Antitumor Drug Delivery System Research Articles

Synergistic Enhancement of Antitumor Efficacy by PEGylated Multi-walled Carbon Nanotubes Modified with Cell-Penetrating Peptide TAT.

In the present study, a cell-penetrating peptide, the transactivating transcriptional factor (TAT) domain from HIV, was linked to PEGylated multi-walled carbon nanotubes (MWCNTs) to develop a highly effective antitumor drug delivery system. FITC was conjugated on MWCNTs-polyethylene glycol (PEG) and MWCNTs-PEG-TAT to provide fluorescence signal for tracing the cellular uptake of the nanocarrier. After loaded with an anticancer agent, doxorubicin (DOX) via π − π stacking interaction, the physicochemical characteristics, release profile and biological evaluation of the obtained nano-sized drug carrier were investigated. The DOX loaded MWCNTs-PEG and MWCNTs-PEG-TAT drug carriers both displayed appropriate particle size, excellent stability, high drug loading, and pH-dependent drug release profile. Nevertheless, compared with DOX-MWCNTs-PEG, DOX-MWCNTs-PEG-TAT showed improved cell internalization, intracellular distribution and potentiated anticancer efficacy due to the TAT-mediated membrane translocation, endosomal escape and nuclear targeting. Furthermore, the therapeutic efficacy of DOX was not compromised after being conjugated with MWCNTs-PEG-TAT and the proposed nanocarrier was also confirmed to have a good biocompatibility. In conclusion, our results suggested that the unique combination of TAT and MWCNTs as a multifunctional drug delivery system might be a powerful tool for improved anticancer drug development.

IRGD-mediated core-shell nanoparticles loading carmustine and O6-benzylguanine for glioma therapy

iRGD (internalizing RGD) with high affinity to αν integrins was reported to enhance tumor penetrability by binding to neuropilin-1 (NRP-1). Based on our previous study, chitosan surface-modified poly (lactide-co-glycolides) nanoparticles (PLGA/CS NPs), loaded with carmustine (BCNU) and its sensitizer (O6-benzylguanine, BG) showed stronger anti-tumor effect than free drugs. In present study, PLGA/CS NPs (NPs) with core-shell structure were prepared and modified with iRGD or mPEG. F98, C6 or U87 cell lines with different receptors levels were selected for in vitro and in vivo studies. After administration of iRGD-mediated NPs, including iRGD-modified NPs (iRGD-NPs) and co-administration of iRGD and NPs (iRGD + NPs), their effects on glioma were compared with NPs. iRGD-NPs showed stronger cytotoxicity and cellular uptake than other groups. iRGD-NPs and iRGD + NPs displayed deeper tumor penetration and stronger anti-invasion effect on three dimensional (3D) glioma spheroids than NPs. On F98 glioma-bearing mice model, iRGD-mediated NPs showed enhanced crossing BBB ability and brain tumor accumulation levels. Correspondingly, the median survival time of iRGD + NPs, iRGD-NPs and NPs groups were 58, 49 and 34.5 days, respectively. Present studies supported the iRGD-mediated strategy to improve the efficacy of antitumor drug delivery system. Importantly, co-administration of iRGD may be a greater way over the conjugation of iRGD.

PH, temperature and reduction multi-responsive polymeric microspheres as drug delivery system for anti-tumor drug: Effect of middle hollow layer between pH and reduction dual-responsive cores and temperature sensitive shells

Multi-responsive polymeric microspheres have attracted more and more interest as drug delivery system (DDS) for anti-tumor drugs because they could achieve “on-demand” drug release, triggered by the tumor micro-environment. Here the pH, temperature and reduction multi-stimuli responsive polymeric microspheres were fabricated via distillation–precipitation polymerization technique, with or without the middle hollow layer between their pH and reduction responsive poly(methacrylic acid) (PMAA) cores and temperature sensitive poly(N-isopropylacrylamide) (PNIPAM) shells. The effect of the hollow layer on their drug loading and drug release performance was investigated in detail. It was found that the PMAA/PNIPAM yolk/shell microspheres with hollow layer possessed a higher drug loading capacity, while the PMAA/PNIPAM core/shell microspheres without hollow layer exhibited a better controlled release behavior. This understanding must be helpful on designing intelligent anti-tumor DDS.

