Micelles of Different Morphologies—Advantages of Worm-like Filomicelles of PEO-PCL in Paclitaxel Delivery

Purpose

Worm-like and spherical micelles are both prepared here from the same amphiphilic diblock copolymer, poly(ethylene oxide)-b-poly (ε-caprolactone) (PEO [5 kDa]–PCL [6.5 kDa]) in order to compare loading and delivery of hydrophobic drugs.

Materials and Methods

Worm-like micelles of this degradable copolymer are nanometers in cross-section and spontaneously assemble to stable lengths of microns, resembling filoviruses in some respects and thus suggesting the moniker ‘filomicelles’. The highly flexible worm-like micelles can also be sonicated to generate kinetically stable spherical micelles composed of the same copolymer.

Results

The fission process exploits the finding that the PCL cores are fluid, rather than glassy or crystalline, and core-loading of the hydrophobic anticancer drug delivery, paclitaxel (TAX) shows that the worm-like micelles load and solubilize twice as much drug as spherical micelles. In cytotoxicity tests that compare to the clinically prevalent solubilizer, Cremophor^® EL, both micellar carriers are far less toxic, and both types of TAX-loaded micelles also show fivefold greater anticancer activity on A549 human lung cancer cells.

Conclusion

PEO–PCL based worm-like filomicelles appear to be promising pharmaceutical nanocarriers with improved solubilization efficiency and comparable stability to spherical micelles, as well as better safety and efficacy in vitro compared to the prevalent Cremophor^® EL TAX formulation.

     

The Evaluation of Therapeutic Efficacy and Safety Profile of Simvastatin Prodrug Micelles in a Closed Fracture Mouse Model

Purpose

To evaluate the therapeutic efficiency of a micellar prodrug formulation of simvastatin (SIM/SIM-mPEG) and explore its safety in a closed femoral fracture mouse model.

Methods

The amphiphilic macromolecular prodrug of simvastatin (SIM-mPEG) was synthesized and formulated together with free simvastatin into micelles. It was also labeled with a near infrared dye for in vivo imaging purpose. A closed femoral fracture mouse model was established using a three-points bending device. The mice with established closed femoral fractures were treated with SIM/SIM-mPEG micelles, using free simvastatin and saline as controls. The therapeutic efficacy of the micelles was evaluated using a high-resolution micro-CT. Serum biochemistry and histology analyses were performed to explore the potential toxicity of the micelle formulation.

Results

Near Infrared Fluorescence (NIRF) imaging confirmed the passive targeting of SIM/SIM-mPEG micelles to the bone lesion of the mice with closed femoral fractures. The micelle was found to promote fracture healing with an excellent safety profile. In addition, the accelerated healing of the femoral fracture also helped to prevent disuse-associated ipsilateral tibia bone loss.

Conclusion

SIM/SIM-mPEG micelles were found to be an effective and safe treatment for closed femoral fracture repair in mice. The evidence obtained in this study suggests that it may have the potential to be translated into a novel therapy for clinical management of skeletal fractures and non-union.

     

Hyaluronic Acid Layer-By-Layer (LbL) Nanoparticles for Synergistic Chemo-Phototherapy

Purpose

The aim of this study was to design hyaluronic acid (HA) layer-by-layer (LbL) nanoparticles, which carried paclitaxel (PTX) and Indocyanine green (ICG) to both tumor cells and tumor associated cells to achieve synergistic chemo-photothermal therapeutic effect.

Methods

The LbL-engineered nanoparticles (PDIH) were prepared by dopamine self-polymerization on PTX nanocrystal to form thin, surface-adherent polydopamine (PDA) films, which subsequently absorbed ICG and HA. The tumor cell and tumor associated cell targeting and antitumor efficacy of PDIH were investigated both in vitro an in vivo using 4 T1 murine mammary cancer cell lines and mice bearing orthotopic 4 T1 breast tumor.

Results

PDIH presented a long-rod shape in TEM and showed enhanced photothermal effect and cytotoxicity upon NIR laser irradiation both in vitro and in vivo. PDIH also displayed high target ability to CD44 overexpressed tumor cells and tumor associated cells mediated by HA. In vivo antitumor study indicated that PDIH therapeutic strategy could achieve remarkable antitumor efficacy.

