Preparation, characterization and biocompatibility of mesoporous bioactive glass/silk fibroin/chitosan composite scaffold with mesenchymal stem/stromal cells

Objective: The three-dimensional biodegradable scaffolds could play an important role in terms of tissue engineering since it serves as the extracellular matrix (ECM) for cells to attach, migrate and proliferate and maintain their differentiated functions. Composite scaffolds composed of both bioactive ceramics and biodegradable polymers are gaining popularity as a scaffold material with degradability, bioactivity and toughness. Silk fibroin/chitosan (SF/CS) scaffold is a blended natural polymeric scaffold with biodegradability, biocompatibility, osteoconductivity, non-toxicity and cytocompatibility. However, SF/CS scaffold mechanical properties and osteoconductivity are far from optimal. The aim of this research was to fabricate novel tri-component composite scaffolds to improve their mechanical properties and osteoconductivity. Methods: The 3D composite scaffolds composed of silk fibroin (SF), chitosan (CS) and mesoporous bioactive glass (MBG) or mesoporous bioactive glass microsphere (MBGM) were fabricated using freeze-drying method. Results: The composition, microstructure and mechanical properties of composite scaffolds were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and a universal mechanical testing machine (UTM). Results demonstrated that all of the scaffolds had pore sizes of 100\u2013300 \ub5m and a porosity of 91.8\u201395.3%. The investigation of the mechanical properties showed that the tri-component scaffolds have higher mechanical strength than the bi-component (SF/CS) scaffolds. The in vitro biocompatibility studies with mesenchymal stem/stromal cells (MSCs) from bone marrow and subcutaneous adipose tissue showed that all the scaffolds are suitable for cellular ingrowth, cell attachment and proliferation. Results from alamarBlue\uae assay indicated that both MBGs/SF/CS and MBGMs/SF/CS composite scaffolds provided a more favorable environment for MSCs attachment and proliferation than that of SF scaffold. Furthermore, MBG/SF/CS and MBGM/SF/CS improve ALP activity of MSCs more than SF/CS scaffolds suggesting their osteoinductive features. Conclusions: This study indicates that both types of composite scaffolds with additional mesoporous bioactive glass provide a better environment for cell attachment, proliferation and differentiation, and could be used as a potential template for tissue engineering