Dual-targeting Drug Delivery System Research Articles

Assessment of the antitumor activity of a cyclopalladated ferrocene compound assisted by a dual-targeting drug delivery system.

One cyclopalladated ferrocene compound CP was synthesized, which showed a good cell cytotoxicity. Assisted by a dual-targeting drug delivery system, the anticancer activity of CP to MDA-MB-468 remained unchanged, but the toxicity to non-tumorigenic cell line NIH3T3 was remarkably reduced. This provided a new path for the development of cyclopalladated ferrocene as an antitumor drug candidate.

Dual targeting mesoporous silica nanoparticles for inhibiting tumour cell invasion and metastasis

The invasion and metastasis of tumour cells are closely correlated with poor prognosis of cancer patients. In this study, a CD44 and N-cadherin dual targeting drug delivery system based on mesoporous silica nanoparticles (MSNs) has been successfully constructed for inhibiting tumour cell invasion and metastasis. Amino modified MSN (MSN/NH2) was first synthesized and then functionalized with hyaluronic acid (HA) and ADH-1, constructing the carrier ADH-1-HA-MSN. Doxorubicin hydrochloride (DOX) was selected as a model anticancer drug. The prepared vector had a spherical shape with a narrow distribution of particle size. Flow cytometry and confocal microscopy studies showed that the modification with HA significantly enhanced CD44-mediated cellular uptake of this nanocarrier. ADH-1-HA-MSN/DOX exhibited higher cytotoxicity compared to non-ADH-1 modified counterparts. Of note, a transwell chamber assay demonstrated that the migration and invasion of tumour cells were markedly inhibited by ADH-1-HA-MSN/DOX. Furthermore, Western blotting analysis revealed that ADH-1-HA-MSN/DOX inhibited tumour cell invasion and metastasis by down-regulating N-cadherin expression. Taken together, these results indicated that ADH-1-HA-MSN might be a promising targeted drug delivery system for inhibiting cancer invasion and metastasis.

Application of dual targeting drug delivery system for the improvement of anti-glioma efficacy of doxorubicin.

Chemotherapy of glioma is always hampered by the unsatisfactory tumor accumulation of drugs, of which the most noticeable obstacle is the limited drug permeability from vessels into tumor inner. In the present study, we developed a novel nanocarrier for the delivery of doxorubicin to brain tumor. Such novel drug delivery system was mainly composed of a tumor homing peptide and DOX-loaded PLA nanoparticles (AP1-NP-DOX). CRKRLDRNC peptide, named as AP1, was a newly glioma affinity peptide which could specifically binds to interleukin-4 receptor (IL-4R), highly expressing on both glioma cells and angiogenesis. Our findings showed that the peptide-functionalized nanoparticles had a high affinity with both tumor cells and vascular endothelial cells. Besides, tumor targeting assay exhibited that AP1 decorated nanoparticles accumulated more in tumor site than the unmodified ones. Moreover, the results of tumor uptake experiments indicated that AP1-NP-DOX might own the ability of blood brain barrier (BBB) penetration. In the anti-glioma study, AP1-NP-DOX exhibited the highest therapeutic effect on tumor-bearing mice compared with the unmodified nanoparticles and free doxorubicin. These results together indicated that AP1-functionalized nanoparticles could represent a promising way to expand the treatment horizons of onco-therapy.

Angiopep-2-conjugated poly(ethylene glycol)-co- poly(ε-caprolactone) polymersomes for dual-targeting drug delivery to glioma in rats.

