Treatment of glioblastoma spheroids with engineered monocytes in a blood-brain barrier microfluidic device

The blood-brain barrier (BBB) represents a selective barrier to the passage of macronutrients to the thinking organ, allowing only the passage of the molecules necessary for the maintenance of the central nervous system (CNS). The barrier is made up of endothelial cells, astrocytes and pericytes and provides resistance to the passage of toxic or harmful substances for the cerebral system. The limited permeability also prevents the free passage of drugs needed to treat cancers such as glioblastoma. The advancement of microfluidic science has generated the possibility of reproducing the BBB in vitro. The goal of this project is the realization of a microfluidic chip that is validated and the implementation of a curative system against glioblastoma that is permeable to the BBB. The device developed in this project is composed of two layers of PDMS separated by a PETE membrane with a porosity of 3 μm and which are glued together by plasma treatment. The treatment generates a chip that is hydraulically sealed. Both the top and bottom layers are equipped with inlet and outlet that allow for proper blood outflow. The two layers share a central area represented by the BBB where the exchange of matter takes place. The lower layer is also equipped with 3 microwells on which the tumor mass will be deposited. Through the leak and permeability assays it was possible to validate the chip as representative of the in vivo blood-brain model. Now the focus is shifted towards studying a curative model for cancer. In particular, the use of spheroidal structures allows to represent the tumor mass very well in vivo. The Live&Dead and ImmunoFluorescence assays demonstrated a high affinity of tumor masses in vitro with those in vivo. The implementation of microwells within the microfluidic device paved the way for the search for a selective curative system for glioblastoma. The use of monocytic TSP-1 and monocytic lines engineered through the uptake of herper simplex or HSV-1 oncolytic viruses led to excellent permeability results of engineered and non-engineered complexes within the tumor mass. Continuous monitoring and images taken in fluorescence fields open an avenue for validation of the curative model.