Page 64 - IJB-8-1

RESEARCH ARTICLE

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 ,
2
1,2
3
3
Rosaria Maria Vetrano , Elisabetta Ceretti , Eleonora Ferraris *
1
1
2
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-ethylene
dioxythiophene):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: Printing of electronics; Aerosol Jet printing; Conductive polymers; Biomedical; Neural tissue engineering
®
*Correspondence to: Eleonora Ferraris, Manufacturing Processes and Systems, Department of Mechanical Engineering, KU Leuven, Sint Katelijne
Waver, 2860, Belgium; eleonora.ferraris@kuleuven.be
Received: November 3, 2021; Accepted: December 20, 2021; Published Online: January 28, 2022

(This article belongs to the Special Section: 3D Printing and Bioprinting for the Future of Healthcare)
Citation: Seiti M, Ginestra PS, Ferraro RM, et al., 2022, Aerosol Jet Printing of Poly(3,4-Ethylenedioxythiophene): Poly(Styrenesulfonate)
®
onto Micropatterned Substrates for Neural Cells In Vitro Stimulation. Int J Bioprint, 8(1):504. http:// doi.org/10.18063/ijb.v8i1.504
1. Introduction central nervous system. Although some symptoms can be
relieved, there are still limited treatments to cure or slow
Neurodegenerative diseases affect millions of people
worldwide. According to the Alzheimer’s Disease down the progression of neurological disorders.
International Report of 2019, people affected by dementia In this context, neural tissue engineering (NTE) can
only is expected to reach 152 million by 2050. This is offer innovative solutions. NTE is a sub-domain of tissue
related with the increased aging of the global population. engineering (TE), and it is defined as a multidisciplinary
One of the causes of brain neurodegenerative diseases is field enabling to develop biomimetic environment of
the progressive dysfunction and limited self-repair of the the nervous system to study neural activities, aiming at

© 2022 Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution License, permitting distribution and
reproduction in any medium, provided the original work is properly cited.
50