Using of phosphate nanocomposites for therapeutics in melanoma model

Abstract

The incidence rates of melanoma have been increasing dramatically in recent years. The search for strategies that increase therapeutic efficiency and reduce side effects is the focus of several studies today. The treatment mainly uses BRAF kinase blocking drugs, however, several studies have demonstrated the efficiency of other chemotherapeutic drugs such as doxorubicin and cisplatin to treat melanoma, but the side effects are limiting factors. The association of chemotherapeutic agents with nanoparticles is a viable alternative to enhance traditional chemotherapy, aiming at reducing side effects. In this study, we present two approaches: the first one intended to adsorb cisplatin on calcium phosphate nanoparticles (NPC), as well as quantify the encapsulated cisplatin in the 91OCis formulation and evaluate its efficiency as carriers for the delivery of drugs to melanoma cells (A375 and B16F10) and predict the selectivity of the formulations using HEK-293 cells. Total X-ray fluorescence spectroscopy (TXRF) analyzes showed that 91OCis encapsulates 9.6 µg of cisplatin every 1 mg and that NPC cannot adsorb cisplatin on its surface. The formulations were not able to reduce cell viability in the tested cell lines, probably because cisplatin is not released from the nanoparticle structure in the case of 91OCis. On the other hand, doxorubicin hydrochloride was associated with calcium phosphate nanoparticles functionalized with hyaluronic acid and polyethylene glycol and tested in a human melanoma model in vitro using the A-375 cell line. The formulations tested showed a significant reduction in IC50 over 48 hours when compared to the free drug (Dox 0.44 ± 0.25; N-DOX 0.13 ± 0.07; NPC+DOX 0.16 ± 0.08 µM) and reduced toxicity in HEK-293 cells. The formulation provided a significant reduction in IC50 over 48 hours (0.142 ± 0.07) when compared to the free drug (0.44 ± 0.25) and reduced toxicity in HEK-293 cells. Both treatments caused DNA damage, tetraploidy after 72 hours, an increase in the nuclear area, and increased activity of senescence-associated beta-galactosidase. Also, there was no formation of colonies after 14 days of incubation preceded by short exposure treatment. Preliminary results indicate that nano-formulated doxorubicin has potential for melanoma treatment since it potentializes doxorubicin activity without changing the mechanism of action, and does not increase toxicity to rat myoblasts of the H9C2 cell line.