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InVitria Blog | Cell Culture and Biotech Manufacturing Insights

High-Performance Production of Viral Vectors for Cell and Gene Therapy Using OptiPEAK HEK293t Complete Media

HEK293t cells are an indispensable tool for the production of the viral vectors at the heart of cell and gene therapy technology. To introduce a way to improve performance, consistency, and safety of your HEK293-based production InVitria’s team released a new video that talks about our serum-free chemically defined media product, OptiPEAK HEK293t Complete Media.

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In this companion blog post, we dive deeper into the manufacturing process behind virus-based cell and gene therapies, and how InVitria’s products are uniquely positioned to solve potential problems with scalability, raw materials, bioreactor compatibility, and regulatory compliance.

Decades of intensive research, trial, and error have finally overcome the enormous technical challenges involved in developing safe and effective cell and gene therapies.

Signaling that the fields of cell and gene therapy are finally coming into their own, 2017 saw the approval of two cellular immunotherapies—tisagenlecleucel (Kymriah)  for pediatric acute lymphoblastic leukemia, and axicabtagene ciloleucel (Yescarta) , for adult diffuse large B-cell lymphoma—as well as a gene therapy based on the adeno-associated virus vector, voretigene neparvovec (Luxturna) for Leber's congenital amaurosis. The FDA now has hundreds of IND applications related to these fields in its review pipeline, and has predicted that by 2025, there will be between 10 and 20 approvals per year in this area.

As the industry reaches critical mass, however, it faces new challenges that have little to do with mechanisms of action or viral genetics.

Manufacturing scalability, clinical and manufacturing regulatory compliance, and a reliable supply of consistent, traceable, well-characterized raw materials for biomanufacturing present looming challenges to commercialization of cell and gene therapies.

Cell and gene therapy technologies like CAR-T, adeno-associated virus vectors, and lentivirus-based vectors depend on the production of recombinant virus particles in a host cell line prior to end-target transfection.

The adherent, immortalized, human cell line HEK293t has become the host of choice for therapeutic viral-vector production due to its versatility, durability of expression, and well-characterized clinical safety profile.

During R&D, HEK293t may be maintained in standard tissue culture flasks. For commercial-scale production they are typically expanded in a bioreactor setup. Aside from glucose, pH buffers, and basic salts, the media that support the growth and expansion of HEK293t and other cultured eukaryotic cells have to be supplemented with specific proteins and nutrients. In research environments, the most common and convenient source of these essential components is fetal bovine serum (FBS) supplied as a product of the commercial beef industry. While FBS destined for the laboratory is sterile-filtered at 0.1 μm during production, it nevertheless remains a complex and undefined substance of variable composition. Even filtered FBS may contain viral RNA and DNA, prion proteins, undefined antigenic molecules, as well as bovine cytokines, hormones, and other substances that can potentially affect cell performance in culture, manufacturing yield, product validation, and clinical safety of the downstream viral isolate. The presence of these undefined contaminates is partly why “heat inactivation” of FBS—and re-filtration of resulting protein aggregates—is part of standard tissue-culture protocols in many research laboratories.

While these undesirable characteristics of FBS have been accepted in the past out of necessity, they can present hurdles for patient safety and regulatory compliance. Further, FBS is not a limitless resource. There is not enough volume to sustain the projected demands of the fast-growing biomanufacturing industry, and production will always be subject to fluctuations in the global, agricultural supply chain.

InVitria’s OptiPEAK line of animal-free, chemically defined, complete media products are specifically tailored to maximize performance, consistency, safety, and efficiency of HEK293t and other cultured cell lines without supplemental serum.

Like all of InVitria’s products, every protein component in OptiPEAK HEK293t Complete Media is fully recombinant, fully human in sequence, and manufactured in the US, in a tertiary-level, animal component-free, ISO 9001 certified facility. InVitria media and their components do not contain undefined plant hydrolysates, human blood-derived components, or animal-derived components.

OptiPEAK HEK293t Complete Media has been optimized to promote superior expansion kinetics of HEK293t both in tissue culture and in scalable bioreactor format for clinical and commercial manufacturing. For example, InVitria has collaborated with PALL Biotech to validate the use of OptiPEAK HEK293t in its iCELLis line of bioreactors.


Advantages to using OptiPEAK HEK293t over FBS-supplemented media in the bioreactor included:

  • 16% reduction in cell doubling times
  • Higher cell density on day of transfection
  • More rapid attachment to carriers
  • Greater glucose consumption
  • Increased reporter gene expression
  • No foaming of media
  • Higher linear feed rate


The bottom line? Transitioning HEK293t and other mission-critical cell cultures can have extensive performance, yield, and safety benefits for basic and translational research, clinical development, and commercial-scale biomanufacturing.

If you’re ready to say goodbye to serum for good, we’re here to help. To learn more about transitioning your cell culture system to complete, chemically defined, serum-free and animal-free media, contact us or follow this link to InVitria’s Custom Media Formulation services page.



Jeanne McAdara Ph.D.

Written by Jeanne McAdara Ph.D.

Dr. McAdara is part of InVitria's medical and scientific communications team. She has been involved in scientific communications for 19 years and is the Principal of Biolexica Health Science Communications. Dr. McAdara earned her Ph.D. in Macromolecular and Cellular Structure and Chemistry from The Scripps Research Institute and was a postdoctoral fellow in the Jonsson Comprehensive Cancer Center, where she studied the biochemical and cellular mechanisms underlying leukemia.