A New Nano-Platform of Erythromycin Combined with Ag Nano-Particle ZnO Nano-Structure against Methicillin-Resistant Staphylococcus aureus

Abstract

Nano-particles have been combined with antibiotics in recent studies to overcome multidrug-resistant bacteria. Here, we synthesized a nano-material in which Ag nano-particles were assembled with a ZnO nano-structure to form an Ag-ZnO (AZO) nano-composite at low temperature. This material was combined with erythromycin (Ery), an antibiotic effective towards gram-positive bacteria, using three different approaches (AZO + Ery (AZE) [centrifuged (AZE1), used separately after 1-h gap (AZE2), without centrifugation (AZE3)]) to prepare a nano-antibiotic against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). X-ray diffraction analysis and transmission electron microscopy confirmed the presence of Ag nano-particles and ZnO nano-structure. The elemental and chemical state of the elements present in the AZO nano-composite were assessed by X-ray photoelectron spectroscopy. The antibacterial activity of AZE samples against both Escherichia coli and S. aureus strains including MRSA was evaluated in antibacterial and morphological analyses. The AZE3 sample showed greater antibacterial activity than the other samples and was comparable to erythromycin. AZE3 was ~20-fold less prone to developing bacterial resistance following multiple exposures to bacteria compared to erythromycin alone. The AZE3 nano-composite showed good biocompatibility with 293 human embryonic kidney cells. Our newly synthesized nano-platform antibiotics may be useful against multidrug-resistant gram-positive bacteria.

Au–ZnO Conjugated Black Phosphorus as a Near-Infrared Light-Triggering and Recurrence-Suppressing Nanoantibiotic Platform against Staphylococcus aureus

“…Similarly, Figure 2 c illustrates the high-resolution TEM (HRTEM) image of the marked region in Figure 2 b. This confirms the presence of Au and ZO NPs, as the distinct lattice fringes with interplanar distances of 0.23 and 0.28 nm depicted in Figure 2 c correspond to the Au (111) [ 26 ] and ZO (100) [ 23 ] planes, respectively. Additionally, the inset of Figure 2 b displays the energy-dispersive X-ray spectrum of the AZB sample.…”

“…Among inorganic nanomaterials, Au [ 1 ], Ag [ 20 , 21 , 22 ], and ZO [ 1 ] nanoparticles (NPs) have been widely used as antibacterial agents. ZO exhibits not only excellent antibacterial properties, but a remarkable ability to inhibit the recurrence of drug resistance by bacteria, as shown in our previous study [ 23 ]. Furthermore, although Au NPs represent the major catalytic and antibacterial components [ 10 , 24 ], they must be pre-treated with ligands to increase their stability, which often affect the intrinsic physicochemical characteristic and subsequent activity of these materials.…”

“…The crystalline phases of the ZO, ZB, and AZB samples were determined from their XRD profiles as depicted in Figure 1 . The XRD reflection peaks of the as synthesized ZO, ZB, and AZB centered at 31.62°, 34.27°, 36.21°, 47.41°, 56.50°, 62.70°, 67.81°, 68.97°, and 76.93° correspond to the (100), (002), (101), (102), (110), (103), (112), (201), and (202) diffraction planes, respectively, which are consistent with the hexagonal ZO (h-ZO) structure (Joint Committee on Powder Diffraction Standards (JCPDS) 36-1451) [ 23 ]. Moreover, some additional peaks were observed at approximately 38.05°, 44.25°, and 64.54° for the AZB sample, which contained the (111), (200), and (220) crystal planes of cubic Au NPs (JCPDS 65-2870) [ 26 ].…”

“…The Zn 2p , Au 4f , and P 2p peaks are shown in Figure 3 b–d, respectively. The two relatively strong peaks centered at 1021.9 and 1045.0 eV in Figure 3 b were assigned to the binding energies of the Zn 2p 3/2 and Zn 2p 1/2 states, respectively [ 23 ]. Moreover, the calculated difference (~23.1 eV) between the Zn 2p 3/2 and Zn 2p 1/2 binding energies corresponded to the Zn 2+ valence state [ 23 ], while Figure 3 c confirmed the formation of metallic Au NPs in the AZB sample.…”

“…The utilized ZO synthesis procedure was described in our previous work [ 23 ]. Initially, 50 mL of 0.2 M aqueous solution of zinc nitrate hexahydrate (Zn(NO 3 ) 2 .6H 2 O, 98%, Sigma-Aldrich, St. Louis, MO, USA) in deionized water was prepared under continuous stirring for 15 min at 25 °C.…”