Critical roles of cationic surfactants in the preparation of colloidal mesostructured silica nanoparticles: control of mesostructure, particle size, and dispersion.

Mesoporous silica nanoparticles are promising materials for various applications, such as drug delivery and catalysis, but the functional roles of surfactants in the formation and preparation of mesostructured silica nanoparticles (MSN-as) remain to be seen. It was confirmed that the molar ratio of cationic surfactants to Si of alkoxysilanes (Surf/Si) can affect the degree of mesostructure formation (i.e.

Aqueous colloidal mesoporous nanoparticles with ethenylene-bridged silsesquioxane frameworks.

Aqueous colloidal mesoporous nanoparticles with ethenylene-bridged silsesquioxane frameworks with a uniform diameter of ∼20 nm were prepared from bis(triethoxysilyl)ethenylene in a basic aqueous solution containing cationic surfactants. The nanoparticles, which had higher hydrolysis resistance under aqueous conditions, showed lower hemolytic activity toward bovine red blood cells than colloidal mesoporous silica nanoparticles.

Dialysis process for the removal of surfactants to form colloidal mesoporous silica nanoparticles.

Colloidal mesoporous silica nanoparticles less than 20 nm in diameter are prepared by dialysis; this simple surfactant removal route can avoid aggregation by sedimentation-redispersion and remove cationic surfactants while retaining the original colloidal state, which is applicable to the preparation of primary nanoparticles carrying a functional organic substance.

Fabrication of hierarchically porous spherical particles by assembling mesoporous silica nanoparticles via spray drying.

A new type of hierarchically porous materials is fabricated by assembling mesoporous nanoparticles via spray drying. Well-dispersed mesostructured silica nanoparticles (MSN), whose particle size distribution was narrow in the range of 20 nm and 50 nm, were prepared by a thermal deposition method. By spray drying a MSN suspension, MSN were assembled into spherical secondary particles.

In vitro activity of lauric acid or myristylamine in combination with six antimicrobial agents against methicillin-resistant Staphylococcus aureus (MRSA).

The objective of this study was to investigate the in vitro activities of lauric acid and myristylamine in combination with six antimicrobial agents against methicillin-resistant Staphylococcus aureus (MRSA). The combination effect of lipids and antimicrobial agents was evaluated by the checkerboard method to obtain a fractional inhibitory concentration (FIC) index. The effects of lauric acid + gentamicin (GM) and lauric acid + imipenem (IPM) combinations were synergistic against the clinical isolates in 12 combinations.

Antimicrobial activity of saturated fatty acids and fatty amines against methicillin-resistant Staphylococcus aureus.

The objective of this study was to investigate the antimicrobial activities of saturated fatty acids and fatty amines against methicillin-resistant Staphylococcus aureus (MRSA). The antimicrobial activity of saturated fatty acids and fatty amines was determined by oxygen meters with multi-channels and disposable oxygen electrode sensors (DOX-96). Lauric acid, the most effective among the saturated fatty acids, showed antimicrobial activity at 400 microg/ml against methicillin-susceptible Staphylococcus aureus (MSSA) and MRSA.

Experimental studies on the effects of the combined use of N-(4-hydroxyphenyl)retinamide (4-HPR) and tamoxifen (TAM) for estrogen receptor (ER)-negative breast cancer.

We investigated the effects of combination therapy with N-(4-hydroxyphenyl)retinamide (4-HPR) and tamoxifen (TAM) on estrogen receptor (ER) negative breast cancer, for which no effective supplementary therapy has been established, using the human breast cancer cell line MDA-MB-231. TAM or 4-HPR alone had little antitumor effect, but the combined use of TAM and 4-HPR had a strong cell growth inhibitory effect. Cell cycle analysis by flow cytometry showed an increased frequency of the G2/M phases in the 4-HPR-TAM combination group.