Division of Advanced Materials and Healthcare Technologies, School of Pharmacy, University of Nottingham, Nottingham, NG7 2, UK.
Departament de Farmacologia, Facultat de Farmàcia I Ciències de L'Alimentació, Toxicologia I Química Terapèutica, Universitat de Barcelona, Av. Joan XXIII 27-31, 08028, Barcelona, Spain.
Mikrochim Acta. 2024 Aug 21;191(9):554. doi: 10.1007/s00604-024-06631-7.
Nano- and micro-carriers of therapeutic molecules offer numerous advantages for drug delivery, and the shape of these particles plays a vital role in their biodistribution and their interaction with cells. However, analysing how microparticles are taken up by cells presents methodological challenges. Qualitative methods like microscopy provide detailed imaging but are time-consuming, whereas quantitative methods such as flow cytometry enable high-throughput analysis but struggle to differentiate between internalised and surface-bound particles. Instead, imaging flow cytometry combines the best of both worlds, offering high-resolution imaging with the efficiency of flow cytometry, allowing for quantitative analysis at the single-cell level. This study focuses on fluorescently labelled silicon oxide microchips of various morphologies but related surface areas and volumes: rectangular cuboids and apex-truncated square pyramid microchips fabricated using photolithography techniques, offering a reliable basis for comparison with the more commonly studied spherical particles. Imaging flow cytometry was utilised to evaluate the effect of particle shape on cellular uptake using RAW 264.7 cells and revealed phagocytosis of particles with all shapes. Increasing the particle dose enhanced the uptake, while macrophage stimulation had minimal effect. Using a ratio particle:cell of 10:1 cuboids and spheres showed an uptake rate of approximately 50%, in terms of the percentage of cells with internalised particles, and the average number of particles taken up per cell ranging from about 1-1.5 particle/cell for all the different shapes. This study indicates how differently shaped micro-carriers offer insights into particle uptake variations, demonstrating the potential of non-spherical micro-carriers for precise drug delivery applications.
治疗分子的纳米和微载体为药物传递提供了众多优势，这些颗粒的形状在其生物分布和与细胞的相互作用中起着至关重要的作用。然而，分析微粒体如何被细胞摄取具有方法学上的挑战。定性方法如显微镜提供详细的成像，但耗时，而定量方法如流式细胞术能够进行高通量分析，但难以区分内化和表面结合的颗粒。相反，成像流式细胞术结合了两者的优点，提供了高分辨率的成像与流式细胞术的效率，允许在单细胞水平上进行定量分析。本研究集中于各种形貌但具有相关表面积和体积的荧光标记氧化硅微芯片：使用光刻技术制造的矩形长方体和尖端截断的正方形金字塔微芯片，为与更常研究的球形颗粒进行可靠比较提供了基础。使用成像流式细胞术评估了颗粒形状对 RAW 264.7 细胞摄取的影响，结果表明所有形状的颗粒都被吞噬。增加颗粒剂量增强了摄取，而巨噬细胞刺激的影响最小。使用 10:1 的颗粒:细胞比，长方体和球体的摄取率约为 50%，即内化颗粒的细胞百分比，每个细胞摄取的平均颗粒数在所有不同形状的约 1-1.5 个颗粒/细胞之间。这项研究表明，不同形状的微载体如何提供对颗粒摄取变化的深入了解，展示了非球形微载体在精确药物输送应用中的潜力。
