Functionalised nanoparticles complexed with antibiotic efficiently kill MRSA and other bacteria

Abstract

Antibiotic-resistant bacterial infections are a vexing global health problem and have rendered ineffective many previously-used antibiotics. Here we demonstrate that antibiotic-linkage to surface-functionalized silica nanoparticles (sNP) significantly enhances their effectiveness against Escherichia coli, and Staphylococcus aureus, and even methicillin-resistant S. aureus (MRSA) strains that are resistant to most antibiotics. The commonly-used antibiotic penicillin-G (PenG) was complexed to dye-labeled sNPs (15 nm diameter) containing carboxyl groups located as either surface-functional groups, or on polymer-chains extending from surfaces. Both sNPs configurations efficiently killed bacteria, including MRSA strains. This suggests that activities of currently-ineffective antibiotics can be restored by nanoparticle-complexation and used to avert certain forms of antibiotic-resistance.

Inorganic nanoparticles engineered to attack bacteria

“…340 The authors termed this effect the 'grenade hypothesis' and postulated that each nanoparticle delivers a concentrated package of antibiotic to a given cells, perhaps overwhelming its resistance mechanism (e.g. A recent study by Decho, Benicewicz, and colleagues found that when complexed to SiO 2 nanoparticles, the common antibiotic penicillin-G is effective in killing penicillinresistant strains of bacterial pathogens, including strains of methicillin resistant Staphylococcus aureus (MRSA), at low total concentrations.…”

Charged Metallopolymer-Grafted Silica Nanoparticles for Antimicrobial Applications

“…14,15 Nanoparticles could be a powerful tool to combat bacterial infections. 16 Antimicrobial agents have been constructed by both organic and inorganic nanoparticles such as silver, 17–19 gold, 20–22 zinc oxide, 23,24 titanium dioxide, 25,26 silica, 27,28 copper oxide, 29 magnesium oxide, 30 carbon-based nanoparticles such as carbon nano-tubes, 31–33 fullerenes, 34 and graphene oxide. 35 In particular, silica nanoparticles have a high chemical, thermal, and colloidal stability and have been found to be useful in biomedical applications due to their biocompatibility, low toxicity, low density, capacity for encapsulation, and easy synthesis.…”

Controlled Radical Polymerization: State-of-the-Art in 2014

“…This is related to the development of new and previously unreachable properties present in polymer hybrids with inorganics and biomolecule components. In the former case, polymers grown from nanoparticles or flat surfaces, dramatically change particles stability, dispersibility and thermomechanical properties, in addition to tremendously enhancing lubricity, antifouling or antibacterial properties (53)(54)(55)(56)(57)(58)(59)(60)(61). Hybrids with proteins or nucleic acids increase stability of proteins in harsh environments, (including temperature, pH, and salts) assist in delivery of genes, and can be used in advanced drug delivery (45,(62)(63)(64)(65)(66)(67)(68)(69)(70)(71).…”