A facile method to prepare a versatile surface coating with fibrinolytic activity, vascular cell selectivity and antibacterial properties.

Clot and thrombus formation on surfaces that come into contact with blood is still the most serious problem for blood contacting devices. Despite many years of continuous efforts in developing hemocompatible materials, it is still of great interest to develop multifunctional materials to enable vascular cell selectivity (to favor rapid endothelialization while inhibiting smooth muscle cell proliferation) and improve hemocompatibility. In addition, biomaterial-associated infections also cause the failure of biomedical implants and devices. However, it remains a challenging task to design materials that are multifunctional, since one of their functions will usually be compromised by the introduction of another function. In the present work, the gold substrate was first layer-by-layer (LbL) deposited with a multilayered polyelectrolyte film containing chitosan (positively charged) and a copolymer of sodium 4-vinylbenzenesulfonate (SS) and the "guest" adamantane monomer 1-adamantan-1-ylmethyl methacrylate (P(SS-co-Ada), negatively charged) via electro-static interactions, referred to as Au-LbL. The chitosan and P(SS-co-Ada) were intended to provide, respectively, resistance to bacteria and heparin-like properties. Then, "host" β-cyclodextrin derivatives bearing seven lysine ligands (CD-L) were immobilized on the Au-LbL surface by host-guest interactions between adamantane residues and CD-L, referred to as Au-LbL/CD-L. Finally, a versatile surface coating with fibrinolytic activity (lysis of nascent clots), vascular cell selectivity and antibacterial properties was developed.