Conclusion

PDIH showed excellent tumor-targeting property and chemo-photothermal therapeutic efficacy.

     

Curcumin Delivery by Poly(Lactide)-Based Co-Polymeric Micelles: An <Emphasis Type="BoldItalic">In Vitro</Emphasis> Anticancer Study

Purpose

This work describes the synthesis of block co-polymeric micelles, methoxy-poly(ethylene glycol)-poly(D,L-lactide) (mPEG-PLA) to encapsulate Curcumin (CUR), thereby improving the dispersibility and chemical stability of curcumin, prolonging its cellular uptake and enhancing its bioavailability.

Methods

CUR-mPEG-PLA micelles, was prepared using the thin-film hydration method and evaluated in vitro. The preparation process was optimized with a central composite design (CCD). Micelles were characterized by size, transmission electron microscopy, loading capacity, and critical micelle concentration (CMC). The cytotoxicity of CUR-mPEG-PLA micelles was investigated against murine melanoma cells, B16F10 and human breast cancer cells, MDA-MB-231.

Results

The average size of the CUR-mPEG-PLA micelles was 110?±?5 nm with polydispersity index in the range of 0.15–0.31, and the encapsulating efficiency for CUR was 91.89?±?1.2, and 11.06?±?0.8% for drug-loading. Sustained release of CUR from micelles was observed with 9.73% CUR release from micelles compared to 64.24% release of free curcumin in first 6 h under sink condition. The CUR-mPEG-PLA was efficiently taken up by the cancer cells, B16F10 and MDA-MB-231. Following 24 h incubation, CUR-mPEG-PLA induced higher cytotoxicity compared to free CUR in MDA-MB-231 cell lines indicating exposure of higher dose of free CUR to cells lead to up-regulation of drug efflux mechanisms leading to decreased cell death in case of free CUR administration.

Conclusion

Our results indicate that the proposed micellar system has the potential to serve as an efficient carrier for CUR by effectively solubilizing, stabilizing and delivering the drug in a controlled manner to the cancer cells.

     

A Computational/Experimental Assessment of Antitumor Activity of Polymer Nanoassemblies for pH-Controlled Drug Delivery to Primary and Metastatic Tumors

Purpose

Polymer nanoassemblies (PNAs) with drug release fine-tuned to occur in acidic tumor regions (pH?<?7) while sparing normal tissues (pH?=?7.4) were previously shown to hold promise as nanoparticle drug carriers to effectively suppress tumor growth with reduced systemic toxicity. However, therapeutic benefits of pH-controlled drug delivery remain elusive due to complex interactions between the drug carriers, tumor cells with varying drug sensitivity, and the tumor microenvironment.

Methods

We implement a combined computational and experimental approach to evaluate the in vivo antitumor activity of acid-sensitive PNAs controlling drug release in pH 5?~?7.4 at different rates [PNA1 (fastest)?>?PNA2?>?PNA3 (slowest)].

Results

Computational simulations projecting the transport, drug release, and antitumor activity of PNAs in primary and metastatic tumor models of colorectal cancer correspond well with experimental observations in vivo. The simulations also reveal that all PNAs could reach peak drug concentrations in tumors at 11 h post injection, while PNAs with slower drug release (PNA2 and PNA3) reduced tumor size more effectively than fast drug releasing PNA1 (24.5 and 20.3 vs 7.5%, respectively, as fraction of untreated control).

Conclusion

A combined computational/experimental approach may help to evaluate pH-controlled drug delivery targeting aggressive tumors that have substantial acidity.

     

Combination Nanopreparations of a Novel Proapoptotic Drug – NCL-240, TRAIL and siRNA

Purpose

To develop a multifunctional nanoparticle system carrying a combination of pro-apoptotic drug, NCL-240, TRAIL [tumor necrosis factor-α (TNF-α)-related apoptosis-inducing ligand] and anti-survivin siRNA and to test the combination preparation for anti-cancer effects in different cancer cells.