In vitro and in vivo uptake studies of PAMAM G4.5 dendrimers in breast cancer.

BackgroundBreast cancer is the second leading cause of cancer death worldwide. Nanotechnology approaches can overcome the side effects of chemotherapy as well as improve the efficacy of drugs. Dendrimers are nanometric size polymers which are suitable as drug delivery systems. To the best of our knowledge, studies on the application of PAMAM G4.5 (polyamidoamine half generation 4) dendrimers as potential drug delivery systems in breast cancer have not been reported. In this work we developed a PAMAM G4.5 dendrimer containing FITC (fluorescein isothiocyanate) dye to study their uptake by murine breast cancer cells and BALB/c mice breast tumors.ResultsWe performed a reaction between FITC and PAMAM G4.5 dendrimers which were previously derivatized with piperazine (linker molecule), characterized them by 1H NMR (proton nuclear magnetic resonance) spectroscopy and MALDI-TOF (matrix-assisted laser desorption/ionization- time-of-flight) mass spectrometry. The experimental data indicated that 2 FITC molecules could be bound covalently at the PAMAM G4.5 dendrimer surface, with 17 FITC molecules probably occluded in PAMAM dendrimers cavity. PAMAM-FITC dendrimer (PAMAM G4.5-piperazinyl-FITC dendrimer) size distribution was evaluated by DLS (dynamic light scattering) and TEM (transmission electron microscopy). The nanoparticle hydrodynamic size was 96.3 ± 1.4 nm with a PdI (polydispersion index) of 0.0296 ± 0.0171, and the size distribution measured by TEM was 44.2 ± 9.2 nm. PAMAM-FITC dendrimers were neither cytotoxic in 4T1 cells nor hemolytic up to 24 h of incubation. In addition, they were uptaken in vitro by 4T1 cells and in vivo by BALB/c mice breast tumors. PAMAM G4.5-piperazinyl-FITC dendrimer intracellular distribution was observed through histologic analysis of the tumor by laser confocal microscopy.ConclusionThese results indicate that PAMAM G4.5 dendrimers enter tumor tissue cells, being good candidates to be used as antitumor drug delivery systems for breast cancer treatment and diagnosis.

The Use ofa Hydrophobic Binding Peptide Modified Lipid Nanocarrier Improving Tumor Distribution and Antitumor Efficacy.

In addition to showing the specific interaction between a generalized ligand and its receptor and the electrostatic effect between positive cell-penetrating peptides and negative cell membranes, our last study demonstrated the hydrophobic interactivity between a hydrophobic binding peptide (HBP) and biomembranes to be favorable in drug delivery. To yield more evidence for this new strategy and to find more effective HBPs, here we designed and established a novel nanomedicine associated with cyclosporin A (CsA) because this peptide is electrically neutral, highly hydrophobic, very stable in vivo and safe at the given dose. First, isothermal titration calorimetry (ITC) and surface plasmon resonance (SPR) studies showed a strong hydrophobic interaction between the CsA molecules and the lipid membrane. The lactate dehydrogenase release assay proved that CsA exhibited low toxicity to cell membranes. These facts encouraged us to explore the potential application of CsA as an HBP to actualize intracellular delivery of nanomedicines for tumor therapy. When conjugated to lipid nanocarriers, CsA significantly enhanced their binding with cells and,. consequently, increased the internalization of recoded nanomedicines into cells. The in vivo experiments further showed that the CsA-associated nanocarriers could achieve better delivery to tumor tissues and improve the tumor therapy of doxorubicin (DOX) compared to the nonmodified control; these findings were identical to the observations-in cell studies. In conclusion, CsA, a readily obtainable molecule with favorable characteristics, is indeed a good candidate for an HBP, and this study provides solid, novel evidence for the use of HBP-based nanocarriers as effective antitumor drug delivery systems.

