Human pluripotent stem cell (hPSC)–derived therapies are entering a new phase of maturity. As more programs move from discovery into translational development and early clinical trials, the selection of starting cell lines—and the workflows used to expand and maintain them—has become a critical bottleneck.
A recent review published in Stem Cell Reports provides one of the most comprehensive assessments to date of clinically available human embryonic stem cell (hESC) and induced pluripotent stem cell (hiPSC) lines suitable for therapeutic development. The authors identify 166 hPSC lines that are currently available for licensing and distribution, while outlining key considerations developers must navigate when selecting a starting material for clinical programs.
From bespoke derivation to off-the-shelf starting materials
Historically, many clinical programs relied on bespoke derivation of pluripotent stem cell lines—an approach that is time-consuming, resource-intensive, and difficult to scale. The review highlights a clear shift away from this model, emphasizing the growing availability of off-the-shelf, well-characterized hPSC lines derived under GMP or GMP-like quality systems.
As access to clinically suitable cell lines improves, attention increasingly shifts upstream to how these cells are expanded, maintained, and recovered—often over extended culture periods and across multiple sites.
Media choice as a translational consideration
While the review focuses on cell line availability, it implicitly highlights another challenge facing the field: ensuring that upstream culture conditions are compatible with translational and therapeutic use.
Many laboratories rely on legacy pluripotent stem cell media, including widely used formulations such as mTeSR™, mTeSR™ Plus, and E8™, which have played an important role in standardizing iPSC maintenance across research settings. However, as programs move closer to manufacturing, questions around formulation transparency, scalability, lot-to-lot consistency, and cost structure become increasingly important.
These considerations have driven growing interest in fully defined, serum-free media that offer comparable performance while providing greater control and long-term flexibility for translational workflows.
Defined media as an alternative for scalable stem cell workflows
At Defined Bioscience, our goal is to support this transition by developing defined, serum-free stem cell media designed to integrate seamlessly into both research and clinical pipelines.
HiDef-B8 (or sometimes referred simply B8) is a fully defined formulation developed as an alternative to legacy media such as mTeSR and E8, offering a transparent composition and compatibility with feeder-free pluripotent stem cell culture. Alongside HiDef-B8, we offer HiDef-S8 for suspension workflows and Ready-CEPT to support improved cell survival and recovery across key handling steps.
Together, these reagents are designed to support reproducibility today while enabling smoother transitions toward GMP manufacturing and therapeutic development tomorrow.
Collaboration across the stem cell ecosystem
Progress in stem cell therapeutics depends on close collaboration across cell line developers, reagent suppliers, academic labs, and translational teams. We’re grateful to work alongside organizations advancing high-quality iPSC lines, including partners such as Allele Biotechnology and Pluristyx, and to see defined culture systems adopted across a wide range of pluripotent stem cell workflows.
We look forward to continuing to work with partners across the ecosystem and to supporting stem cell R&D and therapeutic development with high-quality cGMP and research-grade HiDef-B8, HiDef-S8, and Ready-CEPT.
A practical example: defined media in a clinical iPSC workflow
For those looking to learn more about how defined media can be used in clinical iPSC workflows, we’ve published an application note with Pluristyx describing an example workflow for iPSC expansion, cryopreservation, and recovery using a fully defined reagent system.
This application note is intended as a technical resource for scientists evaluating how defined alternatives to legacy media such as mTeSR or E8 can be integrated into real-world pluripotent stem cell programs:
Building the foundation for the next generation of stem cell therapies
As the stem cell field continues to mature, access to clinically suitable hPSC lines—combined with defined, reproducible, and scalable culture media—will be essential for accelerating translation and reducing risk.
We’re proud to support the infrastructure behind this progress and to work with partners across the ecosystem to help enable the next generation of stem cell–based therapies.
