Extracellular Matrix-Inspired Electrospun Nanofiber-Coated 3D-Printed Polylactic Acid Scaffolds for Bone Regeneration

Abstract

Three dimensional (3D)-printed polylactic acid (PLA) scaffolds have gained significant attention for bone tissue regeneration due to their excellent biocompatibility, tunable architecture, and mechanical strength. However, the hydrophobic and bioinert surface of PLA limits its interaction with cells. To overcome these limitations, in this study, a multistep surface modification strategy is employed by combining 3D printing and electrospinning techniques. Here, 3D-printed PLA scaffolds are first treated with oxygen plasma to generate OPLA scaffolds with enhanced hydrophilicity, followed by coating with alginate (Alg)/poly(ethylene oxide) (PEO)-based electrospun nanofibers incorporated with magnesium phosphate nanoparticles (MP NPs) to develop Alg/PEO/MP/OPLA scaffold. Here, an extracellular matrix (ECM)-inspired electrospun nanofibrous coating provides a biomimetic surface for cell attachment, while poly(ethylene oxide) (PEO) improves the electrospinnability of alginate to obtain uniform nanofibers. Additionally, incorporation of MP NPs in nanofibers offers bioactive cues associated with osteogenic stimulation for bone regeneration. The successful coating of electrospun nanofibers on 3D-printed scaffolds is confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and field emission scanning electron microscopy (FE-SEM). Subsequent in situ mineralization results in calcium phosphate (CaP) deposition on the scaffold (Alg/MP/OPLA/CaP), as confirmed by ATR-FTIR, X-ray diffraction (XRD), and FE-SEM analysis. Further, in vitro cell studies demonstrate that the presence of MP NPs in Alg/MP/OPLA/CaP scaffold significantly improves cell attachment and proliferation over time, combined with enhancement in osteogenic activity. Overall, the developed Alg/MP/OPLA/CaP scaffold provides a bioactive environment for bone regeneration, thus serving as a potential alternative for the repair of critical-sized bone defects.