Surface modification of titanium substrate with a novel covalently-bound copolymer thin film for improving its platelet compatibility

Abstract

Despite of its widely uses in various clinical applications, the titanium-based material still faces different challenges, such as hemocompatibility and anti-biofouling characteristics required in various situations. The objective of this investigation was to develop a novel surface modification strategy for titanium-based material to improve the platelet compatibility that is important in rigorous blood-contacting cardiovascular applications. In this work, a series of copolymers, which composed of novel 6-acryloyloxy hexyl phosphonic acid (AcrHPA) and sulfobetaine methacrylate (SBMA) was synthesized. The phosphonic acid group in these copolymers can impart covalent binding to the titanium substrate while the zwitterionic sulfobetaine functionality is considered being able to reduce the platelet adhesion and activation on the modified titanium substrate. NMR analyses suggested that copolymerization reaction is likely not an ideal statistical reaction but to add the monomers in a random order. Studies have shown that the composition of the monomers affected the surface characteristics and platelet compatibility of these covalent-bound AcrHPA-SBMA copolymers on titanium substrate. Contact angle analysis has shown the addition of SBMA can increase surface hydrophilicity of the spun-coated copolymers. In addition, AFM analyses have revealed that the surface roughness of the spun-coated copolymer layer were varied with the ratio of AcrHPA and SBMA. The most platelet compatible surface was noted on the one modified by the highest amount of SBMA added (i.e. 70 mol%) in copolymerization. In summary, the surface modification scheme presented here would be of potential as well as manufacturing process applicable for future development in blood-contacting titanium-based biomedical devices.

In Vivo Blood-Repellent Performance of a Controllable Facile-Generated Superhydrophobic Surface

“…At present, superhydrophobic modification has already become a research focus to improve the hemocompatibility of titanium surfaces. − Various mechanisms of platelet antiadhesion induced by the superhydrophobic surface have been proposed. The main conclusion is that the amount of adherent platelets is closely related to the effective surface area accessible to the platelets. − Consequently, it is a promising way to achieve a smaller effective area by adopting the Cassie state in superhydrophobic theory .…”

Endothelial Cell-Derived Tethered Lipid Bilayers Generating Nitric Oxide for Endovascular Implantation

“…Titanium is one of the widely used metals for the fabrication of biomedical devices due to its substantial mechanical properties, biocompatibility, and anticorrosion properties . These properties allow titanium to be readily sought after the fabrication of hard tissue replacement in orthopedic or dental applications, cardiovascular stents, and others . Thus, we choose titanium as a substrate to apply the tethered lipid bilayer (tLB) with good stability and biomimicry, and the NO-generating system based on the synthesized organoselenium catalyst.…”

“…28 These properties allow titanium to be readily sought after the fabrication of hard tissue replacement in orthopedic or dental applications, cardiovascular stents, and others. 29 Thus, we choose titanium as a substrate to apply the tethered lipid bilayer (tLB) with good stability and biomimicry, 30 and the NO-generating system based on the synthesized organoselenium catalyst.…”

Biomimetic Principles to Develop Blood Compatible Surfaces

“…Furthermore, the surface roughness can be effectively smoothed by brush grafting with additional positive effects on material biocompatibility (49). Another benefit of the polymer approach is the possibility to prepare zwitterionic copolymers with targeted properties, including high temperature tolerance (50), salt (51, 52) or pH (53) responsivity, biodegradability (54, 55) or incorporation of anchoring groups (56, 57). Polyzwitterions can thereby combine the benefits of macromolecular scaffolds and useful local monomeric zwitterionic properties to yield optimal performance (58).…”