Laboratory for Nanomedicine Research, School of Engineering, Brown University, Providence, RI 02917, USA.
Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2010 Nov-Dec;2(6):635-47. doi: 10.1002/wnan.109.
Numerous biomaterials have provided promising results toward improving the function of injured nervous system tissue. However, significant hurdles, such as delayed or incomplete tissue regeneration, remain toward full functional recovery of nervous system tissue. Because of this continual need for better nervous system biomaterials, more recent approaches to design the next generation of tissue engineering scaffolds for the nervous system have incorporated nanotechnology, or more specifically, nanoscale surface feature dimensions which mimic natural neural tissue. Compared to conventional materials with micron-scale surface dimensions, nanomaterials have exhibited an ability to enhance desirable neural cell activity while minimizing unwanted cell activity, such as reactive astrocyte activity in the central nervous system. The complexity of neural tissue injury and the presence of inhibitory cues as well as the absence of stimulatory cues may require multifaceted treatment approaches with customized biomaterials that nanotechnology can provide. Combinations of stimulatory cues may be used to incorporate nanoscale topographical and chemical or electrical cues in the same scaffold to provide an environment for tissue regeneration that is superior to inert scaffolds. Ongoing research in the field of electrically active nanomaterials includes the fabrication of composite materials with nanoscale, piezoelectric zinc oxide particles embedded into a polymer matrix. Zinc oxide, when mechanically deformed through ultrasound, for example, can theoretically provide an electrical stimulus, a known stimulatory cue for neural tissue regeneration. The combination of nanoscale surface dimensions and electrical activity may provide an enhanced neural tissue regeneration environment; such multifaceted nanotechnology approaches deserve further attention in the neural tissue regeneration field.
许多生物材料在改善受损神经系统组织的功能方面取得了有希望的结果。然而,在神经系统组织的完全功能恢复方面,仍然存在着显著的障碍,如延迟或不完全的组织再生。由于对更好的神经系统生物材料的持续需求,最近设计下一代神经系统组织工程支架的方法已经结合了纳米技术,或者更具体地说,是模仿天然神经组织的纳米级表面特征尺寸的纳米技术。与具有微米级表面尺寸的传统材料相比,纳米材料表现出增强理想神经细胞活性的能力,同时最小化不需要的细胞活性,如中枢神经系统中的反应性星形胶质细胞活性。神经组织损伤的复杂性以及抑制性线索的存在和刺激性线索的缺乏可能需要使用纳米技术提供的定制生物材料进行多方面的治疗方法。刺激线索的组合可用于将纳米级形貌、化学或电线索结合到同一支架中,为组织再生提供优于惰性支架的环境。当前在电活性纳米材料领域的研究包括将纳米级、压电氧化锌颗粒嵌入聚合物基质中制造复合材料。例如,氧化锌通过超声机械变形,理论上可以提供电刺激,这是神经组织再生的已知刺激线索。纳米级表面尺寸和电活性的组合可能提供增强的神经组织再生环境;这种多方面的纳米技术方法值得在神经组织再生领域进一步关注。