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

Jeong Hoon Byeon

doi:10.1038/srep31351

Abstract

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.

Highlights

polyethylene glycol (PEG) incorporation with the Ag-TiO2 particles significantly decreased the cytotoxicity of Ag, and this was comparable with that of TiO2 particles
To functionalize the flame-synthesized TiO2 particles with organic components in a continuous manner, an ultrasound Ag(I)-PEG reaction cell is employed both for efficient hydrosolization of the TiO2 particles and for subsequent incorporation with Ag and PEG on the TiO2 domains (Fig. 1)
In the case of Ag-TiO2@PEG, as shown in Fig. 2c, the different particles are combined as a single agglomerate, and it was clearly observed that darker dots were randomly located on the TiO2 domains, which confirmed that the Ag-TiO2 hybrid structures were successfully assembled

Summary

Jeong Hoon Byeon

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. Numerous approaches have been proposed for fabricating multifunctional biocompatible nanomaterials that consist of inorganic-organic nanocomponents for application in diagnostic and therapeutic fields These nanomaterials usually contain metallic nanoparticles as the core components with biofunctional polymers that endow the nanomaterial with unique physicochemical properties for diagnostic and therapeutic purposes[2,3,4]. More recently, flame-synthesized nanoparticles have often been employed as active materials for biomedical applications via successive incorporation with biocompatible overlayers in a continuous manner[1,6,11]. Since this technique works only for inorganic biomaterials, its application is still limited for generalized use. PEG is employed as overlayers for the Ag-TiO2 nanoparticles since it is known to be nontoxic to mammalian cells (i.e. biocompatible) and non-antigenic[16], which may help it bond with metallic ions[17]

Results and Discussion

Materials and Methods

Additional Information