The ratiometric fluorescence nanoparticle based on SiRB for pH detection of tumor

Tumor pH detection and pH value change monitoring have been of great interest in the field of nanomedicine. In this study, a pH-sensitive near-infrared fluorescence probe SiRB (Si-rhodamine and Boronic acid group) was synthesized by introducing a boronic acid group into the silicon rhodamine structure. ICG (Indocyanine green) as the fluorescence internal standard and SiRB were loaded into PLGA (poly lactic-co-glycolic acid) to form PLGA-SiRB-ICG nanoparticle. The experiments showed that the size of the nanoparticle was about 90 nm, which can reach tumor passively by enhancing permeability and retention effect. PLGA in the acidic environment will accelerate the release of cleavage, and the fluorescence ratio of the two probes can reflect the specific pH value in the tumor. The results indicated that the nanoparticle could quantitatively measure the pH value of the tumor site, which is expected to be used in tumor research and treatment. The nanoparticles were achieved for ratiometric optical pH imaging based on the “on-off” fluorescent probe SiRB. The probe SiRB can be used as a pH indicator and the probe ICG can act as an internal reference. The ratio of the fluorescence intensity of the two probes can reflect the pH values. PLGA serves as a carrier to deliver the two probes simultaneously. [Display omitted]