Abstract

The use of magnetic nanoparticles in nanomedicine keeps expanding and, for most applications, the nanoparticles are internalized in cells then left within, bringing the need for accurate, fast, and easy to handle methodologies to assess their behavior in the cellular environment. Herein, a benchtop-size magnetic sensor is introduced to provide real-time precise measurement of nanoparticle magnetism within living cells. The values obtained with the sensor, of cells loaded with different doses of magnetic nanoparticles, are first compared to conventional vibrating sample magnetometry (VSM), and a strong correlation remarkably validates the use of the magnetic sensor as magnetometer to determine the nanoparticle cellular uptake. The sensor is then used to monitor the progressive intracellular degradation of the nanoparticles, over days. Importantly, this real-time in situ measure is performed on a stem cell-spheroid tissue model and can run continuously on a same spheroid, with cells kept alive within. Besides, such continuous magnetic measurement of cell magnetism at the tissue scale does not impact either tissue formation, viability, or stem cell function, including differentiation and extracellular matrix production.

中文翻译：

---

干细胞-球状组织模型中氧化铁纳米颗粒细胞内生物降解的实时原位磁测量

摘要

磁性纳米粒子在纳米药物中的用途不断扩大，在大多数应用中，纳米粒子先被内化到细胞中，然后留在其中，从而需要精确，快速且易于处理的方法来评估其在细胞环境中的行为。在此，引入了台式大小的磁传感器，以提供实时精确的活细胞内纳米粒子磁性测量。首先将传感器加载的不同剂量的磁性纳米粒子的细胞的值与常规的振动样品磁力法（VSM）进行比较，并且强相关性显着验证了磁性传感器作为磁力计的用途，以确定纳米粒子的细胞吸收。然后将传感器用于监测纳米粒子在几天内进行性的细胞内降解。重要的，原位测量是在干细胞球体组织模型上进行的，并且可以在相同的球体上连续运行，并使细胞保持存活。此外，在组织尺度上对细胞磁性的这种连续磁测量不影响组织形成，生存力或干细胞功能，包括分化和细胞外基质产生。