title: Solution composition impacts fibronectin immobilization on carboxymethyl-dextran surfaces and INS-1 insulin secretion.
abstract: It is shown that solution composition during immobilization plays a critical role in the properties of fibronectin (FN) surfaces and their bioactivity towards insulinoma (INS-1) cell function. X-ray photoelectron spectroscopy revealed FN grafting onto low-fouling carboxymethyl-dextran (CMD) surfaces was successful with solutions composed of 10 μM CaCl(2), 10 μM MgCl(2), 10 μM MnCl(2), and 10 μM and 1mM NaCl, but unsuccessful with those made of 150 mM NaCl or 1× PBS. Circular dichroism and photon correlation spectroscopy revealed that regardless of solution composition, no measurable differences in free FN conformation prevail. AFM imaging of FN-CMD revealed, while there are no quantitative differences in surface roughness, there are some subtle qualitative differences in topography. FN surface immobilization scheme does not influence INS-1 cell growth after 3 and 7 days regardless of the underlying substrate or solution composition. INS-1 cell insulin secretion in response to glucose is affected by the substrate and solution composition during FN immobilization.
authors.affiliation: Laboratoire de bio-ingénierie et de biophysique de l'Université de Sherbrooke, Department of Chemical and Biotechnological Engineering, Université de Sherbrooke, 2500 boulevard de l'Université, Sherbrooke, Québec, J1K 2R1 Canada.
authors.forename: Evan A
authors.initials: EA
authors.lastname: Dubiel
authors.forename: Patrick
authors.initials: P
authors.lastname: Vermette
mesh_terms: D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002942:Circular Dichroism; D003911:Dextrans / Q000737:chemistry* / Q000378:metabolism; D005353:Fibronectins / Q000097:blood / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007340:Insulinoma / Q000378:metabolism* / Q000473:pathology*; D012996:Solutions; D013499:Surface Properties
chemical_list: D003911:Dextrans; D005353:Fibronectins; D007328:Insulin; D012996:Solutions; C014392:carboxymethyl dextran; D005947:Glucose