Alena (Laney) Casella

UC Davis

“Increased surface charge of conductive hydrogels enhances cell adhesion and spreading via protein adsorption”

My research interrogates the relationship between a material’s electrical and physical properties and how the interplay of these properties direct cell behavior. Further, my work seeks to provide insight into how electroactive materials influence cell behavior without external electrical stimulation. Results to date indicate that electrically conductive biomaterials present increased surface charge, which allows for protein adsorption and subsequent cell adhesion.

ABSTRACT

The electrical properties of tissues are a burgeoning area within the field of biomaterials, owing to the regenerative role bioelectricity plays in tissue homeostasis and healing. Many studies have demonstrated the ability of electrically conductive biomaterials to direct differentiation and aid in maturation of electroactive cell types, even in the absence of external stimulation. However, mechanisms dictating improved cell behavior on conductive substrates without stimulation are not well characterized. We hypothesized that conductive gels would facilitate greater protein adsorption due to increased surface charge, and thus improve cell behavior. To interrogate this hypothesis, we prepared hydrogels using different mixtures of agarose and an electrically conductive polymer, PEDOT:PSS. Mesenchymal stromal cells had improved adhesion to and spreading on the conductive gels over the non-conductive control, despite all gels lacking cell adhesion sites. Conductive substrates also facilitated greater adsorption of charged proteins, indicating conductive gels had increased surface charge. These results demonstrate that cell adhesion is upregulated on conductive subtrates, potentially owing to increased electrostatically driven protein adsorption, and begin to describe how conductivity influences cell behavior without external stimulation.
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