Session: 03-13-01: Conference-Wide Symposium on Biomedical Manufacturing & Materials

Paper Number: 110405

110405 - Investigation of the Influence of Nylon-6 vs. Nylon-66 on the Mechanical Performance of Composite Bone Tissue Scaffolds 

Despite recent advances in bone tissue engineering, patient-specific treatment of bone pathology using porous osteoconductive scaffolds has faced clinical challenges, which to a great extent stem from a lack of mechanical strength as well as bioactivity (which are critical for osteogenesis, bone bridging, and ultimately bone healing). There is a need for synthesis of not only biocompatible, but also mechanically strong materials with low immunogenicity for bone regeneration. The goal of this industry-academia research work is to fabricate porous, biologically active, and mechanically robust bone tissue scaffolds for treatment of bone fractures, defects, and diseases. In pursuit of this goal, the overall objective of the work is to systematically investigate the effects of Nylon-6 as well as Nylon-66 on the mechanical properties of bone tissue scaffolds, fabricated using fused deposition modeling (FDM), which is a high-resolution additive manufacturing method. In this study, the fabricated bone scaffolds were composed of cellulose fibers, polyamide (nylon), as well as polyolefin (referred to as PAPC hereafter), having complex internal microstructures, designed based on triply periodic minimal surfaces (including Schwarz Gyroid, Schwarz Primitive, and Schwarz Diamond microstructures). Three types of scaffolding composite materials, i.e., PAPC-I (Nylon-6-based), PAPC-II (Nylon-6-based), and PAPC-V (Nylon-66-based) were utilized in this study. The FDM fabrication of the bone scaffolds was based on a microcapillary nozzle (heated at 215 °C for PAPC-II as well as 235 °C for PAPC-I and PAPC-V) with a diameter of 400 µm, a print speed of 10 mm/s, and a material flow of 120%. Material deposition was on a heated surface, kept at 80 °C for PAPC-II as well as 95 °C for PAPC-I and PAPC-V. A layer height and line width of 200 µm and 300 µm, respectively, were set for the 3D-fabrication process. To avoid filament breakage during the FDM material deposition process, retraction distance as well as retraction speed were reduced to 5 mm and 10 mm/s, respectively. In addition, due to the brittle nature of PAPC-V (having a high Nylon-66 content), it was pre-heated prior to feeding. The mechanical properties (such as elasticity modulus) of the FDM-fabricated bone scaffolds were characterized using compression testing. The PAPC materials were also seeded with mesenchymal stem cells with the aim to assess cell-surface attachment, diffuse proliferation, as well as the biocompatibility of the materials. Furthermore, the mechanical performance of the PAPC materials was contrasted against that of a commercially available composite material (for validation). Overall, the outcomes of this study will pave the way for patient-specific fabrication of mechanically robust and bioactive bone tissue scaffolds with optimal medical properties for the treatment of bone pathology.

Presenting Author: Roozbeh (Ross) Salary Marshall University

Presenting Author Biography: Dr. Roozbeh Ross Salary is an Assistant Professor of Mechanical and Biomedical Engineering in the College of Engineering and Computer Sciences at Marshall University (West Virginia State). His current areas of research include Biomanufacturing, Tissue Engineering, and Regenerative Engineering. Currently, Dr. Salary is serving as the director of the Lab for Advanced Manufacturing Engineering & Systems (LAMES) at Marshall University. Dr. Salary is a recipient of the College of Engineering Research Award as well as Pickens-Queen Teaching Award for excellence in both research and education at Marshall University.

Authors:

Brandon Coburn Marshall University
Robert Joyce FibreTuff
Roozbeh (Ross) Salary Marshall University