Betulin-loaded PEDOT films for regional chemotherapy

Chemotherapy is one of the most commonly used cancer treatments. Even so, it has significant adverse effects on healthy tissues. These effects can be avoided through the use of regional chemotherapy, an approach based on delivering the anti-cancer agents locally, to the site of cancer tissue accumulation. Among the different classes of biomaterials that are used as drug carriers, conducting polymers allow reversible, electrostatic immobilization and controlled release of a variety of compounds. In this work, we describe a method for producing surfaces possessing anti-cancer activity, which are a potential tool for regional chemotherapy. Our method consists of covering the surface with a conducting polymer matrix, followed by loading that matrix with cytotoxic compounds. We have chosen betulin as the model compound for this study, as it is commonly available triterpene that exhibits cytotoxicity against a variety of tumor cell lines. The presence of betulin in the polymer matrix is confirmed by SEM, EDS and IR spectroscopy. The release of betulin is carried out using two protocols, i.e. passive mode (open circuit conditions) or active (application of constant potential) mode. The biological activity of betulin that was released from the matrix is confirmed by its toxic effect against KB and MCF-7 cancer cell lines (IC₅₀ values of 13.34 ± 0.88 μg/mL and 12.57 ± 1.81 μg/mL for KB and MCF-7, respectively). The described method of surface modification is shown to be an effective mean of producing surfaces that possess anti-cancer activity, serving as advantageous materials for regional chemotherapy applications.