Additive manufacturing of biodegradable iron-based particle reinforced polylactic acid composite scaffolds for tissue engineering

Abstract

Abstract Polylactic acid (PLA) based scaffolds have attracted worldwide attention as promising biodegradable implants in bone tissue engineering. PLA matrix is often incorporated with fillers to engineer composite scaffolds with improved mechanical properties and excellent biocompatibility. In the present study, PLA composite scaffolds were additively manufactured utilizing fused filament fabrication (FFF) process by separately employing two different types of iron-based powders including stainless steel 316L and pure iron. The geometrical, thermal, and mechanical properties of the scaffolds, as well as their in-vitro biodegradation, wettability, and cytocompatibility, were thoroughly assessed. With optimized printing parameters, the scaffolds were manufactured with an accurate pore dimension of 0.80±0.08 mm and homogenously distributed iron-based powders in the PLA matrix. The lower linear coefficient of thermal expansion in both PLA/316L and PLA/Iron scaffolds increased the strut width while reducing the surface roughness. Meanwhile, the addition of iron-based powders both enhanced the compressive and flexural modulus, compressive strength, and compressive fatigue resistance, but exhibited no significant reinforcement on the flexural strength and elongation. The results also showed that PLA/Iron scaffold possessed higher in-vitro degradation resistance, superior hydrophilic wetting behavior, and better cytocompatibility, indicating its remarkable prospects in bone tissue engineering applications.