A High-throughput Screening of a Chemical Compound Library in Ovarian Cancer Stem Cells.

BACKGROUND: Epithelial ovarian cancer has a poor prognosis, mostly due to its late diagnosis and the development of drug resistance after a first platinum-based regimen. The presence of a specific population of "cancer stem cells" could be responsible of the relapse of the tumor and the development of resistance to therapy. For this reason, it would be important to specifically target this subpopulation of tumor cells in order to increase the response to therapy. METHOD: We screened a chemical compound library assembled during the COST CM1106 action to search for compound classes active in targeting ovarian stem cells. We here report the results of the high-throughput screening assay in two ovarian cancer stem cells and the differentiated cells derived from them. RESULTS AND CONCLUSION: Interestingly, there were compounds active only on stem cells, only on differentiated cells, and compounds active on both cell populations. Even if these data need to be validated in ad hoc dose response cytotoxic experiments, the ongoing analysis of the compound structures will open up to mechanistic drug studies to select compounds able to improve the prognosis of ovarian cancer patients.

Niosomal approach to brain delivery: Development, characterization and in vitro toxicological studies.

The majority of active agents do not readily permeate into brain due to the presence of the blood-brain barrier and blood-cerebrospinal fluid barrier. Currently, the most innovative and promising non-invasive strategy in brain delivery is the design and preparation of nanocarriers, which can move through the brain endothelium. Niosomes can perform brain delivery, in fact polysorbates, can act as an anchor for apolipoprotein E from blood plasma. The particles mimic LDL and interact with the LDL receptor leading to the endothelial cells uptake. The efficacy of niosomes for anticancer therapeutic applications was correlated to their physicochemical and drug delivery properties. Dimensions and ζ-potential were characterized using dynamic light scattering and asymmetric flow-field fractionation system. Lipid bilayer was characterized measuring the fluidity, polarity and microviscosity by fluorescent probe spectra evaluation. Morphology and homogeneity were characterized using atomic force microscopy. Physicochemical stability and serum stability (45% v/v fetal bovine and human serum) were evaluated as a function of time using dynamic light scattering. U87-MG human glioblastoma cells were used to evaluate vesicle cytotoxicity and internalisation efficiency. From the obtained data, the systems appear useful to perform a prolonged (modified) release of biological active substances to the central nervous system.

Biomedical Applications of Nanodiamonds: An Overview.

Nanodiamonds are a novel class of nanomaterials which have raised much attention for application in biomedical field, as they combine the possibility of being produced on large scale using relatively inexpensive synthetic processes, of being fluorescent as a consequence of the presence of nitrogen vacancies, of having their surfaces functionalized, and of having good biocompatibility. Among other applications, we mainly focus on drug delivery, including cell interaction, targeting, cancer therapy, gene and protein delivery. In addition, nanodiamonds for bone and dental implants and for antibacterial use is discussed. Techniques for detection and imaging of nanodiamonds in biological tissues are also reviewed, including electron microscopy, fluorescence microscopy, Raman mapping, atomic force microscopy, thermal imaging, magnetic resonance imaging, and positron emission tomography, either in vitro, in vivo, or ex vivo. Toxicological aspects related to the use of nanodiamonds are also discussed. Finally, patents, preclinical and clinical trials based on the use of nanodiamonds for biomedical applications are reviewed.