Abstract
Abstract: :
Purpose:Previously we described an acrylamide based reversible hydrogel material with disulfide bonds for use as a lens substitute material, (ARVO abstract 243, 2003). Polyacrylamide was chosen for its high resistance to UV and biodegradation; however, the acrylamide monomer is a known neurotoxin primarily due to the reactive carbon–carbon double bond. Since this double bond is consumed in the polymerization reaction, the formed polymer should not exhibit this toxicity. Because our re–gelling process allows for us to exhaustively wash the formed polymer free of any low molecular weight toxic components, we should be able to produce a biocompatible re–gelled material with little or no toxicity. Methods:To test for leachable materials in the polymer, 300 mg of Acryl–BAC6 (6 mole %) powder that was purified by sohxlet extraction, was dissolved in 10 ml Hank’s balanced salt solution, and allowed to gel. To this gel, 20 ml of 10% CS MEM tissue culture medium was added, then the gel and media were vigorously mixed for 24 hours. Control media was treated in an identical fashion, except no polymer was added. The gel material was removed by centrifugation and filtration. The resultant media was added undiluted to Chinese Hamster Ovarian (CHO) cells in monolayer. Dilutions of 1:2, 1:3 and 1:6, were also tested. Cells were incubated with the treated media for 72 hours at which time, an MTT viability assay was performed, (Bruining et al., Biomaterials 21: 595–604, 2000) . Results:The undiluted material did show some inhibition of cell growth. The morphology of the cells appeared similar to the control media. Toxicity Effect of Treated Media on CHO cells
Conclusions:Bruining et al. considered a 70% cutoff as a measurement of toxicity. This would indicate, that our leachable material from our polymer has a slight toxic effect in the undiluted media. Further studies using a high molecular weight cutoff dialysis tubing to remove low molecular weight toxic components are being conducted.
Keywords: aging • ciliary body • anterior segment