PRM analysis of DCE MR images may enable the early identification of the pathologic response to NAC after the first cycle of chemotherapy, whereas pharmacokinetic parameters (K(trans), kep, and ve) do not.
Purpose: This study was performed to compare the cytotoxicity and magnetic resonance (MR) contrast in diverse cultured cells and xenograft tumors models of two ultra-small superparamagnetic iron oxides (USPIOs), thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) and monocrystalline iron oxide nanoparticles (MION-47).Materials and methods: Transmission electron microscopy (TEM) images and R2 relaxivity values of the TCL-SPION and MION-47 were obtained and the cell viability and cell growth velocity of treated and untreated human fibroblasts and human umbilical vein endothelial cells (HUVEC) were evaluated. The effect of TCL-SPION and MION-47 on the secretion of interlukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), the production of nitric oxides and the mitochondrial membrane potentials in murine macrophage cells (RAW264.7) was compared. Human hepatocellular carcinoma cells (HepG2, 5x105) were subcutaneously injected into nude mice (BALB/c) and in vivo MR imaging of tumors before and after injection with TCL-SPION or MION-47 (12.5 mg Fe/kg) was performed on a 1.5 Tesla MRI scanner.Results: On TEM images, the average core diameter of TCL-SPION was 9 nm whereas that of MION-47 was 5 nm. TCL- SPION (345.0 ± 6.2 mM-1sec-1) had higher relaxivity (R2) than MION-47 (130.7 ± 1.1 mM-1sec-1). Significant changes in cell viability and growth were not found in human fibroblasts and HUVEC exposed to TCL-SPION and MION-47. However, IL-6 and TNF-α secretions increased dose-dependently and significantly in the macrophages treated with MION-47 or TCL-SPION. TCL-SPION had a lower stimulatory effect on IL-6 secretions than did MION-47 (P <0.05) and nitric oxides were produced in the macrophages by MION-47 but not TCL-SPION. A change in the mitochondrial membrane potential of the macrophages was observed 24 hours after the exposure, and MION-47 induced more collapses of the mitochondrial membrane potential than did TCL-SPION. In the in vivo MR imaging, 33.0 ± 1.3% and 7.5 ± 0.4% signal intensity decrease on T2*-weighted images was observed in the tumors injected with TCL-SPION and MION-47, respectively.Conclusion: Due to the modified surface properties and larger core size of its iron oxide nanoparticles, TCL-SPION achieves lower cytotoxicity and better tumor MR contrast than MION-47. Our study suggests that TCL-SPION may be used as a new platform for tumor imaging and therapy monitoring.
ObjectiveTo investigate whether there is a relationship between texture analysis parameters of apparent diffusion coefficient (ADC) maps and histopathologic features of MCF-7 and MDA-MB-231 xenograft models.Materials and MethodsMCF-7 estradiol (+), MCF-7 estradiol (-), and MDA-MB-231 xenograft models were made with approval of the animal care committee. Twelve tumors of MCF-7 estradiol (+), 9 tumors of MCF-7 estradiol (-), and 6 tumors in MDA-MB-231 were included. Diffusion-weighted MR images were obtained on a 9.4-T system. An analysis of the first and second order texture analysis of ADC maps was performed. The texture analysis parameters and histopathologic features were compared among these groups by the analysis of variance test. Correlations between texture parameters and histopathologic features were analyzed. We also evaluated the intraobserver agreement in assessing the texture parameters.ResultsMCF-7 estradiol (+) showed a higher standard deviation, maximum, skewness, and kurtosis of ADC values than MCF-7 estradiol (-) and MDA-MB-231 (p < 0.01 for all). The contrast of the MCF-7 groups was higher than that of the MDA-MB-231 (p = 0.004). The correlation (COR) of the texture analysis of MCF-7 groups was lower than that of MDA-MB-231 (p < 0.001). The histopathologic analysis showed that Ki-67mean and Ki-67diff of MCF-7 estradiol (+) were higher than that of MCF-7 estradiol (-) or MDA-MB-231 (p < 0.05). The microvessel density (MVD)mean and MVDdiff of MDA-MB-231 were higher than those of MCF-7 groups (p < 0.001). A diffuse-multifocal necrosis was more frequently found in MDA-MB-231 (p < 0.001). The proportion of necrosis moderately correlated with the contrast (r = -0.438, p = 0.022) and strongly with COR (r = 0.540, p = 0.004). Standard deviation (r = 0.622, r = 0.437), skewness (r = 0.404, r = 0.484), and kurtosis (r = 0.408, r = 0.452) correlated with Ki-67mean and Ki-67diff (p < 0.05 for all). COR moderately correlated with Ki-67diff (r = -0.388, p = 0.045). Skewness (r = -0.643, r = -0.464), kurtosis (r = -0.581, r = -0.389), contrast (r = -0.473, r = -0.549) and COR (r = 0.588, r = 0.580) correlated with MVDmean and MVDdiff (p < 0.05 for all).ConclusionThe texture analysis of ADC maps may help to determine the intratumoral spatial heterogeneity of necrosis patterns, amount of cellular proliferation and the vascularity in MCF-7 and MDA-MB-231 xenograft breast cancer models.
Jackfruit filum polysaccharide (JFPS) was extracted and confirmed to contain neutral and acidic polysaccharides, largely composed of acidic polysaccharides.
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