Three-dimensional Patterning of Engineered Biofilms with a Do-it-yourself Bioprinter

• Published in: Journal of visualized experiments no. 147
• Main Authors: Spiesz, Ewa M, Yu, Kui, Lehner, Benjamin A E, Schmieden, Dominik T, Aubin-Tam, Marie-Eve, Meyer, Anne S
• Format: Journal Article
• Language: English
• Published: United States 16.05.2019
• Subjects: Biofilms - drug effects; Bioprinting - instrumentation; Escherichia coli - drug effects; Escherichia coli - physiology; Hydrogels - pharmacology; Printing, Three-Dimensional
• ISSN: 1940-087X; 1940-087X
• DOI: 10.3791/59477

Biofilms are aggregates of bacteria embedded in a self-produced spatially-patterned extracellular matrix. Bacteria within a biofilm develop enhanced antibiotic resistance, which poses potential health dangers, but can also be beneficial for environmental applications such as purification of drinking water. The further development of anti-bacterial therapeutics and biofilm-inspired applications will require the development of reproducible, engineerable methods for biofilm creation. Recently, a novel method of biofilm preparation using a modified three-dimensional (3D) printer with a bacterial ink has been developed. This article describes the steps necessary to build this efficient, low-cost 3D bioprinter that offers multiple applications in bacterially-induced materials processing. The protocol begins with an adapted commercial 3D printer in which the extruder has been replaced with a bio-ink dispenser connected to a syringe pump system enabling a controllable, continuous flow of bio-ink. To develop a bio-ink suitable for biofilm printing, engineered Escherichia coli bacteria were suspended in a solution of alginate, so that they solidify in contact with a surface containing calcium. The inclusion of an inducer chemical within the printing substrate drives expression of biofilm proteins within the printed bio-ink. This method enables 3D printing of various spatial patterns composed of discrete layers of printed biofilms. Such spatially-controlled biofilms can serve as model systems and can find applications in multiple fields that have a wide-ranging impact on society, including antibiotic resistance prevention or drinking water purification, among others.