Novel thermoresponsive polymers having biodegradable phosphoester backbones
Novel thermoresponsive polymers having biodegradable phosphoester backbones
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DOI：
10.1021/ma0715573
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发表时间：
2007-11-13
期刊：
影响因子：
5.5
通讯作者：
Akiyoshi, Kazunari
中科院分区：
文献类型：
--
作者：
Iwasaki, Yasuhiko;Wachiralarpphaithoon, Chookaet;Akiyoshi, Kazunari
介绍。热响应聚合物因其在许多领域的多功能性而在研究和技术领域得到广泛研究。聚合物材料的最新趋势是药物输送、1 生物活性分子的分离、2 和组织工程。 3 N-取代丙烯酰胺聚合物被发现具有相分离特性，当加热到某个较低临界溶解温度 (LCST) 以上时，其性能会发生变化。 4-6 特别是，N-异丙基丙烯酰胺 (NIPAAm) 是实现这一目标的最佳单体之一，其均聚物在 32°C 的水溶液中具有 LCST。 7 NIPAAm 可应用于多种共聚单体的聚合，并且聚合物的 LCST 可控制在生理温度附近。 8, 9 此外，活性自由基聚合最近已与 NIPAAm 一起用于制备具有明确结构的智能聚合物。 10-12 虽然 NIPAAm 是一种用于获得热响应性聚合物材料（例如刺激响应性表面、颗粒和水凝胶）的强大单体，但该聚合物不可生物降解。除了刺激响应性之外，生物降解性和生物相容性也是生物医学领域使用的聚合物材料的重要特性。虽然最近提出了一些可生物降解聚合物（例如脂肪族聚酯嵌段共聚物或多肽）的热响应性，13-16 热响应性可生物降解聚合物的分子设计和合成过程仍然受到限制。因此优选研究N-取代的丙烯酰胺聚合物。最近，聚磷酸酯由于其生物相容性以及与天然存在的核酸和磷壁酸的结构相似性而在生物和药物应用中引起了人们的兴趣。聚磷酸酯已被提议用于生物材料领域。 17-20 已提出多种聚磷酸酯的合成路线，包括开环聚合、21、22 缩聚、23 酯交换、24、25 和酶聚合。 26 有
Introduction. Thermoresponsive polymers are widely studied in both research and technology because of their versatility in many fields. Recent trends in polymer materials are drug delivery, 1 separation of bioactive molecules, 2 and tissue engineering. 3 N-substituted acrylamide polymers have been found to have a phase separation characteristic with changes occurring in their properties upon heating above a certain lower critical solution temperature (LCST). 4-6 In particular N-isopropylacrylamide (NIPAAm) is one of the best monomers for accomplishing this and the homopolymer has LCST at 32 C in aqueous solution. 7 NIPAAm can be applied to polymerization with a wide variety of comonomers and the LCST of the polymers can be controlled around physiological temperatures. 8, 9 Furthermore, living radical polymerization has recently been applied with NIPAAm for the preparation of smart polymers with welldefined structures. 10-12 Although NIPAAm is a robust monomer for obtaining thermoresponsive polymer materials such as stimuli-responsive surfaces, particles, and hydrogels, the polymers are not biodegradable.As well as a stimuli-responsive nature, biodegradability and biocompatibility are important characteristics for polymeric materials used in biomedical fields. While the thermoresponsivity of some biodegradable polymers such as aliphatic polyester block copolymers or polypeptides was recently proposed, 13-16 the molecular design and synthetic process of thermoresponsive biodegradable polymers are still limited. N-substituted acrylamide polymers are thus preferably studied. Recently, polyphosphoesters have appeared interesting for biological and pharmaceutical applications because of their biocompatibility and structural similarities to naturally occurring nucleic and teichoic acids. Polyphosphoesters have been proposed for use in the field of biomaterials. 17-20 A variety of synthetic routes for polyphosphoesters has been proposed including ring-opening polymerization, 21, 22 polycondensation, 23 transesterfication, 24, 25 and enzymatic polymerization. 26 There has