Cell Culture Module (CCM)
The Cell Culture Module is a completely automated cell culture facility designed specifically to aid in the study of microgravity effects at the cellular and embryonic levels. The entire hardware unit fits inside a Shuttle middeck locker. The system offers a variety of biological sample maintenance systems, variable temperature settings, options for media delivery and collection of conditioned media samples, and programmed additions of drugs, hormones, radioactive labels, and other experiment support features. The CCM can be reconfigured to meet specific scientific objectives.
+ Version Used During Space Shuttle Missions
Versions of this Hardware
Components of this Hardware
The cells used in the CCM hardware will usually be grown in a bioreactor cartridge. Bioreactor cartridges are inlaid with hollow fibers for media, gas, and the removal of waste products. Generally 4-6 cartridges are flown per experiment zone. Hollow fiber bioreactors allow for cell culture growth in three dimensions. Fiber pore size is variable to allow for different cell growth rates. Fiberless cartridges are also available for culturing larger pieces of tissue. (Specimens can be mounted on screens, cover slips, or agar surfaces instead of hollow fibers.) All cartridges can be modified to fit a variety of configurations and specimens. If required, the cartridge can be coated with cell growth and attachment factors.
In most cases the CCM will be programmed to maintain a constant 37°C environment, but it is possible to hold all samples within an experiment zone at one temperature between 32-39°C, and adjust the temperature on-orbit. The CCM-C configuration is capable of providing a limited amount of 4°C refrigerated space.
Nutrients and gas are provided to the growing cells via a closed-loop flowpath. The one-way flow of liquid has two different nutrient delivery options. The recirculating flow path option directs media flow through the media bag, oxygenator, pump, biochamber, and back to the media bag, allowing growth factors and other products to accumulate. An intermittent feed option periodically pumps fresh media into a short-flow path that recirculates in the same manner as the first option, but the media is eventually diverted to a sump and replaced with fresh media.
The injection system can be used to expose the samples to stimulants, drugs, hormones, chemical labels, and/or fixatives. Injections can be paired with media collections to test various experiment parameters.
Media fraction collection allows for the testing of media at a certain point for the presence or absence of a particular media component, metabolite, or cell product.
Biological Ion Analysis in the Cell Culture Module (BIONA-C)
The BIONA-C is a pH and CO2 monitoring system designed to integrate with the CCM. Along with the ion-selective sensors, the BIONA-C has a measurement, control, and data acquisition system that is integrated with a standard CCM rail. In order to minimize the complexity of control software, the BIONA-C rail was designed to operate as a stand-alone system.
The BIONA-C system consists of a custom-designed fluid path sensor manifold board, data acquisition and storage module, and programmable control electronics to operate the pumps and valves of the fluidics system. The sensor manifold board houses the ion-selective sensors (pH, CO2), temperature sensor, and onboard signal-conditioning electronics.
The BIONA-C rail assembly contains four independent fluid paths that circulate media to support cell growth. Each fluid path flows through a separate bioreactor where fluids can transfer across a permeable membrane to the cell culture but cells cannot enter the fluid path. The sensors are housed in sensor arrays, which are a composition of four ion selective sensors and one temperature sensor. The sensors are sealed in PVC housing with the tips of the sensors in vivo. In two of the fluid paths the sensor arrays are directly in the circulating media path taking constant measurements of the media. Calibration readings of these in-line sensors are only taken before and after flight. For the other two fluid paths, a precision pump periodically transfers media samples from the circulating media path to the sensor. Between media sample readings, calibration fluid is pumped through the sensor array giving a calibration reference for all the sensors real time. Fluid discharged from the sensor arrays goes to a waste sump.
Two of the fluid paths have fresh media feeds once or twice a day, while the other two paths begin with enough media in the circulating path for the entire experiment. All paths have waste sumps so that fluid volumes in the media circulation paths can be matched throughout the experiment.
When operating, the rail maintains the temperature of the bioreactor and oxygenator assembly at 37 °C. The BIONA-C requires only power and ambient environmental conditioning from the CCM host unit.