Restoring continuity of life interrupted

Theseus is developing an AI-guided approach to tissue repair, starting with therapies to reconnect the injured spinal cord.

Different injuries
One development approach

We develop therapies to reconnect injured tissue. AI models guide treatment design; experiments measure how well function returns.

  • Conceptual illustration of disrupted neural fibers reconnecting across an injury. Neural injury

    Restore signal continuity.

    Our first program
  • Conceptual illustration of tissue fibers joining across a surgical wound. Surgical tissue joins

    Rejoin tissue. Prevent leaks.

    Research scope
  • Conceptual illustration of a repaired blood vessel with an open channel. Vascular reconnection

    Restore a continuous vessel.

    Research scope
  • Conceptual illustration of a dense network of scar-forming tissue fibers. Fibrotic healing

    Recover function, not just scar.

    Research scope
A lone silhouette walking through a softly blurred city.
We move through the world without thinking about what makes movement possible.
A person silhouetted against approaching headlights.
In a moment,
everything changes.
900,000 new spinal cord injuries worldwide in 2019. Global Burden of Disease · 2019 estimate ↗
An abstract illustration of luminous neural connections.
An emergency medical team moving a patient on a stretcher toward an ambulance.
Emergency care saves lives. 18,400in the US alone. estimated new traumatic spinal cord injuries every year. NSCISC · Facts & Figures 2025 ↗
A person in a wheelchair, seen in silhouette against a bright window.
A lifetime of consequences.
No cure for a severed spinal cord.
15,400,000 people living with spinal cord injury worldwide in 2021. WHO · Global SCI estimates ↗
An empty wheelchair beside the same bright window.
Survival is not the finish lineMovement · Independence · Life, continued

Neural fusion as a complete therapy

A formulation alone is not a therapy. We are developing the tissue conditions, fusogen formulation, delivery protocol and recovery pathway as one coordinated approach.

Illustration of a spine stabilized with surgical rods

Prepare the repair site

Preserve viable tissue, align the injured ends and establish the mechanical stability that repair requires.

Molecular illustration of a cell membrane

Enable neural fusion

Develop an investigational PEG–chitosan fusogen formulation intended to support membrane repair and neural reconnection.

Concept illustration of an infusion bag labeled NeuroPEG 2

Coordinate delivery

Bring concentration, exposure, timing and treatment sequence into a protocol that can be tested and reproduced.

Illustrative line chart with four trajectories over time

Track recovery

Follow function over time, coordinate rehabilitation and use recovery measurements to refine the whole therapy.

Immunofluorescence of repaired spinal cord tissue: neurofilament-positive axons in red and green with DAPI-stained nuclei in blue
Neural reconnection · Experimental evidence

Severed spinal cords
Restored movement

Following complete spinal cord transection, treated animals regained movement in both rabbit and swine studies. The experimental foundation spans rodents, rabbits, large animals and cadaveric procedures.

Rats
400
Rabbits
20
Swine
10
Cadaveric procedures
30
Immunofluorescence NF-200 / DAPI at the lesion · View study microscopy ↗
Cross-validation · Function, structure, pathways

Recovery measured
Reconnection traced

Movement alone is not enough. Functional scoring, microscopy and axonal tracing cross-check the result at three levels: what the body does, how the tissue connects and where the neural pathways lead.

Published gait sequence showing the same treated pig walking at days 10, 21 and 40, arranged in three rows.
Functional recovery

They walked

Neurological scores tracked recovery over 60 days. This sequence follows one treated animal walking at days 10, 21 and 40.

Figure 2 · Gait sequence ↗
Detail of immunofluorescence microscopy showing neurofilaments and nuclei in spinal cord tissue.
Tissue morphology

Repair, under the microscope

Histology and NF-200 staining reveal tissue continuity and axonal structures at the repair site — a structural check on functional recovery.

Figure 6 · NF-200 / DAPI ↗
FluoroGold tracing in yellow and DAPI-stained nuclei in blue, with enlarged regions on either side of the lesion.
Axonal tracing

Connections, traced

FluoroGold labeling traces neural connections across the lesion. In one treated animal, it provides an anatomical check on reconnection.

Figure 7 · FluoroGold / DAPI ↗

Figures 2 & 7: Lebenstein-Gumovski et al., PLOS One, 2026 · CC BY 4.0 · Resized. Microscopy shown as a detail.

Study details and limitations

The 2026 swine study

Random assignment, blinded neurological scoring, 60-day follow-up. All three treated pigs walked on four limbs; neither control walked independently. Ataxia persisted in treated animals.

Three complementary methods

Function, tissue morphology and axonal tracing were assessed within the same study. Tracing was performed in one treated animal. These are complementary readouts, not independent replications.

Scope of the evidence

The study evaluated local gel and systemic PEG with surgical stabilization and rehabilitation. These animal results do not establish human efficacy. Clinical contusion injuries require separate validation.

Kai Micah Mills

Kai Micah Mills

Thiel Fellow, founder of Cryopets, and co-founder of CryoDAO and HydraDAO. He builds organizations advancing cryopreservation, biological replacement and longevity research.

Michael Lebenstein-Gumovski

Michael Lebenstein-Gumovski

Neurosurgeon and researcher at the Sklifosovsky Institute. He has studied spinal cord injury since 2013, focusing on fusogen-based approaches to restoring neural continuity.

Andrei Panferov

Andrei Panferov

Technology entrepreneur and AI builder. He turns complex, unsolved challenges into mathematical problems that computers can tackle — bringing that approach to the development of biological repair.

Eli Mohamad

Eli Mohamad

Co-founder of CryoDAO, X-Therma and the Organ Preservation Alliance. He is also a founding ambassador of the American Biostasis Foundation.

Let's restore continuity together

Help move tissue repair from an early biological signal toward a reproducible therapy. We welcome scientific collaborators, specialist clinical teams and partners who build for the long term.

Investors

Supporting comparative studies and the work toward clinical translation.

Clinical partners

Surgical centers and teams to co-develop the operative protocol.

Researchers

Collaborators extending the preclinical and translational work.

Strategic collaborators

Industry and institutional partners advancing delivery and translation.