Effect of nitrogen and oxygen incorporated into TMSAA plasma coating on surface‐bound heparin activity

Abstract

ABSTRACT:To investigate the influence of nitrogen and oxygen incorporated into N-trimethylsilylallyamine (TM-SAA) plasma coating on heparin binding to the surfaces, four types of monomer combinations were utilized. Those combinations include TMSAA alone, TMSAA mixed with nitrogen (TMSAA ϩ N 2 ), with air (TMSAA ϩ air), and with oxygen (TMSAA ϩ O 2 ). Fourier transform infrared (FTIR) spectroscopy was employed to study the coating of the bulk structure. The thickness and surface morphology of the coatings were measured using atomic force microscopy (AFM). Electron spectroscopy for chemical analysis (ESCA) and the contact angle were used to investigate the surface elemental composition and hydrophilicity, respectively. It was found that the incorporation of oxygen into the coating formation significantly increased the deposition rate of the TMSAA ϩ O 2 coating, but the heparin activity was the least even though it made the coating surface more hydrophilic. This is considered to have resulted from the loss of nitrogen in the coating structure due to the oxygen replacement to nitrogen. The nitrogen incorporated into the coating had no noticeable effect on the heparin surface-binding ability. The TMSAA ϩ air plasma grafting process exhibited the best heparin attachment to the surface, which could be largely attributed to its highest surface roughness, although the nitrogen composition was decreased to some extent compared to the pure TMSAA plasma coating.

Inhibition of Staphylococcus epidermidis Biofilm by Trimethylsilane Plasma Coating

“…As discussed above, with TMS coating, it is expected that more carbon and silicon will be present on the TMS-coated Ti surface, because monomer TMS [(CH 3 ) 3 -SiH] contains three carbon atoms and one Si atom. Again, the oxygen on the TMS coating could be attributed to the oxidation of the coating material after its exposure to the atmosphere, which has been reported to be observed on the surface of many other plasma-deposited coatings (14,27,39,77,101).…”

Cell attachment and biocompatibility of polytetrafluoroethylene (PTFE) treated with glow-discharge plasma of mixed ammonia and oxygen

“…For NH 3 C O 2 gas mixture plasma, the mass ow rate ratio of NH 3 to O 2 was set at 2 : 3 to see how oxygen and nitrogen, activated in the plasma atmosphere, incorporate into the PTFE surface and consequently affect cell adhesion to the surface. A detailed description of the radio-frequency (RF) glow-discharge plasma deposition system has been reported elsewhere [11,12]. Following plasma treatment, all the wafers were stored in sealed plastic vials in an attempt to alleviate the reaction of air to plasma-treated surfaces and prevent dust from falling onto wafer surfaces.…”

Towards improved artificial lungs through biocatalysis

“…Heparin-coated HFM are increasingly used clinically as a means of preventing blood coagulation and maintaining artificial lung performance [51,52]. Surface immobilization of CA to HFM would likely not replace the need for thromboresistant coatings like heparin, although the enzyme by itself may to some degree reduce thrombus formation by blocking the adsorption of adhesive proteins such as fibrinogen that bind and activate platelets.…”

“…Coating of HFM with heparin requires initial surface amination, often using a polymer spacer to move the heparin molecule off the surface. As both heparin and CA immobilization require reactive amines, these coatings could very well be co-immobilized in a single step [52].…”