Bioactive and antimicrobial macro-/micro-nanoporous selective laser melted Ti-6Al-4V alloy for biomedical applications.

Metal Additive Manufacturing (AM) technology is an emerging technology in biomedical field due to its unique ability to manufacture customized implants [Patients-specific Implants (PSIs)] replicating the complex bone structure from the relevant metal powders. PSIs could be developed through any AM technology, but the ultimate challenge lies in integrating the metallic implant with the living bone. Considering this aspect, in the present study, Ti alloy (Ti-6Al-4V) powder has been used to fabricate scaffolds of channel type macropores with 0-60% porosity using selective laser melting (SLM) and subsequent post-treatments paving way for surface microporosities. Surface chemical and subsequent heat treatments were carried out on thus developed Ti alloy scaffolds to improve its bioactivity, antibacterial activity and osteoblastic cell compatibility. NaOH and subsequent Ca(NO3)2/AgNO3 treatment induced the formation of a nanoporous network structure decorated with Ca-Ag ions. Ag nanoparticles covering the entire scaffold provided antibacterial activity and the presence of Ca2+ ions with anatase TiO2 layer further improved the bioactivity and osteoblastic cell compatibility of the scaffold. Therefore, SLM technology combined with heat treatment and surface modification could be effectively utilized to create macro-micro-nano structure scaffolds of Ti alloy that are bioactive, antibacterial, and cytocompatible.