Biomimetic synthesis of iron oxide nanoparticles from Bacillus megaterium to be used in hyperthermia therapy

Abstract

The suitable structural characteristics of magnetic nanoparticles have resulted in their widespread use in magnetic hyperthermia therapy. Moreover, they are considered a proper and operational choice for pharmaceutical nanocarriers. Using the biomimetic method, we were able to produce iron oxide magnetic nanoparticles from the bacterial source of PTCC1250, Bacillus megaterium, for therangostic diagnosis systems and targeted drug delivery. Some of the benefits of this method include mitigated environmental and biological dangers, low toxicity, high biocompatibility, cheap and short-term mass production possibilities in each synthesis round compared to other biological sources, simple equipment required for the synthesis; and the possibility of industrial-scale production. Bacillus megaterium is a magnetotactic bacteria (MTB) that has a magnetosome organelle capable of orienting based on external magnetic fields, caused by the mineralization of magnetic nanocrystals. Utilizing this capability and adding an iron nitrate solution to the bacterial suspension, we synthesized iron oxide nanoparticles. The extent of synthesis was measured using UV-visible spectrophotometry. The morphology was evaluated using FESEM. The crystallized structure was characterized using RAMAN and XRD. The size and distribution of the nanoparticles were assessed using DLS. The surface charge of the nanoparticles was measured using zeta potential. The synthesis of iron oxide nanoparticles was confirmed using FT-IR, and the magnetic property was measured using VSM. This study is continued to identify industrial and clinical applications.

Keywords: Bacillus megaterium; Hyperthermia; Iron oxide; Nano-biomimetic.

Fig. 1

a Bacterial suspension, b bacterial suspension and the salt solution at the onset, c the bacterial suspension and the salt solution after 20 min, d UV–visible spectrophotometry (UV–vis)

Fig. 2

a Imaging using Field-Emission Scanning Electron Microscopy (FESEM), b, c element mapping using EDS

Fig. 3

a, b X-ray diffraction (XRD) pattern for the suspension containing iron oxide, c Fourier-transform infrared spectroscopy (FTIR), d Raman spectroscopy

Fig. 4

a Size distribution graph for the iron oxide nanoparticles, b Zeta potential diagram and the charge distribution of iron oxide particles

Fig. 5

The VSM spectrum diagram