3D Printed Electroactive Biomaterials for Sensing and Stimulation

NU 2020-005

INVENTORS

Jonathan Rivnay*

Anthony J. Petty II

Cheng Sun

Henry Oliver T. Ware

SHORT DESCRIPTION

A novel post printing functionalization process that allows one to bestow tunable electroactivity on a biocompatible 3D printed hydrogen without sacrificing the resolution of the print.

BACKGROUND

Incorporating electroactive components like conducting polymers, graphene, and carbon nanotubes into biomaterials significantly impacts cellular adhesion, proliferation, and differentiation. It also enables electrical stimulation and sensing to enhance tissue regeneration understanding. However, achieving sufficient electroactivity for stimulation and sensing, coupled with high resolution in three dimensions, remains a persistent challenge. The incorporation of electroactive elements into photopolymerizable biomaterials is particularly difficult due to the interference of conducting elements with the light used for polymerization initiation. This interference hinders the crosslinking process, making it challenging to achieve three-dimensional structures with high resolution and shape fidelity. Previous attempts have resulted in combinations of extremely stiff materials, low-resolution structures, and structures with limited electrical conductivity.

ABSTRACT

Northwestern researchers have developed biocompatible polymer hydrogel composite structures designed as scaffolds for biological tissue growth and regeneration. The method involves creating porous three-dimensional (3D) hydrogel scaffolds with well-defined pore walls, followed by infiltration with a water-soluble, electrically conducting polymer, allowing tunable electroactivity without compromising printing resolution or cytocompatibility. Techniques like 3D extrusion-type printing, including MicroCLIP printing, are employed for scaffold construction. The resulting hydrogel constructs are biocompatible, water-swellable, and cytocompatible. Functionalization options enhance compatibility with electrically conducting polymers. The conducting polymer hydrogel composites exhibit electroactivity, supporting in vitro cell proliferation and differentiation, along with bulk electrical stimulation for tissue growth and regeneration. These versatile scaffolds find application in growing various tissues in vitro or in vivo, including dermal, neural, osteo, chondral, osteochondral, and cardiac tissue, with the potential integration of electrical devices for monitoring and promoting tissue growth.

APPLICATIONS