Pulsed laser deposition of hydroxyapatite on nanostructured titanium towards drug eluting implants

Abstract

Titania nanotubes grown on titanium substrates by electrochemical anodization in glycerol–ammonium fluoride–water system were used to develop efficient drug carrying implants upon coating hydroxyapatite (HA) ceramic. The nanostructured surfaces achieved by anodization were caped with HA crystallites by pulsed laser deposition. The implant substrates were studied for their drug carrying capacity using gentamicin as a model. The nano-tubular surface with HA coating had better drug loading capacity of about 800μg/cm2 gentamicin while the bare anodized substrate carried less than 660μg/cm2. The HA coating alone stored as low as 68μg/cm2 and released the drug within the initial burst period itself. The ceramic coated anodized substrates were found to be more efficient in controlled delivery for longer than 160h with a drug release of 0.5μg/cm2 even towards the end. The substrate with nanostructuring alone delivered the whole drug within 140h. This study proposes the application of laser deposition of HA over nanostructured titanium, which proves to be promising towards controlled drug eluting bioceramic coated metallic prostheses.