Scalable hybrid chemical manufacture to photothermal therapy: PEG-capped phototransducers

Ag-TiO2@polyethylene glycol (PEG) nanoparticles were continuously obtained in a single-pass configuration by appropriately reacting freshly flame-synthesized TiO2 with Ag formed in an ultrasonic aqueous medium containing PEG. When the proposed synthesis was kept constant, the production rate for Ag-TiO2@PEG nanoparticles reached approximately 3 g/h while only using a combination of a lab-scale inverse-diffusion flame (16 mm head diameter) and an ultrasonic Ag(I) cell (50 mL). The synthesized nanoparticles were employed as inducers for in vitro photoinduced therapy to kill cancer cells at different light wavelengths. Measurements of the nanoparticle cytotoxicity revealed that PEG incorporation with the Ag-TiO2 particles significantly decreased the cytotoxicity (cell viability of more than ~91% at 200 μg mL(-1) particle concentration) of Ag, and this was comparable with that of TiO2 particles (cell viability of more than ~90%). When 632 nm and 808 nm light was applied to the nanoparticles in the HeLa cells, the viability of the cells was significantly affected [decreased to ~4% (632 nm) and ~26% (808 nm) at 200 μg mL(-1), 5 min irradiation time] by surface plasmon resonance heating and photothermal therapy.