Green synthesis, antimicrobial, antibiofilm and antitumor activities of superparamagnetic γ-Fe2O3 NPs and their molecular docking study with cell wall mannoproteins and peptidoglycan.

Fatty acids-assisted superparamagnetic maghemite (γ-Fe2O3) NPs was biologically synthesized using extract of polyherbal drug Liv52 (L52E). The NPs were characterized by UV-vis spectroscopy, FT-IR, SEM, TEM, EDX, XRD and VSM. The major biological molecules present in L52E analysed by GC-MS were saturated fatty acids (palmitic acid 21.95%; stearic acid 13.99%; myristic acid 1.14%), monounsaturated fatty acid (oleic acid 18.43%), polyunsaturated fatty acid (linoleic acid 20.45%), and aromatic phenol (cardanol monoene 11.92%) that could imply in bio-fabrication and stabilization of γ-Fe2O3 NPs. The FT-IR spectra revealed involvement of carboxylic group of fatty acids, amide group of proteins and hydroxyl group of phenolic compounds that acts as reducing and capping agents. The synthesized NPs were used to investigate their antimicrobial, antibiofilm activity against P. aeruginosa, MRSA and C. albicans and anticancer activity on colon cancer cells (HCT-116) for biomedical applications. Further, molecular docking study was performed to explore the interaction of Fe2O3 NPs with major cell wall components i.e., peptidoglycan and mannoproteins. The docking studies revealed that Fe2O3 interacted efficiently with peptidoglycan and mannoproteins and Fe2O3 get accommodated into catalytic cleft of mannoprotein. Due to magnetic property, the biological activity of γ-Fe2O3 can be further enhanced by applying external magnetic field alone or in amalgamation with other therapeutics drugs.