Dextran-Polydopamine Dual Coating on 3D-Printed Polycaprolactone Scaffolds as a Potential Biofunctionalization Platform for Bone Tissue Engineering

Three-dimensional (3D) printing has paved the way for the precision manufacturing of patient-specific scaffolds. While personalized 3D-printed bone scaffolds are already in the clinic, further attempts to combine biofunctionalization and drug delivery with these scaffolds are of great interest to improve tissue regeneration and reduce recovery time. This study investigated the dextran-polydopamine (PDA) dual-coated 3D-printed polycaprolactone (PCL) scaffolds as a potential biofunctionalization platform, which will enable the design of more advanced coating systems. Despite PCL being one of the most well-established biomaterials used in manufacturing bone scaffolds, surface modification is essential for its application due to its hydrophobic surface and lack of osteogenic properties. PDA is a bioinspired synthetic polymer, known for its convenient coating strategy, superior osteogenicity, and ability to graft secondary biofunctionalization motifs. However, modifying the surface of PCL with PDA results in aggregates of PDA nanoparticles rather than forming a homogeneous coating layer. Here, dextran was introduced as a dual coating deposited as a thin layer, which further assists cell adhesion and proliferation. Dextran is a biomedical macromolecule with a long history in medicine, which can be used as a drug delivery carrier in various forms, and the focus of this study was to investigate the intricate interplay between dextran and PDA as a dual coating applied to 3D-printed PCL scaffolds, via microstructural, topographical, chemical, and mechanical validation. A series of cell studies using osteoblast-like MG-63 cells was conducted, and it has been confirmed that dextran can be introduced to the PDA-modified PCL scaffold while maintaining the maximum scaffold and cell interaction. Consequently, the present results suggest that the dextran-PDA dual coating offers a promising biofunctionalization platform for designing more complex systems involving dextran-based drug delivery, aimed at application in bone tissue engineering.

3D printing, bone tissue engineering, dextran, polycaprolactone (PCL) & polydopamine (PDA)