A multiphase model for Nanoparticle delivery in microcirculation

In this paper, a particle-cell multiphase model is developed to model Nanoparticle (NP) transport, dispersion, and binding dynamics in blood suspension under the influence of Red blood cells (RBCs). The motion and deformation of RBCs is captured through the Immersed Finite Element Method. The motion and adhesion of individual NPs are tracked through Brownian adhesion dynamics. A mapping algorithm and an interaction potential function are introduced to consider the cell-particle collision. NP dispersion and binding rates are derived from the developed model under various rheology conditions. The influence of RBCs, vascular flow rate, and particle size on NP distribution and delivery efficacy is characterized. A non-uniform NP distribution profile with higher particle concentration near the vessel wall is observed. Such distribution leads to over 50% higher particle binding rate compared to the case without RBC considered. The tumbling motion of RBCs in the core region of the capillary is found to enhance NP dispersion, with dispersion rate increases as shear rate increases. Results from this study contribute to the fundamental understanding and knowledge on how the particulate nature of blood influences NP delivery, which will provide mechanistic insights on the nanomedicine design for targeted drug delivery.

在本文中，建立了一个颗粒 - 细胞多相模型，用于模拟在红细胞（RBCs）影响下血液悬浮液中纳米颗粒（NP）的运输、扩散和结合动力学。通过浸入式有限元方法捕捉红细胞的运动和变形。通过布朗粘附动力学追踪单个纳米颗粒的运动和粘附。引入一种映射算法和一个相互作用势函数来考虑细胞 - 颗粒碰撞。在各种流变条件下，从所建立的模型推导出纳米颗粒的扩散和结合速率。表征了红细胞、血管流速和颗粒大小对纳米颗粒分布和递送效率的影响。观察到一种非均匀的纳米颗粒分布轮廓，在血管壁附近颗粒浓度较高。与不考虑红细胞的情况相比，这种分布导致颗粒结合率高出50%以上。发现红细胞在毛细血管核心区域的翻滚运动增强了纳米颗粒的扩散，且扩散速率随着剪切速率的增加而增加。这项研究的结果有助于从根本上理解和认识血液的颗粒性质如何影响纳米颗粒的递送，这将为靶向药物递送的纳米医学设计提供机制方面的见解。