Deciphering the nanomaterial uptake in a bystander manner invoked by co-administration of functionalized nanoparticles

摘要 纳米材料的细胞生物学是纳米材料应用中一个重要但尚未充分研究的方面 运输到细胞和通过组织。克服细胞膜到达它们的作用部位 其中，纳米颗粒（NP）通常与细胞穿透配体复合。这样的配体包括肽 比如达特（Trans-Activating Transcription）。这些配体与细胞表面受体结合， NP摄取的内吞过程。然而，这些官能化NP的影响和由此产生的纳米颗粒的性质是不确定的。 其他NP的细胞摄取的内吞过程仍然未知。在这份建议中，我的目标是解决这个问题 本文通过对TAT耦合NP（TAT-NP）的研究，提出了一个新的问题。 通过追踪包被有几种细胞穿透肽（包括达特）的纳米颗粒，我们先前发现了一种新的细胞穿透肽。 NP摄取的新型受体依赖性巨胞饮（MP）途径。MP具有相对大的内吞作用， 空泡（直径>200 nm），因此可以更容易地吞噬与纳米颗粒一样大的货物。这里我们 发现TAT-NPs通过激活MP通路，可以将无法进入细胞的旁观者NPs带入细胞 细胞本身。这种旁观者摄取依赖于达特与其受体硫酸乙酰肝素的相互作用 (HS)蛋白聚糖，并通过HS依赖性MP途径发生。我们进一步表明，它只是 对NP型旁观者货物有活性，并且其活性被细胞外的半胱氨酸（Cys）极大地刺激。 在这里，我们的目标是剖析这个旁观者吸收过程。在目标1中，我们将确定 启动旁观者摄取。在目标2和3中，我们将利用基因筛选和其他方法， 确定介导这种旁观者摄取的因素，并确定其货物选择性的性质， Cys调节。在目标4中，我们将探索在生物医学应用中的潜在用途。我建议的 研究具有很大的潜力，可以揭示纳米材料运输的重要细胞机制， 细胞内传递的效率，并开辟了一条新的途径，研究细胞生物学，代谢和 纳米材料输送。

Abstract One important yet understudied aspect in nanomaterial applications is the cell biology of nanomaterial transport into cells and through tissues. To overcome the cell membranes and reach their sites of action within, nanoparticles (NPs) are often complexed with cell-penetrating ligands. Such ligands include peptides like TAT (Trans-Activating Transcription). These ligands engage with cell surface receptors to invoke endocytic processes for NP uptake. However, the impact of these functionalized NPs and the resulting endocytic process on the cellular uptake of other NPs remains unknown. In this proposal, I aim to tackle this problem by studying TAT-coupled NPs (TAT-NP). By tracing NPs coated with several cell-penetrating peptides, including TAT, we previously discovered a novel receptor-dependent macropinocytosis (MP) pathway for NP uptake. MP has relatively large endocytic vacuoles (>200 nm in diameter) and thus can more readily engulf cargo as large as nanoparticles. Here, we found that TAT-NPs, by invoke this MP pathway, can bring into cells bystander NPs that are unable to enter the cells by themselves. This bystander uptake depends on TAT interaction with its receptor, heparan sulfate (HS) proteoglycans, and occurs through the HS-dependent MP pathway. We further showed that it is only active for NP-type bystander cargo, and its activity is greatly stimulated by Cysteine (Cys) outside the cells. Here, we aim to dissect out this bystander uptake process. In the Aim 1, we will determine the prerequisites for initiating the bystander uptake. In the Aim 2 and 3, we will utilize genetic screening and other methods to determine the factors that mediate this bystander uptake, and define its properties of cargo selectivity and Cys regulation. In the Aim 4, we will explore the potential use in biomedical applications. My proposed studies hold great potential for unveiling important cellular machineries for nanomaterial transport, boosting the efficiency of intracellular delivery, and opening up a new avenue to study cell biology, metabolism and nanomaterial delivery.