Methods

Polyethylene glycol-phosphoethanolamine (PEG-PE) – based polymeric micelles were prepared carrying NCL-240. These micelles were used in combination with TRAIL-conjugated micelles and anti-survivin siRNA-S-S-PE containing micelles. All the micelles were characterized for size, zeta potential, and drug encapsulation efficiency. Different cancer cells were used to study the cytotoxicity potential of the individual as well as the combination formulations. Other cell based assays included cellular association studies of transferrin-targeted NCL-240 micelles and study of cellular survivin protein downregulation by anti-survivin siRNA-S-S-PE containing micelles.

Results

NCL-240 micelles and the combination NCL-240/TRAIL micelles significantly increased cytotoxicity in the resistant strains of SKOV-3, MCF-7 and A549 as compared to free drugs or single drug formulations. The NCL-240/TRAIL micelles were also more effective in NCI/ADR-RES cancer cell spheroids. Anti-survivin siRNA micelles alone displayed a dose-dependent reduction in survivin protein levels in A2780 cells. Treatment with NCL-240/TRAIL after pre-incubation with anti-survivin siRNA inhibited cancer cell proliferation. Additionally, a single multifunctional system composed of NCL-240/TRAIL/siRNA PM also had significant cytotoxic effects in vitro in multiple cell lines.

Conclusion

These results demonstrate the efficacy of a combination of small-molecule PI3K inhibitors, TRAIL, and siRNA delivered by micellar preparations in multiple cancer cell lines.

     

A Multi-Functional Tumor Theranostic Nanoplatform for MRI Guided Photothermal-Chemotherapy

Purpose

To develop a multi-functional theranostic nanoplatform with increased tumor retention, improving antitumor efficacy and decreased side effects of chemotherapy drugs.

Methods

GO@Gd nanocomposites was synthesized via decorating gadolinium (Gd) nanoparticles (GdNP) onto graphene oxide (GO), and then functionalized by polyethylene glycol (PEG2000), folic acid (FA), a widely used tumor targeting molecule, was linked to GO@Gd-PEG, finally, doxorubicin (DOX) was loaded onto GO@Gd-PEG-FA and obtained a tumor-targeting drug delivery system (GO@Gd-PEG-FA/DOX). GO@Gd-PEG-FA/DOX was characterized and explored its theranostic applications both in a cultured MCF-7 cells and tumor-bearing mice.

Results

GO@Gd-PEG-FA/DOX could efficiently cross the cell membranes, lead to more apoptosis and afford higher antitumor efficacy without obvious toxic effects to normal organs owing to its prolonged blood circulation and 7.6-fold higher DOX uptake of tumor than DOX. Besides, GO@Gd-PEG-FA/DOX also served as a powerful photothermal therapy (PTT) agent for thermal ablation of tumor and a strong T1-weighted contrast agent for tumor MRI diagnosis. The multi-functional nanoplatform also could selectively kill cancer cells in highly localized regions via the excellent tumor-targeting and MRI guided PTT abilities.

Conclusions

GO@Gd-PEG-FA/DOX exhibited excellent photothermal-chemotherapeutic efficacy, tumor-targeting property and tumor diagnostic ability.

     

Optimization of Weight Ratio for DSPE-PEG/TPGS Hybrid Micelles to Improve Drug Retention and Tumor Penetration

Purpose

To enhance therapeutic efficacy and prevent phlebitis caused by Asulacrine (ASL) precipitation post intravenous injection, ASL-loaded hybrid micelles with size below 40 nm were developed to improve drug retention and tumor penetration.

Methods

ASL-micelles were prepared using different weight ratios of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-polyethyleneglycol-2000 (DSPE-PEG₂₀₀₀) and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) polymers. Stability of micelles was optimized in terms of critical micelle concentration (CMC) and drug release properties. The encapsulation efficiency (EE) and drug loading were determined using an established dialysis-mathematic fitting method. Multicellular spheroids (MCTS) penetration and cytotoxicity were investigated on MCF-7 cell line. Pharmacokinetics of ASL-micelles was evaluated in rats with ASL-solution as control.

