Improving the process of creating 3D printed, patient specific bone scaffolds
“There are several reasons to design the geometry of porous spaces in tissue engineered scaffolds that will be 3D printed in resorbable polymer. First, the pore geometry facilitates cell seeding on the surface. Second, the pore geometry guides the infusion of new (regenerative) tissue into the scaffold. Third, the design of the pores and the material will control the timing and nature of the scaffold’s resorption. We have implemented a gyroid structure (Schoen’s gyroid) in MATLAB (MathWorks, Natick, MA). The program fails at high resolution for high levels of porosity. By converting this algorithm from MATLAB to a Visual Studio (Microsoft, Redmond, WA) C# class I will be able to make the program more reliable and run it in a more powerful visualization environment, Amira (Thermo Fisher Scientific, Waltham, MA). The goal is to create a scaffold of any shape with the gyroid porosity of any level by specifying strut diameter, pore size, and surface area. Surface area is a critical parameter because the lab hypothesizes it controls resorption of the scaffold.
The first step of the conversion process was to take the MATLAB code and translate it to C#, which is what AMIRA uses. At that point the code’s memory handling and surface topology output was improved. Next, our goal is to use Amira to visually overlay the selected porosity and tissue engineered implant shapes. For example, these shapes may be patient-specific scaffolds designed to fit is a defect, such as a gap the skeleton caused by trauma, disease, aging, or a birth defect.
To date I have updated the original MATLAB program so that it could create cylindrical scaffolds of various sizes and porosity that several projects in the lab currently need. I have translated the program exactly into C#, but currently cannot find the reason why the program differs from the MatLab code. I attempted to create a porous scaffold image by overlaying two images. However, the resulting image was incorrect. I am working on that problem currently. This work is expected to continue through summer 2020 and result in a working porosity CAD module in Amira.”