Aerosol Jet® Printing of Poly(3,4-Ethylenedioxythiophene): Poly(Styrenesulfonate) onto Micropatterned Substrates for Neural Cells In Vitro Stimulation

Miriam Seiti; Paola Serena Ginestra; Rosalba Monica Ferraro; Silvia Giliani; Rosaria Maria Vetrano; Elisabetta Ceretti; Eleonora Ferraris

doi:10.18063/ijb.v8i1.504

Aerosol Jet^® Printing of Poly(3,4-Ethylenedioxythiophene): Poly(Styrenesulfonate) onto Micropatterned Substrates for Neural Cells In Vitro Stimulation

Int J Bioprint. 2022 Jan 28;8(1):504. doi: 10.18063/ijb.v8i1.504. eCollection 2022.

Authors

Miriam Seiti^{1

2}, Paola Serena Ginestra², Rosalba Monica Ferraro³, Silvia Giliani³, Rosaria Maria Vetrano¹, Elisabetta Ceretti², Eleonora Ferraris¹

Affiliations

¹ Department of Mechanical Engineering, KU Leuven, 3001, Leuven, Belgium.
² Department of Mechanical and Industrial Engineering, University of Brescia, 25123, Brescia, Italy.
³ Department of Molecular and Translational Medicine, "Angelo Nocivelli" Institute for Molecular Medicine, University of Brescia, ASST Spedali Civili, Brescia, Italy.

Abstract

In neural tissue engineering (NTE), topographical, electrical, mechanical and/or biochemical stimulations are established methods to regulate neural cell activities in in vitro cultures. Aerosol Jet^® Printing is here proposed as enabling technology to develop NTE integrated devices for electrically combined stimulations. The printability of a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT: PSS) commercial ink onto a reference substrate was firstly investigated and the effect of the process parameters on the quality of printed lines was analyzed. The study was then extended for printing thick electrodes and interconnects; the print strategy was finally transferred to a silicon-based wafer with patterned microchannels of proven cellular adhesion and topographical guidance. The results showed values of electrical resistance equal to ~16 Ω for printed electrodes which are ~33 μm thick and ~2 mm wide. The electrical impedance of the final circuit in saline solution was detected in the range of 1 - 2 kΩ at 1 kHz, which is in line with the expectations for bioelectronic neural interfaces. However, cells viability assays on the commercial PEDOT: PSS ink demonstrated a dose dependent cytotoxic behavior. The potential cause is associated with the presence of a cytotoxic co-solvent in the ink's formulation, which is released in the medium culture, even after a post-sintering process on the printed electrodes. This work is a first step to develop innovative in vitro NTE devices via a printed electronic approach. It also sheds new insights the transfer of AJ^® print strategies across different substrates, and biocompatibility of commercial PEDOT: PSS inks.

Keywords: Aerosol Jet® printing; Biomedical; Conductive polymers; Neural tissue engineering; Printing of electronics.