Results

The ASL-micelles prepared with DSPE-PEG₂₀₀₀ and TPGS (1:1, w/w) exhibited small size (~18.5 nm), higher EE (~94.12%), better sustained in vitro drug release with lower CMC which may be ascribed to the interaction between drug and carriers. Compared to free ASL, ASL-micelles showed better MCTS penetration capacity and more potent cytotoxicity. Pharmacokinetic studies demonstrated that the half-life and AUC values of ASL-micelles were approximately 1.37-fold and 3.49-fold greater than that of free ASL.

Conclusions

The optimized DSPE-PEG₂₀₀₀/TPGS micelles could serve as a promising vehicle to improve drug retention and penetration in tumor.

     

Effect of Tumor Relevant Acidic Environment in the Interaction of a <Emphasis Type="Italic">N</Emphasis>-hydroxyindole-2-Carboxylic Derivative with the Phospholipid Bilayer

Purpose

The inhibitors of the human isoform 5 of lactate dehydrogenase (hLDH5) have attracted growing interest as efficient anti-cancer agents. In the present paper, the interactions between an efficient hLDH5 inhibitor (N-hydroxyindole-2-carboxylic derivative) and lipid bilayers based on dipalmitoylphosphatidylcholine (DPPC) were investigated. Additionally, since interstitial acidification plays a key role in tumor pathogenesis and tumor drug therapy, the effect of acidic pH was assessed and correlated to DPPC/drug interaction.

Methods

Four different techniques were used: differential scanning calorimetry, dynamic light scattering, UV-VIS second derivative spectrometry and attenuated total reflection Fourier transformed infrared spectroscopy.

Results

All techniques concur in highlighting a structural change of lipid assembly, susceptible both to pH change and to the presence of the antitumor compound. Lipid vesicles appeared more compact at the lower pH, since the thermal pre-transition from the lamellar gel phase to the ripple gel phase was absent at pH 7.4 and the infrared analysis revealed a stronger acyl chain packing as well as a different hydration degree. Drug interaction was mainly detected in the lipid region including the ester linkages and the first portion of the acyl chains. Furthermore, a lower drug partitioning was recorded at pH 6.6.

Conclusions

The investigated antitumor agent possesses a stable negative charge at the investigated pH values, thus the lower interaction at the acidic pH is mainly ascribable to an environmental effect on lipid assembly. Therefore, drug efficacy under tumor acid conditions may be hampered by the observed lipid membrane constraints, and suggest for the development of suitable prodrugs.

     

Reformulation of Fungizone by PEG-DSPE Micelles: Deaggregation and Detoxification of Amphotericin B

Purpose

Fungizone® (AmB-SD), amphotericin B solubilized by sodium deoxycholate, contains a highly aggregated form of the antifungal agent that causes dose-limiting renal toxicity. With the aim of reducing the formulation’s toxicity by co-delivering monomeric amphotericin B (AmB) and sodium supplementation, we deaggregated AmB-SD with FDA-approved excipient PEG-DSPE in 0.9% NaCl-USP. Herein, we describe a reformulated AmB-SD with PEG-DSPE micelles that results in a less toxic drug with maintained antifungal activity.

Methods

We compared the aggregation state and particle size of AmB-SD alone or combined with PEG-DSPE micelles. In vitro hemolytic activity and in vivo renal toxicity were measured to determine the toxicity of different formulations. In vitro antifungal assays were performed to determine differences in efficacy among formulations.

Results

PEG-DSPE micelles in saline deaggregated AmB-SD. Deaggregated AmB-SD exhibited significantly reduced in vitro and in vivo toxicity. In vitro antifungal studies showed no difference in minimum inhibitory and fungicidal concentrations of AmB-SD combined with PEG-DSPE relative to the drug alone.

Conclusions

Reformulation of AmB-SD with PEG-DSPE micelles in saline facilitates co-delivery of monomeric AmB and sodium supplementation, potentially reducing the dose-limiting nephrotoxicity of AmB-SD. Ease of preparation and commercially available components lead us to acknowledge its potential for clinical use.

