A Near-Infrared Triggered Intracellular pH Regulative PAMAM/O-nitrobenzaldehyde Coated UCNPs for Cancer Therapy

Dendrimers have become effective drug carriers and gene transfection vectors for medical biomaterials. In this experiment, UCNPs (NaGdF4:Tm, Yb@NaGdF4) and three-generation PAMAM dendrimers were prepared firstly; then NaGdF4:Tm, Yb@NaGdF4 was modified by Polyacrylic acid(PAA); PAMAM were grafted to the surface of the modified UCNPs by the reaction between amino groups and carboxyl groups; finally, O-nitrobenzaldehyde was grafted to the surface by Schiff base reaction.The synthesized upconversion materials were coated with PAA and PAMAM, then loaded with O-nitrobenzaldehyde to form spherical nanoparticles. The particle size of prepared nanoparticles is 75 similar to 80 nm. The dendrimer complex can emit ultraviolet light to regulate the pH gradient of aqueous solution under the excitation of near-infrared light (980 nm), and can be used to kill cancer cells by changing the acidity of tissue cells; secondly, the cavity between dendrimers and dendrimers on the surface of the complex can be used in many fields such as drug delivery and gene transfection; the nanoparticles provide a new method for cancer treatment.