Givens Richard S, Yousef Abraham L, Yang Shaorong, Timberlake George T
Department of Chemistry, University of Kansas, Lawrence, KS, USA.
Photochem Photobiol. 2008 Jan-Feb;84(1):185-92. doi: 10.1111/j.1751-1097.2007.00218.x.
A new cross linking reagent based on the first-generation polyamidoamine dendrimer (G.1 PAMAM) has been synthesized by reaction of the PAMAM with eight equivalents of p-nitrophenyl diazopyruvate. The resulting water-soluble octadiazopyruvoyl PAMAM (8G.1 DAP, 1.3) was shown to undergo Wolff rearrangements upon photolysis in methanol at lambda > 300 nm to yield the methyl esters of the ketenes formed from the loss of nitrogen. 8G.1 DAP also forms strong bonds with dehydrated collagen with glass as high as 36 N cm(-2). Collagen to collagen bonds with tensile strengths as high as 92 N cm(-2) were observed with fully dehydrated tissues. The bonding decreased rapidly with increasingly hydrated tissue possibly due to the increased distance between the collagen fibrils and the competition of H2O for the free ketene functions.
通过使第一代聚酰胺 - 胺树枝状大分子（G.1 PAMAM）与八当量的对硝基苯基重氮丙酮酸反应，合成了一种新型交联剂。所得的水溶性八重氮丙酮酸基PAMAM（8G.1 DAP，1.3）在λ> 300 nm的甲醇中光解时会发生沃尔夫重排，生成由氮损失形成的烯酮的甲酯。8G.1 DAP还与脱水胶原蛋白形成强键，玻璃化程度高达36 N cm(-2)。在完全脱水的组织中观察到胶原蛋白与胶原蛋白之间的键，拉伸强度高达92 N cm(-2)。随着组织水合程度的增加，键合迅速减少，这可能是由于胶原纤维之间的距离增加以及H2O对游离烯酮官能团的竞争所致。
