Laser surface alloying is a powerful technique for improving the mechanical and chemical properties of engineering components. In this study, laser surface irradiation process employed in the surface modification off 316L stainless steel substrate using hydroxyapatite-titanium oxide to provide a composite ceramic layer for the suitability of applying this technology to improve the biocompatibility of medical alloys and implants. Fusion of the metal surface incorporating hydroxyapatite-titania ceramic particles using a 30 W Nd:YAG laser at different laser powers, 40, 50 and 70% power and a scan speed of 40 mm s(-1) was observed to adopt the optimum condition of ceramic deposition. Coatings were evaluated in terms of microstructure, surface morphology, composition biocompatibility using XRD, ATR-FTIR, SEM and EDS. Evaluation of the in vitro bioactivity by soaking the treated metal in SBF for 10 days showed the deposition of biomimetic apatite.

Controlled drug release of ciprofloxacin hydrochloride monohydrate has been investigated by loading into the channels of SBA-15 mesoporous silica. Three categories of SBA-15 were prepared by a sol-gel process according to blank SBA-15, calcined SBA-15 and SBA-15 functionalised with 3-aminopropyltriethoxysilane (APTS) in a 1:1 ratio prior to drug loading. The carrier and drug samples were characterised by small-angle X-ray diffraction (SAXRD), N2 adsorption–desorption isotherm measurements, fourier transform infrared spectroscopy (FT-IR) and ultraviolet (UV) spectrophotometry. Controlled drug release was conducted in buffered neutral conditions at room temperature for 24, 48 and 120 h. Maximum desorption was observed in the case of the amino-functionalised SBA-15 after 120 h corresponding to 72·16%, whereas for calcined SBA-15 this amounted to 71·35% and in the case of blank SBA-15 48·34% of the total amount of loaded drug was liberated demonstrating the slow release effect of mesoporous silica.

Redox reaction of samarium ions doped in Al2O3–SiO2 glasses, prepared by a rapid cooling technique of the melts, was examined by the measurement of the optical absorption and fluorescence properties. It was found that the doped samarium ions are easily reduced and oxidized by heating in H2 and O2 gases, respectively. The redox kinetics of samarium in the H2 and O2 atmospheres obey good first-order kinetics. The activation energy for the Sm3+ reduction in the 10Al2O390SiO2 glass was estimated to be ∼70 kJ/mol, which decreased with the increasing Al2O3 content. On the other hand, the activation energies for the oxidation were ∼90 kJ/mol, which only slightly depends on the glass composition. In these glasses, the samarium ions are preferentially surrounded by the Al–O polyhedra, where the oxygen ions are easily removed to form defect centers. It was concluded that the movement of the oxygen ions in the Al–O polyhedra determine the redox equilibrium of the samarium ions.

Biomimetic apatite-forming ability on CO2-laser-irradiated titanium oxide films was examined. Sol–gel-derived amorphous titanium oxide films were crystallized after irradiation of a continuous wave CO2 laser at the power of 5 W. The irradiation induced crystallization of anatase. The apatite-forming ability on the irradiated titanium oxide film was investigated by soaking in a solution with ion concentration 1.5 times those of simulated body fluid (1.5SBF). X-ray diffractometry showed that apatite formed on the laser-irradiated titanium oxide film within 5 days in 1.5SBF, while no apatite formed on the non-irradiated (amorphous) film. The apatite forming ability can be enhanced and given at a desired position by using the CO2 laser-irradiation.

Amorphous calcium silicate coating on a metallic titanium substrate for hard tissue replacement was prepared by a sol-gel method. Calcium silicate film was deposited on a titanium substrate by a spin-coating technique and subsequently heated at 500°C for 2 h in air. The deposited film, which was dense, had thickness of about 800 nm and strongly adhered to the substrate. Biomimetic apatite-forming ability of the deposited films was examined by soaking in simulated body fluid (SBF). Thin film X-ray diffractometry and scanning electron microscopy showed the formation of apatite on the surface after 10 days of soaking in SBF.