The Study Of Artficial Cornea Optical Center PVA Modification

Artificial cornea is a special refractive device which is made of heterogeneous forming material to replace cloudy corneal tissue in eyes. Corneal blindness has become the second largest human blinding disease, However, in the treatment of corneal disease, the donor cornea is far from meeting the needs of corneal transplant, so it is of great importance to study on artificial cornea. Ideal artificial cornea should have good biocompatibility, optical properties and mechanical properties, resolving prolapse and complications after implant surgery.Currently, the most widely used artificial cornea is mainly composed of porous skirt bracket and the optical center. In this paper, chitosan, nano-silver, carboxymethyl chitosan were chosen as raw material, the optical center of artificial cornea was modified by doping modification. The optical properties, mechanical properties, biocompatibility, hydrophilic and other properties were studied.The research includes the following aspects:1. CS/PVA hydrogel material was prepared by doping modification. The effects of CS content on the optical properties were investigated. The results showed that CS/PVA hydrogel material had good thermal stability. The moisture content was about 70.5% ~ 76.4%. Visible light transmittance was between 92% to 98%. The tensile strength and elongation at break meet application requirements.2. Carboxymethyl chitosan PVA composite hydrogel material was prepared by freezing-thawing method and doping modification. The properties of modified material were invesgated. Moisture content was between 76.6% ~ 81.9%. The swelling ratio was about 2.6~3.6. Visible light transmittance was between 95% to 98%. The contact angle decreased from 59° to 29°, which indicated the good hydrophilic properties. Mechanical properties test results confirmed that the material meet the requirements of practical application.3. Nano silver is broad spectrum bactericidal and virucidal compounds. Nano silver/PVA hydrogel material was prepared by doping. The effects of nano silver content on antibacterial, biocompatibility, the moisture content and the mechanical properties were investigated. The results showed that moisture content was between 75.1% ~ 78.4%, tensile strength was between 1.71 MPa ~ 1.83 MPa, elongation at break was between 278.35% ~ 286.41% between, mechanical properties meet the requirements of practical application. Antibacterial test results showed that the composite material played an inhibitory effect on E. coli and S. aureus. The inhibition of E. coli was stronger than S. aureus. Nano silver/PVA hydrogel material had a certain antibacterial properties.4. The biocompatibility evaluation results of nano sliver PVA hydrogel material showed no evidence of acute toxicity, in vitro cytotoxicity are 1 grade, skin reaction are slight. Skin reaction was not up to standard.