Lack of suitable auto/allografts has been delaying surgical interventions for the treatment of numerous disorders and has also caused a serious threat to public health. Tissue engineering could be one of the best alternatives to solve this issue. However, deficiency of oxygen supply in the wounded and implanted engineered tissues, caused by circulatory problems and insufficient angiogenesis, has been a rate-limiting step in translation of tissue-engineered grafts. To address this issue, we designed oxygen-releasing electrospun composite scaffolds, based on a previously developed hybrid polymeric matrix composed of poly(glycerol sebacate) (PGS) and poly(ε-caprolactone) (PCL). By performing ball-milling, we were able to embed a large percent of calcium peroxide (CP) nanoparticles into the PGS/PCL nanofibers able to generate oxygen. The composite scaffold exhibited a smooth fiber structure, while providing sustainable oxygen release for several days to a week, and significantly improved cell metabolic activity due to alleviation of hypoxic environment around primary bone-marrow-derived mesenchymal stem cells (BM-MSCs). Moreover, the composite scaffolds also showed good antibacterial performance. In conjunction to other improved features, such as degradation behavior, the developed scaffolds are promising biomaterials for various tissue-engineering and wound-healing applications.

This study investigated nonstoichiometric nickel oxide thin films prepared via the DC-sputtering technique at different film thicknesses. The prepared films were characterized by a surface profiler for thickness measurement, X-ray diffraction (XRD) for film nature, atomic force microscopy (AFM) for film morphology and roughness, UV-visible-near infrared (UV-vis.-NIR) spectroscopy for optical transmittance spectra of the films, and the photoluminescence (PL) spectra of the prepared films were obtained. The measured film thickness increased from 150 to 503 nm as the deposition time increased. XRD detected the trigonal crystal system of NiO_0.96. The crystallite sizes were mainly grown through (101) and (110) characteristic planes. NiO_0.96 films have a spherical particle shape and their sizes decreases as the film thickness increased. The optical band gap values decrease from 3.817 to 3.663 eV when the film thickness increases. The refractive index was estimated from the Moss relation, while the high-frequency dielectric constant and the static dielectric constant were deduced from the empirical Adachi formula. The photoluminescence behavior of the studied films confirmed the photogeneration of an electron-hole in nickel and oxygen vacancies. Hence, this study confirms the presence of nickel oxide lattice in the hexagonal structure containing the defects originated from the nickel vacancies or the excess of oxygen.