Separation and Detection of Tyrosine and Phenylalanine-derived Oxidative Stress Biomarkers Using Microchip Electrophoresis with Electrochemical Detection

This is the peer reviewed version of the following article: D. B. Weerasekara, S. M. Lunte, Electroanalysis 2022, 34, 1913, which has been published in final form at https://doi.org/10.1002/elan.202100580. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.A method for the determination of selected aromatic amino acid biomarkers of oxidative stress using microchip electrophoresis with electrochemical detection is described. The separation of the major reaction products of phenylalanine and tyrosine with reactive nitrogen and oxygen species was accomplished using ligand exchange micellar electrokinetic chromatography with a PDMS/glass hybrid chip. Electrochemical detection was achieved using a pyrolyzed photoresist film working electrode. The system was evaluated for the analysis of the products of the Fenton reaction with tyrosine and phenylalanine, and the reaction of peroxynitrite with tyrosine

Tocopherol Emulsions as Functional Autoantigen Delivery Vehicles Evoke Therapeutic Efficacy in Experimental Autoimmune Encephalomyelitis

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Molecular Pharmaceutics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/acs.molpharmaceut.8b00887.Contemporary approaches to treating autoimmune diseases like multiple sclerosis broadly modulate the immune system and leave patients susceptible to severe adverse effects. Antigen-specific immunotherapies (ASIT) offer a unique opportunity to selectively suppress autoreactive cell populations but have suffered from marginal efficacy even when employing traditional adjuvants to improve delivery. The development of immunologically active antigen delivery vehicles could potentially increase the clinical success of antigen-specific immunotherapies. An emulsion of the antioxidant tocopherol delivering an epitope of proteolipid protein autoantigen (PLP139–151) yielded significant efficacy in mice with experimental autoimmune encephalomyelitis (EAE). In vitro studies indicated tocopherol emulsions reduced oxidative stress in antigen-presenting cells. Ex vivo analysis revealed that tocopherol emulsions shifted cytokine responses in EAE splenocytes. In addition, IgG responses against PLP139–151 were increased in mice treated with tocopherol emulsions delivering the antigen, suggesting a possible skew in immunity. Overall, tocopherol emulsions provide a functional delivery vehicle for ASIT capable of ameliorating autoimmunity in a murine model