In vitro co-culture model of medulloblastoma and human neural stem cells for drug delivery assessment

Physiologically relevant in vitro models can serve as biological analytical platforms for testing novel treatments and drug delivery systems. We describe the first steps in the development of a 3D human brain tumour co-culture model that includes the interplay between normal and tumour tissue along with nutrient gradients, cell-cell and cell-matrix interactions. The human medulloblastoma cell line 1iW228-3 and human foetal brain tissue were marked with two supravital fluorescent dyes (CDCFDASE, Celltrace Violet) and cultured together in ultra-low attachment 96-well plates to form reproducible single coculture spheroids (d = 600 pm, CV% = 10%). Spheroids were treated with model cytotoxic drug etoposide (0.3-100 p,M) and the viability of normal and tumour tissue quantified separately using flow cytometry and multiphoton microscopy. Etopo side levels of 10 p,M were found to maximise toxicity to tumours ( 6.5% viability) while stem cells maintained a surviving fraction of 40%. The flexible cell marking procedure and high-throughput compatible protocol make this platform highly transferable to other cell types, primary tissues and personalised screening programs. The model's key anticipated use is for screening and assessment of drug delivery strategies to target brain tumours, and is ready for further developments, e.g. differentiation of stem cells to a range of cell types and more extensive biological validation. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.