TY - GEN A1 - Lau, S. A1 - Rangarajan, R. A1 - Krüger-Genge, Anne A1 - Braune, Steffen A1 - Küpper, Jan-Heiner A1 - Lendlein, Andreas A1 - Jung, Friedrich T1 - Age-related morphology and function of human arterial endothelial cells T2 - Clinical Hemorheology and Microcirculation N2 - Endothelialization of cardiovascular implants is regarded as a promising strategy for long-term compatibility. While umbilical vein endothelial cells are typically applied in research, human arterial endothelial cells (HAEC) from elderly donors would be the obvious source for autologous cellularization strategies. In our approach, HAEC from 16 donors of varying age (16–63 years) were divided into two groups (<30 years and >30 years) and analyzed regarding morphology, viability, proliferation, function and senescence status. No age-related differences were found regarding morphology, viability, density, prostacyclin and nitrite secretion or collagen and laminin production. However, the metabolic activity was slightly decreased (p = 0.0374) and the membrane integrity marginally impaired (p = 0.0404) in cells from older donors. Two out of three senescence assays detected more senescence markers in cells from older donors. According to the assays applied here, HAEC from young and elderly donors up to the age of 63 years could be judged equally suitable for autologous cellularization strategies. However, this finding should be regarded with caution due to the extremely large variability between individual donors. Further studies comprising a larger sample size are necessary to investigate this issue more thoroughly. KW - Cardiovascular implants KW - arterial endothelial cells KW - aging KW - senescence KW - donor variability Y1 - 2020 UR - https://content.iospress.com/articles/clinical-hemorheology-and-microcirculation/ch199238 U6 - https://doi.org/10.3233/CH-199238 SN - 1875-8622 SN - 1386-0291 VL - 74 IS - 1 SP - 93 EP - 107 ER - TY - GEN A1 - Schulz, Christian A1 - Krüger-Genge, Anne A1 - Lendlein, Andreas A1 - Küpper, Jan-Heiner A1 - Jung, Friedrich T1 - Potential Effects of Nonadherent on Adherent Human Umbilical Venous Endothelial Cells in Cell Culture T2 - International Journal of Molecular Science N2 - The adherence and shear-resistance of human umbilical venous endothelial cells (HUVEC) on polymers is determined in vitro in order to qualify cardiovascular implant materials. In these tests, variable fractions of HUVEC do not adhere to the material but remain suspended in the culture medium. Nonadherent HUVEC usually stop growing, rapidly lose their viability and can release mediators able to influence the growth and function of the adherent HUVEC. The aim of this study was the investigation of the time dependent behaviour of HUVEC under controlled nonadherent conditions, in order to gain insights into potential influences of these cells on their surrounding environment in particular adherent HUVEC in the context of in vitro biofunctionality assessment of cardiovascular implant materials. Data from adherent or nonadherent HUVEC growing on polystyrene-based cell adhesive tissue culture plates (TCP) or nonadhesive low attachment plates (LAP) allow to calculate the number of mediators released into the culture medium either from adherent or nonadherent cells. Thus, the source of the inflammatory mediators can be identified. For nonadherent HUVEC, a time-dependent aggregation without further proliferation was observed. The rate of apoptotic/dead HUVEC progressively increased over 90% within two days. Concomitant with distinct blebbing and loss of membrane integrity over time, augmented releases of prostacyclin (PGI2, up to 2.91 ± 0.62 fg/cell) and platelet-derived growth factor BB (PDGF-BB, up to 1.46 ± 0.42 fg/cell) were detected. The study revealed that nonadherent, dying HUVEC released mediators, which can influence the surrounding microenvironment and thereby the results of in vitro biofunctionality assessment of cardiovascular implant materials. Neglecting nonadherent HUVEC bears the risk for under- or overestimation of the materials endothelialization potential, which could lead to the loss of relevant candidates or to uncertainty with regard to their suitability for cardiac applications. One approach