Gene Expression and Pulmonary Toxicity of Chitosan-graft- Polyethylenimine as Aerosol Gene Carrier.

Chitosan-graft-polyethylenimine (CHI-g-PEI) copolymer has been used for the improvement of low transfection efficiency of chitosan. The present study aims to test the pulmonary toxicity and efficiency of CHI-g-PEI as an aerosol gene carrier. Mice were exposed to aerosol containing green-fluorescent protein (GFP)-polyethylenimine (PEI) or GFP-CHI-g-PEI complexes for 30 min during the development of our nose-only exposure chamber (NOEC) system.

Three-dimensional assembly of nanoparticles from charged aerosols.

The capability of assembling nanoparticles into a desired ordered pattern is a key to realize novel devices which are based not only on the unique properties of nanoparticles but also on the arrangements of nanoparticles. While two-dimensional arrays of nanoparticles have been successfully demonstrated by various techniques, a controlled way of building ordered arrays of three-dimensional (3D) nanoparticle structures remains challenging. We report that a variety of 3D nanoparticle structures can be formed in a controlled way based on the ion-induced focusing, electrical scaffold, and antenna effects from charged aerosols.

Toxicity and clearance of intratracheally administered multiwalled carbon nanotubes from murine lung.

Carbon nanotubes (CNT) are known to have widespread industrial applications; however, several reports indicated that these compounds may be associated with adverse effects in humans. In this study, multiwalled carbon nanotubes were administered to murine lungs intratracheally to determine whether acute and chronic pulmonary toxicity occurred. In particular, pristine multiwalled carbon nanotubes (PMWCNT) and acid-treated multiwalled carbon nanotubes (TMWCNT) were used in this study.

High-resolution, parallel patterning of nanoparticles via an ion-induced focusing mask.

An ion-induced focusing mask under the simultaneous injection of ions and charged aerosols generates invisible electrostatic lenses around each opening, through which charged nanoparticles are convergently guided without depositing on the mask surface. The sizes of the created features become significantly smaller than those of the mask openings due to the focusing capability. It is not only demonstrated that material-independent nanoparticles including proteins can be patterned as an ordered array on any surface regardless of the conductive, nonconductive, or flexible nature of the substrate, but also that the array density can be increased.