Addressing the challenges of cell and gene therapy development
Cell and gene therapies (CGTs) are revolutionizing medicine by offering treatments for diseases that were once considered untreatable, such as B-cell acute lymphoblastic leukemia and type 1 diabetes. However, the success of these therapies depends on a complex development process that requires precision and control at every stage.
Variable cell culture conditions and manual workflows add strain to the already lengthy and costly development process. Certain cells and CGT products are highly sensitive to environmental changes. Even minor fluctuations in temperature, humidity, or gas concentration can affect cell viability and product integrity, leading to potential losses in time and resources. Manual processes further compromise consistency and reliability in CGT development. Traditional metabolic monitoring methods are labor-intensive, time-consuming, and increase the risk of contamination. Slow manufacturing timelines, low product yields, and high development and production costs—CGT development typically costs about five times more than traditional drugs—exacerbate these challenges, leaving little room for error.
To overcome these obstacles, scientists need advanced tools that provide control, precision, and reliability at every stage of development. Whether it’s maintaining optimal cell culture conditions, implementing continuous metabolic monitoring, or ensuring the stability of finished products, these technologies are crucial for preserving the integrity of CGTs.
Ensuring optimal conditions for CGT development
The sensitive stem cells and primary cells used in CGTs require precise replication of in vivo conditions for proper growth, differentiation, and gene expression. Standard CO2 incubators regulate temperature, humidity, and CO2 concentrations but are prone to disruption and lengthy recovery times after door openings. Each door opening introduces airborne contaminants and causes fluctuations in temperature, humidity, and gas levels, potentially stressing cells and compromising viability and reproducibility.
To achieve the necessary precision and consistency, labs rely on modern incubators with advanced features.
Temperature control system: Incubators must recover quickly from door openings. Direct heat systems recover faster but lack uniformity, while water jacket systems offer uniform heating and recover slowly. Innovations like direct heat and air jacket systems combine rapid recovery with even heating using additional heating elements and high-density foam insulation.
CO2 regulation: CO2 levels are controlled using thermal conductivity (TC) or infrared (IR) sensors. TC sensors are sensitive to temperature and humidity variations, affecting accuracy. IR sensors, which measure light absorption at specific wavelengths, are less affected by environmental changes but require periodic calibration. Dual-beam IR sensors enhance accuracy and reduce recovery times by using an extra filter for real-time auto-calibration.
Oxygen concentration: Standard CO2 incubators maintain atmospheric oxygen levels (around 20 percent), which can be problematic for cells adapted to hypoxic environments, such as stem cells. Prolonged exposure to atmospheric oxygen can lead to chromosomal abnormalities and inconsistent growth. Some incubators now include multi-gas control systems to precisely regulate both CO2 and O2, better replicating in vivo conditions.
Contamination control: Incubators use passive and active measures to prevent contamination. Passive measures include antimicrobial or germicidal interior surfaces, while active systems use vaporized hydrogen peroxide, UV light, and high-heat decontamination cycles to eliminate microorganisms.
By leveraging these advanced features, labs can create and maintain the ideal conditions for CGT development, ensuring the success and integrity of these therapies.
Monitoring metabolic activity
Cell metabolism is crucial for growth and differentiation, making it an essential indicator of cell health. Traditional manual methods involve periodically removing cells from the incubator to measure glucose and lactate levels. This disrupts culture conditions, risking cell growth and contamination. Additionally, these methods often use reagents or markers that render sampled cells unusable, depleting limited cell populations and increasing production costs. The intervals between measurements provide only a snapshot of metabolic activity, potentially obscuring subtle changes and leading to missed opportunities for optimization.
In-line monitoring systems: These innovative systems operate within incubators, enabling continuous glucose and lactate measurement without manual sampling. This reduces contamination risk and disturbance to cell cultures, as cells remain in the incubator, and preserves cells for further evaluation. The systems include a controller, electrochemical in-line sensors placed directly in the culture media, and a detector unit that provides real-time readouts. Unlike continuous sensors or near-infrared devices, electrochemical sensors allow simultaneous measurements of glucose uptake and lactate production, facilitating direct evaluation of changes in the glycolytic pathway of cells. Continuous in-line monitoring systems empower scientists to make proactive adjustments, optimizing culture conditions and enhancing outcomes.
