Investigation of applying chitosan coating on antibacterial and biocompatibility properties of bredigite/titanium dioxide composite scaffolds.

In this study by considering the advantages of bredigite (Br) and titanium dioxide (TiO2) bioceramics, composite scaffolds of bredigite/titanium dioxide were prepared by the gelcasting method, then, to improve the mechanical, biological and antibacterial properties, scaffolds were coated with chitosan (Ch) polymer phase. The phase structure, fundamental groups, chemical composition, and elemental distribution analysis, morphology and the form of porosity were respectively characterized by XRD, FTIR, EDS, and SEM. Mechanical properties and porosity percentage of scaffolds were also measured by the compressive strength test and Archimedean method, respectively. In order to verify the cell compatibility, MG63 bone marrow cells were cultured on the surface of the specimens. The results showed that the addition of titanium dioxide to the scaffold of bredigite resulted in decrease of porosity and increase of compressive strength of scaffolds from 0.299 to 0.687 MPa. Furthermore, the coated scaffold with chitosan polymer reduced porosity from 83 to 63 percent and a remarkable improvement in compressive strength from 0.585 to 2.339 MPa. The results of the antibacterial test showed that in composite scaffolds, The diameter of the inhibition zone is 22 and 29 mm, in the culture media of Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive), respectively. On the other hand, the results of cell compatibility and cell adhesion tests showed that the scaffolds had no toxicity and the growth, proliferation, and adhesion of MG63 bone cells adjacent to the scaffolds was desirable. Therefore, the scaffold in this study can be used as an ideal scaffold for use in bone tissue engineering.