Bousquet A, Perrier-Cornet R, Ibarboure E, Papon E, Labrugère C, Héroguez V, Rodríguez-Hernández J
Laboratoire de Chimie des Polymeres Organiques, LCPO-CNRS-Universite Bordeaux 1, ENSCPB-16, Avenue Pey Berland, 33607 Pessac-Cedex, France.
Biomacromolecules. 2008 Jul;9(7):1811-7. doi: 10.1021/bm8000292. Epub 2008 Jun 3.
In this contribution, the principle of spontaneous surface segregation has been applied for the preparation of polypeptide-functionalized polystyrene microspheres. For that purpose, an amphiphilic diblock copolymer was introduced in the mixture styrene/divinylbenzene and polymerized using AIBN as initiator. During the polymerization, cross-linked particles were obtained in which the diblock copolymer was encapsulated. The amphiphilic diblock copolymers used throughout this study contain a hydrophilic polypeptide segment, either poly(L-lysine) or poly(L-glutamic acid) and a hydrophobic polystyrene block. After 4 h of polymerization, rather monodisperse particles with sizes of approximately 3-4 microm were obtained. Upon annealing in hot water, the hydrophilic polypeptides migrate to the interface, hence, either positively charged or neutral particles were obtained when poly(L-lysine) is revealed at the surface and exposed to acidic or basic pH, respectively. On the opposite, negatively charged particles were achieved in basic pH water by using poly(L-glutamic acid) as additive. The surface chemical composition was modified by changing the environment of the particles. Thus, exposure in toluene provoked a surface rearrangement, and due to its affinity, the polystyrene block reorients toward the interface.
在本研究中，自发表面偏析原理已被应用于制备多肽功能化的聚苯乙烯微球。为此，将两亲性二嵌段共聚物引入苯乙烯/二乙烯基苯混合物中，并以偶氮二异丁腈（AIBN）作为引发剂进行聚合。在聚合过程中，得到了包封有二嵌段共聚物的交联颗粒。本研究中使用的两亲性二嵌段共聚物包含一个亲水性多肽链段，即聚（L-赖氨酸）或聚（L-谷氨酸），以及一个疏水性聚苯乙烯链段。聚合4小时后，得到了尺寸约为3 - 4微米的相当单分散的颗粒。在热水中退火后，亲水性多肽迁移到界面，因此，当聚（L-赖氨酸）暴露在表面并分别处于酸性或碱性pH值时，可得到带正电或中性的颗粒。相反，通过使用聚（L-谷氨酸）作为添加剂，在碱性pH值的水中可得到带负电的颗粒。通过改变颗粒的环境来修饰表面化学成分。因此，暴露于甲苯中会引起表面重排，并且由于其亲和力，聚苯乙烯链段会重新定向到界面。
