The particles were then collected and washed with PBS and analyzed with a Zeta-Potential & Particle Size Analyzer ELSZ-2 (Otsuka Electronics, Osaka, Japan). Next, we calculated the incorporation rate of Hoechst 33342. A 1mL aliquot of emulsion was centrifuged at 15000g for 10min before washing with PBS. The supernatant #P450 animal study randurls[1|1|,|CHEM1|]# was then collected and the concentration of Hoechst 33342 was measured. The incorporation ratio of Hoechst 33342 was calculated using the value of Hoechst 33342 concentration and the amount of supernatant. Unloaded

PLGA particles Inhibitors,research,lifescience,medical were also synthesized to study cellular toxicity of PLGA particles alone. 2.5. In Vitro Release of Hoechst 33342 When in vitro release of Hoechst 33342 from the particles was investigated, 3mL of Hoechst 33342-incorporated Inhibitors,research,lifescience,medical PLGA particles were combined with 7mL saline and incubated at 37°C in a shaking bath. A small amount of incubation solution was collected after 0, 1, 2, 3, and 4 days, and the concentration of Hoechst 33342

in each sample was determined. To quantify the concentration of dye we combined 180μL of either sample or a solution Inhibitors,research,lifescience,medical containing serial amounts of Hoechst 33342 (ranging from 0 to 1000μg/mL) as a control with 20μL a solution containing 20ng of mouse genomic DNA in a 96-well plate format. The fluorescent intensity of each well was then measured using a FXEX station 3. This experiment was performed in duplicate and mean values of fluorescent intensity were calculated. 2.6. In Vivo Experiments Using Hoechst 33342-Incorporated PLGA Particles Inhibitors,research,lifescience,medical in

the Absence or Presence of Dio-Labeling This project was approved by the Ethics Committee for the Care and Use of Laboratory animals of Tohoku University School of Medicine. C57/BL6 mice (8 to 12 weeks old) were housed in the animal room at Tohoku University Institute for Inhibitors,research,lifescience,medical Experimental Animals, Sendai, Japan, with a 12-hour light/dark cycle. The mice were fed a standard murine diet and allowed tap water ad libitum. Hoechst 33342-incorporated PLGA particles dissolved in 200μL PBS were administered to the mice using one of three routes: (i) intravenous administration via the caudal vein, (ii) local injection into the femoral muscle, or (iii) intraperitoneal injection. Mice were sacrificed by cervical dislocation and organs or tissues of interest were removed, fixed with 4% paraformaldehyde, dehydrated Thiamine-diphosphate kinase in 10, 15, and 20% sucrose PBS, mounted in OCT compound, and frozen and stored at −80°C until required. Frozen sections of 5μm in thickness were prepared, washed in PBS, mounted in the water soluble mounting medium, and observed by fluorescence microscopy (model BZ-8100 microscope; KEYENCE, Tokyo, Japan) with or without staining of the plasma membrane with CellMask Plasma Membrane Stain. When the particles without Dio-labeling were administered into the peritoneal cavity, intraperitoneal macrophages were collected 20 or 60 hours after administration.