Sigma receptor-mediated targeted delivery of anti-angiogenic multifunctional nanodrugs for combination tumor therapy

The potential of low molecular weight heparin (LMWH) in anti-angiogenic therapy has been tempered by poor in vivo delivery to the tumor cell and potentially harmful side effects, such as the risk of bleeding due to heparin's anticoagulant activity. In order to overcome these limitations and further improve the therapeutic effect of LMWH, we designed a novel combination nanosystem of LMWH and ursolic acid (UA), which is also an angiogenesis inhibitor for tumor therapy. In this system, an amphiphilic LMWH-UA (LHU) conjugate was synthesized and self-assembled into core/shell nanodrugs with combined anti-angiogenic activity and significantly reduced anticoagulant activity. Furthermore, DSPE-PEG-AA-modified LHU nanodrugs (A-LHU) were developed to facilitate the delivery of nanodrugs to the tumor. The anti-angiogenic activity of A-LHU was investigated both in vitro and in vivo. It was found that A-LHU significantly inhibited the tubular formation of human umbilical vein endothelial cells (HUVECs) (p<0.01) and the angiogenesis induced by basic fibroblast growth factor (bFGF) in a Matrigel plug assay (p<0.001). More importantly, A-LHU displayed significant inhibition on the tumor growth in B16F10-bearing mice in vivo. The level of CD31 and p-VEGFR-2 expression has demonstrated that the excellent efficacy of antitumor was associated with a decrease in angiogenesis. In conclusion, A-LHU nanodrugs are a promising multifunctional antitumor drug delivery system.

The Targeted-liposome Delivery System of Antitumor Drugs.

The liposome delivery system has been intensively explored as novel drug delivery system (DDS) for antitumor drugs, due to its safety, selective cytotoxicity, long circulation and slow elimination in blood, which is favorable for cancer therapy. The liposome-based chemotherapeutics are used to treat a variety of cancers to enhance the therapeutic index of antitumor drugs. Here, the author reviewed the important targets for cancer therapy and the pharmacokinetic behavior of liposomal drugs in vivo, as well as the application of the targeting liposomal system in cancer therapy. Considering further application for clinical use, the great challenges of the liposome-based delivery system were also proposed as follows: 1) prepare stealth liposome with steric stabilization and further enhance the therapeutic effects and safety; 2) explore more safe clinical targets and complementary or different types of targeting liposome; 3) thirdly, more investment is needed on the research of pharmacokinetics of the elements such as the ligands (antibody), PEG and lipids of liposome delivery system as well as safety evaluation. Considering the complex process of the liposomal encapsulation drugs in vivo, the author inferred that there are maybe different forms of the encapsulation drug to be internalized by the tumor tissues at the same time and space, although there are little reports on it.

The anticancer effects of biodegradable nanomagnetic dual natural components on the leptin gene expression in lung cancer

Lung cancer is an invasive and progressive, fatal disease with few treatment choices and poor overall survival rates in nonsurgical stages. Leptin (LEP), an adipocyte derivative cytokine, participates in carcinogenesis. Increased amounts of systemic and pulmonary LEP indicate lung cancer. Curcumin (CUR) and silibinin (SIL) are herbal compounds which have many anticancer properties, but they have hydrophobic structures and low solubility in water. In this study, evaluated CUR–SIL dual drug-loaded poly (ɛ-caprolactone) [PCL]–co-poly ethylene glycol (PEG) magnetic nanoparticles (MNPs) were used to determine the inhibitory effect on LEP gene expression. The physicochemical properties of free and CUR–SIL-loaded PCL–PEG were fully characterized. The cytotoxic effect of CUR–SIL-loaded PCL–PEG magnetic nanoparticles was determined by MTT assay. Afterward, the inhibition of LEP gene expression was specified through real-time PCR. Results indicated that CUR–SIL cytotoxicity is time- and dose-dependent. CUR–SIL loaded MNPs showed the IC50 limit in lower concentrations in comparison to net CUR–SIL. CUR–SIL loaded MNPs reduced LEP expression more than net CUR–SIL. These results revealed the possibilities of CUR–SIL-loaded MNPs as a natural and effective antitumor drug delivery system to fight lung tumors.

Dual loading miR-218 mimics and Temozolomide using AuCOOH@FA-CS drug delivery system: promising targeted anti-tumor drug delivery system with sequential release functions.

