Preparation of near-infrared light responsive upconversion nanoparticles TiO2/(Ca,Y)F2:Tm,Yb for photodynamic antitumor therapy

In this work, near-infrared light responsive upconversion nanoparticles TiO 2 /(Ca,Y)F 2 :Tm,Yb were hydrothermally prepared for tumor control. Moreover, femtosecond laser was adopted to reduce particle size and aggregation of TiO 2 /(Ca,Y)F 2 :Tm,Yb, as a strategy to enhance its dispersity. In vitro studies of the biocompatibility and tumor control efficacy of TiO 2 /(Ca,Y)F 2 :Tm,Yb were carried out via co-culturing human pancreatic carcinoma cells (CFPAC-1). It was found in the absence of near-infrared light, TiO 2 /(Ca,Y)F 2 :Tm,Yb showed no toxicity to CFPAC-1 cells. On contrast, when exposed to near-infrared light, particles exhibited irradiation time, irradiation interval and particle concentration dependent suppression of CFPAC-1 cells proliferation along with portion of S phase cells increase. A nude mouse model with CFPAC-1 cells injection was established and TiO 2 /(Ca,Y)F 2 :Tm,Yb was subsequently applied for in vivo tumor control. A 15 days tracking confirmed the antitumor capability of near-infrared light excited TiO 2 /(Ca,Y)F 2 :Tm,Yb. Overall, we anticipate that the here-introduced TiO 2 /(Ca,Y)F 2 :Tm,Yb can serve as an effective agent for photodynamic antitumor therapy. Graphical Abstract