Hvita system is an opening platform for perfusion culture. The system can be used widely in live cell perfusion culture areas.
Configuration of 3D live cell perfusion system
The system is composed of controller and culture chamber. The controller can carry at most four culture chambers one time. There are four key functional parts. The four parts are temperature control module, gas control module, fluid control module, and system control software module. Both the temperature and the gas concentration are controlled in high accuracy with a PID fuzzy logic algorithm, which make sure the system can keep a stable growth environment. The fluid control module is formed of six independent peristaltic pumps. The flow rates can be controlled from 1μL/min to 7 mL/min, compatible with low to high-speed liquid exchange. The system operation can be controlled through the system software. Operators can set perfusion programs to control the running time and flow rate of the pumps. The software is compliance with GMP traceable requirement. The system operating parameters such as temperature, gas concentration and flow rate can be monitored and recorded for tracking the system status in real-time. Remote monitoring is allowed by using another software installed in personal computer.
Organoid Factory chip (the left vessel) designed for organoid perfusion culture. The chip is connected with a reservoir (the right vessel) through silicon tubes. The silicon tubes can be mounted onto peristaltic pumps. The peristaltic pumps drive medium from reservoirs through tubes to Organoid Factory chips. The chip is divided into a cell seeding area and a medium perfusion area by two pieces of vertical setting microporous membrane. The cell seeding area is surrounded by membranes, and the medium perfusion area is outside the membrane surrounded area. Medium changing Both cell seeding area and medium perfusion area have inlets and outlets. Therefore, medium changing or perfusion operation do not disrupt the growth of cells protected by membrane. More over the porous membrane ensures that medium can exchange from outside in.
Beneficial of 3D live cell perfusion system in organoid culture
Effect of perfusion culture on organoids growth. AO/PI staining shows that statically cultured organoids in plates have more dead cells inside than perfusion culture organoids. Also, organoids cultured dynamically in Hvita system showed higher vitality than those in plate. Organoid growth is in relation with the perfusion rate. The system opens a platform for screening organoids expansion process. The effect of seeding density on organoids vitality was studied. For all the seeding densities (150, 300, 450, 600 organoids per 100 mL), the Hvita group showed higher vitality than plate group. The vitality kept increasing with the seeding density. However, due to limited nutrient transfer rate the vitality cultured in plates showed a climb-up-then-decline trend.
Effect of perfusion culture on organoids apoptosis and phenotype
Compared to organoids in plates, Hvita system got higher live ratio and lower necrosis level. More dead cells in Hvita system tend to commit programmed apoptosis instead of passive cell death. Five marker genes of liver cancer were tested by qPCR. All the fives genes showed higher expression level in Hvita system than in plate, which means the system is benefit for stem cells in organoids differentiating into target phenotype.
Establishing Organs-on-chip model on Hvita perfusion culture platform
Hvita opens a platform for all kinds of perfusion culture, including microfluidics chips which are widely used in establishing organs-on-chip models. Chips can be adapted to silicon tubes through tips and luer tapers. By mounting the silicon tubes on the peristaltic pumps, the microfluidics chips can work inside the Hvita perfusion culture system.
