RESUMO
Nanosilver immobilized on TiO2 nanometric fibers (Ag/TiO2) was produced by solution blow spinning and characterized using scanning electron microscopy, transmission electron microscopy, N2 adsorption/desorption, X-ray diffraction, X-ray photoelectron spectroscopy, water contact angle, and inductively coupled plasma emission spectroscopy analyses. The in vitro antimicrobial and anticancer activities of the produced nanofibers was also investigated. Ag/TiO2 nanofibers revealed a crystalline structure compatible with the rutile crystalline phase, as well as a mesoporous and superhydrophilic nature. XPS profiles showed Ti4+ and Ag0, indicating a strong interaction between the Ag nanoparticles and TiO2. The Ag/TiO2 nanofibers presented antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli. The release of silver ions from 5â¯mgâmL-1 and 50â¯mgâmL-1 of Ag/TiO2 nanofibers was approximately 0.08⯵gâmL-1 and 0.18⯵gâmL-1, respectively. The nanofiber cytotoxicity in both macrophages (ATCC RAW 264.7) and cancer cells (murine AT-84 oral squamous carcinoma cells) was dose-dependent. A concentration of 5â¯mgâmL-1 induced partial suppression growth and migration of cancer cells, while a concentration of 50â¯mgâmL-1 resulted in complete inhibition of proliferation and migration of murine AT-84 cells. The overall results indicate that Ag/TiO2 nanofibers can selectively inhibit the cellular mechanism of AT-84 by apoptosis with DNA damage and cell death. The antimicrobial and anticancer performance of Ag/TiO2 nanofibers is probably the result of its nanometric dimension, high surface reactivity, and the interaction between TiO2 and Ag. Electron transfer at the metal-semiconductor interface and reactive oxygen species production, in addition to the biological activity of released silver ions, confirm the potential for use as an agent in antimicrobial and anticancer therapy.