A cataract is pathology opacity of the lens or capsule of the eye, causing impairment of vision or even blindness. Surgery, with lens extraction and intraocular lens implantation, is still the only currently available treatment. The most common complication after implantation of intraocular lenses (IOLs) is the posterior capsular opacification (PCO) or secondary cataract. This is the result of lens epithelial cells (LECs) proliferation and their transition to mesenchymal cells. In 1997, a Sandwich theory was proposed to elucidate the developmental process of PCO. [1] According to this model, an IOL with higher affinity to LECs will induce a less PCO.
In our research, the pHEMA (Poly(2-hydroxyethyl methacrylate)) based acrylic hydrophilic polymer is subjected to the surface modification by conjugating with the bioactive peptides. The RGD sequence, known for its excellent biocompatibility, is designed to stimulate the biointegration between the LECs and the polymer implant. [2]. From our research, The RGD peptide immobilized onto pHEMA surfaces significantly facilitates the adhesion of the porcine LEC. The peptide immobilized surface retains its biological function even after 10 times of autoclave. On the other hand, the immobilized peptide does not alter the hydrophobicity of the surface, the light transmission, as well as the cytotoxicity of the material. This functionalized biomaterial would possibly prevent the formation of PCO.
[1] J Cataract Refract Surg. 1997 Dec;23(10):1539-42
[2] Trends Biotechnol. 2008 Jul;26(7):382-9