PMC

Preparation of Janus particles Centrifuge the 2 µm silica particle aqueous suspension (10% w/w) at 2,200 x g for 1 min.Pipette 2 µL of sedimentary silica particles into a 1.5 mL microcentrifuge tube and add 500 µL of ethanol (99.5% v/v). NOTE: The supernatant does not need to discarded; just save it in the refrigerator at 4 °C. It does not need to be resuspended before pipetting.Sonicate the ethanol-silica particle suspension using an ultrasonicator (43 kHz, 50 W) for 1 min and then centrifuge it at 2,200 x g for 3 min.Substitute the supernatant with 500 µL of ethanol and repeat step 2.1.3 three times.Substitute the supernatant with 8 µL of ethanol and sonicate the ethanol-silica particle suspension using an ultrasonicator (43 kHz, 50 W) for 3 min. NOTE: About 10 µL of ethanol-silica particle suspension should remain in the tube at this step.Pipette 2 µL of ethanol-silica particle suspension and drop it on a normal glass slide (width: 25 mm, length: 75 mm, and thickness: 1.2 mm) to form a droplet. Note: This quantity of particle suspension is enough to prepare the monolayers for 5-6 slides (2 µL for each slide).Slowly drag the ethanol-silica particle droplet slightly with a cover glass to form a monolayer of silica particles (A).Put the slide with the monolayer of silica particles into a sputtering device to be coated with Au. Remove the air from the sputter chamber at 100 mTorr and inject argon for 10 min (replace the air with argon). Stop injecting argon and then remove the argon from the chamber at 70 mTorr.Set the current to 15 mA for 200 s. (B); Janus particles are already prepared at this step. Drop 20 µL of DI water on the sputtered slide and scrape the Janus particles from the monolayer using a normal 200 µL pipette tip. NOTE: The Janus particles scraped from the monolayer suspend in the DI water droplet at this step.Pipette the Janus particle suspension droplet and drop it into another 1.5-mL centrifuge tube.Use the Janus particle suspension to prepare the sample by diluting it with DI water to a suitable concentration for experiments. NOTE: The concentration of the particle suspension in the experiments described here is about 2,000 counts/µL.

Particle size distributions as measured by wet-SF-ICP-MS (blue) and dry-SF-ICP-MS (red) for 3 suspensions of a small NP: (A) Ag: the mean particle size ± polydispersity of the suspension was 8.5 ± 2.2 with dry introduction and 9.8 ± 3.3 with wet introduction; (B) Au: the mean particle size ± polydispersity of the suspension was 9.8 ± 3.4 with dry introduction and 11.8 ± 3.6 with wet introduction; (C) CeO₂: the mean particle size ± polydispersity of the distribution in the suspension was 6.3 ± 2.0 with dry introduction and 8.0 ± 2.1 with wet introduction.

(a) Mass median aerodynamic diameters (MMAD) of the particle size distribution. Turbuhaler, 200 µg; MMAD, 2.20 µm, (b) Mass median aerodynamic diameters (MMAD) of the particle size distribution. Symbicort Turbuhaler, 60 DPI; MMAD, 2.60 µm, (c) Mass median aerodynamic diameters (MMAD) of the particle size distribution. NE-U22; budesonide suspension, 250 µg/mL; MMAD, 4.52 µm, and (d) Mass median aerodynamic diameters (MMAD) of the particle size distribution. NE-C28; budesonide suspension, 250 µg/mL; MMAD, 3.84 µm.

In vitro time-kill curve (mean ± standard deviation; n=3).
Abbreviations: cfu, colony-forming units; T0.2, tilmicosin-loaded hydrogenated castor oil nanoparticle suspension with a particle size of 900 nm; T1, tilmicosin-loaded hydrogenated castor oil nanoparticle suspension with a particle size of 450 nm; T5, tilmicosin-loaded hydrogenated castor oil nanoparticle suspension with a particle size of 150 nm; TMS, native tilmicosin; MHB, Mueller–Hinton broth.