A new review summarizes the current state of research on ocular collagen and shows how this natural structural protein is being advanced from the analysis of its hierarchical architecture in eye tissues to the development of high-performance biomimetic materials for ophthalmic regenerative medicine.
The review “Ocular collagen: From architecture to biomaterials,” published in the journal Eye Discovery (DOI: 10.1016/j.edisc.2026.100024), comes from researchers at East China University of Science and Technology. It systematically highlights the distribution, structure, and processing of collagen in the cornea, sclera, retina, conjunctiva, and eyelids, and discusses modern methods for producing functional collagen-based implants.
Key Contents of the Review
- Hierarchical Structure and Physiological Significance
In the various eye tissues, collagen forms highly ordered, self-organized networks – from triple helix molecules to fibrils to lamellar structures. This architecture not only ensures mechanical stability and optical clarity (especially in the cornea) but also regulates cell adhesion, migration, proliferation, and differentiation via integrin-mediated signals. The tissue- and site-specific arrangement enables the required functions: transparency in the cornea, strength in the sclera, or protection in the retina. - Processing Techniques for Biomedical Materials
Collagen is characterized by its high processability. Using 3D printing, electrospinning, electrodeposition, or in situ injection, it can be used to produce hydrogels, films, fibers, porous scaffolds, and injectable systems. By precisely controlling fibril alignment, porosity, and geometry, the materials can be adapted to the specific mechanical and structural requirements of individual eye tissues. - Clinical Applications
Collagen-based materials are already used or being researched in numerous areas:
- Cornea: As a transplant substitute or bandage lenses
- Retina/Choroid: As cell carriers, drug depots, or substitutes for Bruch’s membrane
- Surface and Adnexa: For conjunctival reconstruction, eyelid reconstruction, scleral reinforcement, glaucoma surgery, and tear duct reconstruction. The focus is increasingly shifting from pure replacement to functional regeneration.
Objective Evaluation
Strengths of the work:
- The review offers a comprehensive, interdisciplinary overview of protein science, materials engineering, and ophthalmological pathology.
- It emphasizes the need for tissue- and site-specific approaches rather than a generic “collagen-for-everything” strategy.
- Practical relevance: Collagen is considered one of the most promising starting materials for ocular regeneration materials due to its biocompatibility, degradability, and processability.
Weaknesses and open questions:
- This is a purely review article without its own experimental data. The successes presented come predominantly from preclinical studies (in vitro and animal models). Long-term clinical results in large patient numbers are still largely lacking.
- Mechanical weaknesses of pure collagen materials (e.g., insufficient tensile strength or too rapid degradation) remain a challenge. The authors therefore propose hybrid materials (collagen combined with synthetic polymers) and "intelligent" scaffolds with spatiotemporal responsiveness as the next stage of development.
- The transferability from animal or laboratory models to humans has not yet been sufficiently validated for many approaches.
Conclusion:
The work highlights the progress from pure structural analysis to targeted biomaterial-based therapy development in the eye. Collagen has established itself as a versatile platform with the potential to alleviate the shortage of corneal donors and enable complex ocular reconstructions. However, further controlled studies and the optimization of mechanical properties through composite materials will be crucial for the clinical breakthrough. The review provides a solid foundation for future research and development directions in ocular tissue engineering.
