# Photoabsorbing bioinks for expanding 3D printed human liver in situ

> **NIH NIH R01** · UNIVERSITY OF WASHINGTON · 2021 · $741,372

## Abstract

Project Summary/Abstract
 Liver disease is a pressing public health challenge, because unlike most other major killers deaths due
to liver disease are rapidly rising rather than falling. Although liver transplantation prolongs survival, there is a
growing number of patients in need of transplant, but donor supply has remained stagnant. To address this major
medical problem, we are working to build artificial liver tissue that could serve as a bridge or alterative to organ
transplant. A crucial remaining hurdle for developing artificial liver tissue is building the multiscale vasculature
needed to support billions of densely packed hepatocytes. Novel approaches that address this challenge would
transform liver research and therapy.
 Our recent work pushed the field closer to addressing this hurdle by introducing a breakthrough method
for 3D printing volumetric vascular networks in artificial tissues. This advance was made possible by addition of
photoabsorbers to stereolithography bioinks, which enabled millions of voxels to be patterned over many tissue
layers. Yet, tissues produced with stereolithography remain incompletely vascularized and sparsely cellularized,
with functional levels that still fall short of those needed for therapy. We have recently gained important clues
towards addressing this challenge. First, we identified new photoabsorber formulations that substantively
improve print resolution, providing a new route to volumetrically scaling a denser vasculature. Furthermore, we
found that adding biological matrices to bioinks allows us “expand” vasculature and hepatocytes within printed
tissues after implantation in the body to produce tissues with native density. These data lead us to hypothesize
that dual-role bioinks that support both technical and biological modes of scale-up will facilitate generation of
human liver tissue with volumetric vasculature that expands in vivo. Further, such tissue will have hepatic
functional levels sufficient to therapeutically treat liver disease. To test these hypotheses, we established a team
with synergistic expertise in liver and vascular tissue engineering, biomaterials and bioprinting, clinical liver
surgery, clinical hepatology, liver cell biology, and liver metabolism. We will employ our expertise to develop
vascularized bioprinted liver tissue that grows in the body. We will first formulate a new library of bioinks for
projection stereolithography with improved print resolution and bioactivity, to facilitate both 3D printing and in
vivo tissue engineering (Aim 1). We will then 3D print scaled vascular topologies that mimic liver vasculature and
support hepatocyte engraftment (Aim 2). Finally, we will trigger hepatocyte expansion in the tissues to achieve
hepatocyte density and functional levels sufficient to rescue mice with liver injury (Aim 3).
 The real power of this proposal lies in conflating bioprinting and biological modes of tissue scale-up,
which will transform tissue engineering a...

## Key facts

- **NIH application ID:** 10364975
- **Project number:** 1R01DK128551-01A1
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Kelly R Stevens
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $741,372
- **Award type:** 1
- **Project period:** 2021-09-21 → 2025-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10364975

## Citation

> US National Institutes of Health, RePORTER application 10364975, Photoabsorbing bioinks for expanding 3D printed human liver in situ (1R01DK128551-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10364975. Licensed CC0.

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