Advancement in biological and mechanical behavior of 3D printed poly lactic acid bone plates using polydopamine coating: Innovation for healthcare

The metallic biomaterials have been proclaimed to exhibit stress shielding with discharge of toxic ions, leading to polymeric implants attracting interest in 3D Printing domain. In this study, Poly Lactic Acid based 336 bone plates are fabricated using Fused Filament Fabrication with printing parameters being varied. Polydopamine, being biocompatible, is deposited on fabricated bone plates at varying submersion time, shaker speed and coating solutions concentration. The study involves witnessing the effect of printing and coating parameters on biological behavior of bone plates upon preservation in Simulated Body Fluid and Hank's Balanced Salt Solution. The findings propose the close relation of degradation with apatite growth. The highest degradation rate with significant reduction in mechanical characteristics are shown by uncoated bone plates. These bone plates have porous structure at 20% infill density, 0.5 mm layer height, 0.4 mm wall thickness and 100 mm/s print speed which could result in complete degradation with partial healing of bone fracture. The study suggests the preservation of bone plates coated at 120 h' submersion time and 120 RPM shaker speed in 3 mg/ml concentrated solution which showed lower apatite formation. Thus, the coating would slow down degradation of PLA bone plates, resulting in complete healing of bone fracture.