Assessment Method of Remnant α-1, 3-galactosyle Epitopes in Animal Tissue-derived Biomaterials / 生物医学工程学杂志

The aim of this study was to establish an assessment method for determining α-Gal (α-1, 3-galactosyle) epitopes contained in animal tissue or animal tissue-derived biological materials with ELISA inhibition assay. Firstly, a 96 well plate was coated with Gal α-1, 3-Gal/bovine serum albumin (BSA) as a solid phase antigen and meanwhile, the anti-α-Gal M86 was used to react with α-Gal antigens which contained in the test materials. Then, the residual antibodies (M86) in the supernatant of M86-Gal reaction mixture were measured using ELISA inhibition assay by the α-Gal coating plate. The inhibition curve of the ELISA inhibition assay, the R2 = 0.999, was well established. Checking using both α-Gal positive materials (rat liver tissues) and α-Gal negative materials (human placenta tissues) showed a good sensitivity and specificity. Based on the presently established method, the α-Gal expression profile of rat tissues, decellular animal tissue-derived biological materials and porcine dermal before and after decellular treatment were determined. The M86 ELISA inhibition assay method, which can quantitatively determine the α-Gal antigens contained in animal tissues or animal tissue-derived biomaterials, was refined. This M86 specific antibody based-ELISA inhibition assay established in the present study has good sensitivity and specificity, and could be a useful method for determining remnant α-1, 3Gal antigens in animal tissue-derived biomaterials.

Alpha-Gal antigen and immunity risk control of animal-derived medical devices / 中国组织工程研究

BACKGROUND:Medical devices from animals are commonly used in clinical application. Despite their efficiency is widely accepted, their safety, especialy immunity has been concerned. OBJECTIVE:To investigate immunity risk control to medical devices from animals for safety consideration. METHODS:Using “α-Gal antigen, immunity, xenotransplantation” in Chinese and English as the key words, the first author conducted a computer search of Science direct database (www.sciencedirect.com), Wiley-Blackewel database (http://onlinelibrary.wiley.com) and Wanfang database (www.wanfang.com.cn) through screening the titles and abstracts. RESULTS AND CONCLUSION:Increasing evidence shows that, Gal α1-3Gal antigen (α-Gal antigen) is recognized as the major antigen and abundantly expressed on glycoconjugates of non-primate mammals and New World monkeys. In contrast, the α-gal epitope is not expressed on glycoconjugates of humans and Old World monkeys. Instead, they produce a very large amount of natural anti-α-Gal antibody that specificaly binds the α-gal epitope. The binding of human natural anti-α-Gal to α-gal epitopes expressed on non-primate mammal animals was expected to be unique immunological barrier in xenotransplantation. Therefore, it is important to choose raw materials, reduce or eliminate the α-Ggal epitope, establish highα-Ggal epitope detection methods with high sensitivity and good repeatability for achieving a greater safety and efficiency of medical devices from animals.