Nanostructured SL9-CpG Lipovaccines Elicit Immune Response for the Treatment of Melanoma.

Antigen peptides and adjuvants have been extensively investigated for cancer immunotherapy, and they are expected to elicit specific immune responses for cancer treatment. However, the anti-cancer efficacy of antigen peptide and adjuvant-based cancer vaccines has been limited due to the inefficient delivery to draining lymph nodes after administration. Therefore, it is necessary to develop a suitable delivery system to transport antigen peptides and adjuvants. Here, we report a novel type of nanostructured lipovaccines for the treatment of melanoma by delivering antigen peptide (SL9) and oligodeoxynucleotide adjuvant (CpG) to the lymphatic vessels and to the draining lymph node. The SL9-CpG lipovaccines were characterized using dynamic laser scattering (DLS) and transmission electron microscopy (TEM). The lymph uptake, immune response elicitation and treatment effects were evaluated on melanoma-bearing C57BL/6 mice using flow cytometry (FCM), enzyme-linked immunosorbent assay (ELISA) and tumor inhibitory efficacy. The SL9-CpG lipovaccines were uniform with a nanoscale size (~70 nm), had high encapsulation efficiency, and exhibited effective lymph uptake, resulting in activation of specific cytotoxic CD8+ T cells, and release of IFN-γ, and a robust inhibition of tumor growth. Therefore, the nanostructured SL9-CpG lipovaccines offer a promising strategy for melanoma treatment.

Functional chlorin gold nanorods enable to treat breast cancer by photothermal/photodynamic therapy.

BACKGROUND: The existing chemo/radiotherapy fail to eliminate cancer cells due to the restriction of either drug resistance or radio tolerance. The predicament urges researchers to continuously explore alternative strategy for achieving a potent curative effect. METHODS: Functional chlorin gold nanorods (Ce6-AuNR@SiO2-d-CPP) were fabricated aiming at treating breast cancer by photothermal/photodynamic therapy (PTT/PDT). The nanostructure was developed by synthesizing Au nanorods as the photothermal conversion material, and by coating the pegylated mesoporous SiO2 as the shell for entrapping photosensitizer Ce6 and for linking the D-type cell penetrating peptide (d-CPP). The function of Ce6-AuNR@SiO2-d-CPP was verified on human breast cancer MCF-7 cells and MCF-7 cells xenografts in nude mice. RESULTS: Under combinational treatment of PTT and PDT, Ce6-AuNR@SiO2-d-CPP demonstrated a strong cytotoxicity and apoptosis inducing effects in breast cancer cells in vitro, and a robust treatment efficacy in breast cancer-bearing nude mice. The uptake mechanism involved the energy-consuming caveolin-mediated endocytosis, and Ce6-AuNR@SiO2-d-CPP in PTT/PDT mode could induce apoptosis by multiple pathways in breast cancer cells. CONCLUSION: Ce6-AuNR@SiO2-d-CPP demonstrated a robust efficacy in the treatment of breast cancer by photothermal/photodynamic therapy. Therefore, the present study could offer a new promising strategy to treat the refractory breast cancer.

Research of novel biocompatible radiopaque microcapsules for arterial embolization.

Embolic agents, such as microparticles, microspheres or beads used in current embolotherapy are mostly radiolucent, which means the agents are invisible under X-ray imaging during and after the process of embolization, and the fate of these particles cannot be precisely assessed. In this research, a radiopaque embolic agent was developed by encapsulating lipiodol in polyvinyl alcohol. The lipiodol-containing polyvinyl alcohol microcapsules (LPMs) were characterized and evaluated for their morphology, size distribution, lipiodol content, lipiodol release, elasticity, and deliverability through catheter. The radiopacity of LPMs in vials and in living mice was both detected by an X-ray imaging system. The biocompatibility of LPMs was investigated with L929 cells and in mice after subcutaneous injection. Embolization of LPMs to a rabbit kidney was performed under digital subtraction angiography (DSA) and the radiopacity of LPMs was verified by computed tomography (CT).

Modulation of drug-resistant membrane and apoptosis proteins of breast cancer stem cells by targeting berberine liposomes.

The recurrence of breast cancer is associated with drug-resistance of cancer stem cells (CSCs), while overexpression of cell membrane ATP-binding cassette (ABC) transporters and resistance of mitochondrial apoptosis-related proteins are responsible for the drug-resistance of CSCs. The targeting berberine liposomes were developed to modulate the resistant membrane and mitochondrial proteins of breast CSCs for the treatment and prevention of breast cancer relapse. Evaluations were performed on human breast CSCs and CSC xenografts in nude mice. The targeting berberine liposomes were shown to cross the CSC membrane, inhibit ABC transporters (ABCC1, ABCC2, ABCC3, ABCG2) and selectively accumulate in the mitochondria. Furthermore, the pro-apoptotic protein Bax was activated while the anti-apoptotic protein Bcl-2 was inhibited resulting in opening of the mitochondrial permeability transition pores, release of cytochrome c, and activation of caspase-9/caspase-3 enzymes. Significant efficacy of the administrations in mice was observed, indicating that the targeting berberine liposomes are a potential therapy for the treatment and prevention of breast cancer relapse arising from CSCs.

