Hello Bio launches first-in-class small molecule alternative to FGF2
Stable FGFR1 agonists aim to improve reproducibility and reduce feeding frequency in cell culture workflows
20 May 2026Product news
Hello Bio has launched a first-in-class range of small molecule FGFR1 agonists designed as stable alternatives to fibroblast growth factor 2 (FGF2) for stem cell culture. The new TCB compounds aim to help stem cell and organoid researchers worldwide overcome weekend feeding challenges, reduce media change frequency, and improve signalling consistency in pluripotent stem cells, organoids, and neural precursor cell cultures.
Addressing instability of FGF2 in stem cell culture
FGF2 is widely used to maintain pluripotency in stem cells, organoids, and neural precursor cells. However, FGF2 is highly unstable at 37°C, rapidly degrading in culture media and often requiring daily supplementation to maintain effective signalling. This instability contributes to labour-intensive media change schedules, including weekend feeding, and can lead to inconsistent FGFR signalling over time.
New TCB small molecule FGFR1 agonists
Hello Bio has launched a new range of chemically defined small molecule FGFR1 agonists: TCB-32, TCB-541, and TCB-621. These TCB compounds are designed to provide sustained FGFR signalling without the rapid degradation associated with recombinant growth factors such as recombinant FGF2.
Published validation data show that TCB-32 remains active in culture media for over 13 days while delivering overall FGFR exposure comparable to heat-stable FGF2. This extended activity has the potential to enable researchers to move from daily media changes to media change intervals of up to once every 14 days, while maintaining effective FGFR signalling.
Benefits for stem cell workflows and scalability
By replacing unstable recombinant growth factors with stable small molecules, the TCB range has the potential to simplify stem cell culture workflows, reduce media change frequency, and improve signalling consistency over extended culture periods.
The increased stability of the TCB compounds may also help support more reproducible stem cell culture workflows by reducing variability associated with repeated FGF2 supplementation and 'feast-and-famine' signalling cycles. Improved workflow consistency and reduced feeding requirements may support more scalable cell production workflows in research and preclinical applications.
TCB product range
The TCB range includes three small molecule FGFR1 agonists designed for different stem cell culture needs:
- TCB-32 – a robust and well-characterized compound
- TCB-541 – balanced potency for broad stem cell applications
- TCB-621 – the highest-potency analogue for lower working concentrations
These compounds are intended for researchers working with human pluripotent stem cells, organoids, and neural precursor cells who are seeking more stable and reproducible alternatives to recombinant FGF2 in their cell culture media.
Commitment to reproducibility and practical cell culture solutions
Replacing unstable growth factors with small molecule alternatives is an important step towards improving reproducibility and scalability in cell culture. With the TCB range, Hello Bio aims to offer researchers a practical solution that reduces media changes while maintaining consistent signalling and cell performance.
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Frequently asked questions
What are Hello Bio’s new TCB small molecule FGFR1 agonists and how do they compare to recombinant FGF2 for stem cell culture?
Hello Bio has launched a first-in-class range of chemically defined small molecule FGFR1 agonists — TCB-32, TCB-541, and TCB-621 — as stable alternatives to recombinant fibroblast growth factor 2 (FGF2) for stem cell culture. Unlike FGF2, which is highly unstable at 37°C and rapidly degrades in culture media, these TCB compounds are designed to provide sustained FGFR signalling without rapid degradation.
Validation data show that TCB-32 remains active in culture media for over 13 days while delivering overall FGFR exposure comparable to heat-stable FGF2, supporting longer media change intervals of up to once every 14 days while maintaining effective FGFR signalling.
How can TCB-32, TCB-541, and TCB-621 improve pluripotent stem cell, organoid, and neural precursor cell workflows?
The TCB range of small molecule FGFR1 agonists is intended for researchers working with human pluripotent stem cells, organoids, and neural precursor cells who need more stable and reproducible alternatives to recombinant FGF2. By replacing unstable recombinant growth factors with stable small molecules, these compounds can help overcome weekend feeding challenges, reduce the frequency of media changes, and improve signalling consistency over extended culture periods.
Their increased stability may also reduce variability associated with repeated FGF2 supplementation and 'feast-and-famine' signalling cycles, supporting more reproducible and scalable stem cell and organoid culture workflows in research and preclinical applications.
What are the specific roles of TCB-32, TCB-541, and TCB-621 within Hello Bio’s TCB product range for FGFR1 activation?
Hello Bio’s TCB product range includes three small molecule FGFR1 agonists tailored to different stem cell culture needs. TCB-32 is described as a robust and well-characterized compound that has been validated to remain active in culture media for over 13 days while maintaining FGFR exposure comparable to heat-stable FGF2.
TCB-541 offers balanced potency suitable for broad stem cell applications, making it appropriate for a wide range of pluripotent stem cell, organoid, and neural precursor cell cultures. TCB-621 is the highest-potency analogue in the range, designed for use at lower working concentrations while still providing sustained FGFR signalling to support efficient and scalable cell production workflows.