Impact of fiber orientation in electrospun PLA scaffolds on fluid dynamics in a custom microfluidic device

Organ-on-Chip systems are evolving as vital tools in biomedical research, proposing advanced platforms to replicate human tissue microenvironments for drug testing and disease modeling. This study examines how the orientation of polylactic acid (PLA) fibers influences fluid movement in a custom Organ-on-Chip setup. PLA scaffolds were fabricated via electrospinning with either random or aligned fiber orientations. Scanning electron microscopy (SEM) revealed that random scaffolds were 70 µm thick with fibers measuring 1.12 µm, while aligned scaffolds were thinner at 35 µm with fibers of 1.02 µm. Porosity and matrix structure were analyzed to understand the impact of fiber arrangement. Liquid water permeability was tested using a custom 3D-printed device conforming to ISO 7198:2016 standards. Computational fluid dynamics (CFD) simulations, employing the Porous Media Flow Module and Brinkman's equations, predicted flow behavior based on scaffold morphology. A dual-chamber microfluidic chip integrated with pressure sensors allowed real-time measurements to validate the simulations. Results demonstrated that fiber alignment significantly altered scaffold permeability and flow dynamics. These insights are valuable for tissue engineering, offering a validated framework to design microfluidic devices with tailored fluidic environments optimized for specific scaffold architectures.