NER: Intracellular Nanoprobes for Physical Manipulation of Cells

CBET-0707969冬季申请人正在创造细胞内纳米探针，用于使用磁性纳米颗粒(即超顺磁性氧化铁纳米颗粒)对细胞进行物理操作。SPION是机械细胞纳米探测器的优秀候选材料，因为它们可以作为物理执行器，在磁场的作用下产生受控的、由研究人员触发的力。此前，包裹在磁性微球中的SPION已被用来检测细胞对细胞外力的反应。这些研究表明，细胞骨架是一个生物聚合物网络，负责细胞的机械完整性，是一个复杂的机械转导系统的一部分，可以影响许多细胞的功能。然而，这些研究使用的是大颗粒，几乎是细胞大小的一半，这些颗粒通过细胞外表面受体与细胞骨架间接连接。尽管已经尝试在细胞内使用较小的SPION，但这些方法依赖于颗粒内吞作用来传递。颗粒仍然被困在内体中，不能与细胞质结构相互作用。因此，直接操纵细胞骨架的可能性在很大程度上还没有被开发出来。在这项提议中，研究人员将使用SPION作为细胞内的物理纳米探针，直接、有针对性地操纵肌动蛋白细胞骨架。作为一个模型系统，靶向和非靶向细胞骨架操作在成纤维细胞迁移中的作用将被探索。细胞迁移是胚胎发育、神经再生、肿瘤转移和伤口修复的关键因素。使用纳米颗粒控制细胞迁移的能力可能会对发育生物学产生重大影响，并为慢性或灾难性伤口护理提供新的治疗途径。

CBET-0707969 Winter The applicant is creating intracellular nanoprobes for the physical manipulationof cells using magnetic nanoparticles (i.e., supraparamagnetic iron oxide nanoparticles(SPIONs)). SPIONs are excellent candidate materials for mechanical cellular nanoprobesbecause they can serve as physical actuators, producing a controlled, investigator-triggeredforce in response to a magnetic field. Previously, SPIONs encapsulated in magneticmicrospheres have been used to examine the response of cells to extracellular force. Thesestudies demonstrated that the cytoskeleton, a biopolymer network responsible for the mechanicalintegrity of cells, is part of an elaborate mechanotransduction system that can influence manycell functions. However, these studies use large particles, nearly half the size of a cell, whichindirectly interface with the cytoskeleton through extracellular cell surface receptors. Althoughsome attempts have been made to use smaller SPIONs inside a cell, these methods rely onparticle endocytosis for delivery. Particles remain trapped in endosomes, unable to interact withcytoplasmic structures. Thus, the potential to manipulate the cytoskeleton directly remainslargely untapped.In this proposal the investigator will employ SPIONs as physical intracellular nanoprobes for direct, targeted manipulation of the actin cytoskeleton. As a model system, the roleof targeted versus untargeted cytoskeletal manipulation in fibroblast cell migration will be explored. Cell migration is a critical factor in embryonic development, nerve regeneration, tumor metastasis and wound healing repair. The ability to control cell migration using nanoparticles could have substantial implications for developmental biology and provide new therapeutic avenues for chronic or catastrophic wound care.