Researchers at Washington State University (WSU; Pullman, USA) used a commercial 3D printer to create tricalcium phosphate (TCP) scaffolds with 3D interconnected pores. The researchers also examined the effects of silica (SiO(2)) and zinc oxide (ZnO) dopants on the mechanical and biological properties of the scaffolds by X-ray diffraction, and surface morphology of the scaffolds was examined by field emission scanning electron microscopy (FESEM). Mechanical strength was evaluated with a screw-driven universal testing machine.

The results showed that the addition of dopants into TCP increased the average density of pure TCP, and retarded the β to α phase transformation at high sintering temperatures, which resulted in up to 2.5 fold increase in compressive strength. In vitro cell-materials interaction studies confirmed that the addition of SiO(2) and ZnO to the scaffolds facilitated faster cell proliferation when compared to pure TCP scaffolds. The researchers suggest that when paired with actual bone, the scaffold could help new bone to grow on it, ultimately dissolving with no apparent ill effects. The study was published in the November 1, 2011, issue of Dental Materials.

“It's possible that doctors will be able to custom order replacement bone tissue in a few years,” said study coauthor Prof. Susmita Bose, PhD, of the WSU School of Mechanical and Materials Engineering. “If a doctor has a CT scan of a defect, we can convert it to a CAD [computer-aided design] file and make the scaffold according to the defect.”

The 3D TCP scaffold was fabricated on a commercially available ProMetal 3D printer, developed by Ex One company (Irwin, PA, USA), originally designed to make metal objects. The printer works by having an inkjet spray a plastic binder over a bed of powder in layers of 20 microns, about half the width of a human hair. Following the design computer's directions, it creates a channeled cylinder the size of a pencil eraser.

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Washington State University
ProMetal RCT