THE EFFECTS OF DIFFERENT INFILL DENSITIES OF 3D PRINTED POLYAMIDE 12 COMPOSITE ON MC3T3-E1 ADHESION AND PROLIFERATION

Abstract

Fused Deposition Modeling (FDM) three-dimensional printing (3D printing) technology has strong advantages in bone defect reconstruction due to its customizability, simple operation and relatively low cost. The hybrid β-tricalcium phosphate/zirconium oxide (β-TCP/ZrO₂) filled polyamide 12 (PA 12) filament feedstock is a new raw material that has been developed in recent years and is used to make FDM 3D-printed bone defect repair implants. Although previous studies have assessed thermal, mechanical and physical properties of 3D printed composites with in-house β-TCP/ZrO₂ filled PA 12 filament feedstock, the research on the biocompatibility of 3D printed PA 12 composite materials is still insufficient. Additionally, it has been proven that the pore size, porosity and crosslinking of 3D printed composites can affect cell growth and differentiation. The purpose of this article was to evaluate the biocompatibility of the 3D printed PA 12 composites through the use of MC3T3-E1 cells and try to explore the effects of the infill density of the 3D printed PA 12 composites on MC3T3-E1 proliferation. MC3T3-E1 cells were indirectly co-cultured with materials at 60%, 80% and 100% infill densities, respectively. Cell viability on day 1 and 3 was detected by Cell Counting Kit-8. The images of materials surface and cell adhesion on the composites were captured by Field Emission Scanning Electron Microscopy. The results showed that 3D printed PA 12 composite materials with 100%, 80% and 60% infill densities had no obvious cytotoxicity to MC3T3-E1. The 3D printed PA 12 composites had rough surfaces with fixed macropores and irregular micropores, making the composites conducive to cell adhesion. 3D printed PA 12 composites, especially the material with infill density of 80%, showed significant effects in promoting cell adhesion and proliferation.