We report on the preparation and stereolithographic 3D printing of a resin based on the composite between a poly(ethylene glycol) diacrylate (PEGDA) host matrix and a poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) filler, and the related cumulative volatile organic compounds’ (VOCs) adsorbent properties. The control of all the steps for resin preparation and printing through morphological (SEM), structural (Raman spectroscopy) and functional (I/V measurements) characterizations allowed us to obtain conductive 3D objects of complex and reproducible geometry. These systems can interact with chemical vapors in the long term by providing a consistent and detectable variation of their structural and conductive characteristics. The materials and the manufacture protocol here reported thus propose an innovative and versatile technology for VOCs monitoring systems based on cumulative adsorption effects.

The isolation and analysis of circulating biomarkers, the main concern of liquid biopsy, could greatly benefit from microfluidics. Microfluidics has indeed the huge potentiality to bring liquid biopsy into the clinical practice. Here, two polydimethylsiloxane (PDMS)-based microdevices are presented as valid tools for capturing microRNAs biomarkers from clinically-relevant samples. After an extensive study of functionalized polydimethylsiloxane (PDMS) properties in adsorbing/eluting microRNAs, the best conditions were transferred to the microdevices, which were thoroughly characterized. The channels morphology and chemical composition were measured, and parameters for the automation of measures were setup. The best working conditions were then used with microdevices, which were proven to capture microRNAs on all channel surfaces. Finally, microfluidic devices were successfully validated via real-time PCR for the detection of a pool of microRNAs related to non-small cell lung cancer, selected as proof-of-principle. The microfluidic approach described here will allow a step forward towards the realization of an efficient microdevice, possibly automated and integrated into a microfluidic lab-on-a-chip with high analytical potentialities.

The human nigrostriatal pathway, comprising dopaminergic neurons in the ventral midbrain that project to the dorsolateral striatum, is essential for motor control and selectively vulnerable in Parkinson’s disease. How this circuit assembles during human development remains poorly understood, and in vitro models capturing its long-range connectivity and spatial organization have been lacking. Here, we establish a compartmentalized, human stem cell-based model of the nigrostriatal pathway by integrating ventral midbrain and striatal organoids within a custom-engineered microfluidic device that confines cell bodies while guiding axonal growth to recapitulate key aspects of in vivo topography. Functional connectivity was confirmed by retrograde rabies tracing, and optogenetic and pharmacological stimulation. Single-nucleus transcriptomic analysis reveals that axonal target engagement with spatially separated striatal neurons promotes maturation of human dopaminergic neurons and activates transcriptional programs associated with neurotransmitter secretion. Our study establishes a biologically relevant in vitro system for investigating how long-range connectivity regulates neuronal assembly in the nigrostriatal circuit and for modelling key pathological features of Parkinson’s disease.