Brunel Institute for Bioengineering, Brunel University, Uxbridge, London, UK.
Biomaterials. 2013 Jan;34(4):888-901. doi: 10.1016/j.biomaterials.2012.10.049. Epub 2012 Nov 9.
This study reports methods for coating miniature implantable glucose biosensors with electrospun polyurethane (PU) membranes, their effects on sensor function and efficacy as mass-transport limiting membranes. For electrospinning fibres directly on sensor surface, both static and dynamic collector systems, were designed and tested. Optimum collector configurations were first ascertained by FEA modelling. Both static and dynamic collectors allowed complete covering of sensors, but it was the dynamic collector that produced uniform fibro-porous PU coatings around miniature ellipsoid biosensors. The coatings had random fibre orientation and their uniform thickness increased linearly with increasing electrospinning time. The effects of coatings having an even spread of submicron fibre diameters and sub-100 μm thicknesses on glucose biosensor function were investigated. Increasing thickness and fibre diameters caused a statistically insignificant decrease in sensor sensitivity for the tested electrospun coatings. The sensors' linearity for the glucose detection range of 2-30 mM remained unaffected. The electrospun coatings also functioned as mass-transport limiting membranes by significantly increasing the linearity, replacing traditional epoxy-PU outer coating. To conclude, electrospun coatings, having controllable fibro-porous structure and thicknesses, on miniature ellipsoid glucose biosensors were demonstrated to have minimal effect on pre-implantation sensitivity and also to have mass-transport limiting ability.
本研究报告了一种将电纺聚氨酯（PU）膜涂覆在微型植入式葡萄糖生物传感器上的方法，以及它们对传感器功能和作为传质限制膜的效果。为了将纤维直接电纺到传感器表面上，设计并测试了静态和动态收集器系统。首先通过有限元分析（FEA）建模确定了最佳的收集器配置。静态和动态收集器都可以完全覆盖传感器，但动态收集器可以在微型椭圆体生物传感器周围产生均匀的纤维多孔 PU 涂层。涂层具有随机的纤维取向，其均匀厚度随电纺时间的增加呈线性增加。研究了具有均匀分布的亚微米纤维直径和亚 100μm 厚度的涂层对葡萄糖生物传感器功能的影响。增加厚度和纤维直径会导致传感器灵敏度呈统计上无显著下降。测试的电纺涂层对葡萄糖检测范围为 2-30mM 的线性度没有影响。电纺涂层还可以作为传质限制膜，通过显著提高线性度来替代传统的环氧-PU 外涂层。总之，在微型椭圆体葡萄糖生物传感器上涂覆具有可控的纤维多孔结构和厚度的电纺涂层，对植入前的灵敏度几乎没有影响，并且具有传质限制能力。
