title: Diffusion of rhodamine B and bovine serum albumin in fibrin gels seeded with primary endothelial cells.
abstract: Scaffolds with adequate mass transport properties are needed in many tissue engineering applications. Fibrin is considered a good biological material to fabricate such scaffolds. However, very little is known about mass transport in fibrin. Therefore, a method based on the analysis of fluorescence intensity for measuring the apparent diffusion coefficient of rhodamine B and fluorescein-labelled bovine serum albumin (FITC-BSA) is described. The experiments are performed in fibrin gels with and without human umbilical vein endothelial cells (HUVEC). The apparent diffusion coefficients of rhodamine B and FITC-BSA in fibrin (fibrinogen concentration of 4 mg/mL) with different cell densities are reported. A LIVE/DEAD(®) assay is performed to confirm the viability of HUVEC seeded at high densities. Diffusion coefficients for rhodamine B remain more or less constant up to 5×10(5) cells/mL and correlate well with literature values measured by other methods in water systems. This indicates that the presence of HUVEC in the fibrin gels (up to 5×10(5) cells/mL) has almost no effect on the diffusion coefficients. Higher cell densities (>5×10(5) cells/mL) result in a decrease of the diffusion coefficients. Diffusion coefficients of rhodamine B and FITC-BSA obtained by this method agree with diffusion coefficients in water predicted by the Stokes-Einstein equation. The experimental design used in this study can be applied to measure diffusion coefficients in different types of gels seeded or not with living cells.
authors.affiliation: Laboratoire de bio-ingénierie et de biophysique de l'Université de Sherbrooke, Department of Chemical and Biotechnological Engineering, Université de Sherbrooke, Sherbrooke, QC, Canada.
authors.forename: Andriy
authors.initials: A
authors.lastname: Shkilnyy
authors.forename: Pierre
authors.initials: P
authors.lastname: Proulx
authors.forename: Jamie
authors.initials: J
authors.lastname: Sharp
authors.forename: Martin
authors.initials: M
authors.lastname: Lepage
authors.forename: Patrick
authors.initials: P
authors.lastname: Vermette
mesh_terms: D000818:Animals; D002417:Cattle; D002452:Cell Count; D018929:Cell Culture Techniques; D002470:Cell Survival; D004058:Diffusion; D005337:Fibrin / Q000737:chemistry*; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000032:analysis; D005782:Gels / Q000737:chemistry*; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology*; D006801:Humans; D007700:Kinetics; D012235:Rhodamines / Q000032:analysis; D012710:Serum Albumin, Bovine / Q000032:analysis; D013050:Spectrometry, Fluorescence; D023822:Tissue Engineering; D054457:Tissue Scaffolds
chemical_list: D005782:Gels; D012235:Rhodamines; C039217:fluorescein isothiocyanate bovine serum albumin; D012710:Serum Albumin, Bovine; D005337:Fibrin; D016650:Fluorescein-5-isothiocyanate; C029773:rhodamine B