Zhikui Chen

Ultrasound exposure improves the targeted therapy effects of galactosylated docetaxel nanoparticles on hepatocellular carcinoma xenografts.

Purpose The distribution of targeted nanoparticles in tumor tissue is affected by a combination of various factors such as the physicochemical properties of the nanoparticles, tumor hemoperfusion and tumor vascular permeability. In this study, the impact of the biological effects of ultrasound on nanoparticle targeting to liver carcinoma was explored. Methods The copolymer MePEG-PLGA was used to prepare the galactosylated docetaxel nanoparticles (GDN), and the physical and chemical properties as well as the acute toxicity were then assayed. The impact of ultrasound exposure (UE) on tumor hemoperfusion was observed by contrast-enhanced ultrasonography (CEUS), and the distribution of docetaxel in tumors and liver were detected by high performance liquid chromatography (HPLC). In the GDN combined with UE treatment group, the mice were injected intravenously with GDN, followed by ultrasound exposure on the human hepatocellular carcinoma xenografts. Twenty-eight days post-administration, the tumor growth inhibition rate was calculated, and the expression of Survivin and Ki67 in tumor tissues were determined by immunohistochemistry assay and quantitative real-time PCR. Results The mean size of prepared liver-targeting nanoparticles GDN was 209.3 nm, and the encapsulation efficiency was 72.28%. The median lethal dose of GDN was detected as 219.5 mg/kg which was about four times higher than that of docetaxel. After ultrasound exposure, the tumor peak - base intensity difference value, examined by CEUS, increased significantly. The drug content in the tumor was 1.96 times higher than in the GDN treated control. In vivo, GDN intravenous injection combined with ultrasound exposure therapy achieved the best anti-tumor effect with a tumor growth inhibition rate of 74.2%, and the expression of Survivin and Ki67 were significantly decreased as well. Conclusion Ultrasound exposure can improve targeting nanoparticles accumulation in the tumor, and achieve a synergism antitumor effect on the hepatocellular carcinoma xenografts.

Effect of Interstitial Chemotherapy with Ricin Temperature- Responsive Gel for Anti-Breast Cancer and Immune Regulation in Rats

ObjectiveTo explore the effect of ricin temperature response gel on breast cancer and its regulatory effect on immune function in rats.MethodsRicin was purified by chromatography and identified by immunoblotting. The rat subcutaneously transplanted breast cancer model was established. Forty model rats with a tumor diameter of about 3.0 cm were subjected to the study. They were randomized into four groups equally: the model group and three treated groups (blank gel, ricin, ricin-gel) were administered with blank gel, ricin, and ricin temperature response gel via percutaneous intratumor injection, respectively. The tumor was isolated 10 days later for the estimation of tumor inhibition rate (TIR) by weighing, pathologic examination, and detection of tumor apoptosis-associated genes bcl-2 and bax with semiquantitative RT-PCR. Also, peripheral blood was obtained to test T-lymphocyte subsets, the killing function of lymphocytes, and the contents of tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2). The outcomes were compared between groups.ResultsThe TIR in the ricin-gel group was 61.8%, with the pathologic examination showing extensive tumor tissue necrosis. Compared with the model group, after ricin temperature response gel treatment, bcl-2 expression was down-regulated, bax expression was up-regulated, CD4+ lymphocytes and CD4+/CD8 /CD8+ ratio in peripheral blood were increased, the killing function of lymphocytes was enhanced, and the contents of TNF-α and IL-2 were elevated (P<0.05 or P<0.01).ConclusionIntratumor injection of ricin temperature-responsive gel showed significant antitumor effect on breast cancer and could enhance the immune function in the tumor-bearing rat.

Interstitial chemotherapy using thermosensitive gel‐coated ricin in nude mice bearing a human hepatoma

Aim:  To investigate the anti‐tumor effects and mechanisms of interstitial chemotherapy using intra‐tumor injection of thermosensitive gel‐coated ricin in nude mice bearing a human hepatoma.