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Hu W.,Soochow University of China | Hu W.,Yangtze River Pharmaceutical Group | Qiu L.,Jiangnan University | Cheng L.,Soochow University of China | And 4 more authors.
Acta Biomaterialia

To solve the contradiction between long circulation time and effective intracellular drug release, redox and pH-responsive drug delivery system was developed by incorporated redox-sensitive disulfide linkage between poly(amidoamine) dendrimers (PAMAM) and poly(ethylene glycol) (PEG). Doxorubicin (DOX) was loaded into the hydrophobic core of the conjugates to prepare PAMAM-SS-PEG/DOX complexes (PSSP/DOX). In vitro release studies suggested that DOX release from PSSP/DOX complexes followed an redox and acid-triggered manner and increased with increasing PEGylation degree. In vitro cytotoxicity of PSSP/DOX complexes against B16 tumor cells increased with, while cellular uptake decreased with increasing PEGylation degree. Further, intracellular DOX release observation and measurement indicate that the intracellular DOX release played a critical role for the cytotoxicity of DOX-loaded PSSP conjugates. In addition, cellular entry mechanism of the PSSP/DOX study demonstrated that both clathrin- and caveolae-mediated endocytosis were the primary pathways for cellular entry of PSSP/DOX. Finally, in vivo study of PSSP/DOX complexes in B16 tumor-bearing mice indicate that PSSP/DOX could significantly improve antitumor efficiency and present a good safety. The redox and pH-responsive drug delivery system has been demonstrated to be a promising candidate for solid tumor therapy. Statement of Significance: In previous research, pH-sensitive diblock polymer of poly(ethylene glycol)-poly(2,4,6-trimethoxybenzylidene-pentaerythritol carbonate) (PEG-PTMBPEC) was synthesized to facilitate the intracellular anticancer drug release. However, the nanoparticles based on PEG-PTMBPEC get into the tumor cells just relying on the EPR-mediated passive targeting resulting in the low drug accumulation. Therefore, cRGD peptide modified PEG-PTMBPEC polymeric micelles were developed for specific targeted delivery of doxorubicin (DOX) to neovascular cells and tumor cells simultaneously. The precise intracellular target site and effective drug concentration will contribute to enhancing the antitumor toxicity and reducing the systematic toxicity of DOX. The cRGD modified pH-sensitive micellar system is a promising vehicle for intracellular drug delivery to αvβ3 integrin receptor overexpressed tumor cells and neovascular cells. © 2016 Acta Materialia Inc. Source

Wei Y.,Fudan University | Xu S.,Shanghai University | Wang F.,Shanghai Institute of Pharmaceutical Industry | Zou A.,Yangtze River Pharmaceutical Group | And 6 more authors.
Journal of Pharmaceutical Sciences

Lapatinib (LPT) could sensitize human epidermal growth factor receptor-2 (HER-2) positive breast cancer to paclitaxel (PTX) and induce synergetic action with PTX in preclinical test and phase II/III trial. In this study, LPT-conjugated poly (ethylene glycol) (PEG) and poly (lactic acid) (PLA) (LPT-PEG-PLA) was first synthesized and confirmed with 1H Nuclear Magnetic Resonance and Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry, which was used for the preparation of a novel PEG-PLA combined micelles of LPT and PTX (PPM-LP). The obtained PPM-LP exhibited uniform, spherical shape with a size of 25.80 ± 0.47 nm and zeta potential of -3.17 ± 0.15 mv. PTX existed in molecular or amorphous forms in the micelles and superficial LPT could better delay PTX release. The cytotoxicity of PPM-LP with LPT conjugation against SKBr-3 cells (HER-2 positive) was found to be significantly increasing as compared with PPM-PTX, whereas there was no significant difference against MDA-MB-231 cells (HER-2 negative). PPM-LP could escape from endosomes and be distributed into cytoplasm and led to cell arrest in G2/M and G1/S phases simultaneously. Results of nucleus staining and flow cytometry confirmed that LPT could remarkably increase antineoplastic effect of PTX against SKBr-3 cells. All these results demonstrated that PPM-LP may be a promising drug delivery system for HER-2 positive breast cancer. © 2014 Wiley Periodicals, Inc. Source

Peng J.,China Pharmaceutical University | Qi X.,China Pharmaceutical University | Chen Y.,China Pharmaceutical University | Ma N.,China Pharmaceutical University | And 6 more authors.
Journal of Drug Targeting

