Cellulose acetate-gelatin coated boron-bioactive glass biocomposite scaffolds for bone tissue engineering.

In this study, we aimed to prepare and characterize porous scaffolds composed of pure and boron oxide (B2O3) doped bioactive glass (BG) that were infiltrated by cellulose acetate-gelatin (CA-GE) polymer solution for bone tissue engineering applications. Composite scaffolds were cross-linked with glutaraldehyde (GTA) after polymer coating to protect the structural integrity of the polymeric coated scaffolds. The impact of B2O3 incorporation into BG-polymer porous scaffolds on cross-sectional morphology, porosity, mechanical properties, degradation, and bioactivity of the scaffolds was investigated. Human dental pulp stem cells (hDPSCs) were enzymatically isolated and used for cell culture studies. According to scanning electron microscope (SEM) analysis, porous structure of the scaffolds was preserved after polymer coating. After polymer infiltration, porosity of the scaffolds decreased from 64.2% to 59.35% for pure BG scaffolds and from 67.3% to 58.9% for B2O3 doped scaffolds, meanwhile their compressive strengths increased from 0.13 MPa to 0.57 MPa and from 0.20 MPa to 0.82 MPa, respectively. After polymer infiltration, 7% B2O3 incorporated BG scaffolds had higher weight loss and Ca-P layer deposition than pure BG scaffolds, after 14 days of incubation in stimulated body fluid (SBF) at 37oC. Higher attachment and proliferation of hDPSCs were observed on 7% B2O3-BG-CA/GE scaffolds. Additionally, alkaline phosphatase (ALP) activity of the cells was about 1.25 fold higher in this group than that observed on BG-CA/GE scaffolds after 14 days of incubation in osteogenic medium, while their intracellular calcium amounts were 1.7 fold higher than observed on BG-CA/GE after 7 days of incubation in osteogenic medium. Our results suggested that porous cellulose acetate-gelatin coated boron-bioactive glass scaffolds hold promise for bone tissue engineering applications.