The blood–brain barrier is a formidable obstacle for glioma chemotherapy due to its compact structure and drug efflux ability. In this study, a dual-targeting drug delivery system involving Angiopep-2-conjugated biodegradable polymersomes loaded with doxorubicin (Ang-PS-DOX) was developed to exploit transport by the low-density lipoprotein receptor-related protein 1 (LRP1), which is overexpressed in both blood–brain barrier and glioma cells. The polymersomes (PS) were prepared using a thin-film hydration method. The PS were loaded with doxorubicin using the pH gradient method (Ang-PS-DOX). The resulting PS were uniformly spherical, with diameters of ~135 nm and with ~159.9 Angiopep-2 molecules on the surface of each PS. The drug-loading capacity and the encapsulation efficiency for doxorubicin were 7.94%±0.17% and 95.0%±1.6%, respectively. Permeability tests demonstrated that the proton diffusion coefficient across the PS membrane was far slower than that across the liposome membrane, and the common logarithm value was linearly dependent on the dioxane content in the external phase. Compared with PS-DOX, Ang-PS-DOX demonstrated significantly higher cellular uptake and stronger cytotoxicity in C6 cells. In vivo pharmacokinetics and brain distribution experiments revealed that Ang-PS-DOX achieved a more extensive distribution and more abundant accumulation in glioma cells than PS-DOX. Moreover, the survival time of glioma-bearing rats treated with Ang-PS-DOX was significantly prolonged compared with those treated with PS-DOX or a solution of free doxorubicin. These results suggested that Ang-PS-DOX can target glioma cells and enhance chemotherapeutic efficacy.

Neovasculature and circulating tumor cells dual-targeting nanoparticles for the treatment of the highly-invasive breast cancer.

Antiangiogenesis therapy has been served as a potent cancer treatment strategy for decades, yet disrupting neovasculature would provoke tumor cells into invasive growth and result in distal metastasis. The basic cause of cancer metastasis can be traced down to the presence of circulating tumor cells (CTCs) which detach from primary tumor site and act as 'seeds'. Epithelial cell adhesion molecule (EpCAM) is a potential biomarker for selective capture of epithelium-derived CTCs. Here, we integrated tumor neovessles-targetable ligands K237 peptide with Ep23 aptamer against EpCAM into a single drug-loaded nanoplatform using paclitaxel (PTX) as the model drug, aiming at damaging the primary tumor and neutralizing CTCs simultaneously to achieve a synergistic anti-tumor therapeutic effect. Enhanced cellular uptake, cell apoptosis-induction and cell-viability inhibition efficiency of the peptide and aptamer dual-functionalized nanoparticles (dTNP) were observed in both human umbilical vein endothelial cells (HUVEC) and 4T1 cells invitro. Using cone-and-plate viscometer to create venous flow velocity, dTNP was also found to be able to capture CTCs under shear stress. The CTC-targeting and neutralization effect of dTNP in bloodstream and 4T1-GFP cell-derived lung metastasis mice model was confirmed via invivo flow cytometry (IVFC), intravital imaging and confocal microscopy analysis. As a result, the orthotropic breast tumor-bearing mice administrated with PTX-loaded dTNP exhibited the optimal therapeutic effect. Taken together, the findings here provided direct evidence that the tumor neovasculature and CTCs dual-targeting drug delivery system could provide a novel modality for the treatment of highly-invasive breast cancer.

Large amino acid transporter 1 mediated glutamate modified docetaxel-loaded liposomes for glioma targeting

The therapeutic outcome of glioma treatment is rigorously limited by blood–brain barrier (BBB) and infiltrating growth of glioma. To tackle the dilemma, more and more attentions were focused on developing nutrient transporters-mediated dual-targeted drug delivery system, in one side for BBB penetration, another for intracranial glioma targeting. Herein, Large amino acid transporter 1 (LAT1), overexpressed both on BBB and glioma cells, was selected as a target. Docetaxel-loaded glutamate-d-α-tocopherol polyethylene glycol 1000 succinate copolymer (Glu-TPGS) functionalized LAT1-targeting liposomes (DTX-TGL) were applied to enhance the BBB penetration and glioma therapy. The in vivo results of the fluorescent image indicated that TGL possessed an effective BBB penetration than that of unmodified ones in mice. The LAT1 targeting effcicacy and cell cytotoxicity of TGL were investigated in C6 glioma cells. Compared with unmodified liposomes, a significant higher cellular uptake and cell cytotoxicity was found in TGL treated group. Our results indicated that LAT1-targeting docetaxel-loaded liposome paves up a new direction using LAT1 transporter as a good target in designing brain glioma-targeting nanosystems.

