Background: Malignant breast tumors are in developed countries, the most common cancer affecting mainly women. It is estimated that approximately 5-10% of breast cancers are conditioned by genetic family burdens, caused by mutation in the BRCA2 gene. In the course of the treatment doxorubicin is frequently used therapeutics. Despite its therapeutic efficacy, however, it shows high cardiotoxicity. Possibility to increase the therapeutic window, represent nanotransporters. Fullerenes are nanoparticles composed of carbon atoms whose physical-chemical properties indicate high stability. The complex of fullerene and doxorubicin enables the targeted method for the treatment. The aim of this work is to develop a nanotransporter system with an expected cytostatic effect without significant toxic effects.
Material and methods: To 5mg of fullerene 0.5ml of distilled water was added and solution was subsequently placed for 30 min in an ultrasonic bath (50 W). Fullerenes with bound doxorubicin (DOXO) were purified from unbound DOXO by centrifugation (16,000g). For DOXO analysis acetate buffer was used. Fe2O3-NPs were prepared by reduction with borohydride and ammonia. Thereafter Fe2O3-AuNPs were prepared by thermal synthesis.
Results: Carbon nanotransporter (fullerene) for binding of doxorubicin (FULLER-DOXO) was designed and subsequently studied by biophysical methods. We have found that FULLER-DOXO size is larger than 100 nm and the zeta potential is around 24 mV. DOXO, interacts with FULLER by the electrostatic interaction, and its volume increases with the applied concentration (R2 = 0.96). In the following experiment FULLER-DOXO was modified with oligodeoxynucleotide (ODN; 10 µg/ml), and this way was FULLER-DOXO-ODN1 complex prepared. Bound ODN represents a specific sequence for targeting the complex to a point mutation in the BRCA2 gene. In order to prove the interaction magnetic gold nanoparticle modified with the complementary sequence to the test nanotransporter was designed (ODN2-Fe2O3-AuNPs). Formed complex (FULLER-DOXO-ODN1-ODN2-Fe2O3-AuNPs) was subsequently confirmed by several independent techniques.
Conclusion: We assume that the proposed nanoconstruct will be able to use for genetic targeting of anticancer drug.Key words: doxorubicin - breast cancer - fullerenes - magnetic gold nanoparticles The work was realized with the support of the project NANO LPR 2017 Liga proti rakovině Praha and The European Technology Platform for Nanomedicine. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 6. 3. 2017Accepted: 26. 3. 2017.