Precise Bio has made medical and bioprinting history with the successful implantation of PB-001, the world’s first cell-based, 3D-bioprinted corneal implant, in a patient at Rambam Medical Center in Haifa, Israel. The surgery, completed as part of an ongoing Phase 1 trial, marks a major milestone not only for corneal transplantation but for the entire field of regenerative medicine.

While headlines highlight this as a world first, the true significance lies deeper—in how the implant is made, how it functions biologically inside the eye, how it is transported to surgeons worldwide, and what kind of biofabrication platform makes this breakthrough possible.

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A Living Corneal Implant—Not a Decellularized Scaffold

Unlike synthetic corneal substitutes or decellularized grafts, PB-001 contains living, functional human corneal endothelial cells.

The implant consists of:

• A monolayer of viable donor-derived endothelial cells
• Printed onto a thin, transparent, ECM-like scaffold
• Engineered to mimic Descemet’s membrane and the native corneal endothelium

These donor endothelial cells remain alive and functional long-term, just as they do in traditional endothelial keratoplasty (DMEK). Their role is essential—they actively pump fluid out of the cornea, restoring clarity in patients suffering from edema due to endothelial failure.

Because the cornea is immune-privileged, endothelial grafts have some of the lowest rejection rates in medicine. PB-001 leverages:

• Lack of blood vessels
• Immunosuppressive environment of the anterior chamber
• Low antigen expression of endothelial cells
• Thin, antigen-sparse graft geometry
• Short-term topical steroids

These features allow allogeneic endothelial cells to persist indefinitely without systemic immunosuppression.

The result is a living, functional tissue that behaves like a bioengineered DMEK graft.

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How the Implant Integrates in the Eye

Once PB-001 is implanted:

1. The donor endothelial cells attach to the posterior cornea.
2. They begin pumping fluid, clearing edema.
3. Host keratocytes gradually infiltrate the scaffold, remodeling the extracellular matrix over weeks to months.
4. The endothelial monolayer remains donor-derived, but the supporting structure becomes a hybrid of donor architecture and host cellular remodeling.

This pattern mirrors what is seen in:

• DMEK grafts
• Aurion Biotech’s cultured endothelial cell therapy
• Thin stromal substitutes in regenerative ophthalmology

In short, PB-001 becomes a chimeric interface where host and graft complement each other: host cells remodel the structure; donor cells supply the critical pump function.

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The Supply Chain: How PB-001 Gets from Printer to Operating Room

For PB-001 to scale globally, it must function as a real medical product, not a fragile lab specimen.

Precise Bio has designed PB-001 for a streamlined supply chain:

1. Manufactured at a GMP facility (Sheba Medical Center)

Cells are isolated, expanded, and printed entirely under controlled GMP conditions.

2. Cryopreserved as a finished, pre-loaded implant

Precise Bio has emphasized long-term cryopreservation. This has enormous value:

• Enables global distribution
• Allows scheduling flexibility for surgeons
• Permits inventory management like a pharmaceutical product
• Reduces waste compared to donor-dependent eye banks

3. Likely shipped through Carl Zeiss Meditec’s global logistics network

Carl Zeiss Meditec—Precise Bio’s strategic investor and commercialization partner—already has a world-class distribution footprint in ophthalmology. They distribute:

• Intraocular lenses
• Ocular surgical instruments
• Cataract and corneal tools
• Preloaded injectors

ZEISS is the obvious partner to coordinate:

• Global cold chain shipment (dry ice or vapor-phase LN2)
• Temperature-controlled tracking
• Local thawing protocols
• On-site surgical support

4. Pre-loaded for DMEK-style delivery

PB-001 is designed to be delivered through standard DMEK/DSAEK injectors:

• Thaw
• Rinse
• Insert
• Unroll
• Attach

This allows surgeons to adopt it with minimal retraining.

This supply chain—the combination of GMP biofabrication + cryopreservation + ZEISS distribution + familiar surgical workflow—is exactly what makes PB-001 feasible as a commercial-scale product.

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Why This Breakthrough Matters

PB-001 represents a new category:

Biofabricated Corneal Endothelium as a Scalable Therapeutic

Unlike donor corneas, which are limited, perishable, and variable, PB-001 offers:

• Unlimited manufacturing scalability
• Standardized quality
• Long-term frozen shelf life
• Reduced global dependency on eye banking
• Consistent surgical outcomes
• Potential for lower complication rates

And perhaps most importantly:

A single donor cornea can become hundreds of implants.

If successful, PB-001 could transform corneal transplantation from a scarcity-based ecosystem to an abundance-driven model.

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About Precise Bio

Precise Bio is a clinical-stage regenerative medicine company pioneering a proprietary 3D-bio-fabrication platform integrating cell biology, biomaterials engineering, and robotic micro-printing to produce clinical-grade human tissues under GMP conditions. Its lead program, PB-001, is the world’s first 3D-bioprinted corneal implant to enter human trials. With strategic investment and commercialization partnership from Carl Zeiss Meditec, the company is advancing a pipeline of ophthalmic and advanced tissue programs aimed at redefining the future of tissue replacement.

For more information, visit www.precise-bio.com.