and PEEUm + E. Moreover, T cell proliferation was not increased upon interacting with PEEUm directly. CONCLUSION: As PEEUm only elicits a minimal response from naïve monocytes but not from monocytes, peripheral blood mononuclear cells (PBMCs) or T cells, the slight improvement in response to PEEUm + E might not justify the additional effort of coating with a human ECM. Show more

Keywords: Immune response, cardiovascular, polymer, ECM, cytokine

DOI: 10.3233/CH-219114

Citation: Clinical Hemorheology and Microcirculation, vol. 79, no. 1, pp. 205-216, 2021

Authors: Xu, Xun | Nie, Yan | Wang, Weiwei | Ullah, Imran | Tung, Wing Tai | Ma, Nan | Lendlein, Andreas

Article Type: Research Article

Abstract: Human induced pluripotent stem cells (hiPSCs) are a promising cell source to generate the patient-specific lung organoid given their superior differentiation potential. However, the current 3D cell culture approach is tedious and time-consuming with a low success rate and high batch-to-batch variability. Here, we explored the establishment of lung bud organoids by systematically adjusting the initial confluence levels and homogeneity of cell distribution. The efficiency of single cell seeding and clump seeding was compared. Instead of the traditional 3D culture, we established a 2.5D organoid culture to enable the direct monitoring of the internal structure via microscopy. It was found …that the cell confluence and distribution prior to induction were two key parameters, which strongly affected hiPSC differentiation trajectories. Lung bud organoids with positive expression of NKX 2.1, in a single-cell seeding group with homogeneously distributed hiPSCs at 70% confluence (SC_70%_hom) or a clump seeding group with heterogeneously distributed cells at 90% confluence (CL_90%_het), can be observed as early as 9 days post induction. These results suggest that a successful lung bud organoid formation with single-cell seeding of hiPSCs requires a moderate confluence and homogeneous distribution of cells, while high confluence would be a prominent factor to promote the lung organoid formation when seeding hiPSCs as clumps. 2.5D organoids generated with defined culture conditions could become a simple, efficient, and valuable tool facilitating drug screening, disease modeling and personalized medicine. Show more

Keywords: Lung organoid, human induced pluripotent stem cell, cell culture

DOI: 10.3233/CH-219111

Citation: Clinical Hemorheology and Microcirculation, vol. 79, no. 1, pp. 217-230, 2021

Authors: Schulz, Christian | Jung, Friedrich | Küpper, Jan-Heiner

Article Type: Research Article

Abstract: Cell-based in vitro liver models are an important tool in the development and evaluation of new drugs in pharmacological and toxicological drug assessment. Hepatic microsomal enzyme complexes, consisting of cytochrome P450 oxidoreductase (CPR) and cytochrome P450 monooxygenases (CYPs), play a decisive role in catalysing phase-1 biotransformation of pharmaceuticals and xenobiotics. For a comprehensive understanding of the phase-1 biotransformation of drugs, the availability of well-characterized substances for the targeted modulation of in vitro liver models is essential. In this study, we investigated diphenyleneiodonium (DPI) for its ability to inhibit phase-1 enzyme activity and further its toxicological profile in an …in vitro HepG2 cell model with and without recombinant expression of the most important drug metabolization enzyme CYP3A4. Aim of the study was to identify effective DPI concentrations for CPR/CYP activity modulation and potentially associated dose and time dependent hepatotoxic effects. The cells were treated with DPI doses up to 5,000nM (versus vehicle control) for a maximum of 48 h and subsequently examined for CYP3A4 activity as well as various toxicological relevant parameters such as cell morphology, integrity and viability, intracellular ATP level, and proliferation. Concluding, the experiments revealed a time- and concentration-dependent DPI mediated partial and complete inhibition of CYP3A4 activity in CYP3A4 overexpressing HepG2-cells (HepG2-CYP3A4). Other cell functions, including ATP synthesis and consequently the proliferation were negatively affected in both in vitro cell models. Since neither cell integrity nor cell viability were reduced, the effect of DPI in HepG2 can be assessed as cytostatic rather than cytotoxic. Show more

Keywords: Phase-1, biotransformation, CYP, cytochrome P450 monooxygenase, CYP3A4, diphenyleneiodonium, DPI, HepG2, HepG2-CYP3A4, hepatocytes, NADPH-cytochrome P450 oxidoreductase, POR, CPR

DOI: 10.3233/CH-219117

Citation: Clinical Hemorheology and Microcirculation, vol. 79, no. 1, pp. 231-243, 2021