Calcium phosphates Chitosan-Xanthan composite scaffolds associated with mesenchymal stem cells for regenerative dentistry application

Abstract

The aim of this study was to synthesize and characterize polymeric porous scaffolds associated with different calcium phosphates (CaP) and Mesenchymal Stem Cells (MSC) for regenerative dentistry application. Chitosan-Xanthan Scaffolds (CX) were associated with 5% of the two CaP types, Hydroxyapatite (HA) and Brushite (BS). For advanced cell therapies, the scaffolds were associated with MSC. The scaffold structures were characterized by X Ray Diffraction (DRX), Fourier Transformed Infrared (FTIR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy analysis (SEM) and the compressive strength. The in vitro Cytotoxicity was performed and the in vivo Biocompatibility by histomorphometry and inflammatory cells number count. XRD showed the amorphous phase of CX and main peaks of the CaP phases in the HA and BS scaffolds. FTIR showed the amide I and II bands, characteristic of Chitosan, and carboxyl group, characteristic of Xanthan. PO4 bands were found in CaP scaffolds. SEM showed pores and CaP fillers incorporated and adhered to the polymer in the CX-HA, CX-BS, CX-HA + MSC and CX-BS + MSC. Compressive strength and Modulus of Elasticity analysis exhibited higher values for CX-BS scaffolds, followed by CX-HA and CX. All scaffolds showed acceptable cells viability after 24 h and 48 h; however, the CX scaffolds showed higher cell viability in 48 h. CX-BS produced significantly higher inflammatory cells number after 7 and 30 days of implantation. After 60 days of implantation, CX + MSC and CX-HA + MSC showed the lowest inflammatory cells number. The CaP improved the mechanical properties of scaffolds but decreased the cell viability. MSCs improved the inflammatory response after 60 days.