BackgroundDual loading drug delivery system with tumor targeting efficacy and sequential release function provides a promising platform for anticancer drug delivery. Herein, we established a novel AuCOOH@FACS nanogel system for co-delivery miR-218 mimics (as bio-drug) and Temozolomide(as chemo-drug).MethodsDLS and TEM were employed to determine the characteristics of particles and nanogels. The cell viability was calculated for study synergistic effect of both drugs coadministration and in nanogel forms. The amounts of Au uptake were measured by ICP-MS in cell and tumors to quantify the targeting drug delivery efficacy. Tumor weight and mice weight were investigated to study the targeting antitumor efficacy of nanogel system.ResultsThe results revealed that using AuCOOH@FACS nanogel as delivery vehicles, drugs could be targeting delivery to tumor site, the intracellular uptake is enhanced to a greater extent, and significant antitumor efficacy is fold increase compared with free drug administration group, without noticeable system cytotoxicity.ConclusionsThis system offers an efficient approach to cancer therapy and holds significant potential to improve the treatment of cancer in the future.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-015-0216-8) contains supplementary material, which is available to authorized users.

Prodrug-based nano-drug delivery system for co-encapsulate paclitaxel and carboplatin for lung cancer treatment

Context: Paclitaxel (PTX) and carboplatin (CBP) are widely used for the combined chemotherapy of non-small cell lung cancer (NSCLC). However, the development of multidrug resistance of cancer cells, as well as systemic toxic side effects resulting from nonspecific localization of anticancer drugs to non-tumor areas are major obstacles to the success of chemotherapy in treating cancers.Objective: This study aimed to engineer a prodrug-based nano-drug delivery system for co-encapsulate hydrophilic (CBP) and hydrophobic anti-tumor drugs (PTX). This system was expected to resolve the multidrug resistance cause by single drug, and the dual-drug-loaded liposome was also planned to specifically target the cancer cells without obvious influence on normal cells and tissues.Methods: In this paper, PLGA-PEG-CBP was synthesized by the conjugation between the carboxylic group of PLGA-PEG-COOH and the amino group of CBP. Then, self-assembled nanoparticles for combination delivery of PTX and PLGA-PEG-CBP (PTX/CBP NPs) were prepared by solvent displacement technique. The in vitro and in vivo anti-tumor efficacy was assessed in NCL-H460 human non-small cell lung carcinoma cell line.Results: PTX/CBP NPs achieved the highest cytotoxic effect among all formulations in vitro, as compared with single drug delivery NPs. In vivo investigation on NSCLC animal models showed that co-delivery of PTX and CBP possessed high tumor-targeting capacity and strong anti-tumor activity.Conclusions: The PTX/CBP NPs constructed in this research offers an effective strategy for targeted combinational lung cancer therapy.

Docetaxel-loaded single-wall carbon nanohorns using anti-VEGF antibody as a targeting agent: characterization, in vitro and in vivo antitumor activity

A novel antitumor drug delivery system, docetaxel (DTX)-loaded oxidized single-wall carbon nanohorns (oxSWNHs) with anti-VEGF monoclonal antibody (mAb) as a target agent was constructed. DTX was absorbed onto the oxSWNHs via the physical adsorption or π–π interaction. DSPE–PEG–COOH was non-covalently wrapped to the hydrophobic surface of oxSWNHs to improve its water solubility and biocompatibility. The mAb was bonded to the PEG through amide bond. The DTX@oxSWNHs-PEG-mAb (DDS) exhibited suitable particle size (191.2 ± 2.1 nm), good particle size distribution (PDI: 0.196), and negative zeta potential (−24.3 ± 0.85 mV). These features enhanced permeability and retention (EPR) effect and reduced the drug molecule uptake by the reticuloendothelial system. The in vitro drug release followed non-Fickian diffusion (n = 0.6857, R = 0.9924) with the cumulative release of DTX 59 ± 1.35 % at 72 h. Compared with free DTX, the DDS enhanced the cytotoxicity in MCF-7 cell lines in vitro efficiently (IC50: 2.96 ± 0.6 μg/ml), and provided higher antitumor efficacy (TGI: 69.88 %) in vivo. The histological analysis indicated that the DDS had no significant side effect. Therefore, the new DDS is promising to attain higher pharmaceutical efficacy and lower side effects than free DTX for cancer therapy. The research demonstrated that DTX@oxSWNHs-PEG-mAb might have promising biomedical applications for future cancer therapy.

