Attachment of Docetaxel to Multiwalled Carbon Nanotubes for Drug Delivery Applications

In this manuscript we report the development of multiwalled carbon nanotubes—docetaxel conjugate by covalent interaction, involving nucleophilic substitution reaction mechanism. The surface functionalization of nanotubes was carried out by enrichment of carboxylic groups with optimized oxidation treatment. The carboxyl groups were converted to acyl groups followed by covalent attachment of docetaxel to multiwalled carbon nanotubes with a cleavable ester linkage. The drug carbon nanotube conjugate was characterized by Fourier Transform Infra red, UV-Visible, Raman spectroscopy, Scanning and Transmission electron microscopy. The drug release from the conjugate was studied in vitro in phosphate buffers having pH 5, 6.8 and 7.4. It was demonstrated that conjugate showed drug release faster in acidic pH, which resembles the pH of cancerous cells, as compared to buffer of normal cell pH. This property would reduce the drug dosage thereby substantially benefit the antitumor effect and would boost significantly the applications of carbon nanotubes in the biomedicine field.