     

Bioflavonoid Fisetin Loaded α-Tocopherol-Poly(lactic acid)-Based Polymeric Micelles for Enhanced Anticancer Efficacy in Breast Cancers

Purpose

In this study, tocopherol based polymeric micelles were successfully prepared to enhance the anticancer effect of fisetin (FIS) in breast cancer cells.

Methods

The drug-loaded carrier was characterized in terms of physicochemical and in vivo parameters.

Results

Compared to FIS, FIS-TPN showed higher cellular uptake in MCF-7 breast cancer cells as revealed by CLSM and flow cytometry. The cytotoxicity assay results clearly showed that the free FIS and FIS-TPN exhibited a typical dose-dependent toxic effect in MCF-7 breast cancer cells. Especially, enhanced cytotoxic effect of FIS was observed when loaded in a nanocarrier. Free FIS induced a ~11% apoptosis whereas FIS-TPN induced a significantly greater apoptosis of ~20% by the end of 24 h. At 48 h, similar trend continued and free FIS showed ~30% of apoptosis whereas ~42% cell apoptosis was observed in FIS-TPN treated group. Notably, migration of cancer cell was significantly inhibited when treated with FIS-TPN formulations. The FIS-TPN significantly reduced to tumor burden and H&E staining showed the lowest tumor volume and higher cell apoptosis.

Conclusions

All the findings suggest that the fisetin-loaded TPGS-PLA polymeric micelles serve as a potential candidate and promising alternative for the effective treatment of breast cancers.

     

Targeting of Micelles and Liposomes Loaded with the Pro-Apoptotic Drug,NCL-240, into NCI/ADR-RES Cells in a 3D Spheroid Model

Purpose

To develop transferrin (Tf)-targeted delivery systems for the pro-apoptotic drug, NCL-240, and to evaluate the efficacy of this delivery system in ovarian cancer NCI/ADR-RES cells, grown in vitro in a 3D spheroid model.

Methods

Tf-targeted PEG-PE-based micellar and ePC/CHOL-based liposomal delivery systems for NCL-240 were prepared. NCI/ADR-RES cells were used to generate spheroids by a non-adhesive liquid overlay technique. Spheroid growth and development were monitored by size (diameter) analysis and H&E staining. The targeted formulations were compared to untargeted ones in terms of their degree of spheroid association and penetration. A cell viability analysis with NCL-240-loaded micelles and liposomes was performed to assess the effectiveness of Tf-targeting.

Results

Tf-targeted polymeric micelles and Tf-targeted liposomes loaded with NCL-240 were prepared. NCI/ADR-RES cells generated spheroids that demonstrated the presence of a distinct necrotic core along with proliferating cells in the spheroid periphery, partly mimicking in vivo tumors. The Tf-targeted micelles and liposomes had a deeper spheroid penetration as compared to the untargeted delivery systems. Cell viability studies using the spheroid model demonstrated that Tf-mediated targeting markedly improved the cytotoxicity profile of NCL-240.

Conclusion

Transferrin targeting enhanced delivery and effectiveness of micelles and liposomes loaded with NCL-240 against NCI/ADR-RES cancer cells in a 3D spheroid model.

     

Pharmacokinetics,Tissue Distribution and Therapeutic Effect of Cationic Thermosensitive Liposomal Doxorubicin Upon Mild Hyperthermia

Purpose

To evaluate pharmacokinetic profile, biodistribution and therapeutic effect of cationic thermosensitive liposomes (CTSL) encapsulating doxorubicin (Dox) upon mild hyperthermia (HT).

Methods

Non-targeted thermosensitive liposomes (TSL) and CTSL were developed, loaded with Dox and characterized. Blood kinetics and biodistribution of Dox-TSL and Dox-CTSL were followed in B16BL6 tumor bearing mice upon normothermia (NT) or initial hyperthermia conditions. Efficacy study in B16BL6 tumor bearing mice was followed with Dox-TSL or Dox-CTSL upon NT or HT. Efficacy study in LLC tumor bearing mice was performed upon two HT conditions. Intravital microscopy was performed on B16BL6 tumors implanted in dorsal-skin fold window-bearing mice.