Quantitative control of active targeting of nanocarriers to tumor cells through optimization of folate ligand density

The active targeting delivery system has been widely studied in cancer therapy by utilizing folate (FA) ligands to generate specific interaction between nanocarriers and folate receptors (FRs) on tumor cell. However, there is little work that has been published to investigate the influence of the definite density of the FA ligands on the active targeting of nanocarriers. In this study, we have combined magnetic-guided iron oxide nanoparticles with FA ligands, adjusted the FA ligand density and then studied the resulting effects on the active targeting ability of this dual-targeting drug delivery system to tumor cells. We have also optimized the FA ligand density of the drug delivery system for their active targeting to FR-overexpressing tumor cells in vitro. Prussian blue staining, semi-thin section of cells observed with transmission electron microscopy (TEM) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) have shown that the optimal FA density is from 2.3 × 1018 to 2.5 × 1018 per gram nanoparticles ((g·NPs)−1). We have further tried to qualitatively and quantitatively control the active targeting and delivering of drugs to tumors on 4T1-bearing BALB/c mice. As expected, the in vivo experimental results have also demonstrated that the FA density of the magnetic nanoparticles (MNPs) could be optimized for a more easily binding to tumor cells via the multivalent linkages and more readily internalization through the FR-mediated endocytosis. Our study can provide a strategy to quantitatively control the active targeting of nanocarriers to tumor cells for cancer therapy.

Magnetic Fe3O4 nanoparticles grafted with single-chain antibody (scFv) and docetaxel loaded β-cyclodextrin potential for ovarian cancer dual-targeting therapy

In order to improve the therapeutic efficiency and reduce the side effects on nonpathological cells and tissues, targeting drug delivery systems have gained more and more attraction. Here, we report a novel dual-targeting drug delivery system for ovarian cancer therapy. The inner core was made of iron oxide (Fe3O4) nanoparticles, synthesized by co-precipitation method. It was further surface-functionalized with amine groups to link single-chain antibody (scFv) and β-cyclodextrin (β-CD). Docetaxel (TXT) was finally included in the grafted β-CD. FTIR and XPS confirmed the reactions. SEM found that the diameters of these Fe3O4 nanoparticles before and after functionalization were around 40nm. Magnetization test showed that these particles were superparamagnetic. The in vitro release of TXT was concentration-driven and sustained, depending on the renewal rate of release medium. The in vitro flow chamber experiment revealed its magnetic targeting property; modified ELISA and static binding experiments displayed its good affinity to Endoglin, indicating that our drug delivery system has the potential to be dual-targeted to ovarian cancer tissue by externally applied magnetic field and native active binding of grafted scFv to Endoglin, overexpressed by ovarian cancer tissue. MTT assays showed that the TXT released from this drug delivery system continuously inhibited the growth of Skov3 ovarian cancer cells in 72h, better than the control raw TXT. All these results demonstrated a promising dual-targeting drug delivery system with great potential for ovarian cancer therapy.

