Controlled in-cell release of caspase from photodegradable nanoparticles using the PARCEL method

Although local protein activity in the cells is one of the hot topics in life science study, it still has many difficulties to measure or change its activity. Here, we prepared 20 nm-sized protein (caspase)-encapsulated photodegradable nanoparticles and used them to control the amount of caspase released within HeLa cells.Encapsulated caspase was released into the cytosol following irradiation. The increased amount of released caspase led to enhanced cell membrane permeability. These results indicate that the amount of protein released within cells can be regulated by the amount of protein-encapsulated nanoparticles; therefore, this technique would be useful for detailed study of protein function within cells or the control of cellular functions

Extraction of cell-free DNA from urine, using polylysine-coated silica particles

DNA analysis is used for a variety of purposes, including disease diagnosis and DNA profiling; this involves extracting DNA from living organisms. In this study, we prepared polycationic silica particles to extract DNA that has the negatively charged phosphate backbone from solution. The coated particles were prepared by mixing conventional silica gel particles and poly-Lys; these particles could efficiently extract 1.3 mu g of cell-free DNA from 50 mL of (male) urine. It is expected that these easily prepared particles (just a mixture of two commercially available chemicals) can be used as a noninvasive diagnostic tool for genetic disorders such as cancer, diabetes, and hypertension