Improving efficiency of adriamycin crossing blood brain barrier by combination of thermosensitive liposomes and hyperthermia.

Adriamycin (ADM)-encapsulated thermosensitive liposomes (ts-lip-ADM) and common liposomes (lip-ADM) were developed and evaluated. The encapsulation efficiency of the two liposomes were above 99%, and the average sizes of liposomes were about 120 nm. Temperature-dependent drug release from loaded liposomes in vitro was investigated: more than 90% of loaded ADM was released from ts-lip-ADM within 30 min at 42°C, while less than 3% was released from lip-ADM at 42°C beyond 120 min. An in vitro model of blood brain barrier (BBB) was established and evaluated by permeability and transendothelial electrical resistance (TEER). The model was employed to study the permeability of liposomes in vitro. The permeability of ts-lip-ADM could be increased significantly after the temperature was raised to 42°C, which was about 10-16, 22-38, 38-45, 50-105 fold to that of ts-lip-ADM (37°C), lip-ADM (42°C), lip-ADM (37°C) and free ADM, respectively. C6 glioma-bearing mice model was developed and used to evaluate body distribution and anti-tumor efficacy in vivo. Mice were IV injected at a drug dose of 10 mg/kg. After administration the heads of mice were heated in water bath at 42°C for 30 min. The maximum brain concentration of ts-lip-ADM was 6.4, 3.7 fold compared with that of ADM solution and lip-ADM, respectively. The survival time of mice administered ts-lip-ADM (44 d) was remarkably longer than that of other three groups. This study indicates that ADM-encapsulated thermosensitive liposomes combined hyperthermia could enhance ADM delivery across BBB and prolong survival time of glioma-bearing mice.

A potential target associated with both cancer and cancer stem cells: a combination therapy for eradication of breast cancer using vinorelbine stealthy liposomes plus parthenolide stealthy liposomes.

The cancer stem cells play a critical role in both initiation and relapse of the cancers as they are resistant to the most of cytotoxic agents and able to proliferate indefinitely. Vinorelbine stealthy liposomes and parthenolide stealthy liposomes were developed for providing beneficial pharmacological properties and to eradicate cancer stem cells and non-stem cancer cells together by a combination therapy. Cytotoxicity and cancer stem-like cells (side population, SP) identification were performed on human breast cancer cell lines MCF-7 and MDA-MB-231. SP cells were further sorted from MCF-7 cells and characterized. Inhibitory effect was evaluated on the sorted SP and non-SP cells. Antitumor activity was evaluated on MCF-7 xenografts in nude mice. SP cells were identified with a higher percentage in MCF-7 cells (3.8%) and lower in MDA-MB-231 cells (0.6%). Both vinorelbine and parthenolide inhibited the proliferation in MCF-7 and MDA-MB-231 cells. As compared to non-SP cells, inhibitory effect of vinorelbine in the SP cells was lower while a robust inhibitory effect was observed when applying vinorelbine in combination with parthenolide. In the MCF-7 xenografts, stealthy liposomal vinorelbine plus stealthy liposomal parthenolide produced a full inhibitory effect. This combination therapy may provide a potential strategy for eradication of breast cancer by targeting cancer together with cancer stem cells.

Increase of the pharmacological and pharmacokinetic efficacy of negatively charged polypeptide recombinant hirudin in rats via parenteral route by association with cationic liposomes.

Two biodegradable cationic lipids, stearylamine and DC-Chol, were chosen to investigate the effect of cationic lipids on the in vitro and in vivo characteristics of hydrophilic proteins or peptides of low isoelectric point. Thrombin inhibitor recombinant hirudin variant-2 (rHV2) was selected as the model drug. The cationic lipids were found to achieve higher entrapment efficiency of rHV2 in liposomes than zwitterionic lipids. The positively charged liposomes became less positive and relatively stable in serum after loading rHV2. The cationic liposomes induced sustained release of rHV2 in the presence of plasma, significantly prolonged the antithrombotic efficacy and plasma level of rHV2 after intravenous injection in rats in comparison with neutral lipid liposomes, especially for stearylamine group. Both clotting times correlated well with plasma rHV2 levels. No serious adverse events were observed and physical state of rats was satisfactory for all the formulations. Electrostatic interaction between negative charge of rHV2 and cationic liposomes was confirmed and it might affect all the characteristics of rHV2 loaded cationic vehicles. The findings suggest that cationic liposomes may be a potential sustained-release delivery system for parenteral administration of hydrophilic proteins or peptides with low isoelectric point to prolong efficacy and improve bioavailability.

