Fluorine doping into diamond‐like carbon coatings inhibits protein adsorption and platelet activation

Abstract

The first major event when a medical device comes in contact with blood is the adsorption of plasma proteins. Protein adsorption on the material surface leads to the activation of the blood coagulation cascade and the inflammatory process, which impair the lifetime of the material. Various efforts have been made to minimize protein adsorption and platelet adhesion. Recently, diamond-like carbon (DLC) has received much attention because of their antithrombogenicity. We recently reported that coating silicon substrates with fluorine-doped diamond-like carbon (F-DLC) drastically suppresses platelet adhesion and activation. Here, we evaluated the protein adsorption on the material surfaces and clarified the relationship between protein adsorption and platelet behaviors, using polycarbonate and DLC- or F-DLC-coated polycarbonate. The adsorption of albumin and fibrinogen were assessed using a colorimetric protein assay, and platelet adhesion and activation were examined using a differential interference contrast microscope. A higher ratio of albumin to fibrinogen adsorption was observed on F-DLC than on DLC and polycarbonate films, indicating that the F-DLC film should prevent thrombus formation. Platelet adhesion and activation on the F-DLC films were more strongly suppressed as the amount of fluorine doping was increased. These results show that the F-DLC coating may be useful for blood-contacting devices.

Improved Hemolytic Performance of Blood Pump with Fluorine-Doped Hydrogenated Amorphous Carbon Coating

“…However, in the present work, the surface roughness increased with increasing contact angle (smaller surface energy). Hasebe, et al and Yu, et al reported that the surface roughness and microstructure have a negligible influence on the surface energy [23,28], with increasing fluorine content, which is due to changes which is consistent with the present results.…”

“…a-C:H films have also shown promising results in hemocompatible coating technology. To date many types of a-C:H films have been applied to medical devices [17][18][19][20][21][22][23][24].…”

“…Therefore, the low surface energy of a-C:H films has prompted investigation of such coatings for improvement of medical devices that require anti-thrombogenic properties. Hasebe and colleagues reported that fluorine-doping of a-C:H (a-C:H:F) films results in a significant reduction of Young's modulus and the surface free energy, meaning these films could be useful for blood contacting medical devices [20,23]. The numbers of platelets adhering to a-C:H:F films were reported to be significantly lower than that with a-C:H films, and the number and activation of adherent platelets was reduced with a-C:H:F films [23].…”

Fluorine-Incorporated Amorphous Carbon Coating Inhibits Adhesion of Blood Cells to Biomaterials

“…We previously reported that an a-C:H:F film with sufficient C-F bonds on its surface showed excellent antithrombotic properties owing to its hydrophobicity. (16,17) This spectrum led us to expect the improvement of antithrombotic properties, because it is characteristic of an antithrombotic a-C:H:F film.…”

“…(14,15) We previously showed that fluorine doping in a-C:H films contributes to a reduction of blood cell adhesion and adsorption of plasma protein. (16,17) We also reported that a-C:H:F-coated biomaterials can play a nontoxic mediating role in vivo, (18) and we developed fluorine-incorporated a-C:H (a-C:H:F) coating techniques for vascular interventional devices using radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD). (19) However, the adhesion of leukocytes in relation to a-C:H:F has not yet been elucidated.…”