School of Engineering and Materials Science, Institute of Bioengineering, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK.
School of Engineering and Materials Science, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK.
Sci Rep. 2023 Apr 7;13(1):5729. doi: 10.1038/s41598-023-31352-x.
Recapitulating the normal physiology of the microvasculature is pivotal in the development of more complex in-vitro models and organ-on-chip designs. Pericytes are an important component of the vasculature, promoting vessel stability, inhibiting vascular permeability and maintaining the vascular hierarchical architecture. The use of such co-culture for the testing of therapeutics and nanoparticle safety is increasingly considered for the validation of therapeutic strategies. This report presents the use of a microfluidic model for such applications. Interactions between endothelial cells and pericytes are first explored. We identify basal conditions required to form stable and reproducible endothelial networks. We then investigate interactions between endothelial cells and pericytes via direct co-culture. In our system, pericytes prevented vessel hyperplasia and maintained vessel length in prolonged culture (> 10 days). In addition, these vessels displayed barrier function and expression of junction markers associated with vessel maturation, including VE-cadherin, β-catenin and ZO-1. Furthermore, pericytes maintained vessel integrity following stress (nutrient starvation) and prevented vessel regression, in contrast to the striking dissociation of networks in endothelial monocultures. This response was also observed when endothelial/pericyte co-cultures were exposed to high concentrations of moderately toxic cationic nanoparticles used for gene delivery. This study highlights the importance of pericytes in protecting vascular networks from stress and external agents and their importance to the design of advanced in-vitro models, including for the testing of nanotoxicity, to better recapitulate physiological response and avoid false positives.
重现微血管的正常生理学对于开发更复杂的体外模型和器官芯片设计至关重要。周细胞是血管的重要组成部分，可促进血管稳定性、抑制血管通透性并维持血管层次结构。此类共培养物在用于测试治疗药物和纳米颗粒安全性方面的应用越来越多，以验证治疗策略的有效性。本报告介绍了此类应用中使用的微流控模型。首先探索了内皮细胞和周细胞之间的相互作用。我们确定了形成稳定且可重复的内皮网络所需的基本条件。然后，我们通过直接共培养研究了内皮细胞和周细胞之间的相互作用。在我们的系统中，周细胞可防止血管过度增生并维持血管长度在延长的培养（>10 天）中保持稳定。此外，这些血管表现出屏障功能，并表达与血管成熟相关的连接标记物，包括 VE-钙粘蛋白、β-连环蛋白和 ZO-1。此外，周细胞可在受到应激（营养饥饿）时维持血管完整性，并防止血管退化，而内皮细胞的单独培养中则会出现明显的网络分离。当内皮细胞/周细胞共培养物暴露于用于基因传递的高浓度中等毒性阳离子纳米颗粒时，也观察到了这种反应。本研究强调了周细胞在保护血管网络免受应激和外部因素影响方面的重要性，以及它们对于设计更先进的体外模型的重要性，包括用于测试纳米毒性的模型，以更好地重现生理反应并避免假阳性。
