Synergistic bactericidal activity of chlorhexidine-loaded, silver-decorated mesoporous silica nanoparticles

Abstract

Combination of chlorhexidine (CHX) and silver ions could engender synergistic bactericidal effect and improve the bactericidal efficacy. It is highly desired to develop an efficient carrier for the antiseptics codelivery targeting infection foci with acidic microenvironment. In this work, monodisperse mesoporous silica nanoparticle (MSN) nanospheres were successfully developed as an ideal carrier for CHX and nanosilver codelivery through a facile and environmentally friendly method. The CHX-loaded, silver-decorated mesoporous silica nanoparticles (Ag-MSNs@CHX) exhibited a pH-responsive release manner of CHX and silver ions simultaneously, leading to synergistically antibacterial effect against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli . Moreover, the effective antibacterial concentration of Ag-MSNs@CHX showed less cytotoxicity on normal cells. Given their synergistically bactericidal ability and good biocompatibility, these nanoantiseptics might have effective and broad clinical applications for bacterial infections.

Antibacterial and biodegradable tissue nano-adhesives for rapid wound closure

“…After MSNs-NH 2 were generated, small Ag NPs were grown on the silica surface through a facile ultrasonication-assisted method. 33,36 TEM images show Ag-MSNs with an overall size of 61.8±7.3 nm decorated with Ag NPs of 3.3±0.8 nm ( Figure 1B and Figure S1). Ag-MSNs are stable in water and show a lower polydispersity index (0.196), with a negative surface charge (-28.5±3.4 mV) due to their carboxyl group (Table S1).…”

“…The amino-modified MSNs of a small size were prepared via a modified one-pot method. 33 In a typical sol-gel reaction, 1.0 g of hexadecyltrimethylammonium bromide was dissolved in 100 mL of triethanolamine solution (0.5% w/w) and stirred at 80°C for 1 hour. Then, a mixture of 0.6 g of tetraethyl orthosilicate, 0.8 g of bis(3-triethoxysilyl propyl) disulfide and 0.1 g of 3-aminopropyltriethoxysilane was quickly added into the above solution and stirred vigorously for another 4 hours at the same temperature.…”

“…Ag NPs-decorated MSNs were prepared according to our previously reported ultrasonication-assisted method. 23,33 In brief, 100 mg of MSNs-NH 2 was dissolved in 45 mL of deionized water under ultrasonic treatment for 1 hour. Then, the silver ammonia complex cation [Ag(NH 3 ) 2 ] + was prepared by the mixture of 4.5 mL of 5% AgNO 3 solution and 0.5 mL of NH 4 OH, and the silver ammonia complex cation mixture was added into the above solution.…”

“…29,30 To surmount these obstacles, Ag NPs can be easily embedded within MSNs or decorated on MSNs to form Ag-containing MSNs which can protect the Ag NPs from aggregation and release Ag ions in a controlled manner. 27,[31][32][33] Moreover, direct incorporation of a disulfide bond into the framework of MSNs could facilitate their clinical translation as compared to traditional MSNs because of the fast and controllable biodegradation behavior. 34,35 With these findings in mind, we hypothesized that disulfide bond-bridged Ag-MSNs may be employed as an effective and safe tissue adhesive with antibacterial and degradable properties for wound closure and healing, which has never been reported yet.…”

Mesoporous Silica‐Based Materials with Bactericidal Properties

“…Zhou and co‐workers prepared MS NPs decorated with AgNPs and loaded with chlorhexidine . In first step, the authors prepared, following a co‐condensation method, MS NPs functionalized with aminopropyl moieties.…”