Surface-bound poly , steric

In this article, we will discuss the steric repulsion of plasma proteins, platelets, and bacteria by surface-bound poly(ethylene oxide) (PEO). PEO, a neutral hydrophilic polymer, has been used most widely for surface modification of biomaterials. 

Surface modification with hydrophilic polymers, such as poly(ethylene oxide) (PEO), has been beneficial in improving the blo( compatibility of polymeric biomaterials. Surface-bound PEO is expected to prevent plasma protein adsoiption, platelet adhesion, and bacterial adhesion by the steric repulsion mechanism. PEO-rich surfaces have been prepared either by physical adsorption, or by covalent grafting to the surface. Physically adsorbed PEO homopolymers and copolymers are not very effective since they can be easily displaced from the surface by plasma proteins and cells. Covalent grafting, on the other hand, provides a permanent layer of PEO on the surface. Various methods of PEO grafting to the surface and their effect on plasma protein adsorption, platelet adhesion, and bacterial adhesion is discussed. 

In methyl ethyl ketone, poly(2-vinylpyridine) strongly adsorbs onto the silica surface to create a temporally stable bound polymer layer. The resulting hairy particles are sterically stabilized against agglomeration. 

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