Photothermal therapy of cancer cells mediated by blue hydrogel nanoparticles.

Aim: The aim of this study was to investigate in vitro the utility of biologically compatible, nontoxic and cell-specific targetable hydrogel nanoparticles (NPs), which have Coomassie® Brilliant Blue G dye (Sigma-Aldrich, MO, USA) covalently linked into their polyacrylamide matrix, as candidates for photothermal therapy (PTT) of cancer cells.

Materials & Methods: Hydrogel NPs with Coomassie Brilliant Blue G dye covalently linked into their polyacrylamide matrix were fabricated using a reverse micelle microemulsion polymerization method and were found to be 80-95 nm in diameter, with an absorbance value of 0.52. PTT-induced hyperthermia/thermolysis was achieved at 37°C using an inexpensive, portable, light-emitting diode array light source (590 nm, 25 mW/cm(2)).

Results & Conclusion: Hydrogel NPs with Coomassie Brilliant Blue G dye linked into their polyacrylamide matrix are effective in causing PTT-induced thermolysis in immortalized human cervical cancer cell line (HeLa) cells for varying NP concentrations and treatment times. These multifunctional particles have previously been used in cancer studies to enable delineation, for glioma surgery and in photoacoustic imaging studies. The addition of the PTT function would enable a three-pronged theranostic approach to cancer medicine, such as guided tumor surgery with intra-operative photoacoustic imaging and intra-operative PTT.