3D Printed Polymer Scaffolds for Bone Tissue Regeneration

Abstract

The regeneration of bone defects is a significant clinical challenge for patients around the world. The ideal scaffolds for bone tissue repair should provide biocompatibility, pore architecture, biodegradability, mechanical support, and cell attachment sites. Conventionally fabricated polymer scaffolds are still unable to make ideal scaffolds for bone tissue repair due to the lack of all the above mentioned properties. The investigated hypothesis was that increasing pore sizes of the scaffolds would cause an increase in the porosity and a decrease in the compressive modulus. In order to test the hypothesis, we designed three different pore sizes (200, 400, and 800 μm) in three different scaffolds using computer software. Relatively new 3D printing technology was used to print the three different types of porous scaffolds using polycaprolactone (PCL) polymer. These scaffolds were characterized for percent porosity, pore architecture, morphology, mechanical properties, and evaluated for biocompatibility and cell attachment with murine pre-osteoblasts. The percent porosity of these scaffolds (n=7) significantly increased from 13.31 to 61.66 (p<0.001) with the increase in pore size. The average compressive modulus of scaffolds (n=7) significantly decreased with the increase in pore size (p<0.001). The averaged compressive modulus of scaffolds with 200, 400, and 800 μm pores is 82.98 ± 2.02, 61.60 ± 2.59, and 47.16 ± 1.73 MPa, respectively. In addition, PCL scaffolds show biocompatibility as determined by an in vitro cell study. These results have shown that the hypothesis is validated, and these 3D printed porous PCL scaffolds can be potentially used for bone regeneration applications.