In vitro antimicrobial and anticancer properties of TiO2 blow-spun nanofibers containing silver nanoparticles

Abstract

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 5 mg∙mL^-1 and 50 mg∙mL^-1 of Ag/TiO₂ nanofibers was approximately 0.08 μg∙mL^-1 and 0.18 μg∙mL^-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 5 mg∙mL^-1 induced partial suppression growth and migration of cancer cells, while a concentration of 50 mg∙mL^-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.

Keywords: Anticancer activity; Nanofibers; Rutile; Silver; Solution blow spinning.