Design of materials with nanostructured surface to improve hemocompatibility
(2007)
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- Abstract
- The aim of this work is to better understand the influence of the surface properties of a biomaterial on protein adsorption and cell adhesion, in relation with its hemocompatibility. Particularly, the influence of surface nanotopography and of surface chemical modification with polyethylene oxide (PEO) compounds were investigated. For this purpose, flat and nanostructured surfaces were used. Glass, polystyrene, pure polyvinyl chloride substrates as well as pieces of blood bag were chosen as reference surfaces. Surfaces presenting different roughness characteristics were fabricated on glass by combining polycation adsorption and adhesion of polystyrene latex particles (470 and 65 nm in diameter). Depending on the sequence of operations, different surface structures were obtained: layer of particles with a diameter of 470 nm or 65 nm, bimodal roughness (type I) made with one layer of 470 nm separated by 65 nm particles, and bimodal roughness (type II) made by raspberry-like particles produced by adhesion of 65 nm particles on top of 470 nm particles. These different roughnesses are expected to modulate the effect of the surface chemical composition on the interactions of blood components with materials. Except for blood bag, all surfaces were then conditioned by adsorption of PEO compounds which are expected to make them protein repellent. These compounds were Pluronic F68, a block copolymer of polypropylene oxide and polyethylene oxide, and PLL-g-PEG, a copolymer made of a poly-L-lysine backbone on which polyethylene glycol chains are grafted. The hemocompatible character of native and conditioned surfaces was evaluated by studying fibrinogen adsorption in competition with albumin, and platelet adhesion and activation. As expected, the blood bag showed the less fibrinogen adsorption and platelet adhesion in agreement with its hemocompatible character. Pluronic F68 reduced fibrinogen adsorption as well as adhesion and activation of platelets on all substrates, except on glass, while adsorbed PLL-g-PEG was only efficient on glass substrate. The different nanotopographies created by colloidal assembly did not markedly modify the behavior towards blood components. Surface chemistry, in comparison with the designed nanotopographies, was thus the dominant factor influencing hemocompatibility.
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Nonckreman, C. (2007). Design of materials with nanostructured surface to improve hemocompatibility. https://hdl.handle.net/2078.5/124103