Enzyme-Responsive Ag Nanoparticle Assemblies in Targeting Antibacterial against Methicillin-Resistant Staphylococcus Aureus

Abstract

The abuse of antibiotics resulted in the emergence of antibiotics-resistant bacteria, which has raised a great social concern together with the impetus to develop effective antibacterial materials. Herein, the synthesis of biocompatible enzyme-responsive Ag nanoparticle assemblies (ANAs) and their application in the high-efficiency targeted antimicrobial treatment of methicillin-resistant Staphylococcus aureus (MRSA) have been demonstrated. The ANAs could collapse and undergo stable/collapsed transition on approaching MRSA because of the serine protease-like B enzyme proteins (SplB)-triggered decomposition of the branched copolymers which have been employed as the macrotemplate in the synthesis of responsive ANAs. This transition contributed greatly to the high targeting affinity and efficiency of ANAs to MRSA. The minimum inhibitory concentration and minimum bactericidal concentration against MRSA were 2.0 and 32.0 μg mL–1, respectively. Skin wound healing experiments confirmed that the responsive ANAs could serve as an effective wound dressing to accelerate the healing of MRSA infection.

Hybrid Polydopamine/Ag Shell-Encapsulated Magnetic Fe3O4 Nanosphere with High Antibacterial Activity

“…Because Ag nanocrystals have a strong inhibitory effect on a variety of bacteria and show low toxicity to the human body, they are widely used in antibacterial drugs [ 32 ]. In this paper, the antibacterial properties of Fe 3 O 4 @PDA/Ag/PDA core shell nanospheres were studied using Escherichia coli and Staphylococcus aureus as bacterial models [ 33 , 34 ]. Figure 9 is a photograph of colony growth after culturing two bacteria in LB agar medium added with excessive amounts of different test samples for 24 h. It can be clearly observed that after adding excessive Fe 3 O 4 and Fe 3 O 4 @PDA and cultivating for 24 h, the growth of the two bacteria is as good as that of the control group without adding any sample, which shows that the growth of the two bacteria has not been effectively inhibited.…”

Advances in the Application of Nanomaterials as Treatments for Bacterial Infectious Diseases

“…Bacteria-targeting nanomaterials have been widely used to treat bacterial, fungal, viral and parasitic infectious diseases in recent years [7][8][9][10][11][12][13][14], and their applications include direct bactericidal effects [15][16][17][18], encapsulation of probiotics [19], and encapsulation of bactericidal agents [20].…”

“…Inorganic nanomaterials with direct bactericidal effects include calcium silicate (CaSi) [15,21], silver (Ag) [22,23], copper (Cu) [24,25], and gold (Au) NPs [17,18]. Among the inorganic nanomaterials, Ag NPs have been one of the most widely used antimicrobial materials due to their broad-spectrum antibacterial capacity and low propensity to engender drug resistance [18].…”

“…5.5. Skin and Soft Tissue: Targeting Bacteria and Their Biofilms S. aureus is the most noticeable threat contributing to skin and soft tissue infection worldwide, with the capacity to form biofilms during infection [16,17,85]. Near-infraredlight (NIR)-activatable deoxyribonuclease (DNase)-carbon monoxide (CO) MPDA NPs successfully delivered bactericidal CO gas, penetrating impaired S. aureus biofilms and effectively eliminating them through the collaborative therapeutic effect of DNase I and CO gas-potentiated photothermal treatment [20].…”

“…Biocompatible enzyme-responsive Ag NP assemblies (ANAs) are high-efficiency targeted antimicrobial treatments for MRSA and have been utilized as effective wound dressings to accelerate the healing of wounds with MRSA infections [17]. A biomimetic NPbased antivirulence (detained staphylococcal α-hemolysin (Hla)) vaccine that efficiently induced high anti-Hla titers exhibits protective immunity against MRSA skin infections and subsequently decreases the invasiveness of MRSA, preventing dissemination into other organs [132].…”