N-trimethyl chitosan coated nano-complexes enhance the oral bioavailability and chemotherapeutic effects of gemcitabine.

N-trimethyl chitosan (TMC) is a multifunctional polymer that can be used in various nanoparticle forms in the pharmaceutical, nutraceutical and biomedical fields. In this study, TMC was used as a mucoadhesive adjuvant to enhance the oral bioavailability and hence antitumour effects of gemcitabine formulated into nanocomplexes composed of poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) conjugated with d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS). A central composite design was applied to achieve the optimal formulation. Cellular uptake and drug transportation studies revealed the nanocomplexes permeate over the intestinal cells via adsorptive-mediated and caveolae-mediated endocytosis. Pharmacokinetic studies demonstrated the oral drug bioavailability of the nanocomplexes was increased 5.1-fold compared with drug solution. In pharmacodynamic studies, the formulation reduced tumour size 3.1-fold compared with the drug solution. The data demonstrates that TMC modified nanocomplexes can enhance gemcitabine oral bioavailability and promote the anticancer efficacy.

All-stage precisional glioma targeted therapy enabled by a well-designed D-peptide.

Uncontrollable cell proliferation and irreversible neurological damage make glioma one of the most deadly diseases in clinic. Besides the multiple biological barriers, glioma stem cells (GSCs) that are responsible for the maintenance and recurrence of tumor tissues also hinder the therapeutic efficacy of chemotherapy. Therefore, all-stage precisional glioma targeted therapy regimens that could efficiently deliver drugs to glioma cells and GSCs after overcoming multiple barriers have received increasing scrutiny. Methods: A polymeric micelle-based drug delivery system was developed by modifying a "Y-shaped" well-designed ligand of both GRP78 protein and quorum sensing receptor to achieve all-stage precisional glioma targeting, then we evaluated the targeting ability and barrier penetration ability both in vitro and in vivo. In order to achieve all-stage precisional therapy, we need kill both GSCs and glioma related cells. Parthenolide (PTL) has been investigated for its selective toxicity to glioma stem cells while Paclitaxel (PTX) and Temozolomide (TMZ) are widely used in experimental and clinical therapy of glioma respectively. So the in vivo anti-glioma effect of combination therapy was evaluated by Kaplan-Meier survival analysis and immunohistochemical (IHC) examination of tumor tissues. Results: The "Y-shaped" well-designed peptide, termed DWVAP, exhibited excellent glioma (and GSCs) homing and barrier penetration ability. When modified on micelle surface, DWVAP peptide significantly enhanced accumulation of micelles in brain and glioma. In addition, DWVAP micelles showed no immunogenicity and cytotoxicity, which could guarantee their safety when used in vivo. Treatment of glioma-bearing mice with PTL loaded DWVAP modified PEG-PLA micelles plus PTX loaded DWVAP modified PEG-PLA micelles or PTL loaded DWVAP modified PEG-PLA micelles plus TMZ showed improved anti-tumor efficacy in comparison to PTL and PTX loaded unmodified micelles or PTL loaded unmodified micelles plus TMZ. Conclusion: Combination of all-stage targeting strategy and concomitant use of chemotherapeutics and stem cell inhibitors could achieve precise targeted therapy for glioma.

Baicalein enhances the antitumor efficacy of docetaxel on nonsmall cell lung cancer in a ß-catenin-dependent manner.

The side effects of docetaxel have limited its antitumor performances in the treatment of nonsmall cell lung cancer (NSCLC). To address the problem, baicalein, a bioactive flavone that exhibits antitumor activity, was combined with docetaxel so as to achieve better efficacy and lower toxicity. The combination treatment enhanced the stabilization of microtubules and halted the cell-cycle progression, thus synergistically inhibiting the proliferation and inducing the apoptosis of A549 cells and Lewis lung carcinoma cells. The decreased expression of Cyclin-dependent kinase 6 and Cyclin B1 confirmed its regulation in cell cycle, with ß-catenin being an important upstream effector, as evidenced by the decreased expression in the cytoplasm and nucleus as well as the attenuated aggregation in the nucleus. Furthermore, baicalein plus docetaxel evinced better antitumor efficacy by the suppressed tumor growth, increased apoptosis, and decreased tumor angiogenesis in vivo, with no increased toxicity discovered in both tumor-bearing and non-tumor-bearing mice, and an improvement in therapeutic index. This study has demonstrated that baicalein plus docetaxel is an appropriate combination simultaneously with augmented antitumor efficacy and acceptable safety, which might be a promising strategy for patients with advanced NSCLC.

Preparation, characterization and in vivo pharmacodynamic evaluation of thymopentin loaded poly(lactide acid)/poly(lactide-co-glycolide acid) implants.

To avoid the clinical inconvenience of repeated injection of the immune modulator thymopentin (TP5), biodegradable implants comprising a mixed polymer matrix of poly(lactide acid) (PLA) and poly(lactide-co-glycolide acid) (PLGA) were produced using a simple extrusion method. Drug release from these TP5-loaded implants was characterized both in vitro and in vivo. Pharmacodynamic studies were carried out in immunosuppressed rats using the ratio of CD4(+)/CD8(+) cells, determined by flow cytometry, as an index of immunity. The results indicated that the entrapment efficiency of the implants was greater than 98%, but the release rate of TP5 depended on the drug loading. Implants containing less than 10% TP5 showed consistent release over 30 days, with low burst-release both in vitro and in vivo. Improved immunity and survival rates were observed in rats treated by TP5 injection and in rats given middle-to-high dose implants. When the release of TP5 exceeded 0.1 mg/kg body weight/day the CD4(+)/CD8(+) ratios increased in the 3 weeks after implantation, reaching a maximum (91.6% of the normal level) by the end of the third week. The TP5-loaded implants presented here provide a promising alternative to injections and the results support the further development of controlled-release TP5 formulations.

