PPy/PDA nanocomposite Sr-HT-Gahnite Technology: general issues TiO2 nanotubes anisotropic material anti-corrosion coating antibacterial antibacterial activity antifungal aspirin atmospheric plasma spray berberine bio-inspiration bioimplants candida auris coatings composite coating copper nanoparticles corrosion resistance degradation electrical stimulation escherichia coli hydroxyapatite icariin immunomodulatory effect macrophage magnetic poly(vinyl alcohol) gels mangrove matrix-assisted laser desorption/ionization-time of flight mechanical properties