Combination chemotherapy of doxorubicin, all-trans retinoic acid and low molecular weight heparin based on self-assembled multi-functional polymeric nanoparticles

Based on the complementary effects of doxorubicin (DOX), all-trans retinoic acid (ATRA) and low molecular weight heparin (LMWH), the combination therapy of DOX, ATRA and LMWH was expected to exert the enhanced anti-tumor effects and reduce the side effects. In this study, amphiphilic LMWH–ATRA conjugate was synthesized for encapsulating the DOX. In this way, DOX, ATRA and LMWH were assembled into a single nano-system by both chemical and physical modes to obtain a novel anti-tumor targeting drug delivery system that can realize the simultaneous delivery of multiple drugs with different properties to the tumor. LMWH–ATRA nanoparticles exhibited good loading capacities for DOX with excellent physico-chemical properties, good biocompatibility, and good differentiation-inducing activity and antiangiogenic activity. The drug-loading capacity was up to 18.7% with an entrapment efficiency of 78.8%. It was also found that DOX-loaded LMWH–ATRA nanoparticles (DHR nanoparticles) could be efficiently taken up by tumor cells via endocytic pathway, and mainly distributed in cytoplasm at first, then transferred into cell nucleus. Cell viability assays suggested that DHR nanoparticles maintained the cytotoxicity effect of DOX on MCF-7 cells. Moreover, the in vivo imaging analysis indicated that DiR-loaded LMWH–ATRA nanoparticles could target the tumor more effectively as compared to free DiR. Furthermore, DHR nanoparticles possessed much higher anticancer activity and reduced side effects compared to free drugs solution. These results suggested that DHR nanoparticles could be considered as a promising targeted delivery system for combination cancer chemotherapy with lower adverse effects.

PH‐ and β‐cyclodextrin‐responsive micelles based on polyaspartamide derivatives as drug carrier

ABSTRACTA novel kind of graft polymer poly(aspartic acid)‐ethanediamine‐g‐adamantane/methyloxy polyethylene glycol (Pasp‐EDA‐g‐Ad/mPEG) was designed and synthesized for drug delivery in this study. The chemical structure of the prepared polymer was confirmed by proton NMR. The obtained polymer can self‐assemble into micelles which were stable under a physiological environment and displayed pH‐ and β‐cyclodextrin (β‐CD)‐responsive behaviors because of the acid‐labile benzoic imine linkage and hydrophobic adamantine groups in the side chains of the polymer. The doxorubicin (Dox)‐loaded micelles showed a slow release under physiological conditions and a rapid release after exposure to weakly acidic or β‐CD environment. The in vitro cytotoxicity results suggested that the polymer was good at biocompatibility and could remain Dox biologically active. Hence, the Pasp‐EDA‐g‐Ad/mPEG micelles may be applied as promising controlled drug delivery system for hydrophobic antitumor drugs. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1387–1395

Collagen/chitosan film containing biotinylated glycol chitosan nanoparticles for localized drug delivery

The objective of this study was to design a drug delivery system consisting of biotinylated cholesterol-modified glycol chitosan (Bio-CHGC) nanoparticles and fish collagen/chitosan (Col/Ch) film for localized chemotherapy. Bio-CHGC was synthesized, and then its self-assembled nanoparticles were prepared by probe sonication. Doxorubicin (DOX)-loaded Bio-CHGC (DBC) nanoparticles prepared by dialysis had spherical shape, and their sizes were in the range of 330–397nm. Col/Ch/DBC nanoparticle films were fabricated by freeze-drying. SEM showed that the DBC nanoparticles were uniformly distributed into the films, and the films retained their structural integrity. A higher degradation and swelling rate of the drug films led to a higher diffusion rate of the nanoparticles from the films, resulting in an increase in the drug release from nanoparticles. The release of DOX from the films or Bio-CHGC nanoparticles was sensitive to the pH value of the release medium. In addition, the DOX release ratio of the drug films was lower than that of the nanoparticles alone, suggesting that the drug films had a double-sustained effect on the drug release. MTT assay implied that the DBC nanoparticle film showed a higher inhibitory ratio than the film containing nanoparticles without biotin, indicating that biotin moieties in the nanoparticles played an important role in exerting a cytotoxic effect. These data demonstrate that Col/Ch/DBC nanoparticle film has the potential to be used as a localized delivery system for hydrophobic antitumor drugs.

