Rapid Fabrication of Engineered Gradient Tissue Scaffolds Using Cell-Embedded Microbeads

Project Overview

Engineering the spatial organization of cells and the three-dimensional (3D) matrix of proteins that surround them in tissues is crucial to repairing or replacing the tissue's unique function in vivo. Rebuilding gradients of mechanical and chemical properties in tissue engineered constructs, such as for articular cartilage, remains essentially impossible, resulting in billions of dollars spent annually on total joint replacements. Cell-embedded microfabricated hydrogel beads (microbeads) provide a direct path toward engineering tissue biophysical gradients as individual microbeads can be customized, serving as building blocks that can be assembled to fabricate multi-material, multi-stiffness, multi-cellular scaffolds with tunable pore size.

We developed a novel capability to produce high-throughput, tunable cell-laden microbeads leveraging an advanced manufacturing system unique to LLNL. We adapted this fabrication process for live mammalian cells, engineered biocompatible microbeads of varying stiffness, and generated a porous tissue scaffold with a gradient of mechanical stiffness demonstrating the versatility of our approach. This technology provides a means of generating gradient tissues such as cartilage as microbead stiffness and cell density can be easily tuned.

Mission Impact

This work has established a novel and widely adaptable capability at Lawrence Livermore National Laboratory (LLNL) to fabricate customizable living microscale constructs in a high-throughput manner, opening the door to a wide variety of applications such as biosensing, bioremediation, and biofuel/biotherapeutic production. The results of this project directly support the Bio Resilience mission focus area through the development of an advanced biofabrication platform and biomaterial feedstocks. By merging additive manufacturing techniques with bioengineering, this work has driven innovation across two core competencies: bioscience and bioengineering and advanced materials and manufacturing.

Publications, Presentations, and Patents

J. Trujillo, "Generation of a multi-layer scaffold for cartilage regeneration" (Presentation, LLNL Research Slam, Livermore, CA, August, 2023). LLNL-PRES-1079069.

E.M. Wasson, "Life by the Drop: Engineering Human Gradient Tissues Using Cell-Embedded Microbeads" (Presentation, Postdoc Research Slam, Livermore, CA, September 2022). LLNL-PRES-839697.

C. Le-Doux, "Microbead Image Analysis for Rapid Counting and Measurement" (Presentation, LLNL Research Slam, Livermore, CA, August, 2022). LLNL-PRES-838019.