Influence of Heat Treatment of Nitinol Wire on the Properties of Nitinol/Hybrid Layer for Ibuprofen Release

The efficiency of drug delivery from coatings of metallic implants is one of the key factors. The influence of chemical and thermal treatments of nitinol wire on the corrosion properties, deposition of hydroxyapatite(HA)/poly ε-caprolactone-polyethylene glycol (PEG-<i>b</i>-PCL), and the amount of ibuprofen released from that bilayer were studied. The hydroxyapatite layer was electrodeposited by pulse current, while the PEG-<i>b</i>-PCL layer was by drop-coating. It was shown that nitinol wire, chemically treated and thermally heated at 470 °C under optimized conditions, is the most optimal substrate for the deposition of uniform and compact hybrid HA/(PEG-<i>b</i>-PCL) bilayer. Ibuprofen incorporated into this hybrid bilayer exhibits the maximum release into phosphate-buffered saline (PBS) solution. About 80% of ibuprofen is released within 5 h.