Bio-jetted human adipose-derived stem cells remain viable

Direct cell handling processes are increasingly becoming important as they allow the controlled deposition of living cells, with precision for a vast number of applications, spanning the printing of cells in either 2D/3D for the reconstruction of fully functional tissues to the delivery of therapeutic architectures bearing cells and genes of interest. Architectures reconstructed with such cells etc are most useful as models, for studying a wide range of molecular and cellular behaviours, to the development of personalised medicines. Our previous work demonstrated the ability for aerodynamically assisted bio-jets to process single and multiple cell-bearing suspensions, to whole fertilised embryos. Those studies found that the post-treated cells and embryos were indistinguishable from untreated controls. In the present study the authors further validate this jetting technology for the direct handling of stem cells, by demonstrating their viability post-treatment and their capacity to differentiate in comparison to controls. These studies together with our previous work unveil, aerodynamically assisted bio-jets as a platform biotechnology for the direct handling of a wide range of cells and embryos

Bioactive glasses and electrospun composites that release cobalt to stimulate the HIF pathway for wound healing applications

Abstract Background Bioactive glasses are traditionally associated with bonding to bone through a hydroxycarbonate apatite (HCA) surface layer but the release of active ions is more important for bone regeneration. They are now being used to deliver ions for soft tissue applications, particularly wound healing. Cobalt is known to simulate hypoxia and provoke angiogenesis. The aim here was to develop new bioactive glass compositions designed to be scaffold materials to locally deliver pro-angiogenic cobalt ions, at a controlled rate, without forming an HCA layer, for wound healing applications. Methods New melt-derived bioactive glass compositions were designed that had the same network connectivity (mean number of bridging covalent bonds between silica tetrahedra), and therefore similar biodegradation rate, as the original 45S5 Bioglass. The amount of magnesium and cobalt in the glass was varied, with the aim of reducing or removing calcium and phosphate from the compositions. Electrospun poly(ε-caprolactone)/bioactive glass composites were also produced. Glasses were tested for ion release in dissolution studies and their influence on Hypoxia-Inducible Factor 1-alpha (HIF-1α) and expression of Vascular Endothelial Growth Factor (VEGF) from fibroblast cells was investigated. Results Dissolution tests showed the silica rich layer differed depending on the amount of MgO in the glass, which influenced the delivery of cobalt. The electrospun composites delivered a more sustained ion release relative to glass particles alone. Exposing fibroblasts to conditioned media from these composites did not cause a detrimental effect on metabolic activity but glasses containing cobalt did stabilise HIF-1α and provoked a significantly higher expression of VEGF (not seen in Co-free controls). Conclusions The composite fibres containing new bioactive glass compositions delivered cobalt ions at a sustained rate, which could be mediated by the magnesium content of the glass. The dissolution products stabilised HIF-1α and provoked a significantly higher expression of VEGF, suggesting the composites activated the HIF pathway to stimulate angiogenesis