Brief Description
We have developed a process to 3D-print hydrogels that can be spatially patterned with peptide motifs to anchor vascularized organoids and facilitate intraluminal perfusion: providing a bridge between traditional chip-based models and tissue specific organoids.
Problem
Organoids are generally cultured in rocker environments or other dynamic suspension culture systems that facilitate a level of nutrient and oxygen delivery that supports viability, but these approaches cannot mimic the mechanical and biochemical cues exerted by intraluminal perfusion. Although advances in organoid vascularization have resulted in the formation of physiological vascular architecture, the lack of flow within these structures limits their ability to mimic tissue vasculature. Moreover, lack of intraluminal perfusion prevents accurate studies of drug transport, specifically in the context of brain tissue where the blood-brain barrier forms a selective impasse from blood into surrounding tissue.
Solution
Our photoink was used to print a channel with a funnel geometry (1) designed to trap an organoid (2) and facilitate interstitial fluid flow using a Vitroscope (Trondheim, Norway) flow chamber (3).
Technology
Application of interstitial fluid at a flow rate exerting velocities ranging from 5 - 20 micron/s for four days resulted in remodeling of organoid vasculature that facilitated intraluminal perfusion, as evidenced by perfusion with 2-micron fluorescent beads. At the end of the four-day perfusion period, TRITC-labeled polystyrene beads were added to the flow reservoir and perfused into the funnel. Bead velocities were calculated using particle image velocimetry and shown in Figure 3.
Advantages
Combined benefits of chip-based microfluidic in vitro models and tissue specific organoids paves the way for a sustainable alternative to animal testing.
Stage of Development