Advancing micro-vessel models for high-throughput pre-clinical drug screening and physiological disease modelling

Abstract

Conventional pre-clinical drug screening, reliant on 2D cell cultures and animal studies, faces challenges—the former lacks biological complexity, and the latter lacks predictability due to differences between animals and humans from genetic to functional levels. Organ-on-chip technologies have evolved to bridge the gap between preclinical and clinical trials, necessitating human cells for precise predictions of human responses. Considering the significance of the vascular system in various diseases, incorporating vascular units into organ-on-chip devices is critical. For effective drug discovery using vessels-on-chips, achieving high-throughput and consistency between samples is crucial. However, many vessels-on-chips are manually handled during preparation and data collection, reducing throughput and increasing sample-to-sample variations. The conventional closed microfluidic chip format further impedes accessibility, hindering automation. This thesis focuses on two high-throughput micro-vessel models replicating vascular functions under perfusion in a 384-well plate format. These open-top models allow automated preparation and examination, enhancing efficiency in compound screening. The first model features a self-assembled perfusable micro-vascular network on a 384-well plate, co-culturing endothelial cells (EC) with stromal cells in a hydrogel. Automated using a robotic system and a fluorescent plate reader, it supports organ-specific functions and enables nanoparticle transport to target tissues. Utilized for testing cancer therapeutic drugs, it demonstrates dose-related responses in vascular permeability and architectures. The second model is dedicated to crafting micro-vessels of consistent quality for biological testing and disease modeling. It employs a sacrificial material for pre-designed tubular shapes for EC seeding. The integration of automated processes and a straight channel design minimizes sample discrepancies. Furthermore, a tri-culture system enhances barrier integrity, enabling effective drug screening that distinguishes between vasculotoxic and non-vasculotoxic agents with notable sensitivity and specificity. Looking ahead, there is potential to further refine these models to encompass a broader range of vascular diseases, which could lead to novel insights and therapeutic targets.