Advanced 3-D bioprinting

The number of patients on an organ transplant waiting list highly outnumbers the amount of organs available, leading to thousands of organ failure deaths each year. Carnegie Mellon researchers are developing advanced "bioprinters" -- 3-D printers that are able to print soft biomaterials that may someday lead to the printing of organ parts, or even whole organs, that are compatible with the human body.

Publications:

• Three-dimensional printing of complex biological structures by freeform reversible embedding of suspended hydrogels
• 3D bioprinting from the micrometer to millimeter length scales: Size does matter
• 3D Printing PDMS Elastomer in a Hydrophilic Support Bath via Freeform Reversible Embedding

All tissue-forming cells require direct binding to extracellular matrix (ECM). The ECM “scaffold” provides a 3D matrix for spatial organization of the cells and three forms of ECM-to-cell communication. First, ECM structural constituents bind to cell surface integrins and other ECM receptors, which enable cell attachment while also acting as signaling molecules. Second, peptide/protein hormones and their modifiers are immobilized within the ECM and signal cells via their own cell surface receptors. Third, extracellular vesicles (EVs), immobilized within the ECM, deliver a wide variety of cargo constituents to signal cells, including miRNA, growth factors, cytokines, transcription factors, enzymes and lipids. Carnegie Mellon University researchers are thus developing custom, printable ECM bioinks that contain cell binding ECM molecules, growth factors, and, EVs that can be printed into organ constructs.  Where applicable, these bioinks are being customized for the type of organ or tissue being developed.

Publications:

• Engineered spatial patterns of FGF-2 immobilized on fibrin direct cell organization
• Dose-dependent cell growth in response to concentration modulated patterns of FGF-2 printed on fibrin
• Spatially directed guidance of stem cell population migration by immobilized patterns of growth factors
• Inkjet printing of growth factor concentration gradients and combinatorial arrays immobilized on biologicallyrelevant substrates
• Microenvironments engineered by inkjet bioprinting spatially direct adult stem cells toward muscle- and bone-like subpopulations
• Inkjet-based biopatterning of bone morphogenetic protein-2 to spatially control calvarial bone formation
• Engineering spatial control of multiple differentiation fates within a stem cell population
• Precise control of osteogenesis for craniofacial defect repair: the role of direct osteoprogenitor contact in BMP-2-based bioprinting
• Inkjet-based biopatterning of SDF-1beta augments BMP-2-induced repair of critical size calvarial bone defects in mice
• Transforming growth factor beta 1 augments calvarial defect healing and promotes suture regeneration