3D Printed Coral Could Make for Viable Bone Grafts, Say Singapore Researchers

There may soon be a new method for creating bone grafts by incorporating coral materials into 3D printed implants.

Currently, diseased or damaged bones are repaired or regenerated using one of three surgical procedures. Bones can be taken from the patient’s body, extracted from the dead, or a bone substitute can be used from polymers and other materials.

Researchers from the National University of Singapore’s Centre for Additive Manufacturing (AM.NUS) are currently analyzing the potent of using coral materials for custom 3D printed implants for patients with bone disease or fractures needing a bone graft.

Prototypes (left) made with coral powder being 3D printed by a machine (above). Researchers from AM.NUS have been studying the feasibility of custom 3D printing implants with coral materials, in collaboration with Taiwan-based Popeye Marine Biotechnology. Image courtesy of The Strait Times/GIN TAY.

Previously, researchers from New Zealand and Australia explored using other natural elements as inspiration for 3D printing bone grafts as well. Some organizations are even researching using ceramics. (insert photo coral 2.jpg)

In April, a four-month-long project, in collaboration with Taiwan-based Popeye Marine Biotechnology, began. A cultured calcium carbonate coral powder for 3D printing was furnished by Popeye, while AM.NUS oversaw the testing.

Researchers from AM.NUS have been studying the feasibility of custom 3D-printing implants with coral materials, in collaboration with Taiwan-based Popeye Marine Biotechnology. Image courtesy of The Strait Times/GIN TAY.

When asked, a spokesperson with the firm told The Straits Times that there are only six species of corals suitable for use in human bones, but neglected to say which variety it used for the experiment.

According to a senior research fellow at NUS’s Tropical Marine Science Institute, Dr. Jani Tanzil, Scleractinian skeletons have been applied as bone substitutes. These are stony corals from three families: Acropora, the Porites, and Goniopora.

Associate Professor Lu Wen Feng, director of AM.NUS, who managed the NUS arm of the project, said a technique referred to as molding has been used by scientists so far to create coral-made bone implants. Instead, 3D printing might be able to create more intricate models.

Associate Professor Lu Wen Feng (right), director of the National University of Singapore’s Centre for Additive Manufacturing (AM.NUS), with researcher and principal engineer Chang Soon Yee. They are holding 3D-printed objects made from coral powder. Image courtesy of The Strait Times/GIN TAY.

Human bones are sponge-like in nature, not dissimilar to corals given their porous micro-structures. Prof Lu stated that bone grafting techniques have long been studied with corals as the replacement due to this similarity. He stated that cell attachment and bone ingrowth are enhanced by the porosity, which makes coral materials a possible match.

The principal investigator of the study, Prof.  Jerry Fuh, believes that 3D printed bone grafts open the ability customize the shape and porosity of the bone implant for each patient.

A 3D printed bone implant offers a host of benefits such as a more customized fit, and less soft tissue removal, which preserves the tissues condition at the surgical site. Dr. Vincent Seah, an orthopaedic surgeon with the Parkway East and Mount Elizabeth Novena hospitals, explained that the areas of composition and biodegradability of the coral materials still need exploration and that the 3d printed implants have captured a wide amount of interest. (insert photo coral 3.jpg)

Dr. Henry Soeharno, a consultant in the Department of Orthopaedic Surgery at Singapore General Hospital, explained that synthetic bone substitutes create a mapping structure for new bone to grow into, and that the biodegradation of the synthetic material must match the rate of the bone ingrowth, adding that this can take 1 to 2 years.

Moving forward, a possible area researchers will be exploring is how to make the coral powder material biodegradable. Calcium carbonate does not fully biodegrade in the human body, so Prof. Fuh said this would include more additives or chemicals being added to the process. Guaranteeing that the bone implant is able to keep its shape and porous structure at the transplant site so the new bone has time to heal and regrow will be the largest challenge.

One lively area of research, according to NUS’ marine biologist Huang Danwei, is lab-based synthesis of calcium carbonate found in the coral material and limestone. 3D printing solutions will be more tenable in the foreseeable future the faster it becomes to scale up to produce the needed coral-like powder.