Development of analytical methods for functional analysis of intracellular protein using signal-responsive silica or organic nanoparticles

Trimethylammonium modification of a polymer-coated monolith column for rapid and simultaneous analysis of nanomedicines

Drug-containing nanoparticles (nanomedicine) are ideal targeted-drug-delivery systems. However, methods for the simultaneous analysis of the drug within the nanoparticle and free drug in a short time are rather limited. In this study, we developed a polymer-modified monolithic column with cationic groups (trimethylammonium) for the simultaneous analysis of the drug within the nanoparticle and the free drug. The use of the acrylamide group was determined as the optimum connecting group, and the optimum concentration of the modifier was 6%. The prepared column retained the drug within the nanoparticle by anion exchange, and its elution time was controlled by the ionic concentration (tris(hydroxymethyl)aminomethane, Tris) of the mobile phase. The separation of two typical nanomedicines was studied on the prepared column. For DOXIL and Abraxane, the drugs within the nanoparticle were well separated from the free drugs, on the developed column. The developed polymer-coated monolithic column with trimethylammonium modification is expected to enable the rapid analysis of various nanomedicines.

Enrichment of liposomal nanomedicines using monolithic solid phase extraction discs following preactivation with bivalent metal ion solutions

Silicate is an excellent adsorbent because of its large surface area and amenability to surface modification. In this study, the representative liposome nanomedicines DOXIL^® and AmBisome^® were enriched using a silica monolith disc (diameter 4.2 mm, length 1.5 mm) with bimodal pores. Although the nanoparticles passed through the disc without retention when water was used as the preactivation solution, they were strongly retained by the disc when a 1 M bivalent metal (such as Mg²⁺, Ca²⁺, and Ni²⁺) solution was used. Notably, strong affinity was observed to DOXIL, a pegylated liposomal nanoparticle, by the disc composed of 5 μm and 10 nm through- and meso pores, respectively, and nearly 100% of DOXIL was recovered from a 40× diluted solution. Overall, the results demonstrate that monolithic discs are effective for the enrichment of liposomal nanomedicines.

Surface modification of silica nanoparticles using 4-aryloxy boron dipyrromethene (BODIPY) enhances skin permeation

4-Aryloxy boron dipyrromethene (BODIPY) modification of the surface of silica nanoparticles (NPs) improved permeability through the membrane of HaCaT skin cells and swine skin tissue. The 35 nm BODIPY-modified NPs penetrated tape-stripped skin and reached the dermis within 1 h. Since these NPs can encapsulate a variety of molecules including macromolecules, they are expected to serve as effective carriers for the delivery of drugs, genes, and other compounds through skin and into cells.