3D Bioprinting: Strategies and ApplicationsProf Yeong Wai Yee

Singapore Centre for 3D Printing

HP-NTU Digital Manufacturing Corp Lab

School of Mechanical & Aerospace Engineering

Nanyang Technological University

www.yeongresearch.com

#1World’s Best Young

University 2014 – 2021

QS Top 50 Under 50

Flagship 3D Printing research centres @ NTU

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Realize new applications for different industries.

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Design of tissue for Bioprinting

Oil and gas applications

Aerospace industry construction design

3D Bioprinting: The inevitable

5Increasing shape and bioactivity complexity

3D Bioprinting

6Murphy & Atala, Nature Biotechnology 32(8), 2014

3D Bioprinting • Are we there yet?

https://www.biogelx.com/bioprinting-wth-ihydrogels/ https://3dprint.com/235208/bioprinting-101-part-2-hydrogels/

https://www.brinter.com/press-and-news/what-is-3d-bioprinting-part-1-of-6-history-and-significance/

• Conflicting requirements on materials

• Soft and porous hydrogel -friendly to cells but not friendly to process

• High printability material -Good shape fidelity but challenging to host cells inside the material

Material-process relationship

Systems Thinking in 3D Bioprinting

9Murphy & Atala, Nature Biotechnology 32(8), 2014

It’s an overall strategies !

3D Bioprinting Current Strategies in Materials and Processes

https://www.advancedsciencenews.com/3d-printed-heart-with-patients-own-cells/

Strategizing printing processes: Extrusion Bioprinting

• Jia Min Lee; Wai Yee Yeong. (2016). Design and Printing Strategies in 3D Bioprinting of Cell-Hydrogels: A Review. Advanced Healthcare Materials, 5(22), 2856-2865.

Current Strategies in Materials: Material-design

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Optimizing viscosity of bio-ink

Semi-crosslinked, additive of thickening agent

[1] W. Schuurman, P. A. Levett, M. W. Pot, P. R. van Weeren, W. J. A. Dhert, D. W. Hutmacher, et al., "Gelatin-Methacrylamide Hydrogels as Potential Biomaterials for Fabrication of Tissue-Engineered Cartilage Constructs," Macromolecular Bioscience, vol. 13, pp. 551-561, 2013.

[1]

Hydrogel with high Printability Small batch production

Suntornnond, R., Tan, E.Y.S., An, J. et al. A highly printable and biocompatible hydrogel composite for direct printing of soft and perfusable vasculature-like structures. Sci Rep 7, 16902 (2017). https://doi.org/10.1038/s41598-017-17198-0

Current Strategies in Materials : Tool-design

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Co-extrusion of bio-ink and crosslinker

Crosslinker

Bio-ink

Q. Gao, Y. He, J.-z. Fu, A. Liu, and L. Ma, "Coaxial nozzle-assisted 3D bioprinting with built-in microchannels for nutrients delivery," Biomaterials, vol. 61, pp. 203-215, 8// 2015.

Current Strategies in Materials : Time-design

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Sequential deposition of precursor and crosslinker

Hydrogel with rapid crosslink mechanism

C. Li, A. Faulkner-Jones, A. R. Dun, J. Jin, P. Chen, Y. Xing, et al., "Rapid Formation of a SupramolecularPolypeptide–DNA Hydrogel for In Situ Three-Dimensional Multilayer Bioprinting," Angewandte ChemieInternational Edition, vol. 54, pp. 3957-3961, 2015.

Current Strategies in Materials: Process-design

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Deposition of bio-ink into crosslinker Science Advances 23 Oct 2015: Vol.

1, no. 9, e1500758DOI: 10.1126/sciadv.1500758 Three-dimensional printing of complex biological structures by freeform reversible embedding of suspended hydrogels

Strategies in Process : Indirect Bioprinting to achieve high resolution using low viscosity hydrogels

• Improved line resolution

Printing of high-resolution 3D construct

Edgar Y.S. Tan1, Ratima Suntornnond1,*, Wai Yee Yeong1,2 “High resolution novel indirect bioprinting of low viscosity cell-laden hydrogels via model-support bioinksinteraction”, 3D PRINTING AND ADDITIVE MANUFACTURING ( accepted paper)

Resolution of cells : Droplet-based bioprinting process

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Wei Long Ng*, Jia Min Lee*, Wai Yee Yeong, May Win Naing (2017) Microvalve-based bioprinting - process, bio-inks and applications. Biomaterials Science DOI:10.1039/C6BM00861E 5, 632 - 647

Advantages: high resolution can be achieve

Disadvantage:Cells consolidation inside the catridge

Resolution of cells ( consistency and control)

Wei Long Ng, Jia Min Lee, Wai Yee Yeong, and May Win Naing. "Microvalve-based bioprinting–process, bio-inks and applications." Biomaterials Science (2017). DOI: 10.1039/C6BM00861EWei Long Ng, Wai Yee Yeong, and May Win Naing. "Polyvinylpyrrolidone-based bio-ink improves cell viability and homogeneity during drop-on-demand printing." Materials 10, no. 2 (2017): 190.

