ME-20 * CULTURE OF HUMAN GBM CELLS ON ECM-MIMICKING CHITOSAN-HYALURONIC ACID SCAFFOLDS INCREASES MALIGNANCY AND DRUG RESISTANCE

Abstract

Glioblastoma multiforme (GBM) is the most aggressive and deadly malignant primary brain tumor in humans. Development of therapeutics requires extensive screening; however, many therapeutics evaluated with 2D in vitro cultures does not translate well to similar in vivo studies and suffer from lower efficacy in patients. Replicating the in vivo tumor microenvironment in vitro with three-dimensional (3D) porous scaffolds offers the possibility of generating more predictive pre-clinical models to enhance GBM treatment efficacy. In this regard, we developed a chitosan and hyaluronic acid (C-HA) polyelectrolyte complex 3D porous scaffold to mimic the physical and chemical structure of the GBM microenvironment. C-HA scaffolds indicated a highly porous network and limited swelling. The scaffolds had a Young's modulus in the wet state that closely matches the stiffness of native brain. FTIR spectra suggested the formation of a C-HA polyelectrolyte complex due to the ionic interaction between the two polymer components. C-HA scaffold cultures promoted tumor spheroid formation and the overexpression of GBM stem cell markers. Additionally, the invasiveness of GBM cells cultured in C-HA scaffolds was significantly enhanced compared to those grown in 2D cultures as determined by the Boyden chamber invasion assay. C-HA scaffold cultures were also more resistant to temozolomide and doxorubicin, which we found was caused by increased expression of the ABCG2 drug efflux transporter. These findings suggest that C-HA scaffolds provide an in vitro platform that better mimics the in vivo GBM tumor microenvironment ECM as compared to 2D surfaces due to their 3D structure and material composition resembling the native ECM. The C-HA scaffolds demonstrated that they are a viable in vitro platform for GBM evaluation, such as screening of cancer therapeutics, and potentially for other biomedical applications.