Lactoferrin-Modified Poly(ethylene glycol)-Grafted BSA Nanoparticles as a Dual-Targeting Carrier for Treating Brain Gliomas

In this study, a dual-targeting drug delivery system based on bovine serum albumin nanoparticles (BSA-NPs) modified with both lactoferrin (Lf) and mPEG2000 loading doxorubicin (DOX) was designed, and its blood-brain barrier (BBB) penetration and brain glioma cells targeting properties were explored. BSA-NPs were prepared by a desolvation technique, and mPEG2000 was incorporated onto the surface of BSA-NPs by reacting with the free amino-group of BSA to form mPEG2000-modified BSA-NPs (P2000-NPs). Finally, Lf-modified P2000-NPs (Lf-NPs) was obtained by absorbing Lf onto the surface of P2000-NPs via the positive and negative charges interaction at physiological pH. Three levels of mPEG2000 and Lf-modified NPs were prepared and characterized, respectively. The uptake and potential cytotoxicity of different DOX preparations in vitro by the primary brain capillary endothelial cells (BCECs) and glioma cells (C6) were investigated. The dual-targeting effects were studied on the BBB model in vitro, BCECs/C6 glioma coculture model in vitro, and C6 glioma-bearing rats in vivo, respectively. The results exhibited that, with the increase of the amount of both mPEG2000 and Lf, the particle size of NPs increased and its zeta potential decreased. The in vivo pharmacokinetics study in healthy rats exhibited that P2000-NPs with a high level of mPEG2000 (P2000H-NPs) had longer circulation time in vivo. Compared to other NPs, Lf-NPs with high level of both Lf and mPEG2000 (LfH-NPs) showed the strongest cytotoxicity and the highest effectiveness in the uptake both in BCECs and C6 as well as improved the dual-targeting effects. Body distribution of DOX in different formulations revealed that LfH-NPs could significantly increase the accumulation of DOX in the brain, especially at 2 h postinjection (P < 0.05). In conclusion, Lf-NPs were a prospective dual-targeting drug delivery system for effective targeting therapy of brain gliomas.

Study and evaluation of mechanisms of dual targeting drug delivery system with tumor microenvironment assays compared with normal assays

A dual targeting delivery system was developed to completely conquer the two barriers that glioma treatment faces: the blood–brain barrier (BBB) and the brain–glioma barrier. Recently, a system comprising AS1411 aptamer (for glioma targeting) and TGN peptide (for BBB targeting) modified nanoparticles (AsTNPs) was developed, which can effectively target brain glioma and improve the survival of glioma-bearing mice. However, the in vitro models currently used are far too different from the in vivo tumor microenvironment that the glioma targeting delivery system actually faces. In this study, the pharmacology mechanisms of AsTNPs were explored in several models that imitated the tumor microenvironment. AsTNPs can be selectively taken up by endothelial and glioma cells, effectively penetrating the BBB and brain–glioma barriers to reach glioma cells and display their anti-glioma effect. The cell monolayers, tumor spheroids and coculture systems were more suitable in vitro models for the pharmacology evaluation of targeted drug delivery systems.

Nanoparticles of 2-deoxy-d-glucose functionalized poly(ethylene glycol)-co-poly(trimethylene carbonate) for dual-targeted drug delivery in glioma treatment

Based on the facilitative glucose transporter (GLUT) over-expression on both blood–brain barrier (BBB) and glioma cells, 2-deoxy-d-glucose modified poly(ethylene glycol)-co-poly(trimethylene carbonate) nanoparticles (dGlu–NP) were developed as a potential dual-targeted drug delivery system for enhancing the BBB penetration via GLUT-mediated transcytosis and improving the drug accumulation in the glioma via GLUT-mediated endocytosis. In vitro physicochemical characterization of the dual-targeted nanoparticulate system presented satisfactory size of 71 nm with uniform distribution, high encapsulation efficiency and adequate loading capacity of paclitaxel (PTX). Compared with non-glucosylated nanoparticles (NP), a significantly higher amount of dGlu–NP was internalized by RG-2 glioma cells through caveolae-mediated and clathrin-mediated endocytosis. Both of the transport ratios across the in vitro BBB model and the cytotoxicity of RG-2 cells after crossing the BBB were significantly greater of dGlu–NP/PTX than that of NP/PTX. In vivo fluorescent image indicated that dGlu–NP had high specificity and efficiency in intracranial tumor accumulation. The anti-glioblastoma efficacy of dGlu–NP/PTX was significantly enhanced in comparison with that of Taxol and NP/PTX. Preliminary safety tests showed no acute toxicity to hematological system, liver, kidney, heart, lung and spleen in mice after intravenous administration at a dose of 100 mg/kg blank dGlu–NP per day for a week. Therefore, these results indicated that dGlu–NP developed in this study could be a potential dual-targeted vehicle for brain glioma therapy.