"AND" logic gate regulated pH and reduction dual-responsive prodrug nanoparticles for efficient intracellular anticancer drug delivery.

A dual-responsive drug delivery system simulating an AND logic gate is developed by core-cross-linking of a disulfide-containing anticancer prodrug with Cu(2+) for safe and efficient delivery of anticancer drugs. These prodrug nanoparticles are stable and exhibit nearly no premature drug release, and allow a fast drug release under simulated intracellular conditions, realizing a precise drug delivery towards cell nuclei.

Nanomicelles based on X-shaped four-armed peglyated distearylglycerol as long circulating system for doxorubicin delivery

A novel X-shaped four-armed gemini-like peglyated distearylglycerol (Gemini-PEG2K-GCDS), with two hydrophilic PEG heads and two hydrophobic stearic acid tails, was successfully synthesized and used as a nanomicellar carrier for delivery of doxorubicin. The critical micelle concentration of the amphiphilic copolymer was higher than 10−6. Mean particle size and zeta potential of DOX-encapsulated Gemini-PEG2K-GCDS nanomicelles (DOX-GNMs) was 20.4nm and+3.91mv, respectively. Encapsulation efficiency of DOX-GNMs was as high as 94.6 and DOX release was pH-dependent from DOX-GNMs, ensuring the stability of nanomicelles in blood circulation and rapid release of DOX in tumor cells. Pharmacokinetic studies in rats following i.v. administration, DOX-GNMs demonstrated longer retention in blood and larger AUC (19.1-fold of t1/2 and 12.9-fold of AUC) compared with DOX solutions (DOX-Sol). Tissue distribution studies indicate that DOX-GNMs had higher tumor accumulation (4.6-fold) and lower heart toxicity in H22 tumor-bearing mice (17.4-fold) at 48h after administration in comparison with DOX-Sol. Moreover, IC50 of DOX-GNMs increased by 3.3-fold, 2.0-fold and 2.3-fold compared with DOX-Sol in P-gp over-expressing MCF-7/Adr cells after 24h, 48h and 72h, internalized via macropinocytosis-mediated and clathrin-mediated endocytosis. This study suggests that Gemini-PEG2K-GCDS nanomicelle is a promising long circulating delivery system for anti-tumor drugs via extended blood circulation and improved tumor distribution.

Anti-tumor drug delivery system based on cyclodextrin-containing pH-responsive star polymer: In vitro and in vivo evaluation

A cyclodextrin-containing pH-responsive star polymer, with cyclodextrin polymer and pH-sensitive poly(2-(dimethylamino)ethyl methacrylate) as the core and poly(ethylene glycol) as the arm, was evaluated as drug carriers in vitro and in vivo. Doxorubicin (DOX) was successfully loaded into the star polymer to form nanoparticles (DOX-NPs) via host–guest interaction. The physicochemical properties such as drug loading content, size, morphology, stability and physical state of DOX-NPs were characterized in detail by 1H NMR, DLS, SEM and DSC. Uniform and stable DOX-NPs with high encapsulation efficiency of 77.1% were obtained, and they also exhibited sustainable and controllable release of DOX in vitro. The cellular uptake of DOX-NPs was in concentration-, time- and cell type-dependent manners, and the cytotoxicity of DOX-NPs was significantly high toward HeLa and HepG2 cancer cells. Furthermore, in vivo anti-tumor experiment on BALB/c mice bearing cervical tumor showed that DOX-NPs could effectively suppress the growth of tumor without significant side effect. These findings suggest that the cyclodextrin-containing pH-responsive star polymer has a promising potential in developing novel drug delivery system for cancer therapy.

