scholarly journals Towards Biohybrid Lung Development—Fibronectin-Coating Bestows Hemocompatibility of Gas Exchange Hollow Fiber Membranes by Improving Flow-Resistant Endothelialization

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 35
Author(s):  
Michael Pflaum ◽  
Sophie Jurmann ◽  
Katherina Katsirntaki ◽  
Marisa Mälzer ◽  
Axel Haverich ◽  
...  

To provide an alternative treatment option for patients with end-stage lung disease, we aim for biohybrid lung development (BHL) based on hollow fiber membrane (HFM) technology used in extracorporeal membrane oxygenators. For long-term BHL application, complete hemocompatibility of all blood-contacting surfaces is indispensable and can be achieved by their endothelialization. Indeed, albumin/heparin (AH) coated HFM enables initial endothelialization, but as inexplicable cell loss under flow conditions was seen, we assessed an alternative HFM coating using fibronectin (FN). Therefore, endothelial cell (EC) adherence and viability on both coated HFM were analyzed by fluorescence-based staining. Functional leukocyte and thrombocyte adhesion assays were performed to evaluate hemocompatibility, also in comparison to blood plasma coated HFM as a clinically relevant control. To assess monolayer resistance and EC behavior under clinically relevant flow conditions, a mock circulation setup was established, which also facilitates imitation of lung-disease specific blood gas settings. Besides quantification of flow-associated cell loss, endothelial responses towards external stimuli, like flow exposure or TNFα stimulation, were analyzed by qRT-PCR, focusing on inflammation, thrombus formation and extracellular matrix production. Under static conditions, both coated HFM enabled the generation of a viable, confluent, non-inflammatory and anti-thrombogenic monolayer. However, by means of homogenous FN coating, cell retention and physiologic gene regulation towards an improved hemocompatible-and extracellular matrix producing phenotype, was significantly superior compared to the inhomogeneous AH coating. In summary, our adaptable in-house FN coating secures the endothelial requirements for long-term BHL application and may promote monolayer establishment on all other blood contacting surfaces of the BHL (e.g., cannulae).

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 692
Author(s):  
Roland Schopf ◽  
Florian Schmidt ◽  
Johanna Linner ◽  
Ulrich Kulozik

The fractionation efficiency of hollow fiber membranes (HFM) for milk protein fractionation was compared to ceramic tubular membranes (CTM) and spiral wound membranes (SWM). HFM combine the features of high membrane packing density of SWM and the more defined flow conditions and better control of membrane fouling in the open flow channel cross-sections of CTM. The aim was to comparatively analyze the effect of variations in local pressure and flow conditions while using single industrially sized standard modules with similar dimensions and module footprints (module diameter and length). The comparative assessment with varied transmembrane pressure was first applied for a constant feed volume flow rate of 20 m3 h−1 and, secondly, with the same axial pressure drop along the modules of 1.3 bar m−1, similar to commonly applied crossflow velocity and wall shear stress conditions at the industrial level. Flux, transmission factor of proteins (whey proteins and serum caseins), and specific protein mass flow per area membrane and per volume of module installed were determined as the evaluation criteria. The casein-to-whey protein ratios were calculated as a measure for protein fractionation effect. Results obtained show that HFM, which so far are under-represented as standard module types in industrial dairy applications, appear to be a competitive alternative to SWM and CTM for milk protein fractionation.


1987 ◽  
Author(s):  
M R Buchanan ◽  
E Bastida ◽  
J Aznar-Salatti ◽  
P de Groot

It is generally thought that the extracellular matrix (ECM) is thrombogenic.However,one of us (MRB) has reported that the ECM is thromboresistant,and postulated that this was due to the release of endothelial cell (EC) 13-hydroxyoctadecadienoic acid (13-HODE) into the ECM. To test this possibility, we measured platelet adhesion (PLT ADH) onto cultured ECs and their ECMs exposed by 3 methods. We also extracted the ECMs for HPLC analysis of 13-HODE.PLT ADH was expressed as i)adhesion of 3H-adenine labelled platelets/mm2 of ECs or ECMs under static conditions, and ii) % surface^ area coverage measured morphometrically following 5"perfusion with citrated whole blood at 1300 sec-1 in the flat chamber.ECMs were prepared by removing the EC monolayers by freeze thawing , cellulose acetate stripping or NH4OH treatment. PLT ADH to ECs under static and flow conditions were 4700±240/mm2 and 0.1%, respectively, and were associated with 12,6± 1 pg of 13-HODE/mm2 of EC surface (M+SEM). Removal of the ECs by freeze thawing or stripping, resulted in a 18% and 25% increase in PLT ADH to the ECM,under static and flow conditions respectively, and a 80% decrease in ECM associated 13-HODE level. Removal of the EC by NH4OH resulted in a 380% and 770% increase in PLT ADH to the ECM in static and flow conditions. 13-HODE was undetectable.These data support the hypothesis that 13-HODE released from ECs influences the ECM thrombogenecity, and indicate that the residual amounts of components present in the ECMs following EC removal is influenced by the method of ECM preparation.


2015 ◽  
Vol 93 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Lisa A. Joss-Moore ◽  
Robert H. Lane ◽  
Kurt H. Albertine

Perinatal insults, including intrauterine growth restriction, preterm birth, maternal exposure to toxins, or dietary deficiencies produce deviations in the epigenome of lung cells. Occurrence of perinatal insults often coincides with the final stages of lung development. The result of epigenome disruptions in response to perinatal insults during lung development may be long-term structural and functional impairment of the lung and development of lung disease. Understanding the contribution of epigenetic mechanisms to life-long lung disease following perinatal insults is the focus of the developmental origins of adult lung disease field. DNA methylation, histone modifications, and microRNA changes are all observed in various forms of lung disease. However, the perinatal contribution to such epigenetic mechanisms is poorly understood. Here we discuss the developmental origins of adult lung disease, the interplay between perinatal events, lung development and disease, and the role that epigenetic mechanisms play in connecting these events.


2021 ◽  
Author(s):  
Honglei Pang ◽  
Yayu Qiu ◽  
Weipeng Sheng

Abstract To obtain a long-term stable operation of the hollow fiber membrane for using in membrane contact absorption of carbon dioxide (CO2), hybrid polyvinylidene fluoride-silica-hexadecyltrimethoxysilane (PVDF-SiO2-HDTMS) membrane were fabricated via the non-solvent induced phase-inversion method. The surface properties, performance characteristics and long-term stable operation performance of the prepared membranes were compared and analyzed. The results show the outer surface of the prepared membranes exhibited superhydrophobicity because of the formation of rough nano-scale microstructures and the low surface free energy. Due to the addition of inorganic nanoparticles, the mechanical strength of PVDF-SiO2-HDTMS membranes were improved. The long-term stable operation experiments were carried out with the inlet gas (CO2/N2 = 19/81, v/v) at a flow rate of 20 mL/min and the absorbent liquid (1 mol/L DEA) at a flow rate of 50 mL/min. And the result showed that the mass transfer flux of PVDF-SiO2-HDTMS membrane decreased from the initial value of 2.39×10-3 mol/m2s to 2.31×10-3 mol/m2s, which was a decrease of 3% after 20 days. The main benefit is the addition of inorganic nanoparticles, which have strong chemical resistance and high hydrophobicity, thereby preventing structural damage and pore wetting of the membrane. PVDF-SiO2-HDTMS membrane exhibits excellent long-term stable operation performance of CO2.


Author(s):  
Kevin Roberts ◽  
John Taehwan Kim ◽  
Shelby White ◽  
Jamie Hestekin ◽  
Jeffrey C. Wolchok

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