Sublingual delivery of insulin: effects of enhancers on the mucosal lipid fluidity and protein conformation, transport, and in vivo hypoglycemic activity.

The purposes of this study were to evaluate effects of enhancers for sublingual delivering insulin on the mucosal lipid fluidity and protein conformation, transport, and in vivo hypoglycemic activity in normal rats. The effects on sublingual mucosa, and aggregation states of insulin were estimated using fluorescence polarization, and circular dichroism method, respectively. The human immortalized oral epithelial cell monolayer was used for evaluating transport of insulin. Hydroxylpropyl-beta-cyclodextrin (HP-beta-CD), chitosan, polyethylene-polypropylene glycol, polyoxyethylene lauryl ether, polysorbate 80, egg lecithin, or oleic acid, was used as a penetration enhancer, respectively. The fluidity of sublingual mucosal lipid was markedly reduced by these enhancers excluding polysorbate 80, and the secondary structure of the mucosal proteins was also influenced by these enhancers. The hexamers of insulin were dissociated to monomers only by chitosan, polyoxyethylene lauryl ether, and egg lecithin. Nonetheless, plasma glucose levels in normal rats were significantly lowered after sublingual administration of insulin with an enhancer compared with those without an enhancer at the same time-point. The enhancing effects may be due to one or multiple factors: increasing the mucosal lipid fluidity, directly loosing the tight junction of epithelia, and dissociating the hexamers of insulin to monomers. Among these, the opened tight junction may correlate most with the enhancing effect in the mucosal permeability. Because the aggregates of insulin exist, the dissociation of the aggregates by an enhancer would benefit the permeability.

Nasal insulin delivery in the chitosan solution: in vitro and in vivo studies.

The effects of chitosan concentrations, osmolarity, medium and absorption enhancers in the chitosan solution on nasal insulin delivery were studied in vitro and in vivo. The penetration of insulin through the mucosa of rabbit nasal septum was investigated by measuring the transmucosal flux in vitro, while the nasal absorption of insulin in vivo was assessed by the efficiency in lowering the blood glucose levels in normal rats. It was demonstrated that increasing concentrations of chitosan up to 1.5% (w/v) caused an increase in the permeability of insulin across the nasal mucosa. Insulin given intranasally in hypo- or hyperosmotic formulation showed a higher hypoglycemic effect than insulin delivered in isoosmotic formulation. Insulin formulation in chitosan solution prepared with deionized water brought to a higher relative pharmacological bioavailability (Fr) value than that prepared with 50 mM pH 7.4 phosphate buffer. A formulation containing both 1% chitosan and 0.1% ethylenediaminetetraacetic acid (EDTA), 5% polysorbate 80 (Tween 80) or 1.2% beta-cyclodextrin (beta-CD) did not lead to a higher Fr than insulin formulated with 1% chitosan alone. The formulation containing both 5% hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and 1% chitosan was more effective at reducing blood glucose levels than the formulation containing 5% HP-beta-CD or 1% chitosan alone. The studies indicated that chitosan concentrations, osmolarity, medium and absorption enhancers in chitosan solution have significant effect on the insulin nasal delivery. The results of in vitro experiments were in good agreement with that of in vivo studies.

Total coenzyme Q10 concentrations in Asian men following multiple oral 50-mg doses administered as coenzyme Q10 sustained release tablets or regular tablets.

Coenzyme Q(10) (CoQ(10)), a highly lipophilic compound present in the inner mitochondrial membrane, is essential for production of cellular energy in the form of ATP. CoQ(10) is used as a dietary supplement and for treatment of various cardiovascular disorders. Our goal was to compare the CoQ(10) levels in Asians following multiple oral doses administered as sustained release or regular tablets. Twenty healthy male volunteers (19-23 years old) were divided into two equal groups. Each subject in Group I received 50 mg oral doses of coenzyme Q(10) as sustained release tablets once a day for fifteen days, while subject in Group II received 50 mg doses of coenzyme Q(10) regular tablets. The CoQ(10) levels were measured by HPLC-UV (reverse phase ODS column, 10 microm, 250 x 4.6 mm; oven temperature 30 degrees C). Mobile phase was constituted by methanol-ethanol 9 : 1 v/v. Flow rate was 1.5 ml/min and UV detection was carried out at 275 nm. Coenzyme Q(9) was used as an internal standard. CoQ(10) baseline in the morning was 0.88+/-0.48 mg/l. Following 1 week 50 mg/d dosing of CoQ(10), plasma CoQ(10) concentrations increased to 1.85+/-1.03 mg/l for sustained release tablets and up to 1.37+/-0.74mg/l for regular tablets. The net increment proportion in AUC for sustained release and regular tablets were 148.26+/-176.56%, 102.57+/-130.00%, respectively. Both preparations significantly increased the systemic exposure when compared to endogenous baseline.