LDLR-mediated peptide-22-conjugated nanoparticles for dual-targeting therapy of brain glioma

Chemotherapy for brain glioma has been of limited benefit due to the inability of drugs to penetrate the blood–brain barrier (BBB) and non-selective drug accumulation in the entire brain. To obviate these limitations, dual-targeting paclitaxel-loaded nanoparticles were developed by decoration with peptide-22 (PNP–PTX), a peptide with special affinity for low-density lipoprotein receptor (LDLR), to transport the drug across the BBB, and then target brain tumour cells. Enzyme-linked immune sorbent assay (ELISA) revealed that LDLR was over-expressed in C6 cells and brain capillary endothelial cells (BCECs), but low LDLR expression was observed in H92c(2-1) cells. Nanoparticle uptake demonstrated that peptide-22-decorated nanoparticles significantly increased the cellular uptake of nanoparticles by C6 cells and BCECs but not by H92c(2-1) cells, and excess free peptide-22 significantly inhibited the cellular uptake of PNP by C6 cells and BCECs. Cellular uptake mechanism experiments showed that PNP uptake by both BCECs and C6 cells was energy-dependant and caveolae- and clathrin-mediated endocytosis pathway other than macropinocytosis were involved. Dual-targeting effects in an in vitro BBB model showed that peptide-22 decoration on nanoparticles loaded with paclitaxel significantly increased the transport ratio of PTX across the BBB and induced apoptosis of C6 glioma cells below the BBB, and these effects were significantly inhibited by excess free peptide-22. Ex vivo and in vivo fluorescence imaging indicated that PNP labelled with a near-infrared dye could permeate the BBB and accumulate more in the glioma site than unmodified NP. Glioma section observed by fluorescence microscopy further demonstrated PNP distributed more extensively in both glioma bulk and infiltrative region around than unmodified NP. Pharmacodynamics results revealed that the median survival time of glioma-bearing mice administered with dual-targeting PNP–PTX was significantly prolonged compared with that of any other group. TUNEL assay and H&E staining showed that PNP–PTX treatment induced significantly more cell apoptosis and tumour necrosis compared with other treatments. Taken together, these promising results suggested that the dual-targeting drug delivery system might have great potential for glioma therapy in clinical applications.

Dual-targeting Janus Dendrimer Based Peptides for Bone Cancer: Synthesis and Preliminary Biological Evaluation

The development of dual-targeting drug delivery system is helpful to overcome the poor physiochemical properties of chemotherapeutic agents. The RGD sequence has a potential dual-targeting property, with which the chemotherapeutic agents can be delivered to bone tissue and tumor. And the Janus dendrimer which consists of two dendrons with different tasks is useful for improving the effect of polymer on pharmacokinetic properties. In this paper, a Janustype peptide dendrimer which consisted of RGD dimer and 5-FU dimer was synthesized and well characterized by 1H NMR and MS techniques, as well as the other three compounds for contrast. The hydroxyapatite binding assay and drug release study were evaluated. The Janus-type dendrimer with both enhanced targeting property and optimized release property, may reduce the side effects in normal tissues and have potential sustained-release effect. Thus, it may represent a novel opportunity to apply the versatile Janus-type dual-targeting delivery system to applications in bone tumor treatment. Keywords: Bone cancer, dual-targeting, hydroxyapatite, in vitro, Janus dendrimer, peptide, RGD.

