Cell-derived extracellular vesicles can be used as a biomarker reservoir for glioblastoma tumor subtyping

Glioblastoma (GBM) is one of the most aggressive solid tumors for which treatment options and biomarkers are limited. Small extracellular vesicles (sEVs) produced by both GBM and stromal cells are central in the inter-cellular communication that is taking place in the tumor bulk. As tumor sEVs are accessible in biofluids, recent reports have suggested that sEVs contain valuable biomarkers for GBM patient diagnosis and follow-up. The aim of the current study was to describe the protein content of sEVs produced by different GBM cell lines and patient-derived stem cells. Our results reveal that the content of the sEVs mirrors the phenotypic signature of the respective GBM cells, leading to the description of potential informative sEV-associated biomarkers for GBM subtyping, such as CD44. Overall, these data could assist future GBM in vitro studies and provide insights for the development of new diagnostic and therapeutic methods as well as personalized treatment strategies

Noncircular refractive index profile and breakdown of mode degeneracy of vertical cavity surface emitting lasers

Spatially and spectrally resolved near-field images of the transverse mode patterns of vertical cavity surface emitting lasers (VCSELs) are obtained by confocal microscopy with optical spectrum analyzer. A non-circular internal effective index profile of the VCSEL is inferred from the observed wavelength splitting of the degenerated modes. Using the mode intensity patterns associated with their spectral information, an elliptical parabolic profile superposed to a step-like refractive index profile is extracted by fitting the internal structural parameters of VCSEL. Wavelength splitting of the degenerated ${\rm LG} 01 modes is calculated from the fitting results, and is found to be in reasonable accord with our experiment results. © 2012 IEEE