![Sample our Medicine, Dentistry, Nursing & Allied Health journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5944/TOC-Subject-Sample-2021-Medicine-Dentistry-Nursing-Allied-Health.jpg"})
Abstract
Background
Irisin is a cytokine produced by skeletal muscle and usually plays a pivotal role in inducing fat browning and regulating energy expenditure. In recent years, it was found that irisin might be the molecular entity responsible for muscle–bone connectivity and is useful in osteogenesis induction.
Materials and methods
To study its effect on bone regeneration, we developed silk/calcium silicate/sodium alginate (SCS) composite scaffold based on an interpenetrating network hydrogel containing silk fibroin, calcium silicate, sodium alginate. Then we loaded irisin on the SCS before coating it with polyvinyl alcohol (PVA). The SCS/P scaffold was physically characterized and some in vitro and in vivo experiments were carried out to evaluate the scaffold effect on bone regeneration.
Results
The SCS/P scaffold was showed a porous sponge structure pursuant to scanning electron microscopy analysis. The release kinetics assay demonstrated that irisin was stably released from the irisin-loaded hybrid system (i/SCS/P system) to 50% within 7 days. Moreover, osteoinductive studies using bone marrow stem cells (BMSCs) in vitro exhibited the i/SCS/P system improved the activity of alkaline phosphatase (ALP) and enhanced the expression levels of a series of osteogenic markers containing Runx-2, ALP, BMP2, Osterix, OCN, and OPN. Alizarin red staining also demonstrated the promotion of osteogenesis induced by i/SCS/P scaffolds. In addition, in vivo studies showed that increased bone regeneration with better mineralization and higher quality was found during the repair of rat calvarial defects through utilizing the i/SCS/P system.
Conclusion
These data provided strong evidence that the composite i/SCS/P would be a promising substitute for bone tissue engineering.
Supplementary material
Figure S1 SEM image of cross section of the SCS/P scaffold.
Abbreviations: SEM, scanning electron microscopy; SCS/P, silk/calcium silicate/sodium alginate/PVA.
Acknowledgments
This study was supported by the National Natural Science Foundation of China (81620108006, 31500787, 81430012, 51703127, 81801006, 31600777), the National Key Research and Development Program of China (2016YFC1102900), Young Elite Scientist Sponsorship Program by CAST (2017QNRC001), and Shanghai Sailing Program (16YF1406600).
Disclosure
The authors report no conflicts of interest in this work.