Results

Targeting did not cause faster blood clearance of CTSL compared to TSL. Highest uptake of liposomes was observed in spleen, kidneys and liver. Applying HT prior to CTSL administration increased drug delivery to the tumor and CTSL delivered ~1.7 fold higher Dox concentration compared to TSL. Efficacy in B16BL6 murine melanoma showed that HT had a significant effect on CTSL in tumor suppression and prolonged survival. Efficacy in LLC Lewis lung carcinoma tumor model demonstrates that two HT treatments hold promises for a successful treatment option.

Conclusion

CTSL have potency to increase drug efficacy in tumors due to their targeted and drug release functions.

     

Coadministration of Polymeric Conjugates of Docetaxel and Cyclopamine Synergistically Inhibits Orthotopic Pancreatic Cancer Growth and Metastasis

Purpose

The aim of this study was to determine whether co-administration of hedgehog (Hh) pathway inhibitor cyclopamine (CYP) and microtubule stabilizer docetaxel (DTX) as polymer-drug conjugates, methoxy poly(ethylene glycol)-block-poly(2-methyl-2-carboxyl-propylenecarbonate-graft-dodecanol-graft-cyclopamine) (P-CYP) and methoxy poly(ethylene glycol)-block-poly(2-methyl-2-carboxyl-propylene carbonate-graft-dodecanol-graft-docetaxel) (P-DTX) could synergistically inhibit orthotopic pancreatic tumor growth in NSG mice.

Methods

P-DTX and P-CYP were synthesized from mPEG-b-PCC through carbodiimide coupling reaction and characterized by ¹H–NMR. The micelles were prepared by film hydration and particle size was measured by dynamic light scattering (DLS). Cytotoxicity, apoptosis and cell cycle analysis of P-DTX and P-CYP were evaluated in MIA PaCa-2 cells. In vivo efficacy of P-DTX and P-CYP were evaluated in NSG mice bearing MIA PaCa-2 cells derived orthotopic pancreatic tumor.

Results

P-CYP and P-DTX self-assembled into micelles of <90 nm and their combination therapy efficiently inhibited the proliferation of MIA PaCa-2 cells, induced apoptosis and cell cycle arrest at M-phase more efficiently than P-CYP and P-DTX monotherapies. Furthermore, the combination therapy of P-CYP and P-DTX significantly reduced Hh component expression compared to P-CYP alone as determined by Western blot analysis. Lastly, the combination therapy induced greater inhibition of orthotopic pancreatic tumor growth in NSG mice compared to their monotherapies.

Conclusion

Combination of polymer conjugated anticancer drug (P-DTX) with polymer conjugated Hh inhibitor (P-CYP) enhanced pancreatic cancer cell killing, apoptosis as well as in vivo tumor growth inhibition with no obvious toxicities.

     

Notch-1 siRNA and Methotrexate towards a Multifunctional Approach in Rhematoid Arthritis Management: a Nanomedicine Approach

Purpose

Rheumatoid arthritis (RA) is a chronic inflammatory disease and Notch pathway plays a pivotal role in synoviocytes involved in progression of RA.

Methods

Herein, we have designed a self-assembled polymeric micelles based on polycaprolactone-polyethylene glycol (PCL-PEG) and polyethylenimine-polyethylene glycol (PEI-PEG) was prepared and loaded with methotrexate and Notch-1 siRNA for the effective treatment of rheumatoid arthritis.

Results

The MTX/siRNA-loaded polymeric micelles (siM-PM) showed appreciable cellular uptake in Raw264.7 cells which were activated with LPS and did not exhibit any toxicity to Raw264.7 and HUVEC cells. The AUC of siM-PM was 4-fold higher compared to that of free MTX while t1/2 was 6 fold for siM-PM compared to that of free drug indicating the superior pharmacokinetic parameters. Importantly, siM-PM significantly reduced the paw thickness and slowed the disease progression remarkably, indicating that siM-PM is very effective in recovering the edema in arthritic animals. Importantly, 2-fold decrease in arthritic score was observed in siM-PM treated group at the end of day 24. The data clearly reveals anti-inflammatory effect of combinational nanoparticle due to the sequence specific downregulation of Notch-1 expression in the RA clinical models.

