Janus silver mesoporous silica nanobullets with synergistic antibacterial functions.

In this study, we exploited a one-pot method to fabricate cetyltrimethylammonium bromide (CTAB)-loaded Janus silver mesoporous silica nanoparticles (Janus Ag-MSNs@CTAB). These bullet-like nanoparticles had a silver head (80nm in diameter) attached to a mesoporous silica stick (200-300nm in length). The CTAB-loaded nanobullets exhibited a marked affinity for the bacterial cell surface and the simultaneously sustained release behavior of CTAB and silver ions. The minimum inhibitory concentrations (MIC) of Janus Ag-MSNs@CTAB were determined to be 10μg/mL and 20μg/mL for E. coli and S. Aureus, respectively. Importantly, Janus Ag-MSNs@CTAB provided a single-particle nanoplatform with a synergistic effect against both Gram-positive and Gram-negative bacteria. A thorough investigation indicated that CTAB induces a dramatic loss of bacterial membrane integrity, which facilitated the internalization of silver. This report described an efficient and convenient method of synthesizing Janus silver mesoporous silica nanoparticles, and these nanobullets show promising potential in biomedical applications.