The synergic effect of nanosecond fiber laser and drug-loaded electrospun PVA coating on metallurgical and biological characteristics of Ti-6Al-4 V alloy

Abstract

Nowadays, titanium-based implants are widely used to replace damaged or missing body organs. Poor chemical bonding with the bone and infection caused by formation of biofilm on the implant surface are the most common problems with them. So, antibacterial properties and osteoblast adhesion improvement have been intended to address these issues. The aim of this research is cell adhesion improvement and prevention of bacterial infection using surface roughness and in-situ antibiotic drug release. Here, micromachining (nanoseconds) laser with a groove distance of 10, 30, and 50 µm, was used to surface modification. X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), hardness, roughness, and wettability tests were used for physical and metallurgical characterization of surface-modified samples to find the optimum laser processing conditions. Roughness has increased as a result of laser surface modification and surface characteristics of alloy exhibit sensitivity to the groove distance. The lower groove distance indicated the higher roughness and wettability. Martensite phase, α phase, and, Ti₃Al were observed in the fusion zone. Also, the dissolution of the beta phase has occurred in the fusion and the heat-affected zones. No oxidation was observed. All these occurred without any change in bulk. Then optimized sample surfaces were coated by the vancomycin-loaded polyvinyl alcohol solution using electrospinning process, and toxicity, cell adhesion, and drug release rate were evaluated. The results showed laser surface modification and coating did not hurt cell viability. Modified samples demonstrated high cell adhesion and improvement in drug release compared to the unmodified samples. The drug release rate was extended from 4 h to 25 h for modified samples. So, the modified implants could indicate a sustained release of antibiotics as well.