Numerical simulation on the effects of drug release positions in hepatic portal vein for targeting therapy

Surgical excision, radiation therapy and chemical therapy are the main treatments of hepatic carcinoma. Due to good targeting property, controlled drug release and little side-effects, targeting drug delivery system (TDDS) has become the research focus in the field of oncology therapy. This paper established numerical models of hepatic portal bifurcate branches, carried out a comparative study of hemodynamics and drug concentration distribution in the portal vein vessels for different targeted drug releasing positions. The results showed that (1) because of the influence of flow field, the drug concentration in the right branch declines 10% compared with that in the left and main branches, it demonstrated that the drug concentration in the right side of liver was obviously lower than that in the left side; There is the difference of drug concentration between the inside and the outside in both left and right branches, but it is more obvious difference in the right branch than that in the left one. (2) The drug concentration on the inside of the right branch is significantly lower than that of the other regions, it is important to consider drug use on this position. (3) The drug concentration in portal vein bifurcation is proportional to the initial release positions, at the same time the drug release time and the drug diffusion in tissue should be taken into account in order to achieve the best therapeutic effect. So a reasonable initial drug release position is determined according to physiological characteristics and drug release curves of patients.