3D Bioprinting of Acellular Corneal Stromal Scaffolds with a Low Cost Modified 3D Printer: A Feasibility Study

Abstract

Purpose

Loss of corneal transparency is one of the major causes of visual loss, generating a considerable health and economic burden globally. Corneal transplantation is the leading treatment procedure, where the diseased cornea is replaced by donated corneal tissue. Despite the rise of cornea donations in the past decade, there is still a huge gap between cornea supply and demand worldwide. 3D bioprinting is an emerging technology that can be used to fabricate tissue equivalents that resemble the native tissue, which holds great potential for corneal tissue engineering application. This study evaluates the manufacturability of 3D bioprinted acellular corneal grafts using low-cost equipment and software, not necessarily designed for bioprinting applications. This approach allows access to 3D printed structures where commercial 3D bioprinters are cost prohibitive and not readily accessible to researchers and clinicians.

Methods

Two extrusion-based methods were used to 3D print acellular corneal stromal scaffolds with collagen, alginate, and alginate-gelatin composite bioinks from a digital corneal model. Compression testing was used to determine moduli.

Results

The printed model was visually transparent with tunable mechanical properties. The model had central radius of curvature of 7.4 mm, diameter of 13.2 mm, and central thickness of 0.4 mm. The compressive secant modulus of the material was 23.7 ± 1.7 kPa at 20% strain. 3D printing into a concave mold had reliability advantages over printing into a convex mold.

Conclusions

The printed corneal models exhibited visible transparency and a dome shape, demonstrating the potential of this process for the preparation of acellular partial thickness corneal replacements. The modified printing process presented a low-cost option for corneal bioprinting.

Keywords:

• 3D printing
• bioprinting
• cornea
• stroma
• hydrogel

Acknowledgements

The authors want to acknowledge Professor Adam Feinberg for kindly providing the printer modification instructions and the 3D printing files for the syringe extruder components.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data supporting the findings of this study are available from the corresponding author, Katelyn E. Swindle-Reilly, upon request.

Additional information

Funding

This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1343012, and support from The Ohio State University College of Engineering. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors(s) and do not necessarily reflect the views of the National Science Foundation.