Page 40 - Improved endothelialization by silicone surface modification and fluid hydrodynamics modulation- Implications for oxygenator biocompatibility Nasim

tubes interacted with the negatively charged carboxyl groups on collagen, to form carbodiimide bonds through which collagen ionically crosslinked on silicone tubes (Figure 2). AmS Si tubes adsorbed 76% more collagen than Si tubes, 67% more than PSM Si tubes, and 41% more than AAc Si tubes (Table 2). Although PSM Si and Si tubes were capable of linking with collagen, ~20% (PSM Si) and 33% (Si tubes) of the collagen adsorbed was washed out after two times severe washing with water.
Table 1. Abbreviations used for different surface-modified silicone tubes. Tube,
surface modification
silicone
plasma surface-modified silicone
acrylic acid-grafted silicone
aminosilane-grafted silicone
collagen-adsorbed silicone
collagen-immobilized plasma surface-modified silicone collagen-immobilized aminosilane-grafted silicone collagen-immobilized acrylic acid-grafted silicone
Tube, abbreviation
Si
PSM Si AAc Si AmS Si Si-Col PSM Si-Col AmS Si-Col AAc Si-Col
Table 2. Graft density and collagen adsorbed on unmodified and surface-modified silicone tubes before and after washing. Values are mean ± standard deviation for 3 independent experiments. Si-Col, collagen-adsorbed silicone; PSM Si-Col, collagen-immobilized plasma surface-modified silicone; AAc Si-Col, collagen-immobilized AAc-grafted silicone; AmS Si- Col, collagen-immobilized AmS-grafted silicone.
Tube, surface modification
Si-Col PSM Si-Col AAc Si-Col AmS Si-Col
Graft density (mol cm-2)
-
-
5.8 ± 0.4x10-6 4.4 ± 0.2x10-6
Collagen adsorbed before washing (μg cm-2)
15.3 ± 1.7 16.2 ± 2.1
19.1 ± 3.0 27.0 ± 1.8
Collagen adsorbed after washing
(μg cm-2)
10.2 ± 3.2 13.0 ± 1.1
18.8 ± 1.7 27.3 ± 1.2
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