An insight into applications and future perspectives of 3D bioprinting
Traditional tissue engineering methods showed limited success in the fabrication of complex 3D shapes resulting in non-feasible clinical applications. Over the past decade, 3D bioprinting technology emerged as a powerful tool in the field of tissue engineering to fabricate personalized biological constructs bridging the gap between engineered tissue constructs and natural tissues (1).
This article introduces the current applications of 3D bioprinting technologies as well as the challenges this technology poses.
Applications of 3D bioprinting in:
a. Tissue engineering and regenerative medicine: Bioprinting has been used to generate 2D and 3D structures for the fabrication of scaffolds and tissue constructs for tissue regeneration. Scientists were able to fabricate heart valves, blood vessels, myocardial tissue, skin, and nerves using bioprinting technologies such as extrusion- and jetting-based bioprinting to improve clinical outcomes.
For instance, Duan et al. (2,3) used extrusion-based bioprinting to construct a trileaflet heart valve conduit, made of the hybrid hydrogel of hyaluronic acid and gelatin and human aortic valve interstitial cells which was found to be highly viable with a great potential of remodeling.
b. Cell/drug delivery systems: Most conventional medication techniques have low solubility and cannot deliver the desired drug concentration to the diseased site. As a consequence, side effects can occur and the entire body can be addressed by systemic toxicity after infusion.
Therefore, with the aim to reduce systemic side effects and improve drug efficacy, implantable systems with specific prolonged release kinetics, desired doses, and geometries based on 3D printing technology are being developed. For example, extrusion-based 3D bioprinting drug-delivery systems have been studied to target bone infection, pancreatic tumors, and Osteomyelitis (4).
Challenges and future outlook Although 3D bioprinting is a promising innovation offering many advantages compared with conventional tissue engineering methods, challenges in implementation and utilization still exist. One of the major limitations is choosing a method of bioprinting and ink that support all desired characteristics of a particular application (5).
Additionally, the process and technology costs of 3D printers, cellular materials, and computer software are very high. Recently, more novel techniques are being explored to advance 3D bioprinting. One of the recent developments is the novel ceramic-based bioink of calcium phosphate and 3D bioprinting of bone-like tissue that hardens within minutes after being placed in water (6). While such researches are in the early stages of discovery, these novel ideas would strongly advance the field of 3D bioprinting in the coming years.
References
1. Mironov V, Reis N, Derby B. Review: bioprinting: a beginning. Tissue Eng. 2006 Apr;12(4):631-4. doi: 10.1089/ten.2006.12.631. PMID: 16674278.
2. Ker ED, Nain AS, Weiss LE, Wang J, Suhan J, Amon CH, Campbell PG. Bioprinting of growth factors onto aligned sub-micron fibrous scaffolds for simultaneous control of cell differentiation and alignment. Biomaterials. 2011 Nov;32(32):8097-107. doi: 10.1016/j.biomaterials.2011.07.025. Epub 2011 Aug 5. PMID: 21820736.
3. Duan B, Kapetanovic E, Hockaday LA, Butcher JT. Three-dimensional printed trileaflet valve conduits using biological hydrogels and human valve interstitial cells. Acta Biomater. 2014 May;10(5):1836-46. doi: 10.1016/j.actbio.2013.12.005. Epub 2013 Dec 12. PMID: 24334142; PMCID: PMC3976766.
4. Yi, HG., Kim, H., Kwon, J. et al. Application of 3D bioprinting in the prevention and the therapy for human diseases. Sig Transduct Target Ther 6, 177 (2021). https://doi.org/10.1038/s41392-021-00566-8
5. Salgado AJ, Oliveira JM, Martins A, Teixeira FG, Silva NA, Neves NM, Sousa N, Reis RL. Tissue engineering and regenerative medicine: past, present, and future. Int Rev Neurobiol. 2013;108:1-33. doi: 10.1016/B978-0-12-410499-0.00001-0. PMID: 24083429.
6. Romanazzo S., Molley T.G., Nemec S., Lin K., Sheikh R., Gooding J.J., Wan B., Li Q., Kilian K.A., Roohani I. Synthetic Bone-Like Structures Through Omnidirectional Ceramic Bioprinting in Cell Suspensions. Adv. Funct. Mater. 2021;31:2008216. doi: 10.1002/adfm.202008216
