Apoferritin/Vandetanib Association Is Long-Term Stable But Does Not Improve Pharmacological Properties of Vandetanib

A tyrosine kinase inhibitor, vandetanib (Van), is an anticancer drug affecting the signaling of VEGFR, EGFR and RET protooncogenes. Van is primarily used for the treatment of advanced or metastatic medullary thyroid cancer; however, its usage is significantly limited by side effects, particularly cardiotoxicity. One approach to minimize them is the encapsulation or binding of Van in- or onto a suitable carrier, allowing targeted delivery to tumor tissue. Herein, we constructed a nanocarrier based on apoferritin associated with Van (ApoVan). Based on the characteristics obtained by analyzing the average size, the surface ζ-potential and the polydispersive index, ApoVan nanoparticles exhibit long-term stability and maintain their morphology. Experiments have shown that ApoVan complex is relatively stable during storage. It was found that Van is gradually released from its ApoVan form into the neutral environment (pH 7.4) as well as into the acidic environment (pH 6.5). The effect of free Van and ApoVan on neuroblastoma and medullary thyroid carcinoma cell lines revealed that both forms were toxic in both used cell lines, and minimal differences between ApoVan and Van were observed. Thus, we assume that Van might not be encapsulated into the cavity of apoferritin, but instead only binds to its surface.