To investigate the droplet profile with and without cells, using high speed imaging , on-going work with HP-NTU digital manufacturing corp lab

Droplet impact

Increasing resolution using micro or nanodroplet

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• Resolution of print

• Shapes • Control on

Cells Location ( resolution of cells)

Bioprinting is LIVE

Beyond just shape and cell deposition.

The function of the cells is also critical

Bioink with tunable stiffness for Directed Cell Response

Shi P, Laude A, Yeong WY. 2017. Investigation of cell viability and morphology in 3D bio-printed alginate constructs with tunable stiffness. J Biomed Mater Res Part A105A:1009–1018.

Day 7 culture , L929

Cell has more space to accommodate & reproduce

Cell is moderately restrained , may migrate in blebbing shapes

Cells formed spheroids

Functional Extrusion Bioprinting with Cell Alignment

Directing Cell Alignment for Cardiac Patch

Jia Min Lee, and Wai Yee Yeong. "Engineering macroscale cell alignment through coordinated toolpath design using support-assisted 3D bioprinting." Journal of the Royal Society Interface 17, no. 168 (2020): 20200294

Cell patterning

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Bilayer photoreceptor-retinal tissue model: cell distribution

Shi, Pujiang, Yong Sheng Edgar Tan, Wai Yee Yeong, Hoi Yeung Li, and Augustinus Laude. "A bilayer photoreceptor-retinal tissue model with gradient cell density design: A study of microvalve-based bioprinting." Journal of Tissue Engineering and Regenerative Medicine 12, no. 5 (2018): 1297-1306.

F-actin ZO-1 Claudin-1

Interdisciplinary nature of 3D Bioprinting

Interface of Biology: Bioprinted In Vitro Models

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Many organs can be bioprinted, and these physiologically relevant bioprinted in vitromodels could substitute the a combination of animal and in vitro data to supportdecision making.A M Holmes et al, Biofabrication 9 ( 2017 ) 033001

3D Printed Microfluidics Chip

• Jia Min LEE, Meng ZHANG, Wai Yee YEONG. (2016). Characterization and evaluation of 3D printed microfluidic chip for cell processing. Microfluidics and Nanofluidics, 20(1), 1-15

• 3D printing provides design freedom in micro-to-macro fluidics chip designs.

Enable new capabilities in cells processing, and cell-encapsulated droplets production.

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Biology +

Electronics

Flexible 3D Printed Electronics (aerosol jet printing)

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Low cost and flexible carbon nanotube pH sensor for live cell applications

Wearable Bandage based Strain Sensor for Home Healthcare

A Low Cost and Flexible Carbon Nanotube pH Sensor fabricated using Aerosol Jet Technology for Live Cell Applications, Sensors and Actuators B: Chemical, 260, 227-235.

Wearable Bandage-Based Strain Sensor for Home Healthcare: Combining 3D Aerosol Jet Printing and Laser Sintering, ACS Sensors, 4(1), 218-22 DOI: 10.1021/acssensors.8b01293

3D bioprinted flexible and biocompatible hydrogel bioelectronic platform

Biosensors and Bioelectronics,102, 365-371

Living cells inside hydrogel

Bioprinting: Beyond Biology

• Advanced Simulation for 3D printing • Digital nature of 3D Printing enabled data-

driven approaches and machine learning • AI for Bioprinting

Goh, G.D., Sing, S.L. & Yeong, W.Y. A review on machine learning in 3D printing: applications, potential, and challenges. Artif Intell Rev (2020) https://doi.org/10.1007/s10462-020-09876-9Joel Heang Kuan Tan, Swee Leong Sing & Wai Yee Yeong (2020) Microstructure modelling for

metallic additive manufacturing: a review, Virtual and Physical Prototyping, 15:1, 87-105, DOI: 10.1080/17452759.2019.1677345

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Shape Fidelity - Free Form Bioprinting (BioCADapproach) using support-build material + robotics

2) Generating appropriate support structure

GelMA

Pluronic

Ventricle Wall Printed1) Selection of left ventricle

Expanding Processes of Bioprinting

35Biofabrication 2016Biofabrication: reappraising the definition of an evolving field

Summary • Bioprinting is still at emerging stage • 3D Bioprinting evolves fast and

dynamically; researchers must innovate with systems thinking

• Bioprinting is Beyond Biology ( lab on chip, bioelectronics, AI and ML)

• New strategies are expected for optimal cells responses.

• Knowledge and knowhow in material, process and biology will continue to expand.

3D printing & Bioprinting

Scaffold for tissue

engineering

Bioprinting

Micro-tissue ,Organ chip

Biomodel Metal Implant Smart wearable

3D printing of polymer, metal and electronics

Personalized drug platform, bioelectronics

3D printing of implants and tissues

3D printed microfluidic chip

Thank you

www.yeongresearch.com

https://sc3dp.ntu.edu.sg/Pages/Home.aspx

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