CAR T-Cells

The relatively novel cancer treatment, CAR T-Cells, has recently increased in popularity due to promising results in new therapies for medical treatment. The reason why is CAR T therapies offer a different approach from chemo; they use the body’s immune system to locate and kill affected cells allowing patients to avoid hair loss, anemia, fertility difficulties, etc., which generally come with chemotherapy. CAR T-Cells are created by altering the patient’s T Cells to target cancer cells, then cultivated before they are returned to the patient. A failure to develop a patient’s CAR T-Cells will make them resort to chemotherapy to treat their cancer. These cells are sensitive and require a stable environment to ensure their efficacy for patients. This is why monitoring the equipment and environmental conditions is essential.

Many important pieces of equipment are involved in the manufacturing of CAR T-Cells, all of which must be monitored to ensure quality, safety, and accuracy. A key piece of equipment for cultivating CAR T-Cells is a bioreactor. Bioreactors provide a controlled environment for CAR T-Cells, and it is important to monitor various parameters within to ensure the optimal growth and function of the cells. Once grown, it’s important to store them in appropriate conditions to preserve viability and function. At this point, they are typically stored in refrigerators or cryopreservation, depending on how long they will be in storage.

Overall, it is essential to carefully monitor these types of equipment and environmental conditions throughout the manufacturing process to ensure the stability and efficacy of T cells for patients. We’ll discuss these key devices in greater detail below.

Bioreactors

CAR T-Cells are mostly cultured in bioreactors, which provide a controlled environment that supports the optimal growth and function of the cells. It is important to carefully monitor the conditions within the bioreactor, as deviations from the ideal range can cause damage or death to the cells. Some critical parameters to monitor in your bioreactor include:

Temperature: When growing CAR T, the temperature is essential to monitor. For these types of cells, the temperature should be controlled near 37° C, the body’s normal temperature.

pH: The pH of the cell culture media in the bioreactor should be kept within a narrow range that is optimal for the growth and function of the CAR T-Cells. This may vary depending on the specific requirements of the cells, but a pH of around 7.2-7.4 is generally considered optimal for most cells. To ensure you’re generating accurate readings for your bioreactor, it’s best to monitor parameters that directly impact the pH levels, such as CO₂/O₂ levels.

CO₂/O₂: Bioreactors have pH alarms installed, but because factors like sensor age, temperature, and CO₂ degassing can influence these measurements, another way to ensure stable pH levels is by measuring CO₂ and O₂ concentrations. This is where an environmental monitoring system, such as XiltriX, can assist in monitoring. If the pH is too low (below 7.2), the CO₂ concentration can be reduced, and O₂ concentration increased. If the pH is too high (above 7.4), the CO₂ can be increased, and O₂ reduced.

Dissolved Oxygen: Dissolved Oxygen (DO) is critical to monitor within bioreactors to provide insight and alerts as to when air and O₂ should be supplemented. The optimal DO level for the growth of CAR T-Cells will depend on the specific requirements of the cells and the type of bioreactor being used.

Nutrient concentrations: The concentrations of nutrients, such as amino acids, sugars, and vitamins, in the cell culture media should be carefully controlled to ensure that the T cells have sufficient resources to grow and divide.

Agitation: All bioreactors will include an agitator, or an impeller, to continuously stir contents within, and it is significant for cultivating CAR T-Cells to provide consistent access to nutrients within. The impeller generates an efficient mixture between temperature, oxygen, and pH to maximize growth efficacy of the cells. The speed of the impeller in the bioreactor should be carefully controlled to ensure that the cells are not subjected to excessive shear forces, which can damage them.

Other Monitoring Options to Consider for your Bioreactor:

Light Intensity: In general, it is not typically necessary to monitor light intensity during the growth of CAR T-Cells in bioreactors. However, it is generally recommended to avoid exposing cells to direct sunlight or strong artificial light, as this can damage the cells and affect their growth and function. If using a bioreactor with a transparent vessel or culture media that is sensitive to light, it may be necessary to protect the cells from light exposure by using a light-tight container or by shading the vessel with a light-blocking material.

Dry Contacts: A simple alarm that does two things: it detects if a condition has gone out of parameters, and it triggers an alarm in response. Dry contacts don’t supply data on the cause of an alarm; they just alert you when a condition breaches its set limits. For most bioreactors, there is a general alarm to alert you of any parameter being out of limits. Many bioreactors offer multiple dry contacts to cover each of the parameters discussed above.

When selecting your bioreactor, it is important to speak with your vendor about the options of connecting a remote environmental monitoring system, like XiltriX, to the device. All bioreactors will come with a built-in monitoring system and localized alarms, but in an ideal world, all critical parameter data is captured in a single system that allows for remote monitoring and notifications.

Any deviations within these conditions can prevent cells from growing, making monitoring essential for success. Once the cells have finished being cultivated, they are stored in cold storage before the patient can receive them.