Purpose: An octreotide-conjugated polyamidoamine (PAMAM) dendrimer was synthesized and employed as nanocarriers of methotrexate (MTX), for targeting to the somatostatin receptors over-expressed tumor cells. Methods: PAMAM-PEG-octreotide (PPO) and PAMAM-PEG (PPG) were synthesized and characterized. The cellular uptake of fluorescein isothiocyanate (FITC)-labeled PPO (PPO-FITC) and PPG (PPG-FITC) were investigated. The cytotoxicity of MTX and MTX nanoparticles were conducted in the MCF-7 cells. Besides, the pharmacokinetics studies on MTX nanoparticles were carried out in rats. Results: The structure of PPO was verified by NMR detection and the diameter was 11.05 ± 1.80 nm, with the amount of MTX encapsulated by PPO was 30 (molecule/molecule). MTX nanoparticles possessed significantly higher cytotoxicity against MCF-7 cells compared with free MTX, especially the PPO/MTX nanoparticles. Correspondingly, the PPO-FITC carrier had higher cellular uptake efficiency compared to PPG-FITC. In addition, pharmacokinetics studies showed that PPO/MTX nanoparticles increased mean residence time and bioavailability of MTX distinctly. Discussion and conclusion: With further cellular uptake test of FITC-labeled carriers, the enhanced cytotoxicity of PPO/MTX nanoparticles was reasonable to ascribe to the specific receptor-mediated endocytosis induced by octreotide. The present study suggests that this PAMAM-PEG-octreotide nanocarrier opens a new path for treating cancer with higher efficacy. © 2014 Informa UK Ltd. All rights reserved: reproduction in whole or part not permitted. Source

Qi X.,China Pharmaceutical University | Qin J.,China Pharmaceutical University | Ma N.,China Pharmaceutical University | Chou X.,China Pharmaceutical University | And 2 more authors.
International Journal of Pharmaceutics

The aims of this study were to choose a suitable adsorbent of self-microemulsion and to develop a fine solid self-microemulsifying dispersible tablets for promoting the dissolution and oral bioavailability of celastrol. Solubility test, self-emulsifying grading test, droplet size analysis and ternary phase diagrams test were performed to screen and optimize the composition of liquid celastrol self-microemulsifying drug delivery system (SMEDDS). Then microcrystalline cellulose KG 802 was added as a suitable adsorbent into the optimized liquid celastrol-SMEDDS formulation to prepare the dispersible tablets by wet granulation compression method. The optimized formulation of celastrol-SMEDDS dispersible tablets was finally determinated by the feasibility of the preparing process and redispersibility. The in vitro study showed that the dispersible tablets could disperse in the dispersion medium within 3 min with the average particle size of 25.32 ± 3.26 nm. In vivo pharmacokinetic experiments of rats, the relative bioavailability of celastrol SMEDDS and SMEDDS dispersible tablets compared to the 0.4% CMC-Na suspension was 569 ± 7.07% and 558 ± 6.77%, respectively, while there were no significant difference between the SMEDDS and SMEDDS dispersible tablets. The results suggest the potential use of SMEDDS dispersible tablets for the oral delivery of poorly water-soluble terpenes drugs, such as celastrol. © 2014 Published by Elsevier B.V. All rights reserved. Source

Qi X.,China Pharmaceutical University | Jiang Y.,China Pharmaceutical University | Zhang H.,China Pharmaceutical University | Wu Z.,China Pharmaceutical University | Wu Z.,Yangtze River Pharmaceutical Group
Journal of Pharmacy and Pharmacology

Objectives The aim of this study was to prepare a disintegrating gastric floating tablet composed of floating pellets coated with acrylic resin to prolong the gastric residence time and increase the oral bioavailability of famotidine. Methods The gastric floating pellets containing famotidine, stearyl alcohol and microcrystalline cellulose (1 : 10 : 1) were prepared by extrusion-spheronization process and coated with acrylic resin, then compressed into tablets with Avicel PH 301 pellets and cross-linked polyvinylpyrrolidone. The coating weight, volume ratio of Eudragit RL30 D and RS30 D and solid content of coating fluid were optimized by Box-Behnken design. Key findings In 0.1 M HCl, tablets can immediately disintegrate into pellets which can remain floating and sustained drug releasing over 12 h. The AUC0-∞ of famotidine gastric floating pellets (7776.52 ± 1065.93 h ng/ml) administered into rats was significantly higher than that of marketed rapid release tablets Xingfading® (Xingyi, Shanghai, China) (4166.23 ± 312.43 h ng/ml), while the relative bioavailability was 187.01 ± 22.81%. Conclusions The experimental results indicated that the optimized formulation did offer a new gastro retention and sustained release approach to enhance the oral absorption of famotidine. © 2014 Royal Pharmaceutical Society. Source

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