Allotopic colorectal cancer, core shell nanoparticles, cashew gum nanoparticles.

Colorectal cancer (CRC) is among the most studied cancers due to its high incidence and mortality worldwide. Many of its treatments are considered limited and palliative. Therefore, it is imperative to develop new therapeutic and diagnostic options. Among these options, core-shell nanoparticles (NPCS) and cashew gum nanoparticles (NP-GC) stand out, as they have great cytotoxic and antiproliferative potential in the tumor microenvironment (TME), in addition to being able to be associated with chemotherapeutic agents such as oxaliplatin (OXA), forming a platform of hybrid nanosystems capable of reducing the resistance of these chemotherapeutic agents and increasing their arrival in TME. In addition, the NPCS, due to their magnetic capacity, can cause the death of tumor cells by hyperthermia, and with their fluorescent characteristic, they can be traced in the living organism. To explore some of these potentialities, our group synthesized, characterized and tested the action of these hybrid nanosystems in CCR cell culture, and later in an in vivo (murine) model of allopic CCR. As a result, we observed that the core-shell NP-GC associated with OXA had a size of 217nm and a zeta potential of 30.0mV and did not show trypan blue cytotoxicity in CT-26 cells at 4 h, 24 h and 48 h. hs at a concentration of 5µg/mL, subject or not to a magnetic field, for 3 minutes, at the same times and concentration. On the other hand, cell viability to OXA was higher at times of 7.5 µg/mL (p<0.05), 10 µg/mL (p<0.01) and 15 µg/mL (p<0.01 ) at 24 and 48 hours. The next step of our work will be to test the cytotoxicity of NP-GC-CS-OXA at a concentration of 7.5 µg/mL in times from 4 to 48 hours submitted to the magnetic field for 3 minutes, to carry out an apoptosis study by ANEXIN/ PI by flow cytometry under the same conditions in CT-26 cells and evaluate the antitumor activity in CRC allopic tumors.