Saulnier Benjamin, Ponsart Stephanie, Coudane Jean, Garreau Henry, Vert Michel
Research Centre for Artificial Biopolymers, 5473 CNRS Joint Unit, University Montpellier 1, Faculty of Pharmacy, 15 Ave. Ch. Flahault, BP 14491, F-34093 Montpellier Cedex 5, France.
Macromol Biosci. 2004 Mar 15;4(3):232-7. doi: 10.1002/mabi.200300087.
Poly(lactic acid) polymers (PLA) are presently the most attractive compounds in the field of artificial degradable and biodegradable polymers. In order to enlarge the family, and thus the range of accessible properties, stereocopolymers and copolymers with various co-monomers have been synthesized. However, very few are functionalized, i.e. include functional groups attached to the main chains or as part of the side chains. In the search for degradable PLA-type polymers bearing functional groups to serve as intermediates for further chemical modifications, we are exploring two different routes. The first one is copolymerization with a protected hydroxyl-bearing lactide-type monomer, namely 3-(1,2,3,4-tetraoxobutyldiisopropylidene)dioxane-2,5-dione. The second route consists of the formation of a carbanionic site in the alpha-position to intrachain carbonyl functions by using lithium N,N-diisopropylamide followed by the coupling of electrophiles. Recent advances in this search are presented using several examples. In particular, it is shown that OH-functionalized PLA-type macromolecules can be made fluorescent by chemical coupling. It is also shown that substituents can be attached to PLA-type macromolecules in solution or to the surface of PLA-based devices selectively.
聚乳酸聚合物（PLA）目前是人工可降解和生物可降解聚合物领域中最具吸引力的化合物。为了扩大该聚合物家族，进而拓展其可获得的性能范围，人们合成了立体共聚物以及含有各种共聚单体的共聚物。然而，功能化的此类聚合物却非常少，即聚合物主链上或侧链中含有官能团的聚合物很少。在寻找带有官能团的可降解聚乳酸类聚合物作为进一步化学修饰中间体的过程中，我们正在探索两条不同的路线。第一条路线是与一种带有受保护羟基的丙交酯类单体，即3-(1,2,3,4-四氧代丁基二异丙叉基)二氧六环-2,5-二酮进行共聚。第二条路线是通过使用N,N-二异丙基氨基锂在链内羰基官能团的α位形成一个碳负离子位点，然后与亲电试剂进行偶联反应。本文通过几个实例展示了这一研究方向的最新进展。特别值得一提的是，经化学偶联反应后，带有羟基官能团的聚乳酸类大分子能够发出荧光。研究还表明，取代基能够选择性地连接到溶液中的聚乳酸类大分子上，或者连接到基于聚乳酸的器件表面。
