Optimizing Composition of PDTEC/PI2DTEC Tissue Scaffolds for X-Ray Imaging Using Combinatorial Fabrication Methods
Yanyin Yang, Matthew Becker, J Kohn, Carl G. Simon Jr.
Previous studies on (poly(desaminotyrosyl-tyrosine ethyl ester carbonate) (pDTEc) indicated that it is biocompatible, degradable and has good mechanical properties, which make it a candidate material for tissue scaffolds. Yet, pDTEc is radiolucent and hard to image with X-ray imaging techniques. A radio-opaque analog of pDTEc, pI2DTEc, has been made by iodinating the desaminotyrosine ring. However, molecular changes to the polymer often affect physicochemical properties and influence performance. Therefore, it may be advantageous to blend pDTEc with a minimum amount of pI2DTEc to yield a material that not only retains many of the properties of pDTEc but also has radio-opaqueness like pI2DTEc. Thus, continuous gradient scaffold libraries of pDTEc and pI2DTEc were fabricated to determine the optimal blending composition in an efficient, combinatorial approach. The rod-shaped polymer libraries with pI2DTEc content ranging from 17.5 % to 95.4 % were then analyzed by three X-ray imaging techniques: X-ray microradiography, ?CT and dental X-ray radiography. In X-ray microradiographs (540 mAs), the entire range of compositions was visible while the more pI2DTEc contained in the blended scaffold, the better contrast of the image. In comparison, for ?CT, ~50 % pI2DTEc was required for optimal imaging and quantitative analysis of scaffold structural parameters such as degree of anisotropicity, porosity, wall thickness, and pore size. When pI2DTEc content was lower than 50 %, ?CT images of scaffolds can still be obtained. However the contrast is weak making quantitative analysis hard to realize. Furthermore, when dental X ray with significantly lower dose (2 mAs) was applied, good X-ray contrast could only be obtained for the most pI2DTEc-rich compositions.
, Becker, M.
, Kohn, J.
and Simon, C.
Optimizing Composition of PDTEC/PI<sub>2</sub>DTEC Tissue Scaffolds for X-Ray Imaging Using Combinatorial Fabrication Methods, Sigma XI Postdoctoral Poster Presentation, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852716
(Accessed December 2, 2023)