Paclitaxel/hydroxyapatite composite coatings on titanium alloy for biomedical applications

In order to reduce the side effects of chemotherapy, target therapies have been spotlighted. In this study, paclitaxel, the drug for cancer treatment, is electrochemically deposited on Ti alloy as vascular stents for the tumor localized therapy by sustaining drug releasing to achieve the cancer cells apoptosis or the prevention of cancer metastasis. In the experiment, cathodic polarization tests coupled with electrochemical reactions were analyzed to speculate the deposition mechanism, and the field emission scanning electron microscope (FESEM), focused ion beam (FIB) system and Fourier transform infrared spectroscopy (FTIR) to observe the surface morphology and analyze constituent elements. A spectrophotometer (UV visible spectrometer) was used to measure drug loading and release. Finally, MTT Assay was carried out to analyze the cell viability for drug efficacy. It is concluded that paclitaxel can be successfully deposited on the titanium alloy by electrochemical method. Besides, the post-hydroxyapatite coated specimen with high porosity can enhance the drug loading from 395 ± 95 μg/cm² to 572 ± 99 μg/cm², a lower burst release in the first day, a higher sustaining release rate in a month, and the more complete drug release. All results indicate that the paclitaxel/hydroxyapatite composite coating by the electrochemical deposition method is much more effective and promising. - Highlights: • The PTX can be directly deposited on titanium by electrochemical method, without any castor oil. • The specimens can nano-size PTX particles, leading to the increase of drug loading from 395 ± 95 μg/cm² to 572 ± 99 μg/cm². • The specimens show a lower burst release, a higher sustaining release rate, and the more complete drug release. • The MTT tests show that all specimens inhibit the proliferation of human umbilical vein endothelial cell efficiently.