(493b) Synthesis and in Vitro Degradation Characteristics of Vitamin E-Derived Antioxidant Polymers

The type and severity of a host cell or tissue response to a degradable material depends on the toxicity of its low molecular weight degradation products and its rate of degradation. Studies have found out that local accumulation of the low molecular weight water-soluble and water-insoluble biodegradation products of the polymers can trigger an inflammatory response from the host cell or tissue.[1, 2] Oxidative stress, where oxidative species are generated in excess to the antioxidant defense mechanism, plays a major role in such biomaterial induced inflammatory response. We had proposed an idea of synthesizing biodegradable polymers 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 synthesized Vitamin E and trolox based antioxidant polymers using different polymerization schemes. Trolox is a water-soluble analogue of Vitamin E which scavenges free radicals and provides protection from mild forms of oxidative stress.[3] Vitamin E was conjugated to an acrylic acid based backbone through an ester linkage with and without a PEG-spacer. Effect of a PEG-spacer between ester linkage on the degradation characteristic of the polymer was studied. Trolox was polymerized via an polyester, poly(ester-anhydride) and poly(β-aminoester) route. Effect of the chemical structure on the degradation characteristics of trolox based polymers was studied. Polymer nanoparticles synthesized by single emulsion technique were incubated in buffer solutions. Antioxidant activity of the incubation solution resulting from the polymer degradation products was monitored over time using an in vitro assay.

References:

[1] W. W. Jiang, S. H. Su, R. C. Eberhart, L. Tang, J Biomed Mater Res A 2007, 82, 492.

[2] L. A. Matheson, J. P. Santerre, R. S. Labow, J Cell Physiol 2004, 199, 8.

[3] H. S. Chow, J. J. Lynch, 3rd, K. Rose, D. W. Choi, Brain Res 1994, 639, 102.