Effect of chitosan on 3D printed scaffolds with gelatin–hyaluronic acid, hydroxyapatite and magnetic nanoparticles for bone tissues defects repair

Le résumé fourni par la source

Bone is a dynamic and vascularized tissue, with self-healing abilities, efficient in treating minor defects. Bone tissue engineering has focused on materials used to reconstruct large orthopedics defects and 3D (bio)printing is a revolutionary technology able to design well-defined geometries. The paper details the preparation of printable inks based on methacrylated chitosan with different molecular weight, methacrylated gelatin, hyaluronic acid, hydroxyapatite and magnetic nanoparticle, and evaluates the inks printability, and scaffolds properties in correlation with bone repair requirements. The polymers homogenization with magnetic nanoparticles and hydroxyapatite led to gels with rheological characteristics for 3D printing (shear tests in oscillatory or rotational regimes); inks containing short chitosan chains and high hydroxyapatite concentrations showed suitable viscosity and elasticity. The yield stress results suggest that the inks are becoming more resistant to flow by increasing the Cs molecular weight. Scanning electron microscopy images confirmed the 3D printed architecture and the formation of 3D network with interconnected pores, varying from 50 μm to 150 μm, beneficial for bone cells migration and infiltration. Hydroxyapatite content, strongly influenced scaffolds mechanical features (Young modulus), and by tailoring the polymeric/hydroxyapatite phases, 3D printed scaffolds suitable for implantation in low-load bearing sites. On the other hand, the inclusion of magnetic nanoparticles induced ability to respond to external magnetic field and potential to activate complex pathways for osteogenic differentiation. The prepared scaffolds are cytocompatible, the cells preserved their normal morphology and interacted in uniform layers.

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