(499d) Oligo(trolox) – Synthesis and Characterization of An Antioxidant Polymer Additive for the Suppression of Biomaterial Oxidative Stress

Biodegradable polymers and copolymers like poly-lactic acid, poly-lactic-co-glycolic acid are considered to be biocompatible since their biodegradation results in residues that are already present in the body. However, recent studies have found out that local accumulation of both water-soluble and water-insoluble biodegradation products of such polymers trigger an inflammatory response which results in oxidative stress (Jiang, Su et al. 2007). We had proposed an idea of synthesizing biodegradable poly/oligomers having native antioxidant activity, biodegradation of which will result in release of active antioxidants, thereby attenuating the injury caused by oxidative stress and local inflammation.

In this work we polymerized trolox, a synthetic antioxidant, to form poly/oligo(trolox). Trolox is a water-soluble analogue of Vitamin E which scavenges free radicals and provides protection from mild forms of oxidative stress (Chow, Lynch et al. 1994). Polymer/oligomer was synthesized using Steglich Esterification (Wiener and Gilon 1986) and characterized using Fourier Transformed Infrared Spectroscopy (FTIR) and Gel Permeation Chromatography (GPC) was used to determine molecular weight. Effect of reaction conditions (e.g., reactant ratios and temperature) on extent of reaction, molecular weight of oligomer and antioxidant activity was studied. Polymer blending studies with standard degradable biomaterials (e.g., Polylactide and Poly(lactide-co-glyocolide)) was also performed.

References:

Chow, H. S., J. J. Lynch, 3rd, et al. (1994). "Trolox attenuates cortical neuronal injury induced by iron, ultraviolet light, glucose deprivation, or AMPA." Brain Res 639(1): 102-8.

Jiang, W. W., S. H. Su, et al. (2007). "Phagocyte responses to degradable polymers." J Biomed Mater Res A 82(2): 492-7.

Wiener, H. and C. Gilon (1986). "An Improved Method for the Catalytic Preparation of Tert-Butyl Esters of Carboxylic and Fatty-Acids." Journal of Molecular Catalysis 37(1): 45-52.