Automated Covalent Microcontact Bioprinting of Lubricant-Infused Microarrays for Biological Assays

Microcontact bioprinting (µCP), which utilizes elastomeric stamps to transfer biorecognition agents (bioinks) onto substrates, offers advantages such as customizability, cost-effectiveness, and versatility for bioassays. Despite its prevalent use in laboratory settings, µCP faces challenges in achieving the repeatability and reproducibility required for industrial applications. Here, a µCP method is introduced that accommodates the immobilization of various biorecognition agents, while preserving bioactivity for use in bioassays. A key innovation lies in combining µCP with fluorosilanization to enable lubricant-infused surfaces that prevent non-specific attachment, while concurrently enhancing biomolecule immobilization via covalent attachment through a modified bioink formulation. Furthermore, an automated µCP system is integrated, taking critical steps toward industrial scalability. Following optimization with fluorescent proteins, bacterial viruses (bacteriophages) are printed. The bioactivity preservation is confirmed using Pseudomonas aeruginosa bacteriophage microarrays. A bacterial metabolic activity bioassay is conducted, whereby bacteriophage lytic activity led to a visible color difference after 3 h. The introduced µCP is high-throughput, scalable, and highly customizable, demonstrating strong potential for industrial implementation.