Design and evaluation of artificial cornea with core–skirt design using polyhydroxyethyl methacrylate and graphite

Original Paper
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Abstract

Purpose

Artificial cornea is the effective treatment option for corneal blindness. One of the challenges with the artificial cornea is limited, or no tissue integration necessitates reimplantation due to necrosis or corneal melting. We propose here a new formulation approach for core–skirt incorporating graphite in the outer skirt region to improve cell adhesion.

Methods

Hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate were procured from Sigma-Aldrich. Polyhydroxyethyl methacrylate (PHEMA) was synthesized by free radical polymerization of HEMA. PHEMA hydrogel core with graphite incorporated skirt was developed with the help of mould and spacer. Pores were introduced into the skirt by salt leaching technique using sodium chloride as porogen. The porous skirt was improved for its aesthetic appeal of black colour and mechanical strength to sustain intraocular pressure by incorporating graphite. The material properties of the newly developed design were evaluated in terms of wetting behaviour, mechanical strength, water vapour permeability, degradation profile and cell adhesion.

Results

The polymerization of HEMA was confirmed by thin layer chromatography and FTIR. Water content of the polymeric film was optimized at 50% where maximum transparency with required refractive index of 1.4 was obtained. The concentration of salt vital for the essential porosity was also optimized using optical microscopy and scanning electron microscopy. Other properties, namely mechanical strength, water vapour transmission rate and degradation behaviour, showed that the developed design is suitable for ocular applications. Furthermore, cell adhesion study confirmed tissue adhesion in the skirt region but absent in the core.

Conclusion

The core–skirt design may offer an efficient cornea replacement alternative with enhanced tissue integration in addition to desired mechanical behaviour with a clear and aesthetic vision.

Keywords

Artificial cornea Keratoprosthesis Core–skirt design Graphite PHEMA 

Notes

Compliance with ethical standards

Conflict of interest

The authors report no conflict of interest.

Supplementary material

10792_2017_586_MOESM1_ESM.jpg (23 kb)
Supplementary data: Texture analyser report for the needle force applied on the hydrogel. (JPG 23 kb)

