20nm金纳米粒子在大鼠皮肤中穿透与积累的实时监测:SERS技术研究

0 下载量 21 浏览量 更新于2024-08-29 收藏 2.43MB PDF 举报
本研究关注的是纳米科技在生物医学领域的实际应用,特别是对于黄金纳米粒子(GNPs)在皮肤安全性评估中的作用。通过标题"Monitoring the penetration and accumulation of gold nanoparticles in rat skin ex vivo using surface-enhanced Raman scattering spectroscopy"我们可以了解到,研究者采用表面增强拉曼散射(SERS)技术来监测大鼠皮肤组织中20纳米金颗粒的穿透和积累动态。这一实验设计是针对日常生活中的潜在健康隐患,如商业产品意外接触到皮肤或空气污染物可能导致的皮肤污染问题。 在实验过程中,GNPs被局部应用于大鼠皮肤表面,研究人员对皮肤表层以下每15微米深度处的皮肤组织进行SERS光谱记录,直至达到总深度75微米,时间跨度长达150分钟。这种长期、精细的监测有助于科学家们深入了解GNPs如何深入皮肤,以及它们在组织中的分布和可能的生物积累过程。 SERS作为一种非侵入性的光谱分析技术,具有高灵敏度和分子识别能力,能够检测极低浓度的金属纳米粒子,因此在这个实验中,它被作为理想的工具来研究GNPs的皮肤吸收路径。通过分析收集到的SERS信号,研究者可以获取关于GNPs与皮肤细胞相互作用的信息,包括可能的物理吸附、化学键合或者细胞内吞等现象。 此外,该研究可能探讨了GNPs的生物降解、毒性效应以及可能的修复机制,因为深入理解这些过程对于评估纳米材料的安全性和环境影响至关重要。通过揭示GNPs在皮肤中的行为模式,这项研究不仅有助于改进纳米材料的设计和制备,也为制定安全使用标准提供了科学依据。 这项研究对于理解和控制纳米材料对人体健康的影响具有重要意义,特别是在纳米技术日益普及的今天,对纳米粒子的生物行为监测是确保公众健康的关键步骤。

Rab GTPases serve as master regulators of membrane trafficking. They can be activated by guanine nucleotide exchange factors (GEF) and be inactivated by GTPase-activating proteins (GAPs). The roles of some GAPs have been explored in Saccharomyces cerevisiae, but are largely unknown in filamentous fungi. Here, we investigated the role of GAP Gyp3 gene, an ortholog of S. cerevisiae Gyp3, in an entomopathogenic fungus, Metarhizium acridum. We found that MaGyp3 is mainly localized to the endoplasmic reticulum (ER) of vegetative hyphae, nuclei of mature conidia, and both ER and nuclei in invasive hyphae. Lack of MaGyp3 caused a decreased tolerance to hyperosmotic stress, heat-shock and UV-B radiation. Moreover, the ΔMaGyp3 mutant showed a significantly decreased pathogenicity owing to delayed germination, reduced appressorium-mediated penetration and impaired invasive growth. Loss of MaGyp3 also caused impaired fungal growth, advanced conidiation and defects in utilization of carbon and nitrogen sources, while overexpression of MaGyp3 exhibited delayed conidiation on nutrient-rich medium and conidiation pattern shift from microcycle conidiation to normal conidiation on nutrient-limited medium. Mavib-1, a tanscription factor invloved in conidiation by affecting nutrient utilizaiton, can directly bind to the promoter of MaGyp3. ΔMaGyp3 and ΔMavib-1 mutants shared similar phenotypes, and overexpression mutants of MaGyp3 and Mavib-1 (Mavib-1-OE) exhibited similar phenotypes in growth, conidiation and pathogenicity. Reintroduction of the Magyp3 driven by strong promoter gpd in ΔMavib-1 mutant recovered the defects in growth and conidiation for dysfunction of Mavib1. Taken together, our findings uncovered the role of GAP3 in a filamentous pathogenic fungus and and illustrated the upstream regulatory mechanism by direct interaction with Mavib-1.

2023-02-10 上传