From the Operating Room to the Laboratory: Role of the Neuroscience Tissue Biorepository in the Clinical, Translational, and Basic Science Research Pipeline

Recent Developments in Glioblastoma-On-A-Chip for Advanced Drug Screening Applications

Glioblastoma (GBM) is an aggressive form of cancer, comprising ≈80% of malignant brain tumors. However, there are no effective treatments for GBM due to its heterogeneity and the presence of the blood-brain barrier (BBB), which restricts the delivery of therapeutics to the brain. Despite in vitro models contributing to the understanding of GBM, conventional 2D models oversimplify the complex tumor microenvironment. Organ-on-a-chip (OoC) models have emerged as promising platforms that recapitulate human tissue physiology, enabling disease modeling, drug screening, and personalized medicine. There is a sudden increase in GBM-on-a-chip models that can significantly advance the knowledge of GBM etiology and revolutionize drug development by reducing animal testing and enhancing translation to the clinic. In this review, an overview of GBM-on-a-chip models and their applications is reported for drug screening and discussed current challenges and potential future directions for GBM-on-a-chip models.

Detection of IDH mutation in glioma by desorption electrospray ionization (DESI) tandem mass spectrometry

Desorption electrospray ionization (DESI) tandem mass spectrometry (MS) is used to assess mutation status of isocitrate dehydrogenase (IDH) in human gliomas. Due to the diffuse nature of gliomas, total gross resection is not normally achieved during surgery, leading to tumor recurrence. The mutation status of IDH has clinical significance due to better prognosis in IDH-mutant patients. The mutant IDH converts alpha-ketoglutaric acid (α-KG) into 2-hydroxyglutarate (2HG), which accumulates abnormally in cells. Immunohistochemical staining (IHC) and genetic testing, the gold standards, are incompatible with intraoperative applications but DESI tandem mass spectrometry (MS/MS) can be used to assess the mutation status of IDH enzyme from tissue intraoperatively. Here, on off-line evaluation is made of the performance of two different types of mass spectrometers in characterization of IDH mutation status. The intensity of 2HG is measured against glutamate (Glu), an intrinsic reference molecule, in both tandem MS measurements. In both cases using DESI clear separation between IDH-mutant (mut) and IDH-wildtype (wt) samples (p < 0.0001) is observed, despite the short analysis time. Due to the higher detection sensitivity, multiple reaction monitoring experiments using a triple quadrupole show slightly better performance compared to product ion MS/MS performed on a simple linear ion trap. Both DESI-MS platforms are capable of providing information on IDH mutation status, which might in future be used at the time of surgery to support decision-making on resection regions, especially at tumor margins.