초록 |
We examined a three-step process to enhance the durability of the drug-in-polymer matrix on a cobalt chrome substrate (CC). In the first step; ricinoleic acid (RA) was reacted with polished cobalt chrome specimens, forming a carbon-metal covalent bond. Water contact angle, ATR-FTIR, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used to study the formation of the organic molecules. In the second step, RA-molecules were used to initiate the ring-opening polymerization (ROP) of ε-caprolactone (CL). The PCL brushes on the CC surface were characterized using ATR-FTIR, SEM, XPS as well as contact angle measurements. The last step involved ultrasonic coating of the modified CC with a drug-in-polymer matrix [PLLA+sirolimus]. The interfacial adhesion of the drug-in-polymer matrix to the CC-surface was measured by scratch tester. Sirolimus controlled release was tested for 7 weeks using high pressure liquid chromatography. |