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In the present work, microporous membranes based on poly(ε-caprolactone) (PCL) and PCL functionalized with amine (PCL-DMAEA) or anhydride groups (PCL-MAGMA) were realized by solvent-non solvent phase inversion and proposed for use in Guided Tissue Regeneration (GTR). Nanowhiskers of hydroxyapatite (HA) were also incorporated in the polymer matrix to realize nanocomposite membranes. Scanning Electron Microscopy (SEM) showed improved interfacial adhesion with HA for functionalized polymers, and highlighted substantial differences in the porosity. A relationship between the developed porous structure of the membrane and the chemical nature of grafted groups was proposed. Compared to virgin PCL, hydrophilicity increases for functionalized PCL, while the addition of HA influences significantly the hydrophilic characteristics only in the case of virgin polymer. A significant increase of in vitro degradation rate was found for PCL-MAGMA based membranes, and at lower extent of PCL-DMAEA membranes. The novel materials were investigated regarding their potential as support for cell growth in bone repair using multipotent mesenchymal stromal cells (MSC) as a model. MSC plated onto the various membranes were analyzed in terms of adhesion, proliferation and osteogenic capacity that resulted to be related to chemical as well as porous structure. In particular, PCL-DMAEA and the relative nanocomposite membranes are the most promising in terms of cell-biomaterial interactions., (Copyright © 2014 Elsevier B.V. All rights reserved.)

2-(3,4-Dihydroxyphenyl)ethanol (DPE), a naturally occurring phenolic antioxidant molecule found in olive oil, has been reported to exert several biological and pharmacological activities. We studied the effect of this compound on the proliferation and survival of HL60 cell line. Concentrations from 50 to 100 microM DPE, comparable to its olive oil content, caused a complete arrest of HL60 cell proliferation and the induction of apoptosis. This was demonstrated by flow cytometric analyses, poly(ADP-ribose) polymerase cleavage, and caspase 3 activation. The apoptotic effect requires the presence of two ortho-hydroxyl groups on the phenyl ring, since tyrosol, 2-(4-hydroxyphenyl)ethanol, did not induce either cell growth arrest or apoptosis. DPE-dependent apoptosis is associated with an early release of cytochrome c from mitochondria which precedes caspase 8 activation, thus ruling out the engagement of cell death receptors in the apoptotic process. 2-(3,4-Dihydroxyphenyl)ethanol induced cell death in quiescent and differentiated HL60 cells, as well as in resting and activated peripheral blood lymphocytes, while did not cause cell death in two colorectal cell lines (HT-29 and CaCo2). These results suggest that DPE down-regulates the immunological response, thus explaining the well-known antinflammatory and chemopreventive effects of olive oil at the intestinal level., (Copyright 2000 Academic Press.)

Resveratrol (3,5,4'-trihydroxystilbene) is a naturally occurring phytoalexin, found in grapes and wine, which has been reported to exert a variety of important pharmacological effects. We have investigated the activity of resveratrol on proliferation and differentiation of the promyelocitic cell line HL-60. A concentration as low as 30 microM causes a complete arrest of proliferation and a rapid induction of differentiation towards a myelo-monocytic phenotype. Analyses by flow cytometry showed the absence of the G2/M peak and the accumulation of cells in G1 and S phases. Moreover, at the concentrations employed, a very low amount of apoptotic cells was evidenced. A detailed biochemical analysis demonstrated that the G1 phase of the cell division cycle engine was completely unmodified by resveratrol addition, thus indicating that the G1 --> S transition occurs normally. Conversely, after only 24 h treatment, a significant increase of cyclins A and E could be observed along with the accumulation of cdc2 in the inactive phosphorylated form. These data demonstrate that resveratrol causes a complete and reversible cell cycle arrest at the S phase checkpoint., (Copyright 1998 Academic Press.)

A rapid, sensitive and specific high-performance liquid chromatographic method for the simultaneous separation of natural adenosyl-sulphur compounds has been developed. The compounds were separated by using the strong cation-exchange resin Partisil 10 SCX with isocratic elution. The adenosyl-compounds were monitored by an ultraviolet detector operating at 254 nm. Sensitivity was greater than 50 pmoles for all compounds tested and standard curves were found to be linear for concentrations of up to 50 nmoles. The method can be applied to biological samples for the estimation of S-adenosyl-L-methionine,S-adenosyl-L-homocysteine and S-adenosyl-(5')-3-methyl-thiopropylamine and for measurement of enzyme activities involving the above-mentioned compounds.