(123a) Platinum Nanoparticles Efficacy and Toxicity As Cancer Treatment

Nanotechnology is a multidisciplinary field that has many different applications including cancer treatment and detection. Noble metal nanoparticles such as gold, silver or palladium, have shown major potential in the field of medicine and pharmaceutics. In particular, platinum nanoparticles (Pt NPs) have been reported with promising anticancer results. The activity of nanoparticles is based on their small size and high surface area; these properties allow them to penetrate biofilms as well as influence intracellular mechanisms. Recent studies indicate that Pt NPs can be used as a therapy for cancer showing limited toxicity to healthy cells. Hence, in this work, we developed a new treatment option for triple negative breast cancer (TNBC) based on Pt NPs. TNBC is a type of breast cancer that lacks the three common receptors used for immunotherapy and with a tendency to metastasize faster. Therefore, TNBC has a worst prognosis and often chemotherapy is the only treatment option. However, chemotherapy is toxic, has many side effects and some cancers can even develop resistance, therefore, new treatment options are needed to combat TNBC.

The mechanism of action of Pt NPs is not fully understood and needs to be determined to comprehend their efficacy and toxicity as potential cancer treatment. Preliminary studies show that Pt NPs follow a similar mechanism to the platinum-based drug cisplatin where the Pt NPs enter the cell, ionize in the cell, and bind to the DNA, breaking it and inhibiting cell proliferation. Platinum based therapeutics have been a common course of treatment for TNBC. However, their toxicity and side effects prevent the patients to follow a whole course of treatment leaving them without any options. Pt NPs provide an alternative with limited toxicity for such sort of patients. However, the behavior of Pt NPs has not been studied enough in vivo. Furthermore, a common problem of nanoparticles is their accumulation in liver and spleen; therefore, it is important to characterize their biodistribution, before it can be used in clinical trials.

In the present study, Pt NPs were synthesized, and the anticancer activity was tested in vitro against TNBC, showing a remarkable cell death. As the major drawback of traditional chemotherapy is the toxicity, cell viability experiments were also performed on fibroblasts. The results showed no apparent toxicity of Pt NPs for healthy cells in contrast to cisplatin (a common chemotherapeutic drug). Based on the promising results achieved in vitro, the effect of Pt NPs was tested in vivo with mice, showing not apparent toxicity and no mice dead. Biodistribution was quantified using ICP-MS for the different organs of the mice finding the most accumulation in liver and spleen. In summary, this work provides evidence of a potential new treatment for TNBC based on Pt NPs with no apparent toxicity for healthy cells, overcoming one of the major drawbacks of current treatments.