By S. Amanda Ali, PhD
What do biomaterials mean to you? For this orthopaedic scientist, the first thing that comes to mind is the total joint replacement: artificial knees, hips and shoulders made from a variety of materials to reproduce joint function and suit each patient. Introduced in the 1960s to the field of orthopaedics, biomaterials were revolutionary and life changing.
For many people today, biomaterials in the form of contact lenses, dentures, hearing aids, sutures and arterial stents are a part of daily life. These items are used routinely without much thought being given to the technology they represent. For the general public, appreciation of biomaterials largely relates to their use thereof and to their exposure to the field through popular culture. The hospital drama Grey’s Anatomy, for example, featured experimental 3D printing of a heart conduit for a paediatric patient.
For researchers, the ability to harness the power of the stem cell and perfect tissue engineering will allow generation of cartilage for joints, hearts (in part or whole), skin grafts, corneas and so on. And perhaps these tissues will come from a 3D printer. An idea once considered suitable only for science fiction (or a dramatic television series like Grey’s Anatomy), improved 3D printing of tissues is hot off the press – pun intended.
Published in ACS Biomaterials Science & Engineering, Dr. Andrew Ellington and colleagues describe a method for printing macroscale objects using DNA:DNA interactions as a binding agent. Among other advantages, using DNA to assemble microparticles into macro-structures allows control over organization of those structures at the nanometer, micrometer and centimeter scale. DNA-coated polystyrene microparticles can be assembled at the nanometer scale using DNA:DNA complementary interactions. At the micrometer scale, DNA-dependent substructure (smaller tissues) formation can be leveraged to achieve specific patterning. Finally at the centimeter scale, printed gels can be assembled in 3D. Given that the 3D printed scaffolds are able to hold their shape and support the growth of cells, possibilities arise for patterning of organs by substructure. Scalability is facilitated with this approach, as the use of DNA-coated microparticles for DNA-mediated assembly is significantly cheaper compared to conventional DNA nanotechnologies.
For those interested in learning more about this emerging technique, the 32nd Annual Meeting of the Canadian Biomaterials Society will be held at the University of Toronto in May 2015. Speakers such as Dr. Konrad Walus, of the University of British Columbia and Aspect Biosystems Ltd., will be sharing advances at the cutting edge of the biomaterials field. Among other topics relating to 3D printing, you can expect to hear about the use of microfluidic devices for generating 3D hydrogel structures for tissue engineering.
The field of 3D printing of biomaterials is gaining momentum, with this story recently highlighted in ScienceDaily (“DNA ‘smart glue’ could someday be used to build tissues, organs”). With improving technologies, the varied uses of biomaterials are expanding. Surgeries as invasive, debilitating and costly as the total joint replacement will no longer be necessary if cartilage can be printed with biomimetic properties and customized to suit each defect in a joint. So ultimately, what do biomaterials mean to us? Soon enough, anything, everything – if you can conceive it, you can print it.
Amanda Ali recently completed her PhD at the University of Toronto under the supervision of Dr. Benjamin Alman, studying gene expression and cholesterol homeostasis in osteoarthritis. Moving forward, she plans to take a biopsychosocial approach to studying chronic disease, including preventative strategies that can be used to reduce and manage pain. Her interest in writing developed during her time as Journalist and Assistant Managing Editor for the IMS Magazine, a student-led publication translating the health science research of the Institute of Medical Science (IMS) graduate department. Her work includes articles that critically examine the social construction of the biomedical field, including the pipeline for producing scientific knowledge.