Stamatopoulos Konstantinos, Karandikar Sharad, Goldstein Mark, O'Farrell Connor, Marciani Luca, Sulaiman Sarah, Hoad Caroline L, Simmons Mark J H, Batchelor Hannah K
School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Department of Surgery, University Hospitals Birmingham NHS Foundation Trust, Birmingham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, UK.
Pharmaceutics. 2020 Jul 13;12(7):659. doi: 10.3390/pharmaceutics12070659.
This work used in vivo MRI images of human colon wall motion to inform a biorelevant Dynamic Colon Model (DCM) to understand the interplay of wall motion, volume, viscosity, fluid, and particle motion within the colon lumen. Hydrodynamics and particle motion within the DCM were characterized using Positron Emission Tomography (PET) and Positron Emission Particle Tracking (PEPT), respectively. In vitro PET images showed that fluid of higher viscosity follows the wall motion with poor mixing, whereas good mixing was observed for a low viscosity fluid. PEPT data showed particle displacements comparable to the in vivo data. Increasing fluid viscosity favors the net forward propulsion of the tracked particles. The use of a floating particle demonstrated shorter residence times and greater velocities on the liquid surface, suggesting a surface wave that was moving faster than the bulk liquid. The DCM can provide an understanding of flow motion and behavior of particles with different buoyancy, which in turn may improve the design of drug formulations, whereby fragments of the dosage form and/or drug particles are suspended in the proximal colon.
这项研究利用人体结肠壁运动的体内磁共振成像（MRI）图像为具有生物相关性的动态结肠模型（DCM）提供信息，以了解结肠壁运动、体积、粘度、流体和结肠腔内颗粒运动之间的相互作用。分别使用正电子发射断层扫描（PET）和正电子发射粒子跟踪（PEPT）对DCM内的流体动力学和颗粒运动进行了表征。体外PET图像显示，高粘度流体随壁运动且混合较差，而低粘度流体则观察到良好的混合。PEPT数据显示颗粒位移与体内数据相当。增加流体粘度有利于被跟踪颗粒的净向前推进。使用漂浮颗粒显示出在液体表面的停留时间更短且速度更快，表明存在一个比主体液体移动更快的表面波。DCM可以提供对具有不同浮力的颗粒的流动运动和行为的理解，这反过来可能会改进药物制剂的设计，即剂型和/或药物颗粒的碎片悬浮在近端结肠中。
