[Akt involved in diazoxide preconditioning against rat hippocampal neuronal apoptosis induced by anoxia-reoxygenation injury].

OBJECTIVE: Investigate whether preconditioning with diazoxide (DZ), a mitochondrial ATP-sensitive potassium channel opener, could enhance Akt protein to up-regulate Bcl-2/Bax protein ratio against apoptosis. METHODS: Cultured for 9 - 10 d in vitro, the hippocampal neurons of Sprague-Dawley rats were assigned to the following 5 groups randomly: Control (Group A), Anoxia (Group B), Anoxia + DZ100 micromol/L (Group C), Anoxia + DZ100 micromol/L + 5-hydroxydecanoate (Group D), Anoxia + DZ100 micromol/L + LY294002 50 micromol/L (Group E). Prior to oxygen deprivation, the hippocampal neurons were treated with DZ for 1 h per day and this treatment was persisted for 3 d. Each experiment was repeated for three times and each group contained 16 wells or 2 dishes of neurons for each time. Thereafter, neurons were derived of oxygen for 4 h. At 48 h of reoxygenation the neuronal optical density (A) were measured by MTT method, while the apoptotic rates were assayed by annexin V-FITC staining. The expressions of Akt, Bcl-2 and Bax proteins were detected and evaluated by Western blot. RESULTS: Compared with other pretreatment, DZ 100 micromol/L led to the elevation of A, whereas promoted the decrease of apoptotic rate (P < 0.05). Compared with those in other anoxic groups, the expressions of Akt protein and Bcl-2 protein in Group C were increased significantly (P < 0.05), whereas the Bax density were reduced significantly (P < 0.05). Preceding administration of 100 micromol/L DZ took protective effects on the neurons induced by anoxia-reoxygenation. CONCLUSIONS: DZ 100 micromol/L increased Akt protein to up-regulate Bcl-2/Bax protein ratio against apoptosis induced by anoxia-reoxygenation.

Preparation of functionalized cotton fabrics by means of melatonin loaded ß-cyclodextrin nanosponges.

Biofunctional textiles are a new category of advanced materials which combine conventional textiles with advanced drug delivery systems to obtain fabrics able to release active principles through skin. The work presents the synthesis of hyper cross-linked ß-cyclodextrins nanosponges with the carbonyl group acting as bridge between cyclodextrin molecules. The result of the synthesis is a 3-D porous structure, where melatonin molecules have been complexed. The complex has been characterized by elemental analysis, DSC, SEM, XRD and FT-IR spectroscopy and the results confirm that melatonin interacts with the synthesized nanosponge at molecular level. Melatonin loaded nanosponges have been dispersed on cotton fibres, which have proved to be a suitable substrate for durable nanosponge adsorption. The in vitro release tests from the funtionalized fabrics have shown a zero order kinetics, which is typical of a reservoir diffusion controlled system.