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3D Printing of In Vitro Hydrogel Microcarriers by Alternating Viscous-Inertial Force Jetting

Published: April 21st, 2021



1Biomanufacturing Center, Dept. of Mechanical Engineering, Tsinghua University, 2Biomanufacturing and Rapid Forming Technology Key Laboratory of Beijing, 3Department of Mechanical Engineering, Drexel University
* These authors contributed equally

Presented here is a mild 3D printing technique driven by alternating viscous-inertial forces to enable the construction of hydrogel microcarriers. Homemade nozzles offer flexibility, allowing easy replacement for different materials and diameters. Cell binding microcarriers with a diameter of 50-500 µm can be obtained and collected for further culturing.

Microcarriers are beads with a diameter of 60-250 µm and a large specific surface area, which are commonly used as carriers for large-scale cell cultures. Microcarrier culture technology has become one of the main techniques in cytological research and is commonly used in the field of large-scale cell expansion. Microcarriers have also been shown to play an increasingly important role in in vitro tissue engineering construction and clinical drug screening. Current methods for preparing microcarriers include microfluidic chips and inkjet printing, which often rely on complex flow channel design, an incompatible two-phase interface, and a fixed nozzle shape. These methods face the challenges of complex nozzle processing, inconvenient nozzle changes, and excessive extrusion forces when applied to multiple bioink. In this study, a 3D printing technique, called alternating viscous-inertial force jetting, was applied to enable the construction of hydrogel microcarriers with a diameter of 100-300 µm. Cells were subsequently seeded on microcarriers to form tissue engineering modules. Compared to existing methods, this method offers a free nozzle tip diameter, flexible nozzle switching, free control of printing parameters, and mild printing conditions for a wide range of bioactive materials.

Microcarriers are beads with a diameter of 60-250 µm and a large specific surface area and are commonly used for large-scale culture of cells1,2. Their outer surface provides abundant growth sites for cells, and the interior provides a support structure for spatial proliferation. The spherical structure also provides convenience in monitoring and controlling parameters, including pH, O2, and concentration of nutrients and metabolites. When used in combination with stirred tank bioreactors, microcarriers can achieve higher cell densities in a relatively small volume compared to conventional cult....

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1. Cell culture

  1. Supplement high-glucose Dulbecco's modified Minimum Essential Medium (H-DMEM) with 10% fetal bovine serum (FBS), 1% nonessential amino acid solution (NEAA), 1% penicillin G and streptomycin, and 1% Glutamine supplement as culture media for A549 cells.
  2. Culture A549 cells in a CO2 incubator at 37 °C and with 5% CO2
  3. Dissociate cells for subculture using trypsin at approximately 80% confluence.
    1. Use 3 mL of trypsin to treat the cells in.......

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Printheads of varied convergence rates and diameters were fabricated to achieve the printing of multiple types of materials. The nozzles obtained with increasing pull strength are shown in Figure 1B. The nozzles were divided into three areas: reservoir (III), contraction (II), and printhead (I). The reservoir was the unprocessed part of the nozzle, in which the liquid provided static pressure and bioink input for printing. The contraction area was the main part for generating downward drivin.......

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The protocol described here provides instructions for the preparation of multi-types of hydrogel microcarriers and subsequent cell seeding. Compared to microfluidic chip and inkjet printing methods, AVIFJ approach to constructing microcarriers offers greater flexibility and biocompatibility. An independent nozzle enables a wide range of lightweight nozzles, including glass micropipettes, to be used in these printing systems. The highly controllable processing enables parameters including the volume of the reservoir, the .......

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This work was supported by the Beijing Natural Science Foundation (3212007), Tsinghua University Initiative Scientific Research Program (20197050024), Tsinghua University Spring Breeze Fund (20201080760), the National Natural Science Foundation of China (51805294), National Key Research and Development Program of China (2018YFA0703004), and the 111 Project (B17026).


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Name Company Catalog Number Comments
A549 cells ATCC CCL-185 Human non-small cell lung cancer cell line
Bright field microscope Olympus DP70
Confocal microscope Nikon TI-FL
Fetal bovine serum, FBS BI 04-001-1ACS
Gelatin SIGMA G1890
Glass micropipettes sutter instrument b150-110-10
GlutaMAX GIBCO 35050-061
H-DMEM GIBCO 11960-044 Dulbecco's modified eagle medium
Horseradish peroxidase powder SIGMA P6782
Hydrophobic agent 3M PN7026 Follow the manufacturer's instructions and use after dilution
Micro-forge device narishige MF-900
Non-essential amino acids, NEAA GIBCO 11140-050 non-essential amino acids
Penicillin G and streptomycin GIBCO 15140-122
Petri dish SIGMA P5731-500EA
Puller sutter instrument P-1000
Sodium alginate SIGMA A0682
Trypsin GIBCO 25200-056
Type I collagen solution from rat tail SIGMA C3867

