Valdes T I, Moussy F
University of Connecticut Health Center, Center for Biomaterials and Surgical Research, Farmington 06030-1615, USA.
Biosens Bioelectron. 1999 Jun 30;14(6):579-85. doi: 10.1016/s0956-5663(99)00023-8.
Since the perfluorosulfonated ionomer Nafion, commonly used for the protection of biosensors, experiences calcification in a biological environment, we evaluated the efficacy of preincubating Nafion membranes in a FeCl3 solution to reduce the number of nucleation sites responsible for the growth of the calcium phosphate crystals. Nafion membranes were prepared and divided into two groups. In the first group, the Nafion membranes were pre-incubated in 0.1 M FeCl3 for a 24 h period. In the second group, no pre-incubation took place. All membranes were placed in a culture medium for a period of up to 4 weeks. All membranes were then examined for changes in: (1) their surface topography (using scanning electron microscopy (SEM)); (2) their near surface chemical properties (using energy dispersive X-ray (EDX)); and (3) their permeability to glucose. The membranes that were not pre-incubated in FeCl3 showed significant cracking of the Nafion surface, extensive calcium phosphate deposits and a resulting decrease in permeability. In contrast, the membranes treated with FeCl3 showed almost no cracking, very little calcium phosphate deposits and no change in permeability to glucose. This study demonstrated that FeCl3 significantly reduces calcification of Nafion and thus should help in preserving the in vivo function of implantable biosensors that utilize Nafion in their design.
由于常用于生物传感器保护的全氟磺酸离子聚合物Nafion在生物环境中会发生钙化，我们评估了将Nafion膜在FeCl₃溶液中预孵育以减少负责磷酸钙晶体生长的成核位点数量的效果。制备了Nafion膜并将其分为两组。在第一组中，将Nafion膜在0.1 M FeCl₃中预孵育24小时。在第二组中，不进行预孵育。将所有膜置于培养基中长达4周。然后检查所有膜在以下方面的变化：(1) 其表面形貌（使用扫描电子显微镜(SEM)）；(2) 其近表面化学性质（使用能量色散X射线(EDX)）；以及(3) 其对葡萄糖的渗透性。未在FeCl₃中预孵育的膜显示出Nafion表面明显开裂、大量磷酸钙沉积以及由此导致的渗透性降低。相比之下，用FeCl₃处理的膜几乎没有开裂、磷酸钙沉积极少且对葡萄糖的渗透性没有变化。这项研究表明，FeCl₃显著减少了Nafion的钙化，因此应有助于保留在设计中使用Nafion的可植入生物传感器的体内功能。
