Design, fabrication, and evaluation of green mesoporous hollow magnetic spheres with antibacterial activity

Abstract

Hollow silica nanostructures are receiving more attention due to their special features such as low density and very high surface-to-volume ratio compared to other types of nanoparticles. In this research, an efficient method for the synthesis of hollow magnetic spheres with antibacterial properties is investigated. These hollow magnetic spheres are prepared in several steps and identified by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDS), Elemental mapping, High-resolution transmission electron microscopy (HRTEM), and vibrating-sample magnetometer (VSM) techniques. Also, the antibacterial property of magnetic hollow spheres is investigated by the agar diffusion method on the Acinetobacter baumannii, Staphylococcus epidermidis, Proteus mirabilis, Staphylococcus aureus, and Pseudomonas aeruginosa. Due to the high surface-to-volume ratio, their contact level with the surrounding environment is extremely high, which increases the effectiveness of their antibacterial properties. The results of FTIR bond analysis show that TEOS precursor particles established surface bonds with CTAB activators during the synthesis process, and the presence of SiOSi bonds in the range (600–1320 cm−1) indicates the formation of silicate chains. The size of the nanoparticles based on the HRTEM images was estimated to be approximately 40 nm. FESEM images confirmed the spherical shape of nanoparticles with an average size of 350 nm. The antibacterial feature, porous walls and empty space inside the spheres made it possible to facilitate and control the drug release and use it in medicine, especially for wound healing. Also, due to the magnetic properties of the manufactured nanospheres, they can be used in many ways in medical fields, especially in the treatment of cancer. In the continuation of the work, it is suggested to use Ag/Fe3O4@@ magnetic hollow mesoporous spheres (HMS) as a suitable drug carrier due to increasing the efficiency and control of drug delivery with the capabilities of targeting/responding to stimuli, increasing the speed and effect of the drug.