Correlating Corona Composition and Cell Uptake to Identify Proteins Affecting Nanoparticle Entry into Endothelial Cells

The formation of
the biomolecule corona on the surface of nanoparticles
upon exposure to biological fluids critically influences nanocarrier
performance in drug delivery. It has been shown that in some cases
corona proteins can mediate specific nanoparticle interactions with
cell receptors. Within this context, in order to identify corona proteins
affecting nanoparticle uptake, in this work, correlation analysis
is performed between the corona composition of a panel of silica nanoparticles
of different sizes and surface functionalities and their uptake in
four endothelial cell types derived from different organs. In this
way, proteins that correlate with increased or decreased uptake were
identified, and their effects were validated by studying the uptake
of nanoparticles coated with a single protein corona and competition
studies in brain and liver endothelium. The results showed that precoating
nanoparticles with histidine-rich glycoprotein (HRG) alone strongly
decreased uptake in both liver and brain endothelium. Furthermore,
our results suggested the involvement of the transferrin receptor
in nanoparticle uptake in liver endothelium and redirection of the
nanoparticles to other receptors with higher uptake efficiency when
the transferrin receptor was blocked by free transferrin. These data
suggested that changes in the cell microenvironment can also affect
nanoparticle uptake and may lead to a different interaction site with
nanoparticles, affecting their uptake efficiency. Overall, correlating
the composition of the protein corona and nanoparticle uptake by cells
allows for the identification of corona molecules that can be used
to increase as well as to reduce nanoparticle uptake by cells.

纳米颗粒暴露于生物流体后，其表面形成的生物分子冠层（biomolecule corona）会显著影响药物递送纳米载体的性能。已有研究证实，部分场景下冠层蛋白可介导纳米颗粒与细胞受体的特异性相互作用。

在此研究背景下，为筛选出影响纳米颗粒细胞摄取的冠层蛋白，本研究针对一组尺寸与表面功能化修饰各异的二氧化硅（silica）纳米颗粒，分析其生物分子冠层组成与四种不同器官来源的内皮细胞对其摄取量之间的相关性。借此，本研究鉴定出与细胞摄取量升高或降低相关的蛋白，并通过构建单蛋白冠层包被的纳米颗粒摄取实验，以及脑、肝内皮细胞的竞争性摄取实验，验证了这些蛋白的调控作用。

实验结果显示，仅用富组氨酸糖蛋白（histidine-rich glycoprotein, HRG）包被纳米颗粒，可显著降低其在肝与脑内皮细胞中的摄取效率。此外，本研究结果提示，转铁蛋白受体（transferrin receptor）参与了肝内皮细胞对纳米颗粒的摄取过程；当转铁蛋白受体被游离转铁蛋白阻断后，纳米颗粒会转向其他摄取效率更高的受体结合。

上述数据表明，细胞微环境的改变同样会影响纳米颗粒的细胞摄取，并可能改变其与细胞的相互作用位点，进而调控摄取效率。总体而言，将生物分子冠层组成与细胞对纳米颗粒的摄取量进行关联分析，可筛选出可用于提升或降低细胞对纳米颗粒摄取量的冠层生物分子。