208 / 2024-07-15 01:57:38

Cancer phototheranostics using polymeric nanoparticles with thermoresponsive shell

polymeric nanoparticles, thermoresponsive polymers, cancer theranostics, photodynamic therapy, fluorescence bioimaging

Imaging guided drug nanovehicles are among the most rapidly developing domains in cancer nanomedicine. Polymeric nanoparticles (PNPs) are intensively employed as nanocarriers of anticancer drugs and can provide efficient drug loading and controlled release, along with the embedded imaging modalities allowing to assess and monitor biodistribution of the PNPs and their delivery to cancer tissues. This talk will present the results on design, synthesis, characterization of polymeric nanoparticles with thermoresponsive shell (TSPNPs) that can be loaded with optical imaging and phototherapeutic agents to attain cancer phototheranostics. The TSPNPs consist of a solid polysterene core that provides mechanical stability, controlled morphology and narrow size distribution, and a flexible shell of a thermoresponsive  polymer poly-N-isopropylacrylamide (PNIPAM) or co-polymer of NIPAM and acrylamide (AA). The specific temperature range of the thermoresponsive shell shrinking/swelling can be tuned by changing of the shell polymeric content and thickness. The nanoparticle shell is able to efficiently entrap small hydrophobic molecules added to the nanoparticle dispersion and the temperature-dependent shrinking of the nanoparticle shell is found to affect photophysical processes in the entrapped organic molecules (fluorescent dyes and photosensitizers). The observed and assessed by us phenomenon was further employed in applications of TSPNPs for fluorescence imaging and imaging guided photodynamic therapy of cancer.  In the separate approach, the TSPNPs impregnated with fluorescent dye (visible or infrared) were loaded to mesenchymal stem cells that were then systemically injected in metastatic cancer animal model, allowing for cancer targeting and detection of primary tumor and metastases using fluorescence microscopy and near infrared fluorescence imaging.