Silk-derived oxygen-generating electrospun patches for enhancing tissue regeneration: Investigation of calcium peroxide role and its effects on controlled oxygen delivery

The use of oxygen-generating biomaterials (OGBs) in tissue-engineered scaffolds is a fascinating approach to overcome the limitation in providing adequate oxygen for tissue regeneration. However, a more profound understanding is required to develop OGBs. In this study, by encapsulation of calcium peroxide (CPO) with different concentrations (0.1, 0.5 and 1% wt) within the silk fibroin (SF), a natural polymer with the high permeability of oxygen, through electrospinning, the SF-CPO patches were fabricated. Due to the addition of CPO, the diameter of electrospun fibers was increased from 459.77 +/- 97.17 nm to 13.06 +/- 1.79 mu m. FTIR, XRD, WDX, Alizarin Red S and SDS-Page analyses were used to prove the loading and impact of CPO on the properties of the SF-CPO patches. In vitro oxygen release from electrospun fibers confirmed sustained and controllable oxygen release for at least 13 days in the range of approximately 180-260 mmHg. Antibacterial assay indicated the positive effects of CPO presence on the antibacterial properties; by an increment in CPO, the diameter of the inhibition zone has enhanced (25 to 47 mm). Cellular studies (cell adhesion, DAPI and MTT) also illustrated the significant support of oxygen on cell viability and proliferation. Altogether, this study contributed to understanding the impact of SF-CPO combination on fabricating electrospun fibers and seems to have the potential to become promising OGBs for tissue engineering applications.