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Berberine, an bioactive isoquinolin alkaloid from traditional Chinese herbs, is considered to be a promising agent based on its remarkable activity against hepatocellular carcinoma. However, the clinical application of this nature compound had been hampered owing to its properties such as poor aqueous solubility, low gastrointestinal absorption, and reduced bioavailability. Therefore, we developed Janus magnetic mesoporous silica nanoparticles (Fe3O4- mSiO2 NPs) consisting of a Fe3O4 head for magnetic targeting and a mesoporous SiO2 body for berberine delivery. A pH-sensitive group was introduced on the surface of mesoporous silica for berberine loading to develop a tumor microenvironment-responsive nanocarrier, which exhibited uniform morphology, good superparamagnetic properties, high drug-loading amounts, superior endocytic ability, and low cytotoxicity. Berberine-loaded Fe3O4- mSiO2 NPs exerted extraordinarily high specificity for hepatocellular carcinoma cells, which was due to the pH-responsive berberine release, as well as higher endocytosis capacity in hepatocellular carcinoma cells rather than normal liver cells. More importantly, an external magnetic field could significantly improve antitumor activity of Ber-loaded Fe3O4- mSiO2 NPs through enhancing berberine internalization. Taken together, our results suggest that Janus nanocarriers driven by the magnetic field may provide an effective and safe way to facilitate clinical use of berberine against hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

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 (80 nm in diameter) attached to a mesoporous silica stick (200–300 nm 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 10 μg/mL and 20 μg/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. [ABSTRACT FROM AUTHOR]

A facile method for foodborne bacterial enrichment and direct identification from milk samples using Janus magnetic mesoporous silica nanoparticles (Janus M-MSNs) is reported. The fluorescent-magnetic nanorods are fabricated using the one-pot sol-gel process, followed by modification with Escherichia coli antibodies to form fluorescent Janus M-MSNs (Janus M-MSNs-Ab). The Janus M-MSNs-Ab combine the fast magnetic response capacity of the magnetic heads with the strong fluorescence and bacterial-targeting properties of the silica bodies, which results in selective capture and fluorescence identification of E. coli from milk samples containing mixed bacteria. After magnetic separation, complexes of the bacteria and nanoparticles are detected through direct matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), which has a strong, anti-interference performance. Thus, the Janus M-MSNs-Ab synthesized in this study show great sensitivity and effectivity in foodborne bacterial capture and is a promising tool for rapid bacterial detection and investigation when combined with MALDI-TOF-MS. [ABSTRACT FROM AUTHOR]