to minimize the influence from nonadherent endothelial cells could be their removal shortly after observing initial cell adhesion. However, this would require an individual adaptation of the study design, depending on the properties of the biomaterial used. KW - human venous endothelial cells KW - adherent KW - non-adherent KW - viability KW - mediator release Y1 - 2021 UR - https://www.mdpi.com/1422-0067/22/3/1493 U6 - https://doi.org/10.3390/ijms22031493 VL - 22 IS - 3 ER - TY - GEN A1 - Tartivel, Lucile A1 - Blocki, Anna M. A1 - Braune, Steffen A1 - Jung, Friedrich A1 - Behl, Marc A1 - Lendlein, Andreas T1 - An Inverse Shape-Memory Hydrogel Scaffold Switching Upon Cooling in a Tissue-Tolerated Temperature Range T2 - Advanced materials interfaces Y1 - 2022 U6 - https://doi.org/10.1002/admi.202101588 SN - 2196-7350 VL - 9 IS - 6 ER - TY - GEN A1 - Krüger-Genge, Anne A1 - Steinbrecht, Susanne A1 - Küpper, Jan-Heiner A1 - Lendlein, Andreas A1 - Jung, Friedrich T1 - Evidence for cytostatic effect of cyclophosphamide on human vein endothelial cells in cancer therapy: preliminary in vitro results. T2 - Clinical Hemorheology and Microcirculation Y1 - 2018 U6 - https://doi.org/10.3233/CH-189125 SN - 1875-8622 SN - 1386-0291 VL - 69 IS - 1-2 SP - 267 EP - 276 ER - TY - GEN A1 - Krüger-Genge, Anne A1 - Braune, Steffen A1 - Walter, Maria A1 - Kratz, Karl A1 - Küpper, Jan-Heiner A1 - Krengel, M. A1 - Lendlein, Andreas A1 - Jung, Friedrich T1 - Influence of surface treatments of poly(n-butyl acrylate) networks on fibroblasts adhesion, morphology and viability T2 - Clinical Hemorheology and Microcirculation Y1 - 2018 U6 - https://doi.org/10.3233/CH-189130 SN - 1875-8622 SN - 1386-0291 VL - 69 IS - 1-2 SP - 305 EP - 316 ER - TY - GEN A1 - Schulz, Christian A1 - Krüger-Genge, Anne A1 - Jung, Friedrich A1 - Lendlein, Andreas T1 - Aptamer supported in vitro endothelialization of poly(ether imide) films T2 - Clinical Hemorheology and Microcirculation N2 - Implantation of synthetic small-diameter vascular bypass grafts is often associated with an increased risk of failure, due to thrombotic events or late intimal hyperplasia. As one of the causes an insufficient hemocompatibility of the artificial surface is discussed. Endothelialization of synthetic grafts is reported to be a promising strategy for creating a self-renewing and regulative anti-thrombotic graft surface. However, the establishment of a shear resistant cell monolayer is still challenging. In our study, cyto- and immuno-compatible poly(ether imide) (PEI) films were explored as potential biomaterial for cardiovascular applications. Recently, we reported that the initial adherence of primary human umbilical vein endothelial cells (HUVEC) was delayed on PEI-films and about 9 days were needed to establish a confluent and almost shear resistant HUVEC monolayer. To accelerate the initial adherence of HUVEC, the PEI-film surface was functionalized with an aptamer-cRGD peptide based endothelialization supporting system. With this functionalization the initial adherence as well as the shear resistance of HUVEC on PEI-films was considerable improved compared to the unmodified polymer surface. The in vitro results confirm the general applicability of aptamers for an efficient functionalization of substrate surfaces. KW - aptamer KW - endothelialization KW - physical functionalization KW - poly(ether imide) films KW - shear resistance Y1 - 2020 U6 - https://doi.org/10.3233/CH-190775 SN - 1875-8622 SN - 1386-0291 VL - 75 IS - 2 SP - 201 EP - 217 ER - TY - GEN A1 - Lau, S. A1 - Rangarajan, R. A1 - Krüger-Genge, Anne A1 - Braune, Steffen A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner A1 - Lendlein, Andreas A1 - Jung, Friedrich T1 - Effects of acrolein in comparison to its prodrug cyclophosphamide on human primary endothelial cells in vitro T2 - Toxicology in Vitro N2 - Cyclophosphamide (CPA) is one of the most successful anticancer prodrugs that becomes effective after biotransformation in the liver resulting in the toxic metabolite acrolein. Cancer is often accompanied by thromboembolic events, which might be a result of dysfunctional endothelial cells due to CPA treatment. Here, the effect of 1 mM CPA or acrolein (10/50/100/500 μM) on human