Protein Repellent, Surface-Attached Hydrogels Through Spray Coating

Abstract

This work describes a novel technique for the deposition of surface-attached hydrogels, which is based on a combination of spray coating and CH-insertion cross-linking (CHic) to create a protein repellent surface. To this, hydrogel precursor polymers are spray coated onto the surface to be modified, dried, and photo cross-linked in the solid state. Spray coating allows the application of the hydrogel precursors in a fast and flexible way, so that even geometrically challenging substrates can be coated, such as the round surfaces present in the inside of blood collection tubes. Characterization of the coatings shows that the layer thickness and roughness can be controlled in the sub micrometer range by varying coating parameters. Interestingly, the ability for the deposited and attached layer to repel proteins is highly affected by these parameters. For layers with an identical chemical composition, protein repellent and adsorbing layers can be formed depending on the spraying conditions. Finally, protein and human serum repellency of spray coated layers in glass blood collection tubes is investigated and show a drastic improvement over uncoated tubes.