Biocompatibility of ocular prosthesis acrylic resin: in vitro and in vivo analysis

Abstract

The knowledge of ocular prosthesis material's biocompatibility is essential to ensure a safe use in anophtalmic patients. The aim of this study is to evaluate the biocompatibility of N1 acrylic resin for ocular prosthesis, polymerized by different cycles and methods, on human conjunctival cell line and in rats. Acrylic resin samples will be manufactured and divided into 3 groups, according to the polymerization method: N1 resin polymerized in water bath (NRWB), polymerized by microwave energy (NRME), and autopolymerized resin (ANR). For each group, different polymerization cycles will be evaluated. For the in vitro analysis, after the formation of eluates, corresponding to 24 and 72 hours of sample immersion in medium, their cytotoxic effect will be evaluated using MTT assay and Neutral Red, with Chang conjunctival cells. The eluates will be exposed to cells for 24 and 72 hours. Additionally, the production of different cytokines and chemokines through ELISA; mRNA expression of COL IV, TGF ², MMP9, Mcl-1 and caspases-3 and -9, by real time RT-PCR and; the detection of apoptotic cells by annexin V through flow cytometry and; the chemotactic response using a Boyden chamber will be evaluated. For the in vivo analysis, the tissue reaction will be analyzed by the implementation of samples from groups NRWB, NRME and ANR, polymerized according to the manufacturer's recommendation, in the dorsal connective tissue of Wistar rats for 3, 15 and 30 days. The specimens will be stained with hematoxylin and eosin, for qualitative and quantitative evaluations (inflammatory cell count). The specimens (samples and adjacent tissue) will be morphologically and quantitatively assessed, regarding the inflammatory process, and the immunohistochemical analysis will be performed for the detection of IL-1², IL-6, TNF±, IL-17 and CCL20. The quantitative data will be submitted to the test of normal-distribution, and appropriate statistical test will be applied. Keywords: Ocular prosthesis, acrylic resins, immune response, biocompatibility testing.