# Ex Vivo Organotypic Brain Slice Models for Glioblastoma: A Systematic Review

## TL;DR

This paper reviews how brain slice models can help study glioblastoma, a deadly brain cancer, by preserving brain structure and testing treatments more effectively than traditional models.

## Contribution

The paper systematically reviews the use of ex vivo brain slice models for glioblastoma, highlighting their strengths and the need for standardized protocols.

## Key findings

- Ex vivo brain slices effectively model glioblastoma invasion and drug response.
- Methodological differences across studies limit reproducibility and comparison.
- These models show potential for precision oncology but require standardization.

## Abstract

Glioblastoma is considered the most aggressive primary brain tumour and despite advances in surgery, radiotherapy and chemotherapy prognosis remains dire. Preclinical models play a fundamental role in understanding glioblastoma biology and testing novel therapeutic strategies, however both in vitro and in vivo models present important limitations. Ex vivo organotypic brain slice cultures allow the preservation of native brain structure and key microenvironmental features, providing a valuable intermediate platform between cell cultures and animal models. In this systematic review, we summarise and critically analyse the application of ex vivo organotypic brain slice models in glioblastoma research. Moreover, we highlight their main experimental applications, methodological heterogeneity and intrinsic limitations, with particular attention to translational relevance and standardisation challenges. This work aims to provide researchers with a clear framework to understand existing studies and to support the rational design of future ex vivo glioblastoma models.

Background/Objective: This systematic review aims to evaluate ex vivo brain slice models in glioblastoma (GBM) research, with a specific focus on tumour invasion, tumour–microenvironment interactions, and therapeutic response. Methods: A systematic search looking for studies employing ex vivo organotypic brain slice models in GBM research was conducted across multiple databases (January 2010–July 2025) in accordance with PRISMA guidelines. The study was registered in PROSPERO database (CRD420251138341). Inclusion criteria encompassed patient-derived brain slices, hybrid rodent–human slice co-cultures, and microfluidic-integrated ex vivo platforms designed to assess tumour invasion, microenvironmental interactions and therapeutic responses. Exclusion criteria included reviews, abstracts, conference proceedings, in vivo-only studies, purely in vitro models without organotypic integration, and studies not focused on GBM. Results: Twenty-six studies met the inclusion criteria. Among these, 18/26 (69%) investigated GBM invasion, 18/26 (69%) evaluated therapeutic responses, and 5/26 (19%) examined tumour–microenvironment interactions, with several studies spanning multiple domains. Across platforms, organotypic slices consistently recapitulated key features of GBM biology—including perivascular and white-matter-aligned invasion, stromal–immune interactions, and patient-specific drug sensitivity—while engineered systems enhanced perfusion and exposure control. Methodological variability, particularly regarding slice preparation, oxygenation and viability assessment, limits direct comparability between studies. Conclusions: Organotypic brain slice models represent an extremely relevant tool for translational investigations of GBM biology and treatment response. However, substantial methodological heterogeneity together with limited standardisation hamper reproducibility and cross-study validation. Future work should focus on enhancing reproducibility and harmonising protocols to support the development of clinically meaningful precision oncology strategies.