Targeted sonodynamic destruction of glioblastoma cells using antibody-titanium dioxide nanoparticle conjugates.

Aim: We present data on sonodynamic therapy (SDT) against glioblastoma cells utilizing titanium dioxide (TiO2) nanoparticles conjugated to anti-EGFR antibody. Materials & methods: TiO2 nanoparticles were bound to anti-EGFR antibody to form antibody-nanoparticle conjugates (ANCs), then characterized by x-ray photoelectron spectroscopy and transmission electron microscopy. Cells underwent ultrasound and assessment on viability, reactive oxygen species and apoptosis were performed. Results: X-ray photoelectron spectroscopy analysis revealed the formation of an ANC. Transmission electron microscopy showed internalization of the ANCs by glioblastoma cells. With SDT, cell viabilities were reduced in the presence of ANCs, reactive oxygen species production was formed, but minimal effect on apoptosis was seen. Conclusion: For the first time, an ANC can be used with SDT to kill glioblastoma cells.

Light-driven transformation processes of anisotropic silver nanoparticles.

The photoinduced formation of silver nanoprisms from smaller silver seed particles in the presence of citrate anions is a classic example of a photomorphic reaction. In this case, light is used as a convenient tool to dynamically manipulate the shape of metal nanoparticles. To date, very little is known about the prevailing reaction mechanism of this type of photoreaction. Here we provide a detailed study of the shape transformation dynamics as a function of a range of different process parameters, such as photon energy and photon flux. For the first time, we provide direct evidence that the photochemical synthesis of silver nanoprisms from spherical seed nanoparticles proceeds via a light-activated two-dimensional coalescence mechanism. On the other hand, we could show that Ostwald ripening becomes the dominant reaction mechanism when larger silver nanoprisms are grown from photochemically synthesized smaller nanoprisms. This two-step reaction proceeds significantly faster and yields more uniform, sharper nanoprisms than the classical one-step photodevelopment process from seeds. The ability to dynamically control nanoparticle shapes and properties with light opens up novel synthesis avenues but also, more importantly, allows one to conceive new applications that exploit the nonstatic character of these nanoparticles and the ability to control and adjust their properties at will in a highly dynamic fashion.

The citrate-mediated shape evolution of transforming photomorphic silver nanoparticles.

The photoconversion of photomorphic silver nanoparticles from discs to prisms via citrate mediated growth on the twin plane faces of the nanoparticles is demonstrated. This systematic shape evolution from discs to hexagons and then prisms of increasing aspect ratios is a result of the growth process being confined to specific faces of the growing nanoparticles.

Measurements of adult lingual tonsil tissue in health and disease.

OBJECTIVES: To report computed tomography (CT) measurements of lingual tonsil tissue (LTT) in patients with laryngopharyngeal reflux (LPR), obstructive sleep apnea-hypopnea syndrome (OSAHS), both LPR and OSAHS, or neither disease. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary care center. SUBJECTS AND METHODS: Ninety-eight patients with CT scans including the tongue base and complete historical data regarding the presence or absence of symptoms, signs, and laboratory confirmation of LPR and/or OSAHS were included. LTT was measured on CT. Charts of patients meeting inclusion criteria were subsequently reviewed and patients were divided into four groups: 1) those without LPR or OSAHS, 2) those with LPR only, 3) those with OSAHS only, and 4) those with both LPR and OSAHS. Statistical analysis focused on correlating LTT thickness with the presence or absence of LPR and/or OSAHS. RESULTS: The mean LTT thickness for group 1 (21 patients without reflux or OSAHS) was 0.937 mm (range 0-2.67 mm). The mean for group 2 (29 patients with LPR only) was 3.35 mm (range 0-7.4 mm). The mean for group 3 (16 patients with OSAHS only) was 4.29 mm (range 0-9 mm). The mean for group 4 (32 patients with LPR and OSAHS) was 4.00 mm (range 0-19.2 mm). The mean for group 1 was lower than the other 3 groups (P < 0.001). CONCLUSION: CT images including the tongue base allow precise measurement of LTT thickness. LTT > 2.7 mm was not identified in patients without OSAHS or LPR. The mean LTT for patients with LPR and/or OSAHS was significantly greater than for patients without either disease.