How it started: "Cornea in under 10 minutes"
In 2018, a team at Newcastle University demonstrated a proof of concept: bioprinted human cornea in under 10 minutes. The bio-ink combines alginate and collagen with human corneal stromal cells, and the geometry is deposited in concentric trajectories. Cell viability remains high after 3D printing. This is not a ready-made implant, but a scientific breakthrough that showed that 3D printing can build living tissue shaped like a cornea.
A key element is the FRESH method—3D printing in a supporting "jelly bath" of gelatin microparticles. The bath keeps the soft hydrogels stable until they crosslink; then it is removed thermoreversibly. FRESH enabled the dome shape and the thin layers without deformation.
To prepare the ground for personalized implants, scientists scan corneas and generate patient-specific models. This provides a bridge between the medical scan and 3D printing – familiar workflow for our community.
What has advanced since 2018
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Light instead of nozzle: Corneal stroma can be bioprinted with DLP (Digital Light Processing) using bio-inks based on dECM (decellularized corneal matrix) + GelMA. The advantages are smooth surface, high accuracy and good transparency in preclinical models.
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Optics by parameters: Transparency depends on engineering collagen concentration, angle between layers (0°/90°), nozzle diameter and 3D filament fusion; in a new study (2025) an optimised configuration achieves ~89.8% transmittance at 700 nm for collagen hydrogels.
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Clinical use, but not yet a fully bioprinted cornea: Cell‑free BPCDX (double-crosslinked porcine collagen) restores vision in a pilot study with 20 patients; EndoArt® (synthetic endothelial implant) is CE-marked and has seen the first commercial implants in the NHS (2024). These are parallel engineering pathways that reduce dependency on donors.
The context of why all of this is important remains unchanged: ~12.7 million people are waiting for a corneal transplant, and globally there is 1 donor cornea for 70 people in need.
Types of 3D printers and how they relate to corneal bioprinting experiments
1) Extrusion (syringe) — the "bio-equivalent" of FDM/FFF
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How it works: instead of filament for a 3D printer → hydrogel (alginate, collagen, GelMA, dECM).
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How it “hardens”: ionic (Ca²⁺), thermal, enzymatic or photocrosslinking.
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Top benefits: soft tissues, viscous inks, FRESH bath for complex curvatures (such as cornea).
2) 3D Printing Technology (SLA/DLP/LCD) — uses the logic of 3D printer resin, but biohydrogel
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How it works: photosensitive bio-inks (e.g. GelMA + dECM) are polymerized layer by layer with light.
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Strength: smooth optics and nozzle-free high resolution—especially relevant for corneal layers.
3) Inkjet and laser‑assisted (LIFT)
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How it works: deposition of micro-droplets — from ink heads or by laser pulse without a nozzle.
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Strength: precise "ordering" of cells and microarchitectures; often for epithelium/endothelium.
For home and office scenarios: the most meaningful analogy is FDM ↔ hydrogel extrusion and SLA/DLP ↔ photobioprinting. Remember, however, that working with cells requires sterility and regulations – home projects should use cell-free prototypes, not tissues.
FRESH in a nutshell: the "smart support‑bath" for soft materials
The FRESH method (Freeform Reversible Embedding of Suspended Hydrogels) prints into a gelatin suspension that supports each deposited strand; the bath is then removed. Version v2.0 improved particle size and uniformity in the bath → smoother surfaces and more precise contours (important for optics). If you are working with soft gels (even without cells), FRESH is a universal strategy for thin-walled domes and curves.
Scan → model → print: which 3D scanners and medical scans are relevant
Medical measurements for patient-specific cornea
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Corneal topography (Placido‑disk): projects concentric rings onto the cornea and the reflected pattern maps curvature of the front surface. Fast and widely available.
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Scheimpflug tomography (e.g. Pentacam): rotating camera reconstructs 3D map of the front and back surfaces and thickness (pachymetry). Suitable for complex cases.
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AS‑OCT (anterior-segment OCT): "scans" cross sections and volume data — useful for exact geometry and thicknesses.
Consumer/engineering 3D scanners (for your workshop/home)
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Structured Light: projector + cameras, warped light pattern triangulation — highly detailed geometry for product details, prototypes, and anatomical mockups.
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Laser triangulation: laser line/point + camera — robust technology for industry and control.
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Photogrammetry: multiple photos → a 3D model; a budget-friendly option using a smartphone or camera. Excellent for larger objects and context.
At 3dlarge.com we maintain separate categories for 3D printers (FDM, resin/DLP) and 3D scanners (structured light, laser). If you make educational mockups, tools, and gel molds, you'll feel right at home with these devices.
How 3D Printing "Makes" Optics: Settings That Matter
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Angle between layers: orthogonal paths (e.g. 0°/90°) minimize directional scattering.
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Nozzle/Needle Diameter: smaller → fine strands → smoother optics (avoid flow restriction).
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Collagen concentration: lower → higher transmittance, but lower mechanical strength; balance is needed.
A new study (2025) shows ~89.8% transmittance at 700 nm at 0.8% collagen, a 0°/90° layup and 100 μm nozzle (acellular samples).
Where is the development today and what has already reached patients
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No published human clinical trials of a fully bioprinted cornea are available yet. However, bioengineered solutions have entered clinical use: BPCDX (collagen implant, without cells) and EndoArt® (synthetic endothelial membrane, CE; first commercial implantations in the NHS in 2024).
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Why it's important: the global shortage is real— 1 donor cornea for every 70 people in need; therefore 3D printing + biomaterials are strategic.
Practical scenarios for our readers (including home users)
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Anatomical models and teaching models: FDM for speed and cost; resin-based DLP/SLA for fine details (transparent cornea mock-ups for demonstrations).
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Moulds for gels: 3D printing of hollow forms (PLA/PETG/resin) filled with inert gels (without cells) for geometry/optics test.
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3D scan → model → 3D print: structured light/photogrammetry for objects and face mockups; OCT/topography are medical instruments, but the "3D scan → CAD → G‑code" principle is the same.
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Safety: cell/tissue work is not suitable for home use (sterile environment and regulations required). Home projects are cell-free – focus on geometry, optics and mechanics.
If you are looking for 3D printers for home → start with FDM (versatile and cost-effective) and/or resin (DLP/LCD) for fine, transparent models; for digitisation, consider 3D scanners based on structured light. At 3dlarge.com, we have categories and filters by volume, resolution, and materials so you can choose the right tool for the job.
Ethics, regulations and horizon
Human corneal bioprinting remains preclinical—i.e. proof of concept, but no human trials with living cells. On the other hand, there is already a clinical reality: EndoArt®, a synthetic implant, is used in patients with corneal endothelium deficiency. Example: A 91-year-old NHS patient regained his sight thanks to a synthetic corneal endothelial implant, the first of its kind in England.
Long-term observations (over 12–24 months) after the first implantations show a significant reduction in corneal oedema and improvement in visual acuity, with minimal complications. This is an important step towards clinical surgery, proving that engineering solutions can really help — demonstrating scalability, shelf life and freedom from donor constraints.
