Laboratory of GlycoNanotechnology, Biofunctional Nanomaterials Unit, CIC biomaGUNE, Paseo Miramón 182, E-20009 San Sebastián, Spain.
Biomaterials. 2011 Dec;32(36):9818-25. doi: 10.1016/j.biomaterials.2011.09.010. Epub 2011 Sep 21.
Current performance of iron oxide nanoparticle-based contrast agents in clinical use is based on the unspecific accumulation of the probes in certain organs or tissues. Specific targeted biofunctional nanoparticles would significantly increase their potential as diagnostic and therapeutic tools in vivo. In this study, multimodal fluorescent/magnetic glyco-nanoparticles were synthesized from gold-coated magnetite (glyco-ferrites) and converted into specific probes by the covalent coupling of protein G and subsequent incubation with an IgG antibody. The immuno-magnetic-fluorescent nanoparticles were applied to the specific labelling of peripheral blood mononuclear cells (PBMCs) in a complex biological medium, as human blood. We have been able to label specifically PBMCs present in blood in a percentage as low as 0.10-0.17%. Red blood cells (RBCs) were also clearly labelled, even though the inherent T(2) contrast arising from the high iron content of these cells (coming mainly from haemoglobin). The labelling was further assessed at cellular level by fluorescence microscopy. In conclusion, we have developed new contrast agents able to label specifically a cell population under adverse biological conditions (low abundance, low intrinsic T(2), high protein content). These findings open the door to the application of these probes for the labelling and tracking of endogenous cell populations like metastatic cancer cells, or progenitor stem cells that exist in very low amount in vivo.
目前临床应用的氧化铁纳米粒子造影剂的性能基于探针在某些器官或组织中的非特异性积累。特定的靶向生物功能纳米粒子将极大地提高它们作为体内诊断和治疗工具的潜力。在这项研究中，从金包覆的磁铁矿（糖铁酸盐）合成了多模态荧光/磁性糖基纳米粒子，并通过蛋白 G 的共价偶联和随后与 IgG 抗体孵育将其转化为特异性探针。免疫磁性荧光纳米粒子应用于外周血单核细胞（PBMCs）在复杂生物介质（如人血）中的特异性标记。我们已经能够以低至 0.10-0.17%的百分比特异性标记血液中的 PBMCs。红细胞（RBCs）也被明显标记，即使这些细胞（主要来自血红蛋白）中的高铁含量产生固有 T2 对比。细胞水平的标记通过荧光显微镜进一步评估。总之，我们开发了新的造影剂，能够在不利的生物学条件下（丰度低、固有 T2 低、蛋白质含量高）特异性标记细胞群体。这些发现为这些探针在标记和跟踪体内存在的低丰度的内源性细胞群体（如转移性癌细胞或祖细胞干细胞）的应用开辟了道路。
