Physiologically based microenvironment for in vitro neural differentiation of adipose-derived stem cells

The limited capacity of nervous system to promote a spontaneous regeneration and the high rate of neurodegenerative diseases appearance are keys factors that stimulate researches both for defining the molecular mechanisms of pathophysiology and for evaluating putative strategies to induce neural tissue regeneration. In this latter aspect, the application of stem cells seems to be a promising approach, even if the control of their differentiation and the maintaining of a safe state of proliferation should be troubled. Here, we focus on adipose tissue-derived stem cells and we seek out the recent advances on the promotion of their neural differentiation, performing a critical integration of the basic biology and physiology of adipose tissuederived stem cells with the functional modifications that the biophysical, biomechanical and biochemical microenvironment induces to cell phenotype. The pre-clinical studies showed that the neural differentiation by cell stimulation with growth factors benefits from the integration with biomaterials and biophysical interaction like microgravity. All these elements have been reported as furnisher of microenvironments with desirable biological, physical and mechanical properties. A critical review of current knowledge is here proposed, underscoring that a real advance toward a stable, safe and controllable adipose stem cells clinical application will derive from a synergic multidisciplinary approach that involves material engineer, basic cell biology, cell and tissue physiology.

Comparative Oral Absorption of Different Citicoline and Homotaurine Formulations: A Single-Dose, Two-Period Crossover Trial in the Dog

Background: Citicoline and homotaurine are compounds with a potent neuroprotective activity and they have been administered for many years in the treatment of numerous neurodegenerative and ophthalmological diseases, including glaucoma. Initially available only as liquid form, through parenteral route, nowadays citicoline can be administered also as tablet but no data on bioavailability of these different forms are available. In the present study, pharmacokinetics of citicoline in tablet versus vials, each at the therapeutic dose of 500 mg, in addition to 50 mg of homotaurine was investigated. Materials and methods: Ten mixed breed dogs received a single dose of 50 mg oral homotaurine and 500 mg citicoline in tablet and vials with the same dose were administered after a seven days wash-out period. Parameters assessed for citicoline metabolites (cytidine, uridine and choline) were AUC0−t, Cmax and Tmax. Results: Citicoline bioavailability appeared to be slightly higher for the tablet compared to the vial formulation. Cytidine is equivalent in absorption dynamics both for tablet and liquid form;uridine for tablet reaches its maximum and is reabsorbed more quickly while choline for the liquid form reaches the maximum first and is reabsorbed more quickly. Conclusions: Citicoline in tablet and liquid formulation have pharmacokinetic properties leading to a very similar bioavailability.