Stroke is one of the leading causes of long-term disability worldwide, with an estimated one in four adults experiencing one during their lifetime. Current therapeutic options are often limited, and there are no established treatments capable of repairing the residual and permanent neurological damage. This clinical challenge is driving research toward new regenerative medicine approaches aimed at restoring brain tissue after injury.

Stem Cell-Based Regeneration Strategy
A significant advancement has been achieved by a joint research group that includes scientists from the University of Zurich (UZH), such as Christian Tackenberg, and from the University of Southern California (USC), such as Ruslan Rust. The preclinical study demonstrated therapeutic potential in stroke recovery in mouse models, using human Neural Progenitor Cells (NPCs).
These NPCs, which are the cellular precursors of the nervous system, were derived from induced pluripotent stem cells (iPSCs). To ensure clinical translatability, the cells were generated using “xeno-free” protocols (without animal-derived reagents) and are compliant with Good Manufacturing Practice (GMP) standards.

Key Results: Functional Recovery
The results of the study, detailed in the scientific article, provided crucial insights into the therapeutic strategy:
• Timing of intervention: It was established that NPC administration is most effective when performed one week after the stroke. This interval, following the acute phase, maximizes graft survival.
• Cellular integration: The transplanted cells survived and integrated for at least five weeks. Most of them differentiated into mature neurons (78% MAP2-positive), predominantly with GABAergic (44%) and glutamatergic (42%) phenotypes.
• Repair mechanisms: The transplant actively promoted tissue regeneration. New blood vessel formation (angiogenesis) was observed, along with a significant improvement in the integrity of the blood–brain barrier (BBB) and a marked reduction in inflammation in the ischemic area (with a 32% reduction in Iba1 immunoreactivity in the stroke core).
• Motor recovery: The most significant functional effect was the improvement in long-term motor recovery. This was precisely measured through automated gait analysis supported by deep learning techniques.

• Cellular communication (crosstalk): Molecular analysis revealed that GABAergic neurons derived from the transplant act as dominant “senders” in signaling pathways (including NRXN, NRG, NCAM, and SLIT) that promote neuronal regeneration, synaptic plasticity, and axonal guidance.

The Strategic Role of Eternacell in the Context of Regenerative Medicine
These preclinical results provide a solid foundation for the clinical potential of iPSC-derived NPCs. Stroke is considered by researchers to be “one of the next diseases for which a clinical trial becomes possible.”
Eternacell, a Swiss biotech company whose goal is to expand the boundaries of regenerative and anti-aging medicine, is strategically positioned to enable access to these future therapies. Its MyCells service, described as a “biological insurance,” is designed to ensure that individuals are ready to take advantage of such advances.
Eternacell cryopreserves Peripheral Blood Mononuclear Cells (PBMCs). PBMCs represent one of the most reliable and promising cell sources for subsequent reprogramming into iPSCs—the same cell type from which the NPCs used in the stroke study were derived.

Eternacell’s distinctive value in this context lies in two key aspects:
1. Autologous compatibility and preservation of cellular youth: Preserving one’s cells today, while in good health (recommended age range 10 to 65), allows the cellular aging process to be effectively paused. This ensures that the cellular resource available in the future—if needed for the production of new cells—is autologous and therefore perfectly compatible, eliminating the risk of rejection.
2. Clinical standardization: The cryopreservation and processing of PBMCs are carried out entirely in Switzerland in GMP-certified facilities. This compliance is essential, as the cells used in stroke research were also generated using protocols aligned with these standards. This ensures that the sample managed by Eternacell is recognized and acceptable in any therapeutic center worldwide for future clinical use.
Through MyCells, Eternacell provides the essential and qualified cellular resource, acting as a bridge between today’s cellular health and access to advanced cell therapies for neurological and degenerative diseases.

Sources
Weber, R.Z., Achón Buil, B., Rentsch, N.H. et al. Neural xenografts contribute to long-term recovery in stroke via molecular graft-host crosstalk. Nat Commun 16, 8224 (2025).
https://doi.org/10.1038/s41467-025-63725-3
2. Scientists reverse stroke damage with stem cell therapy,
https://www.openaccessgovernment.org/scientists-reverse-stroke-damage-with-stem-cell-
therapy/198421/