Short-Term & Long-Term Storage Techniques for CAR T-Cells

After being grown in a bioreactor, CAR T-Cells should be stored under conditions that will preserve their viability and function. The specific storage conditions will depend on the specific requirements of the cells and their intended uses; however, we’ve included some commonly accepted best practices below for your reference. Here are some general guidelines to follow for short-term storage of CAR T-Cells:

1. Temperature: CAR T-Cells should be stored at a temperature of around 2°C to 8°C, which is the temperature range of a standard laboratory refrigerator. Many labs use residential-grade refrigerators, and they should use industrial refrigerators with a fan to optimize temperature. Storing the cells at a temperature that is too high or too low can damage the cells and reduce their viability and function. While many labs opt to use display screen data for their monitoring, it’s important to have an independent monitoring system, such as XiltriX, to provide the most reliable data in a single dashboard.

2. Humidity: The relative humidity of the storage environment should be kept at around 50-70% to ensure that the cells are not exposed to excessively dry or humid conditions.

3. Light: It is generally recommended to avoid exposing CAR T-Cells to direct sunlight or strong artificial light, as this can damage the cells. If storing the cells in a transparent container, it may be necessary to protect the cells from light exposure by using a light-tight container or by shading the fridge with a light-blocking material.

4. Contamination: It is important to store the CAR T-Cells in a clean environment to minimize the risk of contamination. The storage container should be carefully cleaned and sterilized before use, and the cells should be handled using sterile techniques to minimize the risk of contamination.

If you require long-term storage or shipment of the CAR T-Cells, best practice cryopreservation techniques should be followed to ensure higher viability and metabolic activity after being thawed.

Here are some general guidelines to follow for long-term storage and shipping of CAR T-Cells:

Preparation: Before freezing the cells, it is important to carefully prepare the cells and the freezing medium. The cells should be washed and suspended in a freezing medium, such as a cryopreservation medium, that contains a combination of sugars and other compounds that will protect the cells from damage during freezing.

Cooling rate: The cells should be cooled slowly to minimize the risk of damage. This can be done by placing the cells in a cooling bath or by using a controlled-rate freezer.

Container: The cells should be placed in a cryogenic container, such as a cryovial or cryobag, that is designed for storing cells at low temperatures. The container should be carefully sealed to prevent contamination and leakage.

Storage temperature: The frozen cells should be stored at a temperature of around -190°C, which is the temperature of a liquid nitrogen freezer. This will help to preserve the viability and function of the cells for long periods of time.

Thawing: When the cells are needed, they should be carefully thawed using a controlled-rate thawing process to minimize the risk of damage. The cells should be placed in a water bath or incubator at a temperature of around 37°C until they are fully thawed. A good environmental monitoring system can alert when the temperature is stable to start thawing, or if there is a deviation during the process.

Overall, freezing CAR T-Cells for long-term storage or shipping requires careful preparation and handling to ensure that the cells are preserved and remain viable and functional after thawing.

In addition to the storage conditions we reviewed above, here are a few other parameters you should monitor to ensure proper storage of CAR T-Cells after production:

Door Openings: For cold storage units, monitoring door openings provides essential data that can minimize temperature excursions and help track how often people are going in and out of the unit. The data it provides is invaluable in reporting and analysis.

Backup Power Supplies: Loss of power in electrical equipment has the potential to destroy cells without proper preparation. You’ll need a real-time, continuous monitoring system that alerts you promptly in the event of a power outage so you can protect cells from being damaged or destroyed.

With the sensitivity of the samples, it’s vital to ensure complete visibility of what’s happened throughout its short lifespan. To gain this level of visibility, you need an environmental monitoring system that can monitor all of these critical parameters in a single, easy-to-use dashboard.

Ensuring Stability with an Environmental Monitoring System (EMS)

CAR T-Cell therapy is a type of cancer treatment that involves modifying a patient's T-Cells to recognize and target cancer cells. Bioreactors provide a controlled environment for the cultivation of cells, and it is important to monitor various parameters, such as temperature, pH, CO₂/O₂ levels, dissolved oxygen, nutrient concentrations, and agitation, to ensure the optimal growth and function of the cells. Other factors, such as light intensity and dry contacts, may also need to be considered depending on the specific requirements of the cells and the type of bioreactor being used. Overall, it is important to carefully monitor the equipment and environmental conditions throughout the manufacturing process to ensure the stability and efficacy of CAR T-Cells for patients.

Throughout the process of growing CAR T-Cells, an integrated environmental monitoring system (EMS), like XiltriX, can capture the necessary data on equipment stability and environmental conditions that influence process outcomes. Operators should use this data and real-time alerts to make necessary adjustments throughout the process to preserve the integrity of the CAR T-Cells.

The data captured must be stored in a 21 CFR Part 11 compliant system that also offers an easy-to-view format that can be quickly accessed in an audit or for statistical analysis. Integrating your EMS with your bioreactor may require customization, so it is important to speak with both vendors about integration possibilities and associated costs to ensure they will both satisfy your needs.

Growing CAR T-Cells can be a long and demanding process due to sample sensitivity, but the amount of lives saved by this treatment makes the journey all worth it. In addition, losing cells to freezer failure or conditions going out of range is easily preventable as long as you have the right equipment, system, and support to empower your staff.

With 30+ years of monitoring experience, XiltriX North America can help ensure a constant and stable environment for your CAR T-Cells. This, in turn, can help increase their chances of survival. To learn more about how XiltriX offers complete insight throughout your manufacturing life cycle, schedule a free lab consultation with one of our experts to learn more.