Co-Delivery of Nano-Silver and Vancomycin via Silica Nanopollens for Enhanced Antibacterial Functions

Abstract

Infectious diseases caused by bacteria have led to a great threat to public health. With the significant advances in nanotechnology in recent decades, nanomaterials have emerged as a powerful tool to boost antibacterial performance due to either intrinsic bactericidal properties or by enhancing the delivery efficiency of antibiotics for effective pathogen killing. Vancomycin, as one of the most widely employed antimicrobial peptides, has a potent bactericidal activity, but at the same time shows a limited bioavailability. Silver nanoparticles have also been extensively explored and were found to have a well-recognized antibacterial activity and limited resistance potential; however, how to prevent nanosized Ag particles from aggregation in biological conditions is challenging. In this study, we aimed to combine the advantages of both vancomycin and nano-Ag for enhanced bacterial killing, where both antibacterial agents were successfully loaded onto a silica nanoparticle with a pollen-like morphology. The morphology of nano-Ag-decorated silica nanopollens was characterized using transmission electron microscopy and elemental mapping through energy dispersive spectroscopy. Silver nanoparticles with a size of 10–25 nm were observed as well-distributed on the surface of silica nanoparticles of around 200 nm. The unique design of a spiky morphology of silica nano-carriers promoted the adhesion of nanoparticles towards bacterial surfaces to promote localized drug release for bacterial killing, where the bacterial damage was visualized through scanning electron microscopy. Enhanced bactericidal activity was demonstrated through this co-delivery of vancomycin and nano-Ag, decreasing the minimum inhibition concentration (MIC) towards E. coli and S. epidermidis down to 15 and 10 µg/mL. This study provides an efficient antimicrobial nano-strategy to address potential bacterial infections.

Antibiofilm Effect of Silver Nanoparticles in Changing the Biofilm-Related Gene Expression of Staphylococcus epidermidis

“…This team observed no growth at a concentration of 3.1 µg/mL up to 24 h. In this study, viability was maintained at a concentration of 3 µg/mL, whereas viability was significantly reduced at a concentration of 5 µg/mL [ 22 ]. In a study conducted by Ni et al a 30% decrease in growth was observed after 24 h of S. epidermidis incubation with silver nanoparticles at a concentration of 5 µg/mL and with a particle size of 10–25 nm [ 29 ].…”

Triple Encapsulation and Controlled Release of Vancomycin, Rifampicin and Silver from Poly (Methyl Methacrylate) or Poly (Lactic-Co-Glycolic Acid) Nanofibers

“…In order to improve the efficacy of drugs like vancomycin, gentamicin, and rifampicin, we and others have investigated the use of additives on bone cement to increase the drug release rate or via the use of silver to allow for improved antibacterial effects, allowing the use of lower drug doses [ 8 , 9 , 10 ]. Silver has been shown to have additive effects with vancomycin [ 11 , 12 , 13 ] and rifampicin [ 14 , 15 ] and includes the benefit of expanding the spectrum of bacterial killing to Gram-negative bacteria [ 11 , 15 ].…”

An intriguing approach toward antibacterial activity of green synthesized Rutin-templated mesoporous silica nanoparticles decorated with nanosilver

“…The Ag nanoparticles’ antibacterial properties are related to their ability to attach to cell membranes and then their release into bacterial cells, both of that contribute to their high level of activity. Due to their increased surface energy, Ag nanoparticles, on the other hand, are extremely quickly oxidized and aggregated, limiting their antibacterial efficacy in clinical settings 15 , 16 . To address these challenges, several Ag-carried substances, such as zeolite, carbon, silica, and titanium dioxide, have been created to enhance effectual as well as multipurpose functions in the areas of infection prevention and control, tissue regeneration, wound healing, and the treatment of oral disease 16 – 20 .…”

“…Despite the fact that there are several techniques to synthesize nanostructures 16 , 27 – 30 , their environmentally friendly green synthesis has gained attention over recent years 27 , 31 . When it comes to reductants, green synthesis or novel synthesis methods can make use of a wide range of resources such as plant extracts, microorganisms, biomass, and many other types of chemicals 32 , 33 .…”