Polyoxometalates enriched antibiotic-coated silver nanoparticles for anti-tuberculosis activity

A. Umapathi, D. Jain, H. Madhyastha, P.N. Navya, H.K. Daima
Amity University Rajasthan,

Keywords: polyoxometalates, antibiotic-coated, silver nanoparticles, antimicrobial, nanozyme


Mycobacterium tuberculosis roots highly contagious disease tuberculosis (TB), which causes over 1.3 million deaths worldwide annually. Currently, isoniazid, rifampin, pyrazinamide, ethambutol and streptomycin are used as first-line medication to treat TB. However, development of multidrug resistance (MDR) strains of M. tuberculosis is of great concern for scientific community. To circumvent such circumstances, a range of nanomaterials can be employed due to their diverse sites of action toward microbial cells. In general, nanomaterials cause physical damage, enzyme deactivation, protein and genetic material’s oxidation within the cells etc. leading toward toxicity. Furthermore, nanomaterials can improve carrier efficiency, stability and afford controlled release of drug molecules. However, plausibility of such an action demands robust, precise materials with tunable properties to exert myriad bioactivities to control microbial infections including TB. Therefore, in the present work we have developed a synthesis methodology, wherein “isoniazid” (INH) capped silver nanoparticles (AgNPs) were further surface modified with polyoxometalate (POM) molecules to counter a range of microbial cells. First of all, we have synthesized AgNPs under alkaline experimental condition by employing INH as reducing and stabilizing agent followed by their dialysis to remove any free Ag+ ions, INH and KOH used in synthesis process. After dialysis these antibiotic-coated AgNPsINH were surface enriched by POM molecules namely phospotungstic acid (PTA) and phosphomolybdic acid (PMA) leading towards development of AgNPsINH@PTA and AgNPsINH@PMA, respectively. We have selected POMs for AgNPsINH enrichment due to their known biological potential as antibacterial, antiviral, antifungal and anticancer agents along with their excellent catalytic behavior. We hypothesis that functionalizing such polyanionic POMs on the surface of INH adorned AgNPs further augments their antimicrobial activities. Currently, we are investigating anti-mycobacterial, antibacterial, free radical scavenging, nanozyme mimicking potential of POMs enriched antibiotic-coated AgNPs. All the nanoparticles fabricated during this study have been characterized by UV-VIS spectrometry, Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), transmission electron microscopy (TEM) and Zeta potential analyzer to confirm presence of POMs and INH on the surface of AgNPs along with surface charge, morphology and size distribution profile of nanoparticles.