Fabrication and properties of developed collagen/strontium-doped Bioglass scaffolds for bone tissue engineering

Abstract

This study was conducted to evaluate the bone regeneration effects of collagen/strontium-doped Bioglass (BG-Sr) scaffolds. The present study comprised four parts including designing and fabricating scaffolds, characterization tests such as biodegradation, water uptake, porosity, FTIR (Fourier transform infrared spectroscopy), and SEM (Scanning electron microscope), in vitro tests such as MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)), alkaline phosphatase, calcium assay, Alizarin Red staining, and real-time PCR (Polymerase chain reaction), and ultimately in vivo and histopathological tests such as evaluating bone regeneration, mineralization with Hematoxylin-Eosin, Masson's trichrome and Alizarin Red staining, and histomorphometric studies 4, 8 and 12 weeks after implanting the scaffolds in the skull and femur of 36 rabbits. Significant reductions were observed in degradability, water absorption, and porosity in the BG-Sr samples. In vitro results showed that the synthetic scaffolds were less toxic, stimulated, and induced cell growth. The ALP (Alkaline phosphatase) activity was higher on day 14 than on day 7, and the highest calcium content was observed in the BG-Sr samples on day 14. In line with the SEM and MTT results, the DAPI (Diamidino-2-phenylindole) results confirmed cell proliferation. Moreover, osteocalcin and ALP gene expression were high in the BG-Sr group. The results of the histopathological tests showed high levels of bone formation in the BG-Sr scaffolds. As a scaffold in regenerative medicine, the BG-Sr composite can be an effective product for bone regeneration.