umbilical vein endothelial cells (HUVECs) was analyzed after two days of treatment. The addition of CPA or 10 μM acrolein did not affect HUVECs. However, concentrations of 100 μM and 500 μM acrolein significantly reduced the number of adherent cells by 86 ± 13% and 99 ± 1% and cell viability by 51 ± 29% and 93 ± 8% compared to the control. Moreover, pronounced stress fibers as well as multiple nuclei were observed and von Willebrand factor (vWF) was completely released. Lactate dehydrogenase was 8.5 ± 7.0-fold and 252.9 ± 42.9-fold increased showing a loss of cell membrane integrity. The prostacyclin and thromboxane secretion was significantly increased by the addition of 500 μM acrolein (43.1 ± 17.6-fold and 246.4 ± 106.3-fold) indicating cell activation/pertubation. High doses of acrolein led to HUVEC death and loss of vWF production. This effect might be associated with the increased incidence of thromboembolic events in cancer patients treated with high doses of CPA. KW - Human umbilical venous endothelial cells KW - Acrolein KW - Aneuploidy KW - von Willebrand factor KW - in vitro study Y1 - 2020 U6 - https://doi.org/10.1016/j.tiv.2019.104685 SN - 0887-2333 VL - 62 ER - TY - GEN A1 - Lee, Seahyoung A1 - Ganesan, Ramakrishnan A1 - Krüger-Genge, Anne A1 - Kratz, Karl A1 - Franke, Ralf-Peter A1 - Lendlein, Andreas A1 - Jung, Friedrich T1 - Substrate-enzyme affinity-based surface modification strategy for endothelial cell-specific binding under shear stress T2 - Clinical Hemorheology and Microcirculation N2 - Establishing an endothelial cell (EC) monolayer on top of the blood contacting surface of grafts is considered to be a promising approach for creating a hemocompatible surface. Here we utilized the high affinity interactions between the EC plasma membrane expressed enzyme called endothelin converting enzyme-1 (ECE-1) and its corresponding substrate big Endothelin-1 (bigET-1) to engineer an EC-specific binding surface. Since enzymatic cleavage of substrates require physical interaction between the enzyme and its corresponding substrate, it was hypothesized that a surface with chemically immobilized synthetic bigET-1 will preferentially attract ECs over other types of cells found in vascular system such as vascular smooth muscle cells (VSMCs). First, the expression of ECE-1 was significantly higher in ECs, and ECs processed synthetic bigET-1 to produce ET-1 in a cell number-dependent manner. Such interaction between ECs and synthetic bigET-1 was also detectible in blood. Next, vinyl-terminated self-assembled monolayers (SAMs) were established, oxidized and activated on a glass substrate as a model to immobilize synthetic bigET-1 via amide bonds. The ECs cultured on the synthetic bigET-1-immobilized surface processed larger amount of synthetic bigET-1 to produce ET-1 compared to VSMCs (102.9±5.13 vs. 9.75±0.74 pg/ml). The number of ECs bound to the synthetic bigET-1-immobilized surface during 1 h of shearing (5dyne/cm2) was approximately 3-fold higher than that of VSMCs (46.25±12.61 vs. 15.25±3.69 cells/100×HPF). EC-specific binding of synthetic bigET-1-immobilized surface over a surface modified with collagen, a common substance for cell adhesion, was also observed. The present study demonstrated that using the substrate-enzyme affinity (SEA) of cell type-specific enzyme and its corresponding substrate can be an effective method to engineer a surface preferentially binds specific type of cells. This novel strategy might open a new route toward rapid endothelialization under dynamic conditions supporting the long-term patency of cardiovascular implants. KW - endothelin converting enzyme-1 KW - big endothelin-1 KW - endothelialization KW - shear resistance Y1 - 2020 UR - https://content.iospress.com/articles/clinical-hemorheology-and-microcirculation/ch190736 U6 - https://doi.org/10.3233/CH-190736 SN - 1875-8622 VL - 75 IS - 1 SP - 85 EP - 98 ER - TY - GEN A1 - Lau, S. A1 - Gossen, Maike A1 - Lendlein, Andreas A1 - Jung, Friedrich T1 - Differential sensitivity of assays for determining vein endothelial cell senescence T2 - Clinical Hemorheology and Microcirculation Y1 - 2022 U6 - https://doi.org/10.3233/CH-211294 SN - 1875-8622 SN - 1386-0291 VL - 81 IS - 3 SP - 191 EP - 203 ER -