Programmable bio-ionic liquid functionalized hydrogels for in situ 3D bioprinting of electronics at the tissue interface

Abstract

The increased demand for personalized wearable and implantable medical devices has created the need for the generation of electronics that interface with living systems. Current bioelectronics has not fully resolved mismatches between biological systems and engineered circuits, resulting in tissue injury and pain. Thus, there is an unmet need to develop materials for the fabrication of wearable electronics that are biocompatible at the tissue interface. Here, we developed a tailorable gelatin-based bio-ink functionalized with a choline bio-ionic liquid (BIL) for in situ 3D bioprinting of bioelectronics at the tissue interface. The resultant photocrosslinked polymer is programmable, transparent, ion conductive, and flexible. BILs are stably conjugated with a gelatin methacryloyl (GelMA) hydrogel using photocrosslinking to make BioGel, which routes ionic current with high resolution and enables localized electrical stimulation delivery. Controllable crosslinking, achieved by varying reactants composition, allows the BioGel bio-ink platform for easy and rapid in-situ 3D bioprinting of complex designs directly on skin tissue. Bio-ionic modified polymers thus represent a versatile and wide-applicable bio-ink solution for personalized bioelectronics fabrication that minimizes tissue damage.

Keywords

• In-situ 3D bioprinting
• Bio-ionic liquid functionalization
• Bioelectronics
• Biomaterials
• Biological tissue