In vitro anticancer activity of melanin-like nanoparticles for multimodal therapy of glioblastoma

Glioblastoma (GBM) is one of the most aggressive and hard to treat cancers. Traditional anti-cancer treatment methods have low efficiency and the lifespan after diagnosis is only 12-18 months. Brain tumor cells overexpress many proteins that play an important role in tumor progression and can be used as therapeutic targets. One of the promising approaches in cancer treatment is down-regulation of an extracellular matrix glycoprotein - Tenascin-C (TN-C) through RNA interference therapy. However, the effective delivery of double stranded RNA with one strand complementary to TN-C mRNA sequence is difficult due to rapid degradation by nucleases and low intracellular uptake. Polydopamine (PDA), a biomimetic polymer characterized by high biocompatibility and simple modification ability, is commonly used in nanobiomedicine to create a drug/gene delivery vehicle. Furthermore, photothermal characteristics of this polymer enable its application in photothermal therapy (PTT), which is a great option for cancer treatment. Here we synthesize PDA nanoparticles (NPs) coated with polyamidoamine dendrimers generation 3.0 (DD3.0) for therapeutic anti-TN-C RNA and doxorubicin delivery. As prepared PDA@DD3.0 NPs are then used in combined drug delivery, gene silencing, and PTT of GBM. The obtained materials are analyzed in terms of physicochemical and photothermal properties as well as their cytotoxicity, using human GBM cells. The results demonstrate that the obtained nanocarriers are effective non-viral vehicle for combined therapeutic approach for killing glioma cells via anti-TN-C RNA delivery and combined chemo-PTT therapy (CT-PTT). The application of PDA@DD3.0 NPs contributed to the 3-fold reduction in the proliferation rate of GBM cells, a decrease in the level of TN-C expression (by 30%) and a reduction in the number of viable cells by up to 20%.