Microfluidic study of targeted imaging and photodynamic therapy

The application of nanoparticles as delivery platforms in PDT is a promising alternative for resolving some of the major challenges associated with classic photosensitizers (PSs) such as porphyrin molecules. Polysilsesquioxane nanoparticles (PSQ-NPs) are crosslinked homopolymers formed by the condensation of functionalized trialkoxysilanes. Recent reports have shown that PSQ-NPs can provide an interesting platform for developing PS nanocarriers. Several advantages can be foreseen by using this platform such as carrying a large payload of PSmolecules; their surface and composition can be tailored to develop multifunctional systems. In this work, two PSQ-NP systems with a high payload of photosensitizers were synthesized, characterized, and applied in vitro. The network of these nanomaterials is formed by two different types of porphyrin-based photosensitizers, protoporphyrin-IX and tetrakis(4-carboxyphenyl)porphyrin, chemically connectedvia a redox-responsive linker. Both platforms can be further functionalized with polyethylene glycol and targeting ligands such as folic acid to improve their biocompatibility and target specificity, respectively. The effectiveness of these porphyrin-based hybrid nanomaterials was successfully demonstrated in vitro using cervical human cancer (HeLa), lung (H-460) and colon (HT-29) cancer cells.