A New Label-Free Approach to Glioblastoma Cancer Stem Cell sorting and detection.

Cancer stem cells (CSCs) play critical roles in cancer, making them important targets for new diagnostic and therapeutic approaches. Since CSCs are heterogeneous and not abundant in tumors, and few specific markers for these cells currently exist, new methods to isolate and characterize them are required. To address this issue, we developed a new label-free methodology to isolate, enrich, and identify CSCs from an heterogeneous tumor cell subpopulation using a cell sorting method (Sedimentation Field Flow Fractionation, SdFFF) and a biosensor as a detector. Enrichment was optimized using an original protocol and U87-MG glioblastoma cells cultured in Normal (N) or Defined (D) medium (± Fetal Bovine Serum, FBS) under Normoxic (N, pO2 = 20%) or Hypoxic (H, pO2< 2%) conditions to obtain four cell populations: NN, NH, DN, and DH. After elution of CSCs via SdFFF using the hyperlayer mode (inertial elution mode for micron-sized species), we isolated eight subpopulations with distinct CSC contents based on phenot...