Laboratory of Interfaces and Nanostructures, Institute of Chemistry, Loránd Eötvös University, Budapest 112, P.O. Box 32, H-1518, Hungary.
J Colloid Interface Sci. 2011 Oct 15;362(2):600-6. doi: 10.1016/j.jcis.2011.06.055. Epub 2011 Jul 1.
Biodegradable polyesters such as poly(lactic-co-glycolic acid) copolymers (PLGA) are preferred materials for drug carrier systems although their surface hydrophobicity greatly limits their use in controlled drug delivery. PLGA thin films on a solid support blended with PEG-containing compound (Pluronic) were used as model systems to study the interfacial interactions with aqueous media. Degree of surface hydrophilization was assessed by wettability, and X-ray photoelectron spectroscopy (XPS) measurements. Protein adsorption behavior was investigated by in situ spectroscopic ellipsometry. The degree of protein adsorption showed a good correlation with the hydrophilicity, and surface composition. Unexpectedly, the layer thickness was found to have a great impact on the interfacial characteristics of the polymer films in the investigated regime (20-200 nm). Thick layers presented higher hydrophilicity and great resistance to protein adsorption. That special behavior was explained as the result of the swelling of the polymer film combined with the partial dissolution of Pluronic from the layer. This finding might promote the rational design of surface modified biocompatible nanoparticles.
可生物降解的聚酯如聚（乳酸-共-羟基乙酸）共聚物（PLGA）是药物载体系统的首选材料，尽管它们的表面疏水性极大地限制了它们在控制药物释放中的应用。PLGA 固体支持物上的薄膜与含有 PEG 的化合物（Pluronic）混合，用作模型系统以研究与水介质的界面相互作用。通过润湿性和 X 射线光电子能谱（XPS）测量评估表面亲水化程度。通过原位光谱椭圆术研究蛋白质吸附行为。蛋白质吸附程度与亲水性和表面组成具有很好的相关性。出乎意料的是，发现层厚度在研究范围内（20-200nm）对聚合物薄膜的界面特性有很大的影响。较厚的层表现出更高的亲水性和对蛋白质吸附的强抵抗力。这种特殊行为被解释为聚合物膜溶胀以及部分 Pluronic 从层中溶解的结果。这一发现可能会促进表面改性生物相容性纳米粒子的合理设计。
