06 September 2021, SINGAPORE– The Agency for Science, Technology and Research’s (A*STAR) Institute of Bioengineering and Bioimaging (IBB) and Institute of Molecular Cell Biology (IMCB) have developed a Fluid-supported Liquid Interface Polymerization (FLIP) 3D printer which can rapidly print hydrogel structures with complex geometry, while addressing the key nutrient supply issue in bioprinting.
Hydrogels are used in many biomedical applications, including regenerative medicine and surgical training phantoms. However, the ability to shape hydrogels into complex anatomical structures using additive manufacturing can be challenging due to their low mechanical stiffness.
Using the FLIP 3D printer, a buoyancy-assisted continuous digital light processing (DLP) 3D printing method, the patterns are projected directly onto a thin layer of fluid-supported hydrogel precursor, which serves as a floating liquid projection screen. After printing, the support fluid can be easily removed by rinsing. This approach prevents adhesion of the printed structure to the patterning window (e.g. LCD screens in typical resin-based 3D printers), thus eliminating an additional lifting step between layers that slows down the process.
As a result, FLIP can achieve a faster printing speed compared tothe conventional DLP, and routinely prints at a speed of 200mm/h along the vertical axis for stiffer hydrogels. The continuous printing also helps to improve the smoothness of the printed surfaces, which allows for the end product to be free of layering artifacts.
With an eye on bioprinting applications, A*STAR researchers have devised a strategy to incorporate a second, sacrificial ink, which when removed, creates channels that are able to supply the cells with nutrients, successfully keeping them alive in centimeter-scale printed structures.
Speaking about this work, Dr Cyrus Beh, Principal Investigator, IBB, and Senior Scientist at the Molecular Engineering Laboratory of IMCB, said, “We embarked on this project to address the challenges faced by conventional, extrusion-based bioprinters. The method was designed from the outset to be mild and compatible with cell printing. And while rapid fabrication with soft hydrogels is exciting, the most important aspect of this work is the ability to introduce nutrient supply channels, which will go a long way towards making tissue bioprinting a reality.”
The team demonstrated the printer’s capabilities by 3D printing various models such as the model of Marina Bay Sands (above), as well as fabricating spanning features out of hydrogels as soft as ~7 kPa. They are currently investigating long-term culturing and differentiation of bioprinted cells, as a way to create viable tissues for regenerative medicine purposes.
More information on the study, “A fluid-supported 3D hydrogel bioprinting method”, can be found via the team’s published paper in Biomaterials: https://www.sciencedirect.com/science/article/pii/S0142961221003902
About the Agency for Science, Technology and Research (A*STAR)
The Agency for Science, Technology and Research (A*STAR) is Singapore's lead public sector R&D agency. Through open innovation, we collaborate with our partners in both the public and private sectors to benefit the economy and society. As a Science and Technology Organisation, A*STAR bridges the gap between academia and industry. Our research creates economic growth and jobs for Singapore, and enhances lives by improving societal outcomes in healthcare, urban living, and sustainability. A*STAR plays a key role in nurturing scientific talent and leaders for the wider research community and industry. A*STAR’s R&D activities span biomedical sciences to physical sciences and engineering, with research entities primarily located in Biopolis and Fusionopolis. For ongoing news, visit www.a-star.edu.sg.
About the Institute of Bioengineering and Bioimaging (IBB)
The Institute of Bioengineering and Bioimaging (IBB) is a multi-disciplinary research institute under A*STAR that spearheads translational research at the interface of biology, chemistry, physics, engineering and medicine. IBB’s mission is to develop new technologies and engineering solutions to address health, medical and sustainability challenges. IBB’s research activities are focused on Bioengineering Systems, Biophotonics & Bioimaging, and Biomedical Devices & Diagnostics. The Institute has published numerous papers in leading scientific journals and has filed many patents for its inventions. IBB’s technologies have been commercialised through the establishment of more than 10 spin-off companies.
For more information on IBB, please visit www.a-star.edu.sg/ibb.
About the Institute of Molecular and Cell Biology (IMCB)
The vision of Institute of Molecular and Cell Biology (IMCB) is to be a premier cell and molecular biology institute which addresses the mechanistic basis of human diseases and its mission is to conduct cutting-edge discovery research in disease pathways; to groom early career researchers to be future leaders in research; and to collaborate with the public sector, medical and industry communities for research impact. IMCB plays an important role training and recruiting scientific talents, and has contributed to the development of other research entities in Singapore. Its success in fostering a biomedical research culture in Singapore has catalysed Singapore’s transformation into an international hub for biomedical research, development and innovation.
Funded by A*STAR, IMCB’s use-inspired research comprises 4 major programmes: Neurometabolism in Health and Diseases; Cancer Signalling and Therapies; Cell Biology and Therapies; and Innovative Technologies. IMCB also has two semi-autonomous programmes, the Disease Intervention Technology Laboratory (DITL), and the Molecular Engineering Laboratory (MEL). IMCB’s technologies and platforms focus on Mouse Models of Diseases, Molecular Histopathology, Cellular Microscopy, and Proteomics & Metabolomics.
For more information about IMCB, please visit www.a-star.edu.sg/imcb
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fluid-supported 3D hydrogel bioprinting method
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