Resisting Protein but Promoting Cell Adhesion by Choline Phosphate:A Comparative Study with Phosphorylcholine

Zwitterionic materials are now widely used to fabricate various functionalized surfaces for biomedical applications due to their excellent non-fouling properties.However,a newly-discovered zwitterionic material,choline phosphate(CP),was reported to be cell-adhesive,which makes it different from traditional non-fouling zwitterionic materials such as sulfobetaine,carboxybetaine and phosphorylcholine(PC).To further investigate the properties of CP,a comparative study was conducted and the widely-reported zwitterionic PC was employed as a control which has the same chemical component but opposite orientation of charged groups with CP.For this purpose,CP and PC-functionalized surfaces were prepared by surface-initiated atom transfer radical polymerization(Si-ATRP),and their non-fouling properties were probed by protein adsorption and eukaryotic cell adhesion measurement.Results showed that CP-functionalized surfaces exhibited almost equivalent amounts of adsorbed proteins to that of PC,but they were more beneficial to cells initial adhesion and further spreading in serum-free medium,indicating that CP had a promising prospect of application in tissue engineering.