Quantification of Non-Enzymatic Vitreous Collagen Glycosylation With a Dynamic Light Scattering Device

Abstract

Abstract: : Purpose:The role of non-enzymatic glycosylation in diabetic vitreo-retinopathy and the influence of vitamin C on the progression of this process was investigated in-vitro with a dynamic light scattering device (DLS). Methods:Collagen type II was extracted from porcine and bovine vitreous. The purified collagen has been incubated at 37°C with varying concentrations of glucose (10, 50, 133, 2800 mmol)in the presence or absence of vitamin C. Changes in molecular size over time (2 - 12 weeks) have been monitored with a dynamic light scattering device. Results: Crosslinking of collagen to form larger aggregates is enhanced by increasing glucose concentration over time. Vitamin C in varying concentrations reverses this process in-vitro by degrading the collagen. Dynamic light scattering measurements detected such changes also in very small samples. Conclusions: This in-vitro model proved suitable to study diabetic changes in the vitreous and DLS measurements were a sensitive tool to detect changes in molecular size before visible light scattering occurs.

Keywords: vitreous • diabetic retinopathy • glycoconjugates/glycoproteins