ABSTRACT
Objective To study the different effects from different concentration ratios of polymorphonuclear neutrophil (PMN) to tumor cell (TC) on the process of tumor cell adhesion to endothelial cell (EC) in shear flow. Methods PMNs and TCs with different concentration ratios (PMN-TC ratio) were added into the parallel plate flow chamber, and changes in the numbers of transient and accumulative adhered TCs on ECs at different shear rates (50 s-1，100 s-1，200 s-1) were analyzed. Results The transient and accumulative adhesion of TCs on ECs at PMN-TC ratio of 3︰1 significantly increased as compared to that at PMN-TC ratio of 1︰1, especially under high shear flow condition (100 s-1 and 200 s-1). Moreover, in the 5 minute-observation period, the effect of PMN-TC ratio on TC adhered to ECs occurred earlier when the shear rate increased. Conclusions The increase of PMN-TC concentration ratio can promote TC adhesion to ECs in shear flow, and the research findings provide significant references for studying TC metastasis in blood vessels and the target therapy of tumors.
ABSTRACT
Objective To study the effect of ghost red blood cells (GRBCs) on white blood cell (WBC)-mediated adhesion of tumor cells (TCs) on endothelial cells (ECs) in shear flow. Methods GRBCs with hematocrit (Hct) of 20% were added in the parallel plate flow chamber to observe changes in the number of tethered WBCs on ECs, the collision between TCs and adhesive WBCs, and the number of firmly adhered TCs at different shear rates of 62.5, 100, 200 s-1, respectively. Results GRBCs could increase the number of adhered WBCs on ECs and the collision between TCs and adhesive WBCs, and finally enhance the adhesion of TCs on ECs, especially at high shear rate (200 s-1). However, the adhesion efficiency of TCs was not significantly influenced by GRBCs. Conclusions GRBCs in shear flow can promote TC adhesion on ECs, and the research finding will provide a theoretical basis for cancer therapy.
ABSTRACT
Objective In order to provide a more realistic microvasculature model for the study on tumor hemodynamics and drug delivery, a simulated tumor microvascular network was developed by the technique of numerical simulation and post processing. Method We constructed a tumor microvascular model with host arteriole venule system, in which the variation in vascular branching and dimensions was taken into account. A sensitivity analysis was made for the parameters of the model to evaluate the adjustability of simulated results. The connectivity of the vascular network was tested to ensure the integrity of the network. The vascular network was smoothed afterwards to reduce flow resistance resulting from numerical networks. Results The simulated results are consistent with the characteristics of real tumor microvasculature, which show intact circulation, local adjustability, high network connectivity and smooth degree. Conclusions This study provid a numerical microvasculature model for the research on tumor hemodynamics, drug delivery and vascular targeted therapy.
ABSTRACT
Objective To study the characteristics of micro environmental flow and the process of macromolecular drug delivery in solid tumor. Method3D models simulating tumor hemodynamics and drug delivery were developed. Microcirculation and concentration distribution of two macromolecular drugs in tumor were simulated. ResultsThe model successfully reflected abnormal tumor hemodynamics, which results in impeded drug delivery and uneven concentration distribution of the drug. The results also shows that the drug with lower molecular weight is more easy to spread in tumor and excrete with interstitial fluid flow. In contrast, the drug with higher molecular weight tends to accumulate and maintain an effective concentration in tumor for a longer period. ConclusionsThe results derive from this model can reflect physiological conditions, providing a reliable numerical model for the investigation of tumor micro environment, drug delivery and strategy of therapy.