CEITEC - Central European Institute of Technology, University of Veterinary and Pharmaceutical Sciences Brno, Palackého tř. 1946/1, 612 42, Brno, Czech Republic; Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Palackého tř. 1946/1, 612 42, Brno, Czech Republic; Department of Pharmacology and Toxicology, Veterinary Research Institute, Hudcova 296/70, 621 00, Brno, Czech Republic.
Department of Pharmacology and Toxicology, Veterinary Research Institute, Hudcova 296/70, 621 00, Brno, Czech Republic.
Ticks Tick Borne Dis. 2021 Jan;12(1):101559. doi: 10.1016/j.ttbdis.2020.101559. Epub 2020 Sep 28.
Micro-computed tomography (micro-CT) is an exceptional imaging modality which is limited in visualizing soft biological tissues that need pre-examination contrasting steps, which can cause serious deformation to sizeable specimens like engorged ticks. The aim of this study was to develop a new technique to bypass these limitations and allow the imaging of fed ticks in their natural state. To accomplish this, adult Ixodes ricinus females were allowed to engorge in vitro on blood supplemented with PEGylated gold nanoparticles (PEG-AuNPs). In total, 73/120 females divided into 6 groups engorged on blood enriched with 0.07-2.16 mg PEG-AuNPs per ml of blood. No toxic effect was observed for any of the tested groups compared to the control group, in which 12/20 females engorged on clear blood. The ticks were scanned on a Bruker micro-CT SkyScan 1276. The mean radiodensity of the examined ticks exceeded 0 Hounsfield Units only in the case of the two groups with the highest concentration. The best contrast was observed in ticks engorged on blood with the highest tested concentration of 2.16 mg/mL PEG-AuNPs. In these ticks, the midgut and rectal sac were clearly visible. Also, the midgut lumen volume was computed from segmented image data. The reduction in midgut volume was documented during the egg development process. According to this pilot study, micro-CT of ticks engorged on blood supplemented with contrasting agents in vitro may reveal additional information regarding the engorged ticks' anatomy.
微计算机断层扫描（micro-CT）是一种特殊的成像方式，它仅限于可视化需要预检查对比步骤的软生物组织，这可能会导致像膨胀的蜱虫这样的大标本严重变形。本研究的目的是开发一种新技术来克服这些限制，并允许以其自然状态成像饱血的蜱虫。为此，允许体外饱血的成年硬蜱雌性在含有聚乙二醇化金纳米颗粒（PEG-AuNPs）的血液中饱血。总共，120 只雌性中的 73 只分为 6 组，每毫升血液中富含 0.07-2.16 毫克 PEG-AuNPs 的血液中饱血。与对照组相比，任何测试组都没有观察到任何毒性作用，对照组中 20 只雌性中有 12 只在清澈的血液中饱血。蜱虫在 Bruker micro-CT SkyScan 1276 上进行扫描。只有在两个最高浓度组中，被检查的蜱虫的平均放射密度才超过 0 亨氏单位。在最高测试浓度为 2.16 毫克/毫升 PEG-AuNPs 的血液中饱血的蜱虫中观察到最佳对比度。在这些蜱虫中，中肠和直肠囊清晰可见。此外，从中肠的分割图像数据计算出中肠腔体积。在卵发育过程中记录到中肠体积的减少。根据这项初步研究，体外补充对比剂的饱血蜱虫的 micro-CT 可能会揭示有关饱血蜱虫解剖结构的更多信息。
