Heid Susanne, Unterweger Harald, Tietze Rainer, Friedrich Ralf P, Weigel Bianca, Cicha Iwona, Eberbeck Dietmar, Boccaccini Aldo R, Alexiou Christoph, Lyer Stefan
Department of Otorhinolaryngology-Head and Neck Surgery, Section of Experimental Oncology and Nanomedicine (SEON), Else Kröner-Fresenius-Stiftungsprofessur, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany.
Physikalisch-Technische Bundesanstalt, Braunschweig und Berlin, 10587 Berlin, Germany.
Int J Mol Sci. 2017 Aug 24;18(9):1837. doi: 10.3390/ijms18091837.
Superparamagnetic iron oxide nanoparticles (SPIONs) have attracted great attention in many biomedical fields and are used in preclinical/experimental drug delivery, hyperthermia and medical imaging. In this study, biocompatible magnetite drug carriers, stabilized by a dextran shell, were developed to carry tissue plasminogen activator (tPA) for targeted thrombolysis under an external magnetic field. Different concentrations of active tPA were immobilized on carboxylated nanoparticles through carbodiimide-mediated amide bond formation. Evidence for successful functionalization of SPIONs with carboxyl groups was shown by Fourier transform infrared spectroscopy. Surface properties after tPA immobilization were altered as demonstrated by dynamic light scattering and ζ potential measurements. The enzyme activity of SPION-bound tPA was determined by digestion of fibrin-containing agarose gels and corresponded to about 74% of free tPA activity. Particles were stored for three weeks before a slight decrease in activity was observed. tPA-loaded SPIONs were navigated into thrombus-mimicking gels by external magnets, proving effective drug targeting without losing the protein. Furthermore, all synthesized types of nanoparticles were well tolerated in cell culture experiments with human umbilical vein endothelial cells, indicating their potential utility for future therapeutic applications in thromboembolic diseases.
超顺磁性氧化铁纳米颗粒（SPIONs）在许多生物医学领域引起了极大关注，并用于临床前/实验性药物递送、热疗和医学成像。在本研究中，开发了一种由葡聚糖壳稳定的生物相容性磁铁矿药物载体，用于在外部磁场下携带组织纤溶酶原激活剂（tPA）进行靶向溶栓。通过碳二亚胺介导的酰胺键形成，将不同浓度的活性tPA固定在羧化纳米颗粒上。傅里叶变换红外光谱显示了SPIONs成功羧基功能化的证据。动态光散射和ζ电位测量表明，tPA固定后表面性质发生了变化。通过消化含纤维蛋白的琼脂糖凝胶测定了与SPION结合的tPA的酶活性，其活性约相当于游离tPA活性的74%。颗粒在储存三周后，活性略有下降。通过外部磁铁将负载tPA的SPIONs引导至模拟血栓的凝胶中，证明了有效的药物靶向性且蛋白质未丢失。此外，在用人脐静脉内皮细胞进行的细胞培养实验中，所有合成类型的纳米颗粒都具有良好的耐受性，表明它们在血栓栓塞性疾病未来治疗应用中的潜在效用。