  1. Chen, A. K., Reuveny, S., Oh, S. K. W. Application of human mesenchymal and pluripotent stem cell microcarrier cultures in cellular therapy: Achievements and future direction. Biotechnol Advances. 31, 1032-1046 (2013).
  2. Li, B., et al. Past, present, and future of microcarrier-based tissue engineering. Journal of Orthopaedic Translation. 3, 51-57 (2015).
  3. Badenes, S. M., Fernandes, T. G., Rodrigues, C. A. V., Diogo, M. M., Cabral, J. M. S. Microcarrier-based platforms for in vitro expansion and differentiation of human pluripotent stem cells in bioreactor culture systems. Journal of Biotechnol. 234, 71-82 (2016).
  4. de Soure, A. M., Fernandes-Platzgummer, A., Da Silva, C. L., Cabral, J. M. S. Scalable microcarrier-based manufacturing of mesenchymal stem/stromal cells. Journal of Biotechnol. 236, 88-109 (2016).
  5. Naqvi, S. M., et al. Living cell factories - electrosprayed microcapsules and microcarriers for minimally invasive delivery. Advanced Materials. 28, 5662-5671 (2016).
  6. Sarkar, S., et al. Chitosan: A promising therapeutic agent and effective drug delivery system in managing diabetes mellitus. Carbohydrate Polymers. 247, (2020).
  7. Sulaiman, S. B., Idrus, R. B. H., Hwei, N. M. Gelatin microsphere for cartilage tissue engineering: current and future strategies. Polymers. 12, (2020).
  8. Huang, L., Abdalla, A. M. E., Xiao, L., Yang, G. Biopolymer-based microcarriers for three-dimensional cell culture and engineered tissue formation. International Journal of Molecular Sciences. 21, (2020).
  9. Isiklan, N., Tokmak, S. Development of thermo/pH-responsive chitosan coated pectin-graft-poly(N, N-diethyl acrylamide) microcarriers. Carbohydrate Polymers. 218, 112-125 (2019).
  10. Lau, T. T., Wang, C., Wang, D. A. Cell delivery with genipin crosslinked gelatin microspheres in hydrogel/microcarrier composite. Composites Science & Technology. 70, 1909-1914 (2010).
  11. Lau, T. T. Hydrogel-microcarrier composite systems for cell delivery in tissue engineering. Acta Biomaterialia. 10, 1646-1662 (2014).
  12. Kwon, Y. J., Peng, C. A. Calcium-alginate gel bead cross-linked with gelatin as microcarrier for anchorage-dependent cell culture. Biotechniques. 33, 218 (2002).
  13. Leach, J. B., Bivens, K. A., Patrick, C. W., Schmidt, C. E. Photocrosslinked hyaluronic acid hydrogels: natural, biodegradable tissue engineering scaffolds. Biotechnology & Bioengineering. 82, 578-589 (2003).
  14. Kurisawa, M., Chung, J. E., Yang, Y. Y., Gao, S. J., Uyama, H. Injectable biodegradable hydrogels composed of hyaluronic acid-tyramine conjugates for drug delivery and tissue engineering. Chemical Communications. 34, 4312-4314 (2005).
  15. Yao, R., Alkhawtani, A. Y. F., Chen, R., Luan, J., Xu, M. Rapid and efficient in vivo angiogenesis directed by electro-assisted bioprinting of alginate/collagen microspheres with human umbilical vein endothelial cell coating layer. International Journal of Bioprinting. 5, 194 (2019).
  16. Mahou, R., Vlahos, A. E., Shulman, A., Sefton, M. V. Interpenetrating alginate-collagen polymer network microspheres for modular tissue engineering. Acs Biomaterials Science & Engineering. 4 (11), 3704-3712 (2017).
  17. Aftab, A., et al. Microfluidic platform for encapsulation of plant extract in chitosan microcarriers embedding silver nanoparticles for breast cancer cells. Applied Nanoscience. 10, 2281-2293 (2020).
  18. Park, W., et al. Microfluidic-printed microcarrier for in vitro expansion of adherent stem cells in 3D culture platform. Macromolecular Bioscience. 19, (2019).
  19. Chui, C., et al. Electrosprayed genipin cross-linked alginate-chitosan microcarriers for ex vivo expansion of mesenchymal stem cells. Journal of Biomedical Materials Research Part A. 107, 122-133 (2019).
  20. Min, N. G., Ku, M., Yang, J., Kim, S. Microfluidic production of uniform microcarriers with multicompartments through phase separation in emulsion drops. Chemistry of Materials. 28 (5), 1430-1438 (2016).
  21. Park, W., Jang, S., Kim, T. W., Bae, J., Lee, E. A. Microfluidic-printed microcarrier for in vitro expansion of adherent stem cells in 3D culture platform. Macromolecular Bioscience. 19, (2019).
  22. Xu, T., Kincaid, H., Atala, A., Yoo, J. J. High-Throughput Production of Single-Cell Microparticles Using an Inkjet Printing Technology. Journal of Manufacturing Science & Engineering. 130, 137-139 (2008).
  23. Rao, W., et al. Enhanced enrichment of prostate cancer stem-like cells with miniaturized 3D culture in liquid core-hydrogel shell microcapsules. Biomaterials. 27 (27), 7762-7773 (2014).
  24. Choi, C. H., Weitz, D. A., Lee, C. S. One step formation of controllable complex emulsions: From functional particles to simultaneous encapsulation of hydrophilic and hydrophobic agents into desired position. Advanced Materials. 25, 2536-2541 (2013).
  25. Choi, A., Seo, K. D., Kim, D. W., Kim, B. C., Dong, S. K. Recent advances in engineering microparticles and their nascent utilization in biomedical delivery and diagnostic applications. Lab On A Chip. 17 (4), 591-613 (2017).
  26. Liu, T., Pang, Y., Zhou, Z., Yao, R., Sun, W. An integrated cell printing system for the construction of heterogeneous tissue models. Acta Biomaterialia. 95, 245-257 (2019).
  27. Hassan, K., et al. Functional inks and extrusion-based 3D printing of 2D materials: a review of current research and applications. NANOSCALE. 12, 19007-19042 (2020).
  28. Vithani, K., et al. An overview of 3D printing technologies for soft materials and potential opportunities for lipid-based drug delivery systems. Pharmaceutical Research. 36, (2019).

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