9-NC-loaded folate-conjugated polymer micelles as tumor targeted drug delivery system: preparation and evaluation in vitro.

In this study, folate-conjugated polymer micelles were synthesized by mixing folate-poly(ethylene glycol)-distearoylphosphatidylethanolamine (FA-PEG-DSPE) and methoxy-poly(ethylene glycol)-distearoylphosphatidylethanolamine (MPEG-DSPE) to encapsulate anticancer agent 9-nitro-camptothecin (9-NC). Formulations were characterized by critical micellization concentration (CMC) values of copolymers, micelle particle size, zeta-potential, encapsulation efficiency and drug loading efficiency. The molar ratio of FA-PEG-DSPE and MPEG-DSPE was chosen to avoid the macrophages and at the same time express highly active targeting ability. The targeting ability of folate-conjugated polymer micelles was investigated against three kinds of tumor cell lines (HeLa, SGC7901 and BXPC3). The drug efficacy in vitro of folate-conjugated polymer micelles was evaluated by using the methylthiazoletetrazolium (MTT) method. The results showed that the CMC values of MPEG-DSPE and FA-PEG-DSPE were 0.97 x 10(-5)M and 1.0 x 10(-5)M, respectively. The average size of folate-conjugated micelle was about 21-24 nm and the micelle size distribution of both empty and drug-loaded micelles were rather narrow. The encapsulation efficiency and drug loading efficiency were 97.6% and 4.64%, respectively. The drug-loaded micelles were stable during storage at 4 degrees C for 4 weeks. Micelles maintain the similar size and did not show 9-NC leakage. The best molar ratio of FA-PEG-DSPE and MPEG-DSPE in folate-conjugated micelles was 1:100 which can effectively solubilize 9-NC, avoid the macrophages in vitro and has a higher anti-tumor activity than both drug-loaded MPEG-DSPE micelles and free anticancer agents. The folate-conjugated polymer micelle which can avoid the macrophages is a kind of promising carrier for poorly soluble anticancer agents via folate receptor (FR) that mediated endocytosis to target tumor cells.

Development and evaluation of novel itraconazole-loaded intravenous nanoparticles.

The purpose of this study was to present novel intravenous itraconazole-loaded nanoparticles (ITZ-NPs) using human serum albumin (HSA) as drug carrier materials. The ITZ-NPs were prepared by nanoparticle albumin bound technology involving a series of homogenization and lyophilization procedures. The ITZ-NPs powder could be easily reconstituted and provide stable solutions at a wide range of concentrations at 25 degrees C for 24h. In safety test, the ITZ-NPs caused mild hemolysis below the concentration of 10mg/mL and were well tolerated at the dose of 160 mg/kg in mice, indicating better biocompatibility than cyclodextrin formulation of itraconazole (ITZ-CD). The pharmacokinetic parameters of itraconazole and its major metabolite, hydroxyl-itraconazole, of ITZ-NPs had no differences from those of ITZ-CD in mice. For the ITZ-NPs group, the distributions of itraconazole in the lung, liver and spleen were higher than those for ITZ-CD group. It was of significance that ITZ-NPs increased the drug distribution in lung which was always the portal to fungal infection. These results indicate that the ITZ-NPs can be a potential intravenous formulation of itraconazole.

[Targeting therapy of magnetic doxorubicin liposome in nude mice bearing colon cancer].

OBJECTIVE: To investigate the effect of magnetic doxorubicin liposome (MDL) in the targeting treatment of nude mice bearing colon cancer. METHODS: Human colon cancer line LoVo cells were implanted hypodermically into nude mouse. Two weeks after the mouse was killed and the tumor was taken out and cut into small pieces to be retransplanted into nude mice so as to establish an experimental model. MDL was prepared by reverse-phase evaporation method. The particle size and structure of MDL were evaluated. Eighteen nude mice with colon cancer were divided into 3 groups of 3 mice: free DOX group, MDL (-) group (no magnetic field was added to the tumor surface), and MDL (+) group (magnetic field with the strength of 4,500 G was added). DOX of the dosage of 5 mg/kg was injected through the caudal vein in these 3 groups. Then the mice were killed 30 minutes after. Fluorescence spectrophotometry was used to examine the concentrations of DOX in the tissues and plasma. Another 36 nude mice with colon cancer were divided into 6 groups of 6 mice: normal saline group (as controls), DOX group, blank liposome group, magnetic liposome group, MDL (-) group (non-magnetic alloy was implanted into the tumor), and MDL (+) group (rare earth magnet was implanted into the tumor). The body weight, longest diameter of tumor, and short diameter vertical to the longest diameter were calculated regularly. The mice were killed 11 days after. The tumors were taken out to undergo staining and light microscopy. Flow cytometry was used to examine the apoptosis of tumor cells. RESULTS: The particle size of MDL was 230 nm and the magnetic particles (Fe(3)O(4)) were evenly distributed within the liposome. The DOX concentration in tumor tissue of the MDL (+) group was remarkably higher than those of the DOX and MDL (-) groups (both P < 0.05). The DOX concentration in heart and kidney of the DOX group were higher than those of the other 2 groups, and the plasma DOX concentrations of the DOX group was significantly lower than those of the other groups (all P < 0.05). The growth speed of tumor in the MDL (+) group was significantly lower, and the tumor weight was significantly less than in other groups. CONCLUSION: Magnetic doxorubicin liposome, as a carrier of anticancer drug, has a good targeting function toward the magnetite and has a significant anticancer effect.