Ai Hua, Meng Hongdi, Ichinose Izumi, Jones Steven A, Mills David K, Lvov Yuri M, Qiao Xiaoxi
Department of Biomedical Engineering and Institute for Micromanufacturing, Louisiana Tech University, Ruston, LA 71272, USA.
J Neurosci Methods. 2003 Sep 30;128(1-2):1-8. doi: 10.1016/s0165-0270(03)00191-2.
Electrostatic layer-by-layer (LbL) self-assembly, a novel method for ultrathin film coating has been applied to silicone rubber to encourage nerve cell adhesion. The surfaces studied consisted of precursor layers, with alternating cationic poly(ethyleneimine) (PEI) and anionic sodium poly(styrenesulfonate) (PSS) followed by alternating laminin and poly-D-lysine (PDL) layers or fibronectin and PDL layers. Film growth increased linearly with the number of layers. Every fibronectin/PDL and laminin/PDL bilayer was 4.4 and 3.5 nm thick, respectively. All layers were more hydrophilic than the unmodified silicone rubber surface, as determined from contact angle measurements. Of the coatings studied, a PDL layer was the most hydrophilic. A multilayer film with composition [PSS/PEI]3+[fibronectin/PDL]4 or [PSS/PEI]3+[laminin/PDL]4 was highly favorable for neuron adhesion, in contrast to bare silicone rubber substrate. The film coated on silicone rubber is biocompatible for cerebellar neurons with active viability, as shown by lactate dehydrogenase (LDH) assay and fluorescence cellular metabolism observations. These results demonstrate that LbL self-assembly provides an effective approach to apply films with nanometer thickness to silicone rubber. Such only few nanometer thick films are biocompatible with neurons, and may be used to coat devises for long-term implant in the central nervous system.
静电逐层（LbL）自组装是一种用于超薄薄膜涂层的新方法，已应用于硅橡胶以促进神经细胞黏附。所研究的表面由前体层组成，先交替沉积阳离子聚（乙烯亚胺）（PEI）和阴离子聚苯乙烯磺酸钠（PSS），然后交替沉积层粘连蛋白和聚-D-赖氨酸（PDL）层或纤连蛋白和PDL层。膜的生长随层数呈线性增加。每一个纤连蛋白/PDL和层粘连蛋白/PDL双层分别为4.4纳米和3.5纳米厚。通过接触角测量确定，所有层都比未改性的硅橡胶表面更亲水。在所研究的涂层中，PDL层最亲水。与裸露的硅橡胶基材相比，具有[PSS/PEI]3+[纤连蛋白/PDL]4或[PSS/PEI]3+[层粘连蛋白/PDL]4组成的多层膜对神经元黏附非常有利。如乳酸脱氢酶（LDH）测定和荧光细胞代谢观察所示，涂覆在硅橡胶上的膜对具有活性活力的小脑神经元具有生物相容性。这些结果表明，LbL自组装为将纳米厚度的薄膜应用于硅橡胶提供了一种有效方法。这种仅几纳米厚的薄膜与神经元具有生物相容性，可用于涂覆用于中枢神经系统长期植入的装置。
