A novel oleanolic acid-loaded PLGA-TPGS nanoparticle for liver cancer treatment.

OBJECTIVES: Hepatocellular carcinoma is the third most common cause of cancer death. Oleanolic acid (OA) is a natural triterpenoid, has many important biological actions, including antitumor effect, but its poor solubility often leads to poor pharmacodynamics. The aim of our work is to make OA-loaded poly (lactide-co-glycolide)-d-α-tocopheryl polyethylene glycol 1000 succinate (PLGA-TPGS) nanoparticles (OPTN) to improve its efficacy to liver cancer and characterize it. METHODS: OPTN were prepared by ultrasonic emulsification-solvent evaporation technique using PLGA with or without the addition of TPGS (OPN). The coumarin-6-loaded nanoparticles were used as a fluorescence marker. The nanoparticles were characterized for surface morphology, surface charge, particle size, drug loading, encapsulation efficiency, in vitro drug-release, cellular uptake, cytotoxicity by human liver cancer cell line HepG2 cells, and therapeutic effect in vivo. KEY FINDINGS: The prepared nanoparticles were found to be spherical in shape. The in vitro drug-release profile of both nanoparticle formulations showed a biphasic release pattern. There was an increased level of uptake and cytotoxicity of OPTN in the HepG2 cells compared with that of OPN. The treatment of OPTN group was better than OPN and FS groups in vivo. CONCLUSION: The results showed advantages of OPTN in terms of sustainable release and efficacy in liver cancer chemotherapy compared with OPN. OPTN could be acted as a novel and new dosage form to be used in cancer treatment study.

Preparation and characterization of curcumin thermosensitive hydrogels for intratumoral injection treatment.

OBJECTIVES: This paper describes the development and optimization of curcumin thermosensitive hydrogels (CTH), a kind of gel injection for intratumoral injection treatment. METHODS: Aimed at increasing the content and stability of effective components, an optimal formulation of CTH was chosen based on the results from orthogonal tests and the optimal pH was determined by stability test. To investigate the hydrogels drug release in vitro, residence time by RP-HPLC and therapeutic effects on ascitic hepatocarcinoma cell strain with high metastasis potential in lymphatic system (HCA-F) solid tumors in mice. KEY FINDINGS: The selected optimal formulation of CTH was: 0.2% curcumin, 20% poloxamer 407, 4% poloxamer 188, 8% polyethylene glycol 400, 12% 1,2-propanediol and pH was 6.0. The drug release determined by RP-HPLC fit to the Higuchi model. The residence time of CTH was longer than the curcumin suspensions. Intratumoral injection of the CTH can effectively inhibit the growth of HCA-F solid tumors in mice. CONCLUSIONS: The CTH prepared in this test demonstrates proper gel temperature and viscosity. It improves the solubility of curcumin with a relatively long period of drug release in vitro and residence time. Intratumoral injection of the CTH can effectively inhibit the growth of HCA-F solid tumors in mice.

Liver-targeting Resibufogenin-loaded poly(lactic-co-glycolic acid)-D-α-tocopheryl polyethylene glycol 1000 succinate nanoparticles for liver cancer therapy.

Liver cancer remains a major problem around the world. Resibufogenin (RBG) is a major bioactive compound that was isolated from Chansu (also called toad venom or toad poison), which is a popular traditional Chinese medicine that is obtained from the skin secretions of giant toads. RBG has strong antitumor effects, but its poor aqueous solubility and its cardiotoxicity have limited its clinical use. The aim of this study was to formulate RBG-loaded poly(lactic-co-glycolic acid) (PLGA)-D-α-tocopheryl polyethylene glycol 1000 succinate nanoparticle (RPTN) to enhance the treatment of liver cancer. RPTN, RBG-loaded PLGA nanoparticle (RPN), and RBG/coumarin-6-loaded PLGA-D-α-tocopheryl polyethylene glycol 1000 succinate nanoparticle (RCPTN) were prepared. The cellular uptake of RCPTN by HepG2 and HCa-F cells was analyzed using confocal laser scanning microscopy. Apoptosis was induced in HepG2 cells by RPTN, RBG solution (RS), and 5-fluorouracil solution (used as the negative controls), as assayed using flow cytometry. LD50 (median lethal dose) values were determined for RS and RPTN, and the liver-targeting properties were determined for RCPTN in intravenously injected mice. A pharmacokinetic study was conducted in rats, and the in vivo therapeutic effects of RPTN, RPN, and RS were examined in a mouse tumor model. The results showed that RCPTN simultaneously delivered both coumarin-6 and RBG into HepG2 and HCa-F cells. The ratio of apoptotic cells was increased in the RPTN group. The LD50 for RPTN was 2.02-fold higher than the value for RS. Compared to RS, RPTN and RPN both showed a significant difference in vivo not only in the pharmacodynamic study but also in anticancer efficacy, and RPTN performed much better than RPN. The detection indexes for drug concentration and fluorescence inversion microscopy images both demonstrated that RCPTN was much better at targeting the liver than RS. The liver-targeting RPTN, which displayed enhanced pharmacological effects and decreased toxicity for the loaded drug RBG, is therefore a promising intravenous dosage form that may be useful in the treatment of liver cancer.