Silica-Coated Magnetic Nanoparticles for Vancomycin Conjugation

Moustafa M Abdelaziz; Amr Hefnawy; Asem Anter; Menna M Abdellatif; Mahmoud A F Khalil; Islam A Khalil

doi:10.1021/acsomega.2c03226

Silica-Coated Magnetic Nanoparticles for Vancomycin Conjugation

ACS Omega. 2022 Aug 16;7(34):30161-30170. doi: 10.1021/acsomega.2c03226. eCollection 2022 Aug 30.

Authors

Moustafa M Abdelaziz¹, Amr Hefnawy², Asem Anter³, Menna M Abdellatif⁴, Mahmoud A F Khalil⁵, Islam A Khalil⁶

Affiliations

¹ Department of Bioengineering, The University of Kansas, Lawrence, Kansas 66045, United States.
² Smyth Laboratory, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, United States.
³ Microbiology Unit, Drug Factory, College of Pharmaceutical Sciences and Drug Manufacturing, Misr University of Science and Technology (MUST), 6th of October, Giza 12582, Egypt.
⁴ Department of Industrial Pharmacy, College of Pharmaceutical Sciences and Drug Manufacturing, Misr University for Science and Technology, Giza 12582, Egypt.
⁵ Department of Microbiology and Immunology, Faculty of Pharmacy, Fayoum University, Fayoum 63514, Egypt.
⁶ Department of Pharmaceutics, College of Pharmaceutical Sciences and Drug Manufacturing, Misr University of Science and Technology (MUST), 6th of October, Giza 12582, Egypt.

Abstract

Drug resistance is a global health challenge with thousands of deaths annually caused by bacterial multidrug resistance (MDR). Efforts to develop new antibacterial molecules do not meet the mounting needs imposed by the evolution of MDR. An alternative approach to overcome this challenge is developing targeted formulations that can enhance the therapeutic efficiency and limit side effects. In this aspect, vancomycin is a potent antibacterial agent that has inherent bacterial targeting properties by binding to the D-Ala-D-Ala moiety of the bacterial peptidoglycan. However, the use of vancomycin is associated with serious side effects that limit its clinical use. Herein, we report the development of vancomycin-conjugated magnetic nanoparticles using a simple conjugation method for targeted antibacterial activity. The nanoparticles were synthesized using a multistep process that starts by coating the nanoparticles with a silica layer, followed by binding an amide linker and then binding the vancomycin glycopeptide. The developed vancomycin-conjugated magnetic nanoparticles were observed to exhibit a spherical morphology and a particle size of 16.3 ± 2.6 nm, with a silica coating thickness of 5 nm and a total coating thickness of 8 nm. The vancomycin conjugation efficiency on the nanoparticles was measured spectrophotometrically to be 25.1%. Additionally, the developed formulation retained the magnetic activity of the nanoparticles, where it showed a saturation magnetization value of 51 emu/g, compared to 60 emu/g for bare magnetic nanoparticles. The in vitro cell biocompatibility demonstrated improved safety where vancomycin-conjugated nanoparticles showed IC₅₀ of 183.43 μg/mL, compared to a much lower value of 54.11 μg/mL for free vancomycin. While the antibacterial studies showed a comparable activity of the developed formulation, the minimum inhibitory concentration was 25 μg/mL, compared to 20 μg/mL for free vancomycin. Accordingly, the reported formulation can be used as a platform for the targeted and efficient delivery of other drugs.