Mechanically adaptive nanocomposites for neural interfacing
Mechanically adaptive nanocomposites for neural interfacing
复制标题
DOI：
10.1557/mrs.2012.97
复制
发表时间：
2012-06-01
期刊：
影响因子：
5
通讯作者：
Weder, Christoph
中科院分区：
文献类型：
--
作者：
Capadona, Jeffrey R.;Tyler, Dustin J.;Weder, Christoph
用植入大脑皮层的微电极记录神经信号对于一系列临床应用是潜在有用的。然而，这种神经接口的广泛使用到目前为止被扼杀，因为现有的皮质内电极系统很少允许神经活动的一致的长期记录。这种限制通常归因于植入电极表面附近的瘢痕形成和神经元死亡。有人提出，现有电极材料和脑组织之间的机械性能不匹配是导致这些事件的重要因素。为了缓解这个问题，我们利用海参真皮的结构作为蓝图，设计一类新的机械自适应材料作为“智能”皮质内电极的基底。我们证明，这些原本刚性的聚合物纳米复合材料在暴露于模拟的生理和体内条件下时大大软化。这些生物启发材料的自适应性质使它们可用作电极的基础，这些电极足够坚硬以易于植入，随后软化以更好地匹配大脑的硬度。初步的组织学评价表明，机械自适应神经假体可以更快地稳定神经细胞群在设备接口比刚性系统，这预示着改善皮质内设备的功能。
The recording of neural signals with microelectrodes that are implanted into the cortex of the brain is potentially useful for a range of clinical applications. However, the widespread use of such neural interfaces has so far been stifled because existing intracortical electrode systems rarely allow for consistent long-term recording of neural activity. This limitation is usually attributed to scar formation and neuron death near the surface of the implanted electrode. It has been proposed that the mechanical property mismatch between existing electrode materials and the brain tissue is a significant contributor to these events. To alleviate this problem, we utilized the architecture of the sea cucumber dermis as a blueprint to engineer a new class of mechanically adaptive materials as substrates for "smart" intracortical electrodes. We demonstrated that these originally rigid polymer nanocomposites soften considerably upon exposure to emulated physiological and in vivo conditions. The adaptive nature of these bioinspired materials makes them useful as a basis for electrodes that are sufficiently stiff to be easily implanted and subsequently soften to better match the stiffness of the brain. Initial histological evaluations suggest that mechanically adaptive neural prosthetics can more rapidly stabilize neural cell populations at the device interface than rigid systems, which bodes well for improving the functionality of intracortical devices.