Nanoparticle Delivery in Prostate Tumors Implanted in Mice Facilitated by Either Local or Whole-Body Heating

Abstract

This work discusses in vivo experiments that were performed to evaluate whether local or whole-body heating to 40 °C reduced interstitial fluid pressures (IFPs) and enhanced nanoparticle delivery to subcutaneous PC3 human prostate cancer xenograft tumors in mice. After heating, 0.2 mL of a previously developed nanofluid containing gold nanoparticles (10 mg Au/mL) was injected via the tail vein. The induced whole-body hyperthermia led to increases in tumor and mouse body blood perfusion rates of more than 50% and 25%, respectively, while the increases were much smaller in the local heating group. In the whole-body hyperthermia groups, the IFP reduction from the baseline at the tumor center immediately after heating was found to be statistically significant when compared to the control group. The 1 h of local heating group showed IFP reductions at the tumor center, while the IFPs increased in the periphery of the tumor. The intratumoral gold nanoparticle accumulation was quantified using inductively coupled plasma mass spectrometry (ICP-MS). Compared to the control group, 1 h or 4 h of experiencing whole-body hyperthermia resulted in an average increase of 51% or 67% in the gold deposition in tumors, respectively. In the 1 h of local heating group, the increase in the gold deposition was 34%. Our results suggest that 1 h of mild whole-body hyperthermia may be a cost-effective and readily implementable strategy for facilitating nanoparticle delivery to PC3 tumors in mice.

The future opportunities and remaining challenges in the application of nanoparticle‐mediated hyperthermia combined with chemo‐radiotherapy in cancer

“…Elevated IFP would prevent anticancer agents from entering deeper tumor tissue (Kozono et al, 2013; Nikmaneshi et al, 2021). Gu et al have shown that whole‐body hyperthermia can lead to significant reductions in the IFPs of PC3 tumors and an increase in the blood perfusion rates in the mouse body after heating (Gu et al, 2021). In addition, according to Gu et al's research in 2020, significant IFP decreases of 45% immediately after heating, 47% 2 h later, and 52% 24 h later were seen in the experimental group (Gu et al, 2020).…”