A new amido phosphonate derivative of carboxymethylcellulose with an osteogenic activity and which is capable of interacting with any Ti surface.

A new phosphonate derivative of carboxymethylcellulose (CMC) was recently synthesized (CMCAPh). The phosphonate polysaccharide was obtained by using a carbodiimide-like activating agent for carboxylic groups and 2-aminoethyl-phosphonic acid to create an amide bond between the amine of the phosphonate agent and the carboxylic acids of CMC. The polymer was characterized by (31)P NMR, FT-IR, and potentiometric titration. CMCAPh showed different properties from CMC and its amidated derivative polymer CMCA. The behavior in solution of CMCAPh polymer towards normal human osteoblasts (NHOst) was studied in vitro, monitoring the cell proliferation, cell differentiation, and osteogenic activity and was then compared with the amidic derivative of carboxymethylcellulose (CMCA). Furthermore, CMCAPh was used to coat titania disks with the aim of increasing the osteogenic activity of implant surfaces. The polymer film on the titania surface was characterized by AFM and TOF-SIMS analysis. An ATR FT-IR study was carried out to evaluate the polymer bonding mode onto the titanium surface. Osteoblast morphology was evaluated by SEM. Adhesion analysis of NHOst demonstrated a better adhesion on the titanium surface coated with CMCAPh than on the bare titanium surface.

The effects of the electric fields on hydrogels to achieve antitumoral drug release.

The achievement of electrochemotherapy was obtained using electrodes covered with guar gum (GG) hydrogel swollen in a sulfate bleomycin solution. The bleomycin delivery into the plasma membranes of cancer cells occurs only when field strength (V/cm) was applied, decreasing the drug contact with healthy tissues. The effect of the delivered bleomycin at different concentrations was examined on tumoral mouse fibroblast (NIH3T3) and human coronary artery endothelial cells. The GG hydrogel released the drug only when the field strength was applied and the amount depended on the electromotive force. Consequently, cellular survival depended on the field strength. Moreover in vitro results showed a bigger cellular mortality of the NIH3T3 compared with endothelial cells. The best parameters to be utilized in electrochemotherapy were ascertained.

New bis-cresol-bridged bis(1,4,7-triazacyclononane) ligand as receptor for metal cations and phosphate anions.

The synthesis and characterization of a new bis([9]aneN3) ligand (H2L) containing two [9]aneN3 macrocyclic moieties separated by a 2,2'-methylene-bis-cresol (cresol = 4-methyl-phenol) unit is reported. A potentiometric and (1)H NMR study in aqueous solution reveals that H2L is in a zwitterionic form, and protonation of the cresolate oxygens occurs only with the formation of the highly charged (H5L)(3+) and (H6L)(4+) species at acidic pH values. The coordination properties of H2L toward Cu(II), Zn(II), Cd(II), and Pb(II) were studied by means of potentiometric and UV spectrophotometric measurements. The ligand gives both mono- and binuclear complexes in aqueous solution. At acidic pH values the ligand forms stable binuclear [M2H2L](4+) complexes, where each metal is coordinated by two amine groups of [9]aneN3 and the deprotonated oxygen of the adjacent cresol unit; the remaining amine group is protonated. Deprotonation of the [M2H2L](4+) species at alkaline pH values affords [M2L](2+) complexes, where all amine groups of the [9]aneN3 moieties are involved in metal coordination. Binding of mono-, di- and triphosphate, and adenosine triphosphate (ATP) was studied by means of potentiometric, (1)H and (31)P NMR measurements and by molecular dynamics simulations. The receptor forms stable 1:1 adducts with di-, triphosphate, and ATP, while the interaction with monophosphate is too low to be detected. In the complexes both the [9]aneN3 moieties act cooperatively in the substrate binding process. The stability of the adducts increases in the order diphosphate < triphosphate < ATP. This trend is explained in terms of increasing number of charge-charge interactions between the phosphate chains and the protonated [9]aneN3 subunits and, in the case of ATP, of stacking interactions between the adenine and cresol units.