Amanda Patrícia Gonçalves, Karoline Hellen Madureira de Melo, Daniela Aparecida Silva, Marcela de Sá Hauck, Mariá Aparecida Braga Rocha E Oliveira, Isabela Malo Lopes, Gabriela Pereira Paschoalini, José Ésio Bessa Ramos Junior, Renko de Vries and Anésia Aparecida dos Santos

Cancer is a devastating disease whose treatment tends to be very aggressive due to its side effects and low selectivity. Nanotechnology has emerged as an alternative in medicine, especially in cancer treatments. In this case, molecular tools can be used to enhance chemotherapy delivery-drugs nanoparticles, making them more selective. DNA molecules have been suggested as a great material for nano-constructions once it can be associated with some chemotherapy molecules such as doxorubicin and cisplatin. In 2014, Hernandez-Garcia and colleagues designed the C4S10K12 protein, a synthetic viral coat protein which self-assembles with dsDNA molecules forming rod-shaped virus-like nanoparticles. Based on these insights, we designed a biopolymeric doxorubicin-carrier nanoparticle coated by the C4S10K12 protein and evaluated its stability in physiological conditions as well its internalization, cytotoxicity and selectivity on murine melanoma tumor cells lines. Through non-denaturing electrophoresis we demonstrated that DNA molecules remain intact in physiological conditions and can tolerate the action of DNAse enzyme. Fluorescence Microscopy showed that the constructed nanoparticle can enter melanoma murine tumor cells after 1 hour of treatment and release its content inside those cells after 12 hours. This controlled and delayed release caused an increase in doxorubicin cytotoxicity when compared to non encapsulated-doxorubicin treated cells, which was demonstrated through MTT assays. These experiments also showed that the DNA-Doxorubicin complex coated by C4S10K12 was more toxic to tumor cells than to non tumor cells, which did not occur in non encapsulated-doxorubicin treatment. These results show that our construction is a stable nanoparticle capable of entering tumor cells in vitro, triggering increased cytotoxicity and selectivity. These features demonstrate that these nanoparticles have a high potential for chemotherapy and open new perspectives to study drug-targeting in tumor microenvironments.