Centrifugation-Free Magnetic Isolation of Functional Mitochondria Using Paramagnetic Iron Oxide Nanoparticles.

Subcellular fractionation techniques are of tremendous importance in the field cellular biology, drug development, and many others. With the emergence of organelle targeted nanoparticle (NP) platforms, it is getting increasingly important to isolate target organelles in order to determine localization and activity of these agents. Mitochondria targeted NPs attracted attention of researchers around the globe since dysfunctions of this organelle can result in a wide range of diseases. Conventional mitochondria isolation methods involve high-speed centrifugation. The inherent problem associated with high speed centrifugation-based isolation of NP-loaded mitochondria using these conventional methods can arise from settling down of NPs along with the organelle irrespective of whether these NPs are truly associated with mitochondria or not. We report development of a mitochondria-targeted paramagnetic iron oxide nanoparticle, Mito-magneto, that enables isolation of mitochondria under the influence of a magnetic field. The mitochondria isolated using this centrifugation-free method are not only intact, pure and respiration active but also eliminates artifacts that are typically associated with isolation of NP-loaded mitochondria using centrifugation.

亚细胞分级分离技术在细胞生物学、药物开发等诸多领域都极为重要。随着细胞器靶向纳米颗粒（NP）平台的出现，为了确定这些试剂的定位和活性，分离靶细胞器变得越来越重要。线粒体靶向纳米颗粒引起了全球研究人员的关注，因为该细胞器的功能障碍可导致多种疾病。传统的线粒体分离方法涉及高速离心。使用这些传统方法基于高速离心分离负载纳米颗粒的线粒体所带来的固有问题可能源于纳米颗粒与细胞器一起沉降，无论这些纳米颗粒是否真的与线粒体相关。我们报道了一种线粒体靶向的顺磁性氧化铁纳米颗粒——Mito - magneto的研发，它能够在磁场作用下分离线粒体。使用这种无离心方法分离的线粒体不仅完整、纯净且具有呼吸活性，还消除了通常与使用离心法分离负载纳米颗粒的线粒体相关的假象。