Conclusions

Overall, nanomedicine-based delivery of MTX and siRNA could overcome the side effects of small molecules and could improve the therapeutic effect of siRNA in rheumatoid arthritis.

     

Pharmacokinetics and Biodistribution of GDC-0449 Loaded Micelles in Normal and Liver Fibrotic Mice

Purposes

To determine the pharmacokinetic parameters and biodistribution of GDC-0449 loaded polymeric micelles after systemic administration into common bile duct ligation (CBDL) induced liver fibrotic mice.

Methods

We used GDC-0449 encapsulated methoxy poly (ethylene glycol)-block-poly (2-methyl-2-carboxyl-propylene carbonate)-graft-dodecanol (PEG-PCD) non-targeted polymeric micelles for GDC-0449 delivery to normal and liver fibrotic mice. To maximize GDC-0449 delivery to hepatic stellate cells (HSCs), mixed micelles formulations with 10, 20 and 30% w/w mannose-6-phosphate (M6P)-conjugated micelles were administered to normal and liver fibrotic mice for targeting M6P/IGF-IIR overexpressed on activated HSCs and biodistribution of GDC-0449 was determined at 30 and 120 min post systemic administration.

Results

GDC-0449 distributed to all major organs after systemic administration of drug loaded micelles, with higher accumulation in the liver of both normal and fibrotic mice. The plasma concentration versus time profiles suggest rapid clearance of GDC-0449 after systemic administration of drug loaded micelles in both normal and fibrotic mice, with similar plasma clearance (CL), area under the curve (AUC_int) and volume of distribution at steady state (V_ss). However, there is significant increase in GDC-0449 accumulation in the liver when M6P-conjugated mixed micelles were injected, with the highest GDC-0449 concentration in the liver with mixed micelles carrying 30% M6P-conjugated polymer. HSCs accounted for 14.19% of GDC-0449 accumulation for M6P-targeted micelles in fibrotic mice compared to 5.62% of non-targeted micelles in the liver uptake study.

Conclusion

M6P-conjugated GDC-0449 loaded mixed micelles may be used as a potential drug delivery vehicle for treating liver fibrosis.

     

A Simple and Improved Active Loading Method to Efficiently Encapsulate Staurosporine into Lipid-Based Nanoparticles for Enhanced Therapy of Multidrug Resistant Cancer

Purpose

This study was aimed at developing a new active loading method to stably encapsulate staurosporine (STS), a water insoluble drug, into lipid-based nanoparticles (LNPs) for drug targeting to tumors.

Methods

A limited amount of DMSO was included during the active loading process to prevent precipitation and facilitate the loading of insoluble STS into the aqueous core of a LNP. The drug loading kinetics under various conditions was studied and the STS-LNPs were characterized by size, drug-to-lipid ratio, drug release kinetics and in vitro potency. The antitumor efficacy of the STS-LNPs was compared with free STS in a mouse model.

Results

The drug loading efficiency reached 100% within 15 min of incubation at a drug-to-lipid ratio of 0.31 (mol) via an ammonium gradient. STS formed nano-aggregates inside the aqueous core of the LNPs and was stably retained upon storage and in the presence of serum. A 3-fold higher dose of the STS-LNPs could be tolerated by BALB/c mice compared with free STS, leading to nearly complete growth inhibition of a multidrug resistant breast tumor, while free STS only exhibited moderate activity.

Conclusion

This simple and efficient drug loading method produced a stable LNP formulation for STS that was effective for cancer treatment.

     

Membrane Loaded Copper Oleate PEGylated Liposome Combined with Disulfiram for Improving Synergistic Antitumor Effect <Emphasis Type="BoldItalic">In Vivo</Emphasis>

Purpose

This work aims to create a novel Cu²⁺ liposome with excellent loading stability and develop synergistic effect with disulfiram (DSF) for the treatment of tumor.

Methods

Copper oleate was incorporated into the liposome membrane via alcohol injection method in this work. In vitro release test was applied to evaluate the release profile of the liposomes. Pharmacokinetic studies were performed in rats and the antitumor efficacy was assessed in mice bearing hepatoma xenografts.

