Nanostructured functionalized magnetic platforms for the sustained delivery of cisplatin: Synthesis, characterization and in vitro cytotoxicity evaluation.

Cisplatin has demonstrated extraordinary anticancer activity against a variety of solid tumors. However, its clinical efficacy is contrasted by its toxicity profile. Having in mind the need to reduce the toxicity, promote a sustained release and enhance the body-circulation time of cisplatin, herein novel nanocarriers consisting of core-shell silica-coated iron oxide nanoparticles functionalized with dicarboxylic acid groups were prepared and characterized. Cisplatin was conjugated with the functionalized nanoparticles by surface tethering. Controlled release of cisplatin was observed without burst effect and in a sustained profile for up to 3 days. In vitro studies showed cytotoxic and antiproliferative effects of the cisplatin nanoconjugates against a human pancreatic cancer cell line. Importantly, when compared with free cisplatin, nanoconjugates exhibited lower cytotoxic effects regarding nonmalignant human duct pancreatic cells.

Synthesis, structural characterization, cytotoxic properties and DNA binding of a dinuclear copper(II) complex.

In this study a novel dinuclear copper(II) complex with adenine and phenanthroline has been synthesized and its structure determined by single crystal X-ray diffraction. In the dinuclear complex [Cu2(µ-adenine)2(phen)2(H2O)2](NO3)4·0.5H2O (phen=1,10-phenanthroline) (1) the two Cu(II) centres exhibit a distorted square pyramidal coordination geometry linked by two nitrogen donors from adenine bridges leading to a Cu-Cu distance of 3.242(3)Å. Intramolecular and intermolecular π⋯π interactions as well as an H-bonding network were observed. The antitumor capacity of the complex has been tested in vitro against human cancer cell lines, cervical carcinoma (HeLa) and colorectal adenocarcinoma (Caco-2), by metabolic tests, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide as reagent. The complex 1 has remarkable low IC50 values of 0.87±0.06µM (HeLa) and 0.44±0.06µM (Caco-2), when compared with values for cisplatin against the same cell lines. The interaction of complex 1 with calf thymus DNA (CT DNA) was further investigated by absorption and fluorescence spectroscopic methods. A binding constant of 5.09×10(5)M(-1) was obtained from UV-vis absorption studies.

Silicate and borate glasses as composite fillers: a bioactivity and biocompatibility study.

Composites filled with a silicate glass (CSi) and a new borate glass (CB) were developed and compared in terms of their in vitro behaviour both in acellular and cellular media. Acellular tests were carried out in SBF and the composites were characterized by SEM-EDS, XRD and ICP. Biocompatibility studies were investigated by in vitro cell culture with MG-63 osteoblast-like and human bone marrow cells. The growth of spherical calcium phosphate aggregates was observed in acellular medium on all composite surfaces indicating that these materials became potentially bioactive. The biological assessment resulted in a dissimilar behavior of the composites. The CSi demonstrated an inductive effect on the proliferation of cells. The cells showed a normal morphology and high growth rate when compared to standard culture plates. Contrarily, inhibition of cell proliferation occurred in the CB probably due to its high degradation rate, leading to high B and Mg ionic concentration in the cell culture medium.

Transfer of vascularized extensor tendons from the foot to the hand with a dorsalis pedis flap.

The use of the dorsalis pedis flap with vascularized extensor tendons was presented. An anatomic study has been carried out that has shown that the vascularization of the foot extensor tendons can be exclusively dependent on the blood contribution coming from the dorsalis pedis artery. In two cases that are presented and followed up for over a year after the surgery, the functional results obtained are good in the hand and aesthetically acceptable in the foot.