Fig. 1

Microfluidic devices validation. a – b Conventional photolithography techniques were used to create the microfluidic devices with precise and specific dimensions. Scale bars = 100 μM. c Scheme of the microfluidic devices dimensions (left). Profilometry was performed to confirm the microchannels dimensions (right). d Sensory neurons (SNs) derived from rat dorsal root ganglia were seeded in the central compartment of the devices. Rat bone marrow derived endothelial cells (ECs) were cultivated in the lateral compartments. After 4 days of culture, cells were fixed and stained with β-III tubulin (SNs in green) and phalloidin (ECs in red). The neurites emitted by the sensory neurons were able to cross the microchannels and go from the central compartment to the lateral ones (white arrowheads) where they closely interact with endothelial cells. Scale bar = 100 μm. e Transmission Electron Microscopy was performed to confirm this close interaction and showed vesicles in ECs (black arrowheads). Scale bar = 100 nm