Abstract 6495: Development of a drug screening platform of glioblastoma utilizing microgel encapsulation
Authors: Brittany A. Payan, Annika Carrillo Diaz de Leon, Tejasvi Anand, Gunnar B. Thompson, Brendan A. C. Harley
Journal: Cancer Research (2025)

Abstract Background. We report a method to encapsulate glioblastoma (GBM) cells in maleimide-functionalized gelatin (GelMAL) microparticles for in vitro drug screening. GBM is the most common primary malignant brain tumor. Standard of care is surgical resection followed by treatment with the alkylating agent temozolomide (TMZ). GBM cells that evade surgery eventually become resistant to TMZ and lead to recurrence of tumors in patients. Hydrogels have been implemented as matrices for 3D culture that can recapitulate tumor biology and tumor microenvironment. However, bulk hydrogels require large numbers of cells per construct and possess inherent diffusional limits. With only four drugs currently FDA-approved for GBM treatment, there is a need for a platform capable of accelerating the identification of new therapies in a highly controlled and physiologically relevant environment. Hydrogel microparticles allow encapsulation of GBM cells in a tailorable 3D matrix, rapid diffusion to limit spatial hypoxia gradients, and ease of handling for high-throughput screens (HTS). Methods. U87MG cells are encapsulated in GelMAL microparticles using a flow-focusing microfluidic device. Viability and proliferation of GBM cells is assessed via LIVE/DEAD cell imaging kit and double stranded DNA (dsDNA) quantification, respectively. We record a response from encapsulated cells after TMZ exposure (0-1000 µM) via cellular activity using alamarBlue. Results. Cellular viability within microfluidic emulsion is limited by shear forces exhibited in the microfluidic device. Here, we report a method to encapsulate GBM cells in microgels and retain cellular viability. Increasing levels of dsDNA suggest maintenance of cellular health in microgels and indicate a proliferative population of encapsulated cells. Metabolic profile of encapsulated cells shows a decrease in cellular activity in response to increasing concentrations of TMZ, concurrent with 2D and bulk hydrogel culture. Ongoing experiments will assess cellular behavior post-movement by liquid handler of encapsulated cells to establish a drug screening platform amenable for HTS. Conclusion. We have developed a method to reliably encapsulate GBM cells into GelMAL microgels while retaining viability. The recorded cellular activity of encapsulated cells in response to TMZ demonstrates the utilization of microgels as an in vitro drug screening platform. We will leverage this platform to examine drug response in vitro amenable for high-throughput screening to identify possible therapeutics for TMZ resistant tumors. Citation Format: Brittany A. Payan, Annika Carrillo Diaz de Leon, Tejasvi Anand, Gunnar B. Thompson, Brendan A. C. Harley. Development of a drug screening platform of glioblastoma utilizing microgel encapsulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6495.