Synthesis and characterization of spherical magnetite/biodegradable polymer composite particles
Synthesis and characterization of spherical magnetite/biodegradable polymer composite particles
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DOI：
10.1006/jcis.2001.7579
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发表时间：
2001-08-01
影响因子：
9.9
通讯作者：
Delgado, AV
中科院分区：
文献类型：
--
作者：
Gómez-Lopera, SA;Plaza, RC;Delgado, AV
首先描述了一种制备由磁铁矿核和可生物降解的聚（dl -丙交酯）聚合物涂层形成的胶体颗粒的方法。该方法基于所谓的双乳技术，用于获得装载治疗药物的聚合物球，用作药物传递载体。这项工作的目的是，以一种可重复的、相当简单的方式，获得既对磁场有反应，又能作为药物输送系统使用的胶体颗粒。为了研究在多大程度上实现了这一目标，我们将复合粒子的结构、化学成分和表面性能与核和涂层材料的结构、化学成分和表面性能进行了比较。虽然磁铁矿的表面性质没有完全被掩盖，但初步研究表明，合成的新材料表现出介于磁铁矿和聚乳酸球之间的行为。因此，电泳测量作为pH的函数表明，核/壳胶体的等电点（pH(iep) = 5.2）介于磁铁矿（pH(iep) = 7）和聚合物（pH(iep) < 2）之间。当对三种类型的粒子进行表面热力学研究时，得出了类似的结论：固体表面自由能的电子给体分量是对表面组成最敏感的量。聚（dl -丙交酯）接近于非极性材料，这一事实导致表面自由能的电子给体成分明显下降，尽管在电子受体和极性范德华成分中也可以观察到涂层的影响。(C) 2001学术出版社。
A method for preparing colloidal particles formed by a magnetite nucleus and a biodegradable poly(DL-lactide) polymer coating is first described. The method is based on the so-called double-emulsion technique, employed to obtain polymeric spheres loaded with therapeutic drugs, to be used as drug delivery vectors. The aim of this work was to obtain, in a reproducible and rather simple way, colloidal particles that were both magnetic field responsive, and useful as drug delivery systems. In order to investigate to what extent is this target achieved, we compare the structure, chemical composition, and surface properties of the composite particles with those of the nucleus and the coating material. Although the surface properties of the magnetite core are not completely masked, this preliminary study shows that the synthetic new material displays a behavior intermediate between that of magnetite and poly (DL-lactide) spheres. Thus, electrophoresis measurements as a function of pH shows that the isoelectric point (pH(iep) = 5.2) of core/shell colloids is in between those of magnetite (pH(iep) = 7) and polymer (pH(iep) < 2). A similar conclusion is reached when a surface thermodynamic study is performed on the three types of particles: the electron-donor component of the surface free energy of the solids is the quantity that appears to be most sensitive to the surface composition. The fact that poly(DL-lactide) is close to being a nonpolar material gives rise to a measurable decrease in the electron-donor component of the surface free energy, although the effect of coating is also observable in the electron-acceptor and the apolar van der Waals component. (C) 2001 Academic Press.