The introduction of nanoparticles to intact plant cells is promising as a transporting technique of a wide range of functional molecules. Among various molecular delivery methods, femtosecond laser photoinjection possesses target selectivity at a single cell level and is potentially applicable for many types of materials. However, for plant cells, the vacuoles’ turgor pressure and the thick cell wall limit the application of photoinjection to only small objects. In this work, we overcome these limitations by employing a single pulse irradiation from a femtosecond laser amplifier. After laser irradiation on intact tobacco BY-2 cells, 80 nm fluorescent nanoparticles dispersed in a cell culture medium were successfully injected into their cytoplasm. This breakthrough would lead to a vast utilization of nanoparticles containing functional molecules for single cell manipulation in plant physiological study and genetic engineering. Such an injection was observed even when the laser pulse was focused neither on the cell wall nor on the cell membrane, but beside the cells. With these results, we suggest pore formation on the cell membrane by instantaneous deformation induced by an intense femtosecond laser pulse as an injection mechanism of nanoparticles. Reported photomechanical effects of the amplified femtosecond laser on the permeability of the biological membrane would offer new perspectives in biophotonics.

中文翻译：

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使用飞秒激光放大器将荧光纳米粒子光注射到完整的植物细胞中

将纳米颗粒引入完整的植物细胞中有望作为多种功能分子的转运技术。在各种分子递送方法中，飞秒激光光注射在单个细胞水平上具有目标选择性，并且可能适用于多种类型的材料。但是，对于植物细胞，液泡的膨胀压力和厚的细胞壁限制了光注入仅应用于小的物体。在这项工作中，我们通过使用飞秒激光放大器的单脉冲辐射克服了这些限制。在完好无损的烟草BY-2细胞上进行激光照射后，将分散在细胞培养基中的80 nm荧光纳米颗粒成功注入其细胞质中。这一突破将导致包含功能分子的纳米粒子在植物生理学研究和基因工程中被广泛用于单细胞操作。即使当激光脉冲既不在细胞壁上也不在细胞膜上而是在细胞旁边时，也观察到这种注射。有了这些结果，我们建议由强飞秒激光脉冲引起的瞬时变形在细胞膜上形成孔，这是纳米粒子的注入机理。已报道的飞秒激光对生物膜渗透性的光机械效应的报道将为生物光子学提供新的视角。即使当激光脉冲既不在细胞壁上也不在细胞膜上而是在细胞旁边时，也观察到这种注射。有了这些结果，我们建议由强飞秒激光脉冲引起的瞬时变形在细胞膜上形成孔，这是纳米粒子的注入机理。已报道的飞秒激光对生物膜通透性的光机械效应的报道将为生物光子学提供新的视角。即使当激光脉冲既不在细胞壁上也不在细胞膜上而是在细胞旁边时，也观察到这种注射。有了这些结果，我们建议由强飞秒激光脉冲引起的瞬时变形在细胞膜上形成孔，这是纳米粒子的注入机理。已报道的飞秒激光对生物膜渗透性的光机械效应的报道将为生物光子学提供新的视角。