The Effect of Polyhydroxyethylmethacrylate (Poly-HEMA), as a Cell Culture Substrate, on Viable and Preserving Nature of Retinal Pigment Epithelium (RPE) Cells

Document Type : Original Article (s)

Authors

1 National Institute of Genetic Engineering and Biotechnology, Tehran, Iran

2 Assistant Professor, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran

3 Assistant Professor, Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran

4 Assistant Professor, Iranian Blood Transfusion Organization Research Center, Tehran, Iran

Abstract

Background: Retinal pigment epithelium (RPE) cells play an important role in the maintenance of normal function of the retina. Tyrosinase is a marker of RPE cells that functions in synthesis of melanin. Polymer of polyhydroxyethylmethacrylate (Poly-HEMA) is the basic component of contact lenses. We investigated the effect of Poly-HEMA, as a cell culture substrate, on viable and preserving nature of RPE cells.Methods: RPE cells between passages 2 and 5 were cultured on Poly-HEMA (12 mg/ml) in 24 wells culture palates. Dulbecco's modified Eagle's medium (DMEM/F12) + 10% Fetal bovine serum (FBS) were used to nourish cultured cells on polystyrene and Poly-HEMA coated vessels. Morphology, the rate of cell proliferation and cell death of RPE cells cultured on Poly-HEMA polymer were evaluated in periodic times. Real-time polymerase chain reaction (RT-PCR) was performed to evaluate tyrosinase in cultured RPE cells.Findings: The cells cultured on Poly-HEMA formed many colonies. These colonies could be re-cultured on polystyrene. The number of RPE cells on Poly-HEMA and polystyrene were the same while the proliferation rate of the cultured cells on Poly-HEMA was reduced; no remarkable cell death was detected on polymer and on polystyrene plates. The giant colonies which were formed on Poly-HEMA were re-cultured. The expression of tyrosinase gene was detected 434.65 in cultured RPE cells on the polymer.Conclusion: Poly-HEMA is a hydrophobic polymer. When RPE cells were cultured on Poly-HEMA they could not adhere to substrate and formed many colonies. Based on our study, Poly-HEMA did not induce cell death in RPE cells but the proliferation of cells was reduced. Tyrosinase expression revealed that Poly-HEMA could support RPE cultures to establish their population as the main constituents of the giant colonies.

Keywords


  1. Klimanskaya I, Hipp J, Rezai KA, West M, Atala A, Lanza R. Derivation and comparative assessment of retinal pigment epithelium from human embryonic stem cells using transcriptomics. Cloning Stem Cells 2004; 6(3): 217-45.
  2. Strauss O. The retinal pigment epithelium in visual function. Physiol Rev 2005; 85(3): 845-81.
  3. Willermain F, Caspers-Velu L, Nowak B, Stordeur P, Mosselmans R, Salmon I, et al. Retinal pigment epithelial cells phagocytosis of T lymphocytes: possible implication in the immune privilege of the eye. Br J Ophthalmol 2002; 86(12): 1417-21.
  4. Pons M, Marin-Castano ME. Nicotine increases the VEGF/PEDF ratio in retinal pigment epithelium: a possible mechanism for CNV in passive smokers with AMD. Invest Ophthalmol Vis Sci 2011; 52(6): 3842-53.
  5. Baraboi VA. Melanin: structure, biosynthesis, biological functions. Ukr Biokhim Zh 1999; 71(4): 5-14. [In Russian].
  6. Limb GA, Daniels JT. Ocular regeneration by stem cells: present status and future prospects. Br Med Bull 2008; 85: 47-61.
  7. Barton DE, Kwon BS, Francke U. Human tyrosinase gene, mapped to chromosome 11 (q14----q21), defines second region of homology with mouse chromosome 7. Genomics 1988; 3(1): 17-24.
  8. Elejalde BR, Holguin J, Valencia A, Gilbert EF, Molina J, Marin G, et al. Mutations affecting pigmentation in man: I. Neuroectodermal melanolysosomal disease. Am J Med Genet 1979; 3(1): 65-80.
  9. Kwon BS, Haq AK, Pomerantz SH, Halaban R. Isolation and sequence of a cDNA clone for human tyrosinase that maps at the mouse c-albino locus. Proc Natl Acad Sci USA 1987; 84(21): 7473-7.
  10. Klein PA, Xiang JH, Kimura AK. Melanoma cells growing in aggregates on a non-adhesive poly(HEMA) substrate exhibit polykaryocytosis but do not develop an increased metastatic capability. Clin Exp Metastasis 1984; 2(4): 287-95.
  11. Studenovska H, Slouf M, Rypacek F. Poly(HEMA) hydrogels with controlled pore architecture for tissue regeneration applications. J Mater Sci Mater Med 2008; 19(2): 615-21.
  12. Lombello CB, Malmonge SM, Wada ML. Poly-HEMA and Poly-HEMA-poly(MMA-co-AA) as substrates for culturing Vero cells. J Mater Sci Mater Med 2000; 11(9): 541-6.
  13. Flynn L, Dalton PD, Shoichet MS. Fiber templating of poly(2-hydroxyethyl methacrylate) for neural tissue engineering. Biomaterials 2003; 24(23): 4265-72.
  14. Seidel JM, Malmonge SnM. Synthesis of Poly-HEMA hydrogels for using as biomaterials. Bulk and solution radical-initiated polymerization techniques. Materials Research 2000; 3: 79-83.
  15. Goda T, Ishihara K. Soft contact lens biomaterials from bioinspired phospholipid polymers. Expert Rev Med Devices 2006; 3(2): 167-74.
  16. Chirila TV. Melanized poly(HEMA) hydrogels: basic research and potential use. J Biomater Appl 1993; 8(2): 106-45.
  17. Sajadi SM, Samiei Sh, Kheirandish M, Ataiei Z, Meshkani R, Kavari M, et al. The association of FXIII Val34Leu polymorphism with thrombotic events in patients referring to Iranian Blood Transfusion Organization. Sci J Iran Blood Transfus Organ 2008; 4(4): 247-52.
  18. Soheili Z, Samiei S. Real time PCR: principles and application. Hepat Mon 2005; 5(3): 83-7.
  19. Packard RB, Garner A, Arnott EJ. Poly-HEMA as a material for intraocular lens implantation: a preliminary report. Br J Ophthalmol 1981; 65(8): 585-7.
  20. Glowacki J, Trepman E, Folkman J. Cell shape and phenotypic expression in chondrocytes. Proc Soc Exp Biol Med 1983; 172(1): 93-8.
  21. Jeyanthi R, Rao KP. Controlledrelease of anticancer drugs from collagen-poly(HEMA) hydrogel matrices. J Controlled Rel 1990; 13(1): 91-8.
  22. Kon M, de Visser AC. A poly(HEMA) sponge for restoration of articular cartilage defects. Plast Reconstr Surg 1981; 67(3): 288-94.