First cell-patterning of primary, patient-derived mesenchymal glioblastoma brain cancer cells on parylene-C/SiO2 substrates.

The mesenchymal subtype of the WHO grade IV Glioblastoma (GBM) is the most common and lethal form of adult brain cancer, characterised by its rapid growth, invasiveness and colonisation. Current standard of care includes surgical resection, chemotherapy and radiotherapy. Despite this, mortality remains dismal with median patient survival of less than 15 months after treatment. For these reasons, the World Health Organisation (WHO) classifies GBM as an incurable disease. To address this challenge, the GBM scientific community are investigating new approaches to gain insights into GBM function and its communication mechanisms. These efforts aim to establish alternative therapies to slow or halt the infiltration of this aggressive cancer. In this article we demonstrate the variability between two adult patient-derived mesenchymal GBM brain cancer cell-lines and show how they can be patterned onto grid networks of biocompatible parylene-C on SiO2 substrates. Thus, providing a first step for GBM Ca2+ communication to be repeatedly and reliably studied. We determine the node size, node spacing and track length that provides the best cytoplasmic coverage of parylene-C for GBM brain cancer cells using five patterning indices, namely: the parylene-C adhesion index (PAI), SiO2 adhesion index (SAI), node nuclei index (NNI), grid quality index (GQI), and overall patterning index (OPI). In addition, we determine the best serum, cell seeding density and incubation period in vitro to encourage GBM cell patterning. We illustrate high fidelity of the patterned GBM brain cancer networks and to demonstrate cell functionality we show that the patterned GBM cells respond to ATP stimulus with Ca2+ transients. The significance of this work is that we provide a biomaterial platform that enables the detailed investigation of Ca2+ communication within GBM tumour networks. Such a platform may enable the GBM scientific community to test new therapeutics that target the Ca2+ signalling which is involved in the rapid infiltrative tumour growth, a property which currently makes treatment ineffective.