In the rapidly evolving field of CAR-T cell therapy, achieving efficient T-cell activation and viral transduction is essential for producing potent, consistent, and scalable products.
Recombinant Human Fibronectin (rhFN) — particularly its cell-binding fragment (e.g., CH-296, also known as RetroNectin®) — has emerged as a key component in modern ex vivo T-cell manufacturing. Acting as a molecular bridge between viral vectors and T cells, rhFN greatly enhances gene transfer efficiency while supporting robust activation and proliferation under serum-free, GMP-compatible conditions.
1. Boosting Viral Transduction Efficiency
Mechanism:
rhFN binds both integrins (VLA-4, VLA-5) on the T-cell surface and viral envelope proteins on retroviral or lentiviral vectors. This dual interaction brings viral particles and T cells into close proximity, effectively concentrating the virus at the cell membrane.
Benefit:
This proximity dramatically improves viral transduction efficiency, allowing higher CAR expression even with low viral titers or challenging primary T-cell populations. The result: greater productivity and reduced vector usage — both critical for cost-effective CAR-T manufacturing.
2. Promoting Robust T-Cell Activation and Expansion
Mechanism:
When T cells attach to rhFN-coated surfaces, integrin engagement provides an additional co-stimulatory signal that complements anti-CD3/CD28 stimulation.
Benefit:
This synergistic activation leads to stronger proliferation, improved viability, and sustained functionality during expansion. The outcome is a healthier, more potent CAR-T product ready for downstream processing.
3. Enabling Serum-Free and Xeno-Free Manufacturing
Benefit:
rhFN is produced in animal-component-free systems, ensuring consistency, safety, and regulatory compliance. Its compatibility with serum-free and xeno-free workflows supports fully defined, scalable CAR-T processes — a growing industry priority for clinical and commercial production.
4. Supporting Closed-System and Scalable Processing
Benefit:
rhFN can be easily coated onto culture flasks, bags, or bioreactor matrices, seamlessly integrating into closed or semi-closed systems. This setup minimizes contamination risks and facilitates GMP-compliant large-scale manufacturing, improving reproducibility and efficiency across production runs.
Practical Tips for Using Recombinant Human Fibronectin
|
Application Step |
Recommendation |
Notes |
|
Surface Coating Concentration |
10–20 µg/mL rhFN |
Dilute in PBS or serum-free medium; coat 1–2 hours at room temp or overnight at 4°C |
|
T-Cell Seeding Density |
1–2 × 10⁶ cells/mL |
For optimal integrin engagement and viral contact |
|
Vector Type Compatibility |
Retroviral and lentiviral vectors |
Effective for both γ-retrovirus and pseudotyped lentivirus |
|
Media Type |
Serum-free or xeno-free medium |
rhFN supports attachment and proliferation without serum |
|
System Integration |
Suitable for culture flasks, bags, and microcarriers |
Compatible with closed-system processing |
Yeasen Recombinant Human Fibronectin Products
Yeasen provides two recombinant human fibronectin products suitable for CAR-T cell manufacturing:
|
Feature |
92619ES (CH-296) |
40113ES (Full-Length) |
|
Source |
Rice endosperm cells |
Rice endosperm cells |
|
Form |
Lyophilized powder |
Lyophilized powder |
|
Applications |
Viral transduction, cell matrix |
Serum reduction, cell matrix |
|
Expression System |
CHO Cells |
Rice Seeds |
|
Tag |
His |
Non |
|
Batch Consistency |
High |
High |
|
Endotoxin |
<0.5 EU/μg |
<0.5 EU/μg |
|
Viral Contamination Risk |
None |
None |
Features:
- High Purity: ≥95% as confirmed by SDS-PAGE, ensuring reliable performance in cell culture and transduction assays.
- Freeze-Dried Powder: Convenient storage and long shelf life, easy to reconstitute when needed.
- Low Endotoxin: Ultra-low endotoxin levels, safe for direct use in sensitive cell cultures, including primary T cells.
Perfomance:
1. High Purity

Figure 1. Human Fibronectin on SDS-PAGE under reduced condition. The purity is greater than 90%.
2. ED50 and Specific Activity

Figure 2. The ED50 as determined by a celI proliferation assay using B16-F1 mouse melanoma cells is less than 1.1 μg/mL, corresponding to a specific activity of > 1.17 X 107 IU/mg. Fully biologically active when compared to standard.
3. Superior Performance: Increased cell yield and enhanced viability

Figure 3. Enhanced Expansion of Primary Human T Cells Using Yeasen Recombinant Human Fibronectin.
Primary human T cells were cultured on surfaces coated with Yeasen rhFN or a competitor product. Yeasen rhFN supported superior T-cell activation and proliferation, demonstrating higher cell yield and viability compared to supplier C*.
Related Product
|
Name |
Cat. No. |
Size |
|
92619ES03/08/10/60/80 |
1 mg/5 mg/10 mg/100 mg/1 g |
|
|
40113ES03/08/10 |
1 mg/5 mg/10 mg |