Ensuring stability in CGT storage
To maintain their stability, CGT products must be stored at ultra-low (-40°C to -80°C) or cryogenic (-150°C and below) temperatures, depending on the specific product’s requirements. Reliable and stable cold storage solutions with narrow uniformity and consistency are essential for preserving product integrity.
iStock, Volodymyr Kalyniuk
Liquid nitrogen freezers: Traditionally, liquid nitrogen freezers have been used to preserve CGT products. However, they come with logistical and operational challenges. Beyond gas and delivery fees, hidden costs such as cylinder rentals and gas waste from off-gassing or differential pressure can accumulate. Supply chain disruptions, like delivery delays or shortages, pose risks since freezers cannot maintain required temperatures without a steady liquid nitrogen supply. Additional concerns include health and safety risks, contamination of submerged samples, uneven cooling in the vapor phase, and the energy-intensive nature of liquid nitrogen production.
Mechanical freezer technology: Advancements in mechanical freezer technology now allow these systems to achieve and maintain consistent ultra-low and cryogenic temperatures without the need for liquid nitrogen. These freezers offer a sustainable and cost-effective alternative for CGT applications. They use standard refrigeration cycles and refrigerants to provide uniform cooling throughout the chamber. Energy-efficient technologies help reduce operational costs and carbon footprints without compromising performance. Features such as dual cooling systems with independent refrigeration circuits provide redundancy, ensuring necessary temperatures are maintained even if one circuit fails. Integrated monitoring and predictive performance technology add further assurance by detecting potential failures and alerting users.
By leveraging these advanced mechanical freezers, labs can ensure the stability and integrity of CGT products, overcoming the limitations of traditional liquid nitrogen storage.
Driving innovation in CGT
PHC Corporation of North America has developed lab equipment tailored to support CGT workflows at every stage. Their CO2 and multi-gas incubators, equipped with dual-beam IR sensors and a direct heat and air jacket heating system, deliver precise environmental control to create uniform conditions that closely replicate in vivo environments. These incubators also incorporate passive and active contamination control methods. Passive decontamination is achieved in all models through inCu-saFe® interiors, which inhibit pathogen growth and provide the long-term durability that stainless steel offers. Active methods include the SafeCell™ UV lamp, 180°C high-heat decontamination cycles, and vaporized hydrogen peroxide cycles for comprehensive protection of sensitive cell cultures.
When it comes to metabolic monitoring, PHCbi’s LiCellMo®* system offers uninterrupted and highly accurate measurements of glucose and lactate concentrations, without the need for labor-intensive manual sampling or specialized cell culturing equipment. This approach also reduces the risk of contamination, preserves valuable samples, measures and records large amounts of data, and allows for timely adjustments for improved culture conditions.
PHCbi’s reliable cold storage solutions maintain the stability of CGT products at ultra-low and cryogenic temperatures. The TwinGuard® Series ultra-low temperature freezers feature dual, independent refrigeration circuits, intuitive electronic controls, onboard monitors, and a frost-mitigating cabinet design. Rigorous testing for temperature uniformity and long-term reliability guarantees consistent performance and sample protection. PHCbi’s mechanical cryogenic freezers incorporate VIP® Plus insulation, creating a thin-walled, highly efficient cabinet that does not require liquid nitrogen. An insulated inner door improves temperature uniformity and minimizes cold air loss during door openings or power outages, while a microprocessor-based controller offers accurate management of critical set points.
By providing researchers with reliable, precise, and innovative tools, PHCbi’s advanced technologies support the success of life-changing therapies and drive continued innovation in CGT development.
To learn more, visit phchd.com/us/biomedical
References
- “FDA approval brings first gene therapy to the United States.” https://www.fda.gov/news-events/press-announcements/fda-approval-brings-first-gene-therapy-united-states
- “FDA Approves First Cellular Therapy to Treat Patients with Type 1 Diabetes.” https://www.fda.gov/news-events/press-announcements/fda-approves-first-cellular-therapy-treat-patients-type-1-diabetes
- “Paying for CRISPR cures: The economics of genetic therapies.” https://innovativegenomics.org/news/paying-for-crispr-cures/
- “Benefits of oxygen control in the cell culture incubator.” https://markitbiomedical.com/knowledge-center/files/11574_1_PHCbi_Phys_Oxygen_Whitepaper_vf.pdf
- “Issues in contamination and temperature variation in the cryopreservation of animal cells and tissues.” https://opsdiagnostics.com/notes/cryogenicstorage.htm
*LiCellMo® is available for purchase in the U.S., Canada, and select other geographies globally. For research and education use only, not for use in diagnostic procedures in the U.S. or Canada. This product has not been approved or cleared as a medical device by the U.S. Food and Drug Administration or Health Canada.