Veccharelli Kate M, Tong Venus K, Young Jennifer L, Yang Jerry, Gianneschi Nathan C
Department of Chemistry and Biochemistry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093, USA.
Chem Commun (Camb). 2016 Jan 11;52(3):567-70. doi: 10.1039/c5cc07882b. Epub 2015 Nov 6.
Polylactic acid (PLA) has found widespread use in plastics and in biomedical applications due to its biodegradability into natural benign products. However, PLA-based materials remain limited in usefulness due to difficulty of incorporating functional groups into the polymer backbone. In this paper, we report a strategy for PLA functionalization that establishes the preparation of highly derivatized materials in which ring opening metathesis polymerization (ROMP) is employed as a graft-from polymerization technique utilizing a norbornene-modified handle incorporated into the PLA backbone. As a demonstration of this new synthetic methodology, a PLA-derived nanoparticle bearing imidazole units protected with a photolabile group was prepared. The morphology of this material could be controllably altered in response to exposure of UV light or acidic pH as a stimulus. We anticipate that this graft-from approach to derivatization of PLA could find broad use in the development of modified, biodegradable PLA-based materials.
聚乳酸（PLA）因其可生物降解为天然良性产物而在塑料和生物医学应用中得到广泛应用。然而，由于难以将官能团引入聚合物主链，基于PLA的材料在实用性方面仍然受到限制。在本文中，我们报告了一种PLA功能化策略，该策略确立了高衍生化材料的制备方法，其中开环易位聚合（ROMP）被用作接枝聚合技术，利用并入PLA主链的降冰片烯修饰的手柄。作为这种新合成方法的一个实例，制备了一种带有用光不稳定基团保护的咪唑单元的PLA衍生纳米颗粒。该材料的形态可以根据紫外光照射或酸性pH刺激而可控地改变。我们预计，这种对PLA进行衍生化的接枝方法可在开发改性的、可生物降解的PLA基材料中得到广泛应用。
