Page 38 - Improved endothelialization by silicone surface modification and fluid hydrodynamics modulation- Implications for oxygenator biocompatibility Nasim

Figure 1. Flow loop chamber used for assessing the stability of endothelial cells on unmodified and surface-modified silicone tubes under fluid shear stress.
NO quantification -
NO release by endothelial cells was measured as nitrite (NO2 ) accumulation in the medium after 6 days of culture, using Griess reagent including 1% sulfanilamide, 0.1% naphtylethelene-diamine-dihydrochloride, and 2.5 M H3PO4 [36-39]. The absorbance was measured at 545 nm with a microplate reader (Stat Fax-2100, Miami, FL). Serial dilutions of NaNO2 in the medium were used as standard curve.
Statistical analysis
All data were expressed as means ± standard deviation (SD). To compare any significant differences between unmodified and surface-modified silicone tubes, one-way analysis of variance was used. The significance of differences among means was determined by post-hoc comparisons, using Bonferroni’s method. Two way analysis of variance with pairwise comparison was used to assess differences among means between groups and over time. A probability (p) value of less than 0.05 (p<0.05) was taken as the level of significance.
RESULTS
In this study surface modification of silicone tubes was performed to introduce peroxide (–OO), carboxyl (–COOH) or amine (–NH2) functional groups with or without immobilized collagen for improvement of endothelialization, cell stability,
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