The University of Connecticut has created a hydrogel suitable for supporting 3D printed bones. Without such support the bone cells would not be able to hold a form and would perish when exposed to an uncontrolled environment.
The research was conducted by Stephanie T. Bendtsen of the Institute of Materials Science and Sean P. Quinnell from the Department of Biomedical Engineering under the supervision of Professor Mei Wei. The findings are published as Development of a novel alginate-polyvinyl alcohol-hydroxyapatite hydrogel for 3D bioprinting bone tissue engineered scaffolds in the Journal of Biomedical Materials Research.
Made from seaweed, PVA and calcium
The University of Connecticut’s hydrogel is made from a mix of 3 substances:
- Alginate: extracted from seaweed which is often the base of hydrogels
- Polyvinyl alcohol (PVA): a material used in water-soluble supports for 3D prints and not to be confused with PVA glue which is acetate and not alcohol
- And hydroxyapatite: which is the main calcium mineral found in bones
The study tested seven different material solutions, aiming to discover the perfect balance between viscosity, printability, design-fidelity and an ability to control cell cultures. First, cells extracted from mice skulls (MC3T3 osteoblasts) were 3D bioprinted in the gel in a typical crosshatch design used as patches for skulls.
Formulations 5 and 6 were singled out as the best possible combinations, and monitored over time for their ability to stay intact. After 14 days in a controlled incubation, both formulations were still viable scaffolds for stem cells.
The conclusion of the study finds that,
Bioprinting of this novel alginate-polyvinyl alcohol-hydroxyapatite hydrogel formulation to produce scaffolds for bone repair has the potential to provide individualized treatment of defects and promote enhanced, uniform healing.
Other researchers at the Shanghai successfully produced a 3D printable bioglass ink capable of making similar skull patches. A South Korean research team has also developed a particular method of 3D printing with stem cells to encourage bone proliferation.
Though it may yet be sometime before we can re-grow bones as if by magic, 3D bioprinting is proving to be a valuable mode for bone tissue research.
Clip shows the moment Harry Potter’s bones are turned to rubber in the Chamber of Secrets film. Property of Warner Bros. Pictures
Featured image shows detail of Alastair Mackie’s ‘Untitled (sphere)’, 2000-9 made of mouse skulls. Photo by Tessa Angus, courtesy of All Visual Arts.