Thermally Triggered Drug Delivery by Polyhedral Oligomeric Silsesquioxane Co -Conjugated with Gold as a Nano-Drug Carrier in Cancer Therapy

Nanoparticles can be modified with polymers and bioactive molecules aiming to achieve full efficiency in therapy and specific targeting. Polyhedral oligomeric silsesquioxane (POSS) is an organic-inorganic (RSiO1.5)8 hybrid material that consists of a –Si-O- inorganic core surrounded by tunable organic moieties. POSS is a highly symmetrical, cage-like structure, possible to add functional groups, both organic and inorganic in precision. POSS has been synthesized and characterized using FT-IR, 1H NMR, EDAX, SEM, and TEM. It has been developed along with the thiol end group and paves a space for cross-linked nanostructures formationPOSS-SH. Voids and spaces in the POSS cross-linked nanocarrier give enough space for drug loading up to 50 weight percentages. Here the therapy is done with the help of drug delivery application in an acidic medium found in the cancer cell site and acts as an internal trigger for drug releasefrom POSS. T h e Presence of thiol end terminal has a greater affinity for attachment of gold which in turn provides an add-on application of photo dynamic therapy this combination is gold POSS- SH-Au. Cell viability studies proved that the POSS nanostructures are biocompatible. Thedeveloped POSS nanostructures can even be activated at acidic conditions, used for sustained release of drugs at specific targets, and provide in-vivo stability until they reache the tumor site. ThePOSS-SH-Au resulted an improvement in aqueous stability as its chains have the tendency to wraparound the siloxane cage and prevent the water from getting close to the siloxane frameworks. Keywords: POSS, Crosslinked POSS nanodrug carrier, Cancer drug delivery, Gold nanoparticles, Upconverting nanoparticles.