Results

The copper oleate liposome (Cu(OI)₂-L) was formulated and the loading efficiency were more than 85%. TEM images confirmed that the Cu(OI)₂-L had a spherical morphology with an average diameter of 100 nm. Cu(OI)₂-L displayed a biphasic release profile, with >70% retained drug over 8 h incubation in PBS at pH 7.4. Pharmacokinetic studies demonstrated that Cu(OI)₂-L had a prolonged circulation time and increased AUC when compared to the injection of copper oleate solution. The antitumor efficacy test demonstrated an enhanced tumor inhibition rate with the treatment of Cu(OI)₂-L and DSF nanoparticles, indicating an improved synergistic antitumor effect.

Conclusions

The Cu(OI)₂-L was suitable to be employed in combination with disulfiram for tumor treatment and can also open up opportunities for targeted delivery of copper.

     

A Mixed Micelle Formulation for Oral Delivery of Vitamin K

Purpose

To develop a stable micellar formulation of vitamin K for oral delivery, because the commercial and clinically used formulation of vitamin K (Konakion® MM) destabilizes at gastric pH resulting in low bioavailability of this vitamin in neonates with cholestasis.

Methods

Mixed micelles composed of EPC, DSPE-PEG 2000 and glycocholic acid, with and without vitamin K, were prepared by a film hydration method. The influence of pH on the stability of the micelles was analyzed by dynamic light scattering (DLS). The critical micelle concentration (CMC) was determined by fluorescence spectroscopy using pyrene and the morphology was evaluated by transmission electron microscopy . Caco-2 cells were used to study the cytocompatibilty.

Results

Mixed micelles with mean diameters from 7.1 to 11.0 nm and a narrow size distribution (PDI?<?0.2) were obtained after 3 membrane extrusion cycles. Konakion® MM formed aggregated particles at gastric pH, which was avoided through steric stabilization by introducing PEG. TEM showed that mixed micelles had a spherical size (diameter of around 10 nm) with a narrow size distribution in agreement with the DLS results. The loading capacities for vitamin K of mixed micelles with varying molar fractions of DSPE-PEG and EPC (from 0/100 to 50/50 (mol/mol)) were 10.8–5.0 w%, respectively. The mixed micelles showed good cytocompatibility at concentrations of glycocholic acid between 0.12 and 1.20 mM.

Conclusions

Mixed micelles with superior stability to Konakion® MM at low pH were obtained by introducing DSPE-PEG 2000. These are therefore attractive oral formulations for vitamin K.

     

Transferrin-Modified Vitamin-E/Lipid Based Polymeric Micelles for Improved Tumor Targeting and Anticancer Effect of Curcumin

Purpose

Transferrin receptor (TfR) is up-regulated in various malignant tumors not only to meet the iron requirement, but also to increase the cell survival via participation in various cellular signaling pathways. Here we explored transferrin as ligand for Poly(ethylene Glycol) (PEG)-ylated vitamin-E/lipid (PE) core micelles (VPM).

Methods

Transferrin modified polymer was synthesized and drug loaded micelles were evaluated in 2D Hela and HepG2 cancer cells for cellular uptake and cytotoxicity and in 3D Hela spheroids for growth inhibition, uptake and penetration studies.

Results

Targeted (Tf-VPM) and non-targeted (VPM) micelles showed mean hydrodynamic diameter of 114.2?±?0.64 nm and 117.4?±?0.72 nm and zeta potential was ?22.8?±?0.62 and ?14.8?±?1.74 mV, respectively. Cellular uptake study indicated that the Tf-CVPM were taken up by cancer cells (Hela and HepG2) with higher efficiency. Enhanced cytotoxicity was demonstrated for Tf-VPM compared to CVPM. Marked spheroid growth inhibition following treatment with Tf-CVPM was observed compared to the treatment with non-targeted CVPM.

Conclusions

The developed transferrin-modified micelles have improved ability to solubilize the loaded drugs and could actively target solid tumors by its interaction with over-expressed transferrin receptors. Therefore, the nano-micelles could be further explored for its potential utilization in cancer therapy.