Discriminative ionic capabilities on hydrogen-bond transition from the mode of ordinary water to (Mg, Ca, Sr)(Cl, Br)₂ hydration

It has been a long pursuit to discriminate the ionic roles of mono- and di-valent salt solutions in modulating the hydrogen bonding network and solution properties. We attended this issue by examining the effect of concentrated YX 2 (Y[dbnd]Mg, Ca, Sr; X[dbnd]Cl, Br) solvation on O:H–O bonds transition from the mode of ordinary water to hydration in terms of the number fraction f YX2 (C) and the segmental O:H–O bond phonon stiffness shift Δω(C) with C being the solute concentration. The invariant df Y (C) / dC at C ≤ <0.05 suggests that the small Y 2+ forms a constantly-sized hydration droplet with weak responding to interference of other ions because its hydrating H 2 O dipoles screen mostly its electric field. However, the number inadequacy of the highly-ordered hydrating H 2 O dipoles partially screens the large X − . The X − ↔ X − electrostatic repulsion weakens its electric field. The concentration-trend consistency of the f YX2 (C), the solution conductivity σ YX2 (C), and surface stress (contact angle) θ YX2 (C) for YX 2 solutions clarifies their common origin of ionic polarization. However, the Jones–Dale notion disobedience of the viscosity η YX2 (C) suggests the dominance of the inter-ion repulsion.Submitted/Accepted versionFinancial support received from Natural Science Foundation of China (Nos. 11872052(YL); 21875024(CQ)), and the Science Challenge Project (No. TZ2016001) of China are acknowledged

A simple method to isolate structurally and chemically intact brain vascular basement membrane for neural regeneration following traumatic brain injury

Abstract Background The brain vascular basement membrane (brain-VBM) is an important component of the brain extracellular matrix, and the three-dimensional structure of the cerebrovascular network nested with many cell-adhesive proteins may provide guidance for brain tissue regeneration. However, the potential of ability of brain-VBM to promote neural tissue regeneration has not been examined due to the technical difficulty of isolating intact brain-VBM. Methods The present study developed a simple, effective method to isolate structurally and compositionally intact brain-VBM. Structural and component properties of the brain-VBM were characterized to confirm the technique. Seed cells were cocultured with brain-VBM in vitro to analyze biocompatibility and neurite extension. An experimental rat model of focal traumatic brain injury (TBI) induced by controlled cortical impact were conducted to further test the tissue regeneration ability of brain-VBM. Results Brain-VBM isolated using genipin showed significantly improved mechanical properties, was easy to handle, supported high cell viability, exhibited strong cell adhesive properties, and promoted neurite extension and outgrowth. Further testing of the isolated brain-VBM transplanted at lesion sites in an experimental rat model of focal TBI demonstrated considerable promise for reconstructing a complete blood vessel network that filled in the lesion cavity and promoting repopulation of neural progenitor cells and neurons. Conclusion The technique allows isolation of intact brain-VBM as a 3D microvascular scaffold to support brain tissue regeneration following TBI and shows considerable promise for the production of naturally-derived biomaterials for neural tissue engineering. Graphical Abstrac