References

  1. 1.
    Kadakia A, Keskar V, Titushkin I, Djalilian A, Gemeinhart RA, Cho M (2008) Hybrid superporous scaffolds: an application for cornea tissue engineering. Crit Rev Biomed Eng 36:441–471CrossRefPubMedGoogle Scholar
  2. 2.
    Chirila TV, Crawford GJ (1998) Artificial cornea. Prog Polym Sci 23:447–473CrossRefGoogle Scholar
  3. 3.
    National Eye Institute. Facts about the cornea and corneal disease, viewed 8th October 2014, http://www.nei.nih.gov/health/cornealdisease
  4. 4.
    Chen J, Li Q, Xu J, Huang Y, Ding Y, Deng H et al (2005) Study on biocompatibility of complexes of collagen–chitosan–sodium hyaluronate and cornea. Artif Organs 29:104–113CrossRefPubMedGoogle Scholar
  5. 5.
    Chirila TV (2001) An overview of the development of artificial corneas with porous skirts and the use of PHEMA for such an application. Biomaterials 22:3311–3317CrossRefPubMedGoogle Scholar
  6. 6.
    Garg P, Krishna PV, Stratis AK, Gopinathan U (2005) The value of corneal transplantation in reducing blindness. Eye 19:1106–1114CrossRefPubMedGoogle Scholar
  7. 7.
    Myung D, Koh W, Bakri A, Zhang F, Marshall A, Ko J et al (2007) Design and fabrication of an artificial cornea based on a photolithographically patterned hydrogel construct. Biomed Microdevices 9:911–922CrossRefPubMedGoogle Scholar
  8. 8.
    Baker MV, Brown DH, Casadio YS, Chirila TV (2009) The preparation of poly(2-hydroxyethyl methacrylate) and poly{(2-hydroxyethyl methacrylate)-co-[poly(ethylene glycol) methyl ether methacrylate]} by photoinitiated polymerisation-induced phase separation in water. Polymer 50:5918–5927CrossRefGoogle Scholar
  9. 9.
    Hassan E, Deshpande P, Claeyssens F, Rimmer S, Macneil S (2014) Amine functional hydrogels as selective substrates for corneal epithelialization. Acta Biomater 10:3029–3037CrossRefPubMedGoogle Scholar
  10. 10.
    Hicks CR, Crawford GJ, Lou X, Tan DT, Snibson GR, Sutton G et al (2003) Corneal replacement using a synthetic hydrogel cornea, AlphaCor: device, preliminary outcomes and complications. Eye 17:385–392CrossRefPubMedGoogle Scholar
  11. 11.
    Baino F, Vitale-brovarone C (2014) Bioceramics in opthalmology. Acta Biomater 10:3372–3397CrossRefPubMedGoogle Scholar
  12. 12.
    Eriksson C, Nygren H (1997) The initial reactions of graphite and gold with blood. J Biomed Mater Res 37:130–136CrossRefPubMedGoogle Scholar
  13. 13.
    Stary V, Bacakova L, Hornik J, Chmelik V (2003) Biocompatibility of the surface layer ofpyrolitic graphite. Thin Solid Films 433:191–198CrossRefGoogle Scholar
  14. 14.
    Rotem A (1994) Effect of implant material properties on the performance of a hip joint replacement. J Med Eng Technol 18:208–217CrossRefPubMedGoogle Scholar
  15. 15.
    Zainuddin, Barnard Z, Keen I, Hill DJT, Chirila TV, Harkin DG (2008) PHEMA hydrogels modified through the grafting of phosphate groups by ATRP support the attachment and growth of human corneal epithelial cells. J Biomater Appl 23:147–168CrossRefPubMedGoogle Scholar
  16. 16.
    Gulsen D, Chauhan A (2006) Effect of water content on transparency, swelling, lidocaine diffusion in p-HEMA gels. J Memb Sci 269:35–48CrossRefGoogle Scholar
  17. 17.
    Hu Y, Topolkaraev V, Hiltner A, Baer E (2001) Measurement of water vapor transmission rate in highly permeable films. J Appl Polym Sci 81:1624–1633CrossRefGoogle Scholar
  18. 18.
    Legeais JM, Renard G, Parel JM, Serdarevic O, Mei-Mui M, Pouliquen Y (1994) Expanded fluorocarbon for keratoprosthesis cellular ingrowth and transparency. Exp Eye Res 58:41–52CrossRefPubMedGoogle Scholar
  19. 19.
    Zellander A, Wardlow M, Djalilian A, Zhao C, Abiade J, Cho M (2014) Engineering copolymeric artificial cornea with salt porogen. J Biomed Mater Res A 102:1799–1808CrossRefPubMedGoogle Scholar
  20. 20.
    Bao X, Li W, Lu M, Zhou ZR (2016) Experiment study on puncture force between MIS suture needle and soft tissue. Biosurf Biotribol 2:49–58CrossRefGoogle Scholar
  21. 21.
    Chirila TV, Yu DY, Chen YC, Crawford GJ (1995) Enhancement of mechanical strength of poly(2-hydroxyethyl methacrylate) sponges. J Biomed Mater Res 29:1029–1032CrossRefPubMedGoogle Scholar
  22. 22.
    Lou X, Chirila TV, Clayton AB (1997) Hydrophilic sponges based on 2-hydroxyethyl methacrylate. IV. Novel synthetic routes to hydroxyl-containing crosslinking agents and their effect on the mechanical strength of sponges. Int J Polym Mater 37:1–14CrossRefGoogle Scholar
  23. 23.
    Jiang H, Zuo Y, Zhang L, Li J, Zhang A, Li Y, Yang X (2014) Property-based design: optimization and characterization of polyvinyl alcohol (PVA) hydrogel and PVA-matrix composite for artificial cornea. J Mater Sci Mater Med 25:941–952CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2017

Authors and Affiliations

  1. 1.Department of Medical DevicesNational Institute of Pharmaceutical Education and Research-AhmedabadPalaj, GandhinagarIndia

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