title: Study of albumin and fibrinogen membranes formed by interfacial crosslinking using microfluidic flow.
abstract: Microfluidics enables scale reduction in sample volume with obvious benefits for reagent conservation. In contrast to conventional macro-scale flow, microfluidics also offers unprecedented control over flow dynamics. In particular, laminar flow is readily achieved, allowing for new analytical and synthetic strategies. Here, two parallel flows of buffer and xylene were used to create a stable liquid-liquid interface within linear micro-channels. These, respectively, carried protein (albumin or fibrinogen) and an acyl chloride to effect protein crosslinking. This created robust, micro-membranes at the interface that bisected the fluid channel. Membrane formation was self-limiting, with fibrinogen membranes showing greater solute permeability than albumin, based on dye transport (Ponceau S, Meldola Blue). The crosslinker isophthaloyl dichloride led to thinner, less permeable membranes than terephthaloyl chloride. Larger surface area membranes formed at a static liquid-liquid interface served as a more physically accessible model and allowed precise electrochemical determination of acetaminophen, catechol and peroxide diffusion coefficients, which confirmed the greater fibrinogen permeability. Scanning electron microscopy (SEM) of the membranes also indicated a higher population of discrete nanopores at the fibrinogen surface. A crosslinking pH had a strong effect on overall permeability. Adhesion of B50 neuronal cells was demonstrated, and it is proposed that the membranes could facilitate cell growth through bidirectional nutrient supply in a micrbioreactor format.
authors.affiliation: IRC in Biomedical Materials, Department of Physics, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
authors.forename: Hong
authors.initials: H
authors.lastname: Chang
authors.forename: Rachel
authors.initials: R
authors.lastname: Khan
authors.forename: Zimei
authors.initials: Z
authors.lastname: Rong
authors.forename: Andrei
authors.initials: A
authors.lastname: Sapelkin
authors.forename: Pankaj
authors.initials: P
authors.lastname: Vadgama
mesh_terms: D000818:Animals; D002460:Cell Line; D003432:Cross-Linking Reagents; D004058:Diffusion; D005340:Fibrinogen / Q000737:chemistry* / Q000378:metabolism; D005353:Fibronectins / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D008853:Microscopy; D008855:Microscopy, Electron, Scanning; D008962:Models, Theoretical; D010078:Oxazines / Q000737:chemistry; D010539:Permeability; D010795:Phthalic Acids / Q000737:chemistry; D016062:Porosity; D051381:Rats; D012710:Serum Albumin, Bovine / Q000737:chemistry* / Q000378:metabolism
chemical_list: D003432:Cross-Linking Reagents; D005353:Fibronectins; D008567:Membranes, Artificial; D010078:Oxazines; D010795:Phthalic Acids; D012710:Serum Albumin, Bovine; C005559:Meldola blue; D005340:Fibrinogen; C059743:terephthaloyl chloride