Molecularly cleavable bioinks facilitate high-performance digital light processing-based bioprinting of functional volumetric soft tissues

Soft tissue fabrication using digital light processing remains challenging. Here the authors present a molecular cleavage approach to achieve high-performance bioprinting of constructs with tissue-matching mechanical properties and structural complexity. Digital light processing bioprinting favors biofabrication of tissues with improved structural complexity. However, soft-tissue fabrication with this method remains a challenge to balance the physical performances of the bioinks for high-fidelity bioprinting and suitable microenvironments for the encapsulated cells to thrive. Here, we propose a molecular cleavage approach, where hyaluronic acid methacrylate (HAMA) is mixed with gelatin methacryloyl to achieve high-performance bioprinting, followed by selectively enzymatic digestion of HAMA, resulting in tissue-matching mechanical properties without losing the structural complexity and fidelity. Our method allows cellular morphological and functional improvements across multiple bioprinted tissue types featuring a wide range of mechanical stiffness, from the muscles to the brain, the softest organ of the human body. This platform endows us to biofabricate mechanically precisely tunable constructs to meet the biological function requirements of target tissues, potentially paving the way for broad applications in tissue and tissue model engineering.

Automated summary

The authors present a molecular cleavage approach to achieve high-performance bioprinting of constructs with tissue-matching mechanical properties and structural complexity. Their method allows for improvements in cellular morphological and functional properties across various tissue types, enabling precise tunability of mechanical properties for target tissues. This platform has the potential for broad applications in tissue and tissue model engineering.