Near infrared light activated upconversion nanoparticles (UCNP) based photodynamic therapy of prostate cancers: An in vitro study.

Photodynamic therapy (PDT), has a potential to cure cancerous prostate tissue with minimal side effects. Traditional PDT, however, mostly utilized visible (VIS) light range with direct application of hydrophobic photosensitizers which may not be adequate in clinical practice for especially deep-seated cancer cells because of poor penetration of VIS wavelengths. Here, we report near infrared light (NIR) induced and dual photosensitizers (PS) encapsulated PDT strategy to reduce prostate cancer cells - PC3. The designed nanoplatform (MC540/ZnPc-UCNP@Au), in this study, include upconversion nanoparticles (UCNP) synthesis to convert NIR light into multiple VIS wavelengths, porous silica coating to upload dual photosensitizers (MC540/ZnPc), and gold (Au) functionalization to enhance PDT treatment. High chemical stabilization provided MC540/ZnPc-UCNP@Au show excellent biocompatibility, and efficient PDT treatment for prostate cancer cells. In fact, the fluorescence of the synthesized nanoplatforms, upon NIR light excitation, can produce considerable amount of ROS in 5 min, as it is well matched with the absorption of MC540, ZnPc and Au nanoparticles (np). In addition, the easy visualization of cellular internalized/adsorbed nanoplatforms reveal the in situ cell imaging possibility for diagnosis. Based on the evidence of the results, NIR light activated MC540/ZnPc-UCNP@Au may offer a PDT technique for the treatment of prostate cancer.