Using 3D Printing to Develop Bone-Like Structures that Contain Living Cells – AZoM

AZoM speaks withDr. Iman Roohani from UNSW.Dr.Roohani is part of a team of researchersthat developed a technique referred to as Ceramic Omnidirectional Bioprinting in Cell-Suspensions (COBICS). This techniquecould allow surgeons to print structures that can be submerged in water and hardened within just minutes, resembling natural bone.Even more revolutionary, the structures contain living cells that continue to grow after they are implanted.

We have developed a technique (COBICS) that enables printing constructs with the same chemistry to native bone mineral at room temperature with living cells. These structures are the most accurate mimics of the bone tissue. COBICS can print complex and biologically relevant architecture constructs without the need for sacricial support materials, on-spot and laborious post-processing steps.

COBICS has two main components. A chemically cross-linked microhydrogel bath with optimized yield-stress properties that support the printing of the ceramic ink, the second component, in the presence of live cells. The ink is a calcium phosphate paste with a specific formulation that allows the material to be used directly in the aqueous environment, without the need for any post-processing steps, such as high-temperature treatments, that are required for other types of existing ceramic materials.

Once ink comes in contact with the microgel, nanocrystalization kicks off at the interface between ink and hydrogel, which further locks the filament in place. Since this ink can harden quickly without imposing adverse effects on living cells, COBICS enables printing within a suspension of living cells to achieve complex bone shapes, where the cells integrate to form natural bone tissue.

Traditional bone grafts, particularly synthetic ones, are mostly fabricated from ceramic materials at high temperatures, which disallows integration with cells and growth factors. Moreover, due to high temperature processing, the microstructure of such grafts does not resemble the native bone.

COBICS paves the way to fabricate autologous graft like structures in the laboratory, which significantly reduces the risks and drawbacks involved in harvesting these grafts from the patient in the clinical setting by using only cells from the patient or other sources of regenerative cells. This also could enable patient-specific real-time bone reconstruction where the bioprinter could directly print new bone into the resected space.

You could even isolate the patient's stem cells before surgery for inclusion with the ink to improve the integration of the new bone into the surgery site or in dental reconstruction. In another example, drugs could be integrated with the ink for sustained release over time to increase natural bone formation, combat bacteria, or influence the immune system (e.g., enhance wound healing).

The ink has an essential role in printing the constructs by the COBICS technique. The optimization process of formulating the ink took around 2 years since we had to ensure that ink has several properties that were mutually exclusive. Those properties included biocompatibility, being printable, proper setting time, adequate strength and firmness after printing, and printing in contact with the microgel bath.

We have an ongoing animal study at the moment, that will hopefully confirm our hypothesis that there should be no harmful components in our material.Thus far, all of our tests with human cells in the laboratory have confirmed high biocompatibility. We plan to scale up our production of bone-like grafts and test the regenerative properties of the printed grafts in large animal models before proceeding with humantrials and regulatory approval.If everything goes well and we findexternal funding support,we are optimistic the technique may be ready for the clinic within 5 years.

Readers can check out the full article at https://doi.org/10.1002/adfm.202008216.

From 2010 to 2014, Dr. Roohani studied and received his Ph.D. degree at the School of Aerospace, Mechanical and Mechatronic Engineering at the University of Sydney (USYD) in Sydney, Australia. From 2016 to 2020, he worked in the field of biomaterials and tissue engineering as the National Health and Medical Research Council (NHMRC) early career fellow, first in the biomedical engineering department at the University of Sydney, and then at the School of Chemistry in the University of New South Wales (UNSW).

Dr. Roohani is interested in the use of biomaterials as the bone substitute, drug delivery and instructive source for cells. More specifically, his interests comprise synthesis and development of a range of bioceramics, including calcium phosphates, understanding of the interaction between living cells and synthetic substrates, and translation of the application of these materials and concepts to clinical applications.

Dr. Roohani is the inventor of several patented products, including the COBICs techniques. He is the author of more than 60 peer-reviewed publications (h index of 23), book chapters, and 3 patent applications.

ResearchGate: https://www.researchgate.net/profile/Iman_Roohani

Twitter: @ImanRoohani

Email:[emailprotected]

Google Scholar:https://scholar.google.com.au/citations?user=NyzEeygAAAAJ&hl=en

Disclaimer: The views expressed here are those of the interviewee and do not necessarily represent the views of AZoM.com Limited (T/A) AZoNetwork, the owner and operator of this website. This disclaimer forms part of the Terms and Conditions of use of this website.

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Using 3D Printing to Develop Bone-Like Structures that Contain Living Cells - AZoM