Chemical coatings relying on the self-polymerization of catechol for retrievable vena cava filters

The heparin-dopamine conjugate was synthesized by an amidation reaction between heparin's carboxyl and dopamine's amine, whereas the paclitaxel (PTX)-catechol conjugate was prepared via an esterification reaction between the carboxyl in 3-catechol-1-acetic acid and PTX's hydroxyl. The former can be chemically coated on a Ti-Ni alloy substrate via pH sensitive self-polymerization of the catechol moieties in aqueous solution, and the latter can also be chemically attached to a Ti-Ni alloy substrate in acetone by the thermo-sensitive self-polymerization of catechol. Successful chemical coating of heparin and PTX can be proven by static contact angle and XPS measurements, respectively. In vitro evaluation showed that the heparin coating exhibited anti-thrombosis properties, whereas the PTX coating also illustrated anti-intimal hyperplasia properties. Consequently, the promising potential to develop chemical coatings relying on the self-polymerization of catechol moieties to effectively extend the in vivo retention time of retrievable vena cava filters in the clinic was shown. After covalent conjugation with catechol, heparin and paclitaxel can be chemically coated on a Ti-Ni alloy to endow anti-thrombosis and anti-intimal hyperplasia properties, respectively.