Fabrication PEGDA/ANFs biomaterial as 3D tissue engineering scaffold by DLP 3D printing tecshnology

Abstract

Although traditional fabrication methods (electrospinning, solvent casting, freeze drying, etc…) can be used to produce scaffold, unfortunately, each of them has many limitations such as difficulty to control distinct 3D structure and porosity. These limitations can be easily overcome by unconventional techniques such as Fused Deposition Method (FDM), Selective Laser Sintering (SLS) and Stereolithography (SLA) to produce tissue engineering scaffold. Among the three, SLA offers the lowest cost, fastest printing speed and highest resolution. Digital light processing (DLP) 3D printing process is one of the SLA techniques which has been used a lot to fabricate tissue engineering scaffold based on Poly (ethylene glycol) diacrylate (PEGDA) material. However, there is no report published on the fabrication of tissue engineering scaffold based PEGDA filled with Aramid Nanofiber (ANFs). Hence, the feasible parameter setting for fabricating this material using DLP technique is currently unknown. The aim of this work is to establish the best feasible condition to fabricate PEGDA/ANFs 3D scaffold. ANFs was synthesized first from macro size Kevlar fiber prior to crosslinking with Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO) photoinitiator. The mixing ratio of PEGDA resin to ANFs was fixed to 9:1. The concentration of TPO was varied at 0.5, 1.0 and 1.7% wt. while the resin concentration was fixed at 30% during the mixing to produce three set of biomaterials. Calibration printing was conducted prior to actual printing with the purpose of eliminating unprintable TPO concentration. The final scaffold was printed using DLP machine (FEMTO…) at two different curing times i.e 70 and 80s to obtain a good shape and printable 3D structure. The synthesized ANFs showed that a single diameter in nano size at a range of 50 nm ~ 80 nm was able to produce. During calibration printing, it was found that 1.7%wt of TPO failed to produce a 3D profile shape. The final printing results of 0.5%wt and 1%wt of TPO were compared after being cured at 70s and 80s. It was observed that the printed 3D scaffold of 1%wt TPO at 70s curing time produces the most discernable shape of tensile specimen (ISO 37:2011) than the other three conditions. The findings from this study can be potentially used a guideline for developing a 3D structure of tissue engineering scaffold by using DLP 3D printing process.