The Influence of Cuprorivaite Nanoparticles on the Physicomechanical and Biological Performance of <scp>3D</scp>‐Printed Scaffold Based on Carboxymethyl Chitosan Combined With Zein for Bone Tissue Engineering

This study demonstrates a new degradable 3D-printed carboxymethyl chitosan (CMC)/zein bone scaffold loaded with different content of cuprorivaite (Cup) nanoparticles which labeled as CMCS/Z/Cup. Only a few studies have utilized these components to fabricate a three-component porous osteogenic scaffold. The aim of this study was to comprehensively assess the mechanical and biocompatibility of the nanocomposite which synthesized by 3D printing method. For this purpose, the Cup powder was initially synthesized through sol-gel process and its confirmation was proved using techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Then, three CMC/Z scaffolds were made with different Cup contents: group A (0 wt.% Cup), group B (2.5 wt.% Cup) and group C (5 wt.% Cup). The scaffolds were well-ordered microporous with a high porosity and pore connectivity, as observed by morphological analysis by SEM. Additionally, the pore size of group B was more homogeneous than that of groups A and C. There were no significance differences in physicochemical characterization among the three groups. Mechanical properties analysis showed that values of compression modulus are significantly increased with addition of 2.5% Cup nanoparticles into CMCS/zein matrix, from 1.2 to 9.6 MPa. The incorporation of Cup nanoparticles into CMCS along with zein can provide a suitable substrate for the growth of osteoblast cells after implantation, as indicated by the results of in vitro degradation. The scaffolds were cultured in vitro with MG-63 cells, showing that cell viability increased with the Cup content, 95%, 105%, and 110% for the pure polymeric scaffold, and scaffolds reinforced with 2.5% and 5% Cup, respectively. As a result, the scaffolds designed in this study possess the ability to be used in bone tissue engineering due to having characteristics similar to natural bone.