Preparation and evaluation of RGD and TAT co-modified paclitaxel loaded liposome

To prepare Arg-Gly-Asp (RGD) and cell penetrating peptide TAT co-modified paclitaxel loaded liposome (RGD/TAT-LP-PTX) for MCF-7 cell inhibition. The co-modified liposome was prepared by film-ultrasonic method. The appearance, particle size and zeta potential were evaluated. The cellular uptake by MCF-7 cells in vitro was used to evaluate the targeting efficiency. The anti-proliferation efficiency of RGD/TAT-LP-PTX was evaluated by MTT assay. Tumor spheroids were used to evaluate anti-tumor ability of RGD/TAT-LP-PTX in vitro. The particle diameter of the co-modified liposome was (138.8 ± 12.4) nm with the Zeta potential of (25.85 ± 2.75) mV. The entrapment efficiency of PTX was 88.3%. The RGD/TAT-LP uptaken by MCF-7 cells at 4 h was 1.79 times higher than that at 2 h. The co-modified liposome uptaken by MCF-7 cells was 2.25 and 2.72 times higher than that of TAT-LP and RGD-LP, respectively. The anti-proliferation rate of RGD/TAT-LP-PTX increased with time. The inhibition rate of RGD/TAT-LP-PTX for MCF-7 cells at 48 h was 1.78 times higher than that at 24 h. The MTT assay demonstrated the cell viability of RGD/TAT-LP-PTX was 1.65, 1.82 and 2.55 times higher than that of TAT-LP-PTX, RGD-LP-PTX and LP-PTX, respectively. Co-modified liposome may serve as a promising breast cancer delivery system for antitumor drugs.

Nanoparticles generated by PEG-Chrysin conjugates for efficient anticancer drug delivery

Nanoparticle-based drug delivery systems promise the safety and efficacy of anticancer drugs. Herein, we presented a facile approach to fabricate novel nanoparticles generated by PEG-Chrysin conjugates for the delivery of anticancer drug doxorubicin. Chrysin was immobilized on the terminal group of methoxy poly(ethylene glycol) (mPEG) to form mPEG-Chrysin conjugate. The conjugates were self-assembled into nanoparticles. Doxorubicin (DOX) was loaded in the nanoparticles. The self-assembly, drug release profiles, interactions between nanoparticle and drug, cellular uptake and in vitro anticancer activity of the DOX loaded nanoparticles were investigated. The results showed that the mean diameters of drug loaded nanoparticles were below 200nm. Strong π–π stacking interaction was tested within the drug loaded nanoparticles. The drug release rate was closely related to the chain length of PEG, shorter PEG chain resulted faster release. The mPEG-Chrysin conjugate was non-toxic to both 3T3 fibroblasts and HepG2 cancer cells. The cellular uptake measurements demonstrated that the mPEG1000-Chrysin nanoparticles exhibited higher capability in endocytosis. The IC50 of drug loaded mPEG1000-Chrysin nanoparticles was 4.4μg/mL, which was much lower than that of drug loaded mPEG2000-Chrysin nanoparticles (6.8μg/mL). These nanoparticles provided a new strategy for fabricating antitumor drug delivery systems.

Polymeric micelles with small lipophilic moieties for drug delivery

The aim of this study was to develop a new polymeric micelle delivery system for antitumor drugs. An amphiphile of methoxypoly(ethylene glycol)-histidine-di(cinnamic acid) (PEGHC) with a small lipophilic moiety instead of a hydrophobic biodegradable polymer chain was synthesized and characterized. The PEGHC self-assembled into micelles. The critical micelle concentration (CMC) was tested. 9-Nitro-20(s)-camptothecin (9-NC) was used as a model drug for encapsulation. The size and morphology of both blank and 9-NC loaded micelles were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The release profile of 9-NC loaded micelles was studied. HepG2 liver cancer cells were incubated with the drug-loaded micelles to investigate the in vitro anticancer efficiency. The results showed that the 9-NC loaded micelles exhibited high accumulated release rate (>85%) and efficient in vitro anticancer activity.