Enhancing surface chemistry and wetting behavior of laser-modified Ti–6Al–4V surgical titanium alloy surfaces through wet deposition of biogenic hydroxyapatite

Abstract

This study focuses on enhancing the surface properties of surgical titanium alloys (Ti–6Al–4V) to optimize their suitability for biomedical implant applications. Direct laser writing (DLW) was used to modify the titanium surface and facilitate the deposition of biohydroxyapatite (BHA) particles through wet deposition and the coalescence phenomenon. Four types of etching patterns were tested, resulting in biomimetic bone-like surfaces with microtextured features, exhibiting suitable hydrophilic characteristics for biomedical implants. The resulting surfaces were characterized structurally, morphologically, chemically, and in terms of wettability. X-ray diffraction was performed to validate the titanium alloy composition and determine the crystallite size of BHA particles, both before and after thermal treatment. Optical and electron microscopy results demonstrated that the etching pattern density directly impacts the distribution and anchoring of BHA particles, with denser patterns leading to better particle fixation. Dense etching patterns were found to reduce the wettability of Ti surfaces. However, after coating with BHA particles, the contact angle decreased, resulting in more wettable surfaces. Energy-dispersive X-ray spectroscopy (EDS) mapping revealed variations in elemental distribution across different samples, providing an elemental composition analysis that supports the findings from optical and electron microscopy. The effectiveness of BHA deposition is closely tied to the density and pattern of the surface texturization. Overall, this study presents a straightforward yet effective methodology to optimize the surface properties of titanium alloys, potentially enhancing their compatibility with biological tissues.