A 3D bioelectrical interface to assess colorectal cancer progression in vitro

Abstract

Conducting polymers such as PEDOT have attracted considerable attention in the tissue engineering field to add an active electrical read-out to 3D cell cultures. However, PEDOT is normally copolymerized with PSS− that possibly degrades acidic by-products in the long-term. Given this drawback, it is preferable to tailor PEDOT:polyelectrolyte dispersions that better meet the morphological and physiological microenvironment of the human tissues. Herein, a novel bioelectrical interface in the shape of a 3D porous scaffold made of the conducting PEDOT/hyaluronic acid (HA) and collagen (COL) is presented. For this purpose, first, the oxidative chemical polymerization of 3,4-ethylenedioxythiophene (EDOT) was carried out in the presence of the biopolymers. Then, porous scaffolds were constructed by freeze-drying the dispersions which allows good control of pore size and morphology, showing unique mechanical properties. Interestingly, these biocompatible, conducting scaffolds successfully support growth of 3D cell cultures of sw480 colon adenocarcinoma cancer cells, achieving good cell attachment and proliferation. When integrated with electrodes, they further allow real-time electrical monitoring of cell growth and proliferation. Upon the addition of the flavonoid morin, cell apoptosis and death were monitored by electrochemical impedance spectroscopy and optical immunostaining., demonstrating the promise of these scaffolds for cancer cell progression modeling. We believe that our findings have demonstrated the great promise of combining PEDOT with biopolymers for cancer cell progression modeling but also will be of interest in broader applications in the fields of biomedicine, wearable electronics, and prospectively applied to clinic.