New Grafting Material Made from Sea Urchin Spines

Using a hydrothermal reaction, the researchers converted the spines to biodegradable magnesium-substituted tricalcium phosphate (β-TCMP) scaffolds, while still maintaining the spines' original interconnected, porous structure. The fracture strength of the hydrothermally converted β-TCMP scaffolds was ∼9.3 MPa, comparable to that of human trabecular bone.

Tests conducted on rabbits and beagles showed that bone cells and nutrients could flow through the pores and promote bone formation. Also, the scaffold degraded easily as it was replaced by the new growth. New bone formed along outer surfaces of the β-TCMP scaffolds one month after implantation, and grew into the inner open-cell spaces within three months. Fusion of the beagle lumbar facet joints using a Ti-6Al-4V cage and β-TCMP scaffold showed near complete degradation and replacement by newly formed bone ten months after implantation. The study was published on March 2, 2017, in ACS Applied Materials & Interfaces.

Marine calcium carbonate (CaCO3) skeletons have tailored architectures created by nature, which give them structural support and other functions. For example, seashells have dense lamellar structures, while coral, cuttlebone, and sea urchin spines have interconnected porous structures.