Semi-interpenetrated polymeric near-infrared absorbing nanogels for efficient photothermal therapy of cancer

FECHNER; KAR; M.A. MOLINA; STEFANIE WEDEPOHL; CALDERÓN

Simposio; 11th International Symposium in Polymer Therapeuthics; 2016

INTRODUCTIONIn recent years, several near-infrared (NIR) light absorbing nanomaterials have been developed for photothermal therapy of cancer.[1] However, the biological fate of inorganic nanomaterials limits their clinical utilizations. Therefore, polymers like polyaniline (PANI) or polypyrrole (PPY) recently attracted attention in terms of their ability to convert NIR light to heat.[2] Although, these polymers suffer from their poor water solubility which limits their advanced applications towards in vivo systems. Semi-interpenetration (sIPN) describes the fact that one liner polymer is entangled in the network of another three-dimensional crosslinked polymer. It is an excellent tool for the synthesis of advanced composites as, in contrast to a copolymerization, the individual properties of the polymers are preserved.[3] Therefore, we used sIPN method to introduce PANI and PPY into the network of biocompatible, thermoresponsive nanogels to gain NIR absorbing, thermoresponsive NGs designed for efficient photothermal treatment of cancer. RESULTS AND DISCUSSIONIn this work, we developed a family of polymeric NIR absorbing nanogels, studied their physicochemical properties, and evaluated their biological applications. The biocompatible, thermoresponsive nanogels are made from hyperbranched polyglycerol as macromolecular cross-linker and thermoresponsive poly(N-isopropylacrylamide) or poly(N-isopropylmethacrylamide). NIR sensitivity was introduced to the thermoresponsive nanogels by semi-interpenetration with PANI or PPY through in situ polymerisation into the network of the nanogels (Figure 1). The physicochemical characterizations of the water-soluble composites were accomplished successfully. All sIPN NGs show a strong heating capacity upon NIR irradiation. The biological evaluations showed no cytotoxicity of the sIPN NGs itself, but strong effects on cell viability if illuminated with NIR.[4-5] In addition, first in vivo studies indicate a good tolerability of the NGs and show good antitumor efficiencies.[4-5]