Surface functionalization of magnetite nanoparticles with natural and multipotent antioxidants as potential nanoantioxidants and antimicrobial agents / Syed Tawab Shah

Syed Tawab , Shah (2022) Surface functionalization of magnetite nanoparticles with natural and multipotent antioxidants as potential nanoantioxidants and antimicrobial agents / Syed Tawab Shah. PhD thesis, Universiti Malaya.

	PDF (The Candidate's Agreement) Restricted to Repository staff only Download (214Kb)
	PDF (Thesis PhD) Download (4Mb)

Abstract

Nanoparticles of Fe3O4 with enhanced hydrophilic/lipophilic properties were synthesized using a co-precipitation approach of Fe2+ and Fe3+ ions in a basified aqueous solution followed by a surface functionalization. Two surfacing strategies (in-situ and post-synthesis methods) were used to coat nanoparticles with natural antioxidants and synthetic multipotent antioxidants (MPAO). MPAO were synthesized and characterized by NMR. The functionalized nanoparticles (IONP@AOx) were characterized by FTIR, XRD, Raman, HRTEM, FESEM, VSM and EDX. IONP@A have average particles size 6-8 nm for in-situ synthesis, which are ultra-small particles as compared to unfunctionalized magnetite (IONP) and post functionalized magnetite with average size of 10 and 11 nm respectively. The nanoparticles also showed high saturation magnetization of about 45−59 emu/g. Prior to commencement of experimental lab work, Prediction Activity Spectra of Substances (PASS) software was used to predict the biological activities of antioxidants and it is found that experimental antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay are in good agreement with the simulated results. Furthermore, the half maximal inhibitory concentration (IC50) values of DPPH antioxidant assay revealed a 2–4 fold decrease as compared to unfunctionalized IONP. The functionalization has enhanced the free radical scavenging properties of IONPs up two to four times. In addition to antioxidant activity, functionalized IONP proved outstanding antimicrobial activity while testing on different bacterial and fungal strains. The advantage of the developed nanoantioxidants is that (because of their high hydrophilicity/lipophilicity) they could interact with biological species such as enzymes, proteins, amino acids and DNA. The results reveal that the synthesized nanoparticles can be successfully used for the development of biomedicines which can be subsequently applied as antioxidant, anti-inflammatory, antibacterial and anticancer agent.

Actions (For repository staff only : Login required)