Surface Modification of Polycarbonate Urethane with Zwitterionic Polynorbornene via Thiol‐ene Click‐Reaction to Facilitate Cell Growth and Proliferation

Abstract

Herein, we grafted the zwitterionic polynorbornene onto polycarbonate urethane (PCU) film surface by a convenient route of thiol‐ene click‐chemistry. The PCU film surface was first treated with hexamethylene‐1,6‐diisocynate and subsequently with two different thiol agents (l‐cysteine and β‐marcaptoethanol) in the presence of di‐n‐butyltin dilaurate (DBTDL) to immobilize sulfhydryl groups onto the surface. Here, DBTDL acted as selective catalyst for the reaction between surface‐tethered isocyanates and amine/hydroxyl groups in thiol agents over that of free thiol groups. In the next step, zwitterionic polynorbornene (poly(NSulfoZI)) having functionalizable double bonds was grafted onto these surfaces by photo‐initiated thiol‐ene click‐reaction. The modified surfaces were characterized by water contact angle and XPS analysis. Moreover, the cytocompatibility of these surfaces was investigated by model endothelial cells, EA.hy926, for 1, 3, and 7 d culture times, which showed enhanced cell adhesion and growth. Therefore, the poly(NSulfoZI) functionalized PCU surface using l‐cysteine as thiol agent could be a good candidate for tissue engineering material application.