Antibacterial nanosilver: defeating resistance, prolonged effects, mechanisms, and potential applications

Antibiotics have traditionally been used to fight bacterial infections until the emergence of antibiotic-resistant bacteria. Methicillin-resistant Staphylococcus aureus (MRSA) is a challenging stated infection, not only in... [ view full abstract ]

Antibiotics have traditionally been used to fight bacterial infections until the emergence of antibiotic-resistant bacteria. Methicillin-resistant Staphylococcus aureus (MRSA) is a challenging stated infection, not only in hospital environments [1,2] but also in the community reservoir [3,4], causing deaths [5,6]. This resistance dilemma has made it compelling to apply alternative antibacterial agents. Silver (Ag) is an alternative arsenal used in medical applications, such as wound dressings, to fight the antibiotic-resistant bacteria. Despite the tremendous interest in commercial antibacterial applications of Ag, there has been little agreement on the exact mechanism of antibacterial action of Ag NPs. On the other hand, Ag NPs might easily be aggregated, losing their antibacterial properties. Therefore, docking Ag NPs on carriers, forming composites can bridge the aggregation problem. Moreover, immobilization can endow Ag NPs intriguing antibacterial applications owing to the prolonged Ag release. Consequently, I will demonstrate our approach of immobilizing Ag NPs onto silica, allowing for the prolonged Ag release and antibacterial properties [7]. The defeat of MRSA and Escherichia coli by the immobilized Ag NPs will also be presented, in light of our results, along with a comparative applicable example for the prolonged antibacterial properties of a gauze-impregnated with the immobilized Ag NPs and a commercial Ag-containing dressing [7]. I will further unveil the mechanisms of antibacterial effects of the immobilized Ag NPs, using transmission electron microscope (TEM) and scanning TEM (STEM). We foresee the promising prolonged antibacterial properties of the immobilized Ag NPs for wound dressing applications [7].

References

[1] Church, D. et al. Clin. Microbiol. Rev. 2006, 19, 403–434.

[2] Strohal, R. et al. J. Hosp. Infect. 2005, 60, 226–230.

[3] Chambers, H. F. Emerging Infect. Dis. 2001, 7, 178–182.

[4] Okuma, K. et al. J. Clin. Microbiol. 2002, 40, 4289–4294.

[5] Leaper, D. J. Int. Wound J. 2006, 3, 282–294.

[6] Centers for Disease Control and Prevention (CDC). MMWR Morb. Mortal. Wkly. Rep. 1999, 48, 707–710.

[7] Mosselhy, D. A. et al. Nanomaterials 2017, 7, 261.