Using Fomitopsis pinicola for bioinspired synthesis of titanium dioxide and silver nanoparticles, targeting biomedical applications

Abstract

The current study proposes a bio-directed approach for the formation of titanium oxide and silver nanoparticles (TiO₂ and Ag NPs), using a wild mushroom, Fomitopsis pinicola, identified by 18S ribosomal RNA gene sequencing (gene accession no. MK635350) and phenotypic examination. NP synthesis was confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance UV-visible spectroscopy (DR-UV), and scanning and transmission electron microscopy (SEM/TEM). Furthermore, the impact of NPs on Escherichia coli and Staphylococcus aureus and a human colon cancer cell line (HCT) were evaluated by MIC/MBC and MTT assays, respectively, along with structural morphogenesis by different microscopy methods. The results obtained showed that TiO₂ and Ag NPs were found to be significantly active, however, slightly enhanced antibacterial and anticancer action was seen with Ag NPs (10-30 nm). Such NPs can be utilized to control and treat infectious diseases and colon cancer and therefore have potential in a range of biomedical applications.

Scheme 1. Biosynthesis of TiO₂ and Ag NPs using the extract of F. pinicola.

Fig. 1. Photographs of brown rot basidiomycetes: F. pinicola, (a) under view showing pores (b) basidiospores at 40×.

Fig. 2. Phylogenetic tree of F. pinicola indicated as .

Fig. 3. X-ray diffraction spectra of (a) TiO₂ and (b) Ag NPs.

Fig. 4. FT-IR spectra of (a) TiO₂ and (b) Ag NPs.

Fig. 5. (a and b) shows the diffuse reflectance spectra of TiO₂ and Ag NPs.

Fig. 6. (a) SEM and (b) TEM images of TiO₂ NPs; (c) SEM and (d) TEM images of Ag NPs.

Fig. 7. MIC/MBC assay: (a) E. coli and (b) S. aureus treated with different conc. of TiO₂ NPs: (c) E. coli and (d) S. aureus treated with different conc. of Ag NPs.

Fig. 8. SEM micrographs of treated bacteria at concentration obtained as its MIC (a) E. coli control (untreated cells); (b) E. coli treated TiO₂ NPs; (c) E. coli treated Ag NPs; (d) S. aureus control (untreated cells); (e) S. aureus treated TiO₂ NPs; (f) S. aureus treated Ag NPs.

Fig. 9. Cell viability of HCT-116 cells by MTT assay on treatment with TiO₂ NPs after 48 h and cell morphology analysis (a) control; & (b) treated with 8.0 μg mL⁻¹, analyzed by light microscope. (c) Control, & (d) treated 8.0 μg mL⁻¹ analyzed by confocal scanning microscope. Data are the mean ± SD of three different experiments. Difference between two treatment groups were analysed by Student's t test where **p < 0.01, p-values were calculated by Student's t-test. No changes were observed in control group.

Fig. 10. Cell viability of HCT-116 cells by MTT assay on treatment with Ag NPs after 48 h and cell morphology analysis (a) control; & (b) treated with 8.0 μg mL⁻¹, analyzed by light microscope. (c) Control, & (d) treated 8.0 μg mL⁻¹ analyzed by confocal scanning microscope. Data are the mean ± SD of three different experiments. Difference between two treatment groups were analysed by Student's t test where **p < 0.01, p-values were calculated by Student's t-test. No changes were observed in control group.