Quantum Dots Conjugated with Fe3O4-Filled Carbon Nanotubes for Cancer-Targeted Imaging and Magnetically Guided Drug Delivery

A novel and specific nanoplatform for in vitro simultaneous cancer-targeted optical imaging and magnetically guided drug delivery is developed by conjugating CdTe quantum dots with Fe(3)O(4)-filled carbon nanotubes (CNTs) for the first time. Fe(3)O(4) is filled into the interior of the CNTs, which facilitates magnetically guided delivery and improves the synergetic targeting efficiency. In comparison with that immobilized on the external surface of CNTs, the magnetite nanocrystals inside the CNTs protect it from agglomeration, enhance its chemical stability, and improve the drug loading capacity. It also avoids magnetic nanocrystals-induced quenching of fluorescence of the quantum dots. The SiO(2)-coated quantum dots (HQDs) attached on the surface of CNTs exhibit favorable fluorescence as the hybrid SiO(2) shells on the QDs surface prevent its fluorescence quenching caused by the CNTs. In addition, the hybrid SiO(2) shells also mitigate the toxicity of the CdTe QDs. By coating transferrin on the surface of the herein modified CNTs, it provides a dual-targeted drug delivery system to transport the doxorubicin hydrochloride (DOX) into Hela cells by means of an external magnetic field. The nanocarrier based on the multifunctional nanoplatform exhibits an excellent drug loading capability of ca. 110%, in addition to cancer-targeted optical imaging as well as magnetically guided drug delivery.

Dual-targeting delivery system for bone cancer: synthesis and preliminary biological evaluation

Chemotherapy in treatment of malignant tumors has many side effects due to the poor physiochemical properties and the toxicity to normal tissues. The dual-targeting drug delivery system combining two high-affinity ligands can target anticancer drug primary to the diseased tissue, then to the tumor, which provides both greater efficacy of treatment and less harm to normal tissues. In this paper, a novel dual-targeting moiety RGD7 (R-G-D-D-D-D-D-D-D; Nonapeptide for bone cancer combining D6 peptide as bone target moiety and RGD peptide as tumors target moiety was contracted. A series of bone and/or tumor targeting conjugates have been synthesized in a convergent approach and well characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS) techniques. The hydroxyapatite (HAP) binding, water solubility, the drug release and the distribution in vivo were evaluated. All the conjugates were water-soluble and able to release the parent drugs in vitro. The bone-targeting property of the dual-targeting delivery system was enhanced from the results of the HAP binding and the distribution in vivo. The experiment for verifying tumor targeting property was underway. These results provided an effective entry to the development of a new dual-targeting delivery system for bone cancer.

Anti-glioblastoma efficacy and safety of paclitaxel-loading Angiopep-conjugated dual targeting PEG-PCL nanoparticles

Therapeutic effect of glioma is often limited due to low permeability of delivery systems across the Blood-Brain Barrier (BBB) and poor penetration into the tumor tissue. In order to overcome the two barriers, we proposed Angiopep-conjugated PEG-PCL nanoparticles (ANG-PEG-NP) as a dual targeting drug delivery system for glioma treatment basing on low density lipoprotein receptor related protein (LRP) receptor not only over-expressed on BBB but also on glioma cells. This system could transport across BBB through LRP-mediated transcytosis and then targeted glioma via LRP-mediated endocytosis. In this study, we evaluated the preliminary availability and safety of ANG-PEG-NP for glioma treatment. The penetration, distribution, and accumulation into 3D glioma spheroid and in vivo glioma region of ANG-PEG-NP were obviously higher than that of plain PEG-PCL nanoparticles (PEG-NP). The anti-glioblastoma efficacy of paclitaxel (PTX) loading ANG-PEG-NP was significantly enhanced as compared to that of Taxol and PEG-NP. Preliminary safety results showed that no acute toxicity to hematological system, liver, kidney and brain tissue was observed after intravenous administration with a dose of 100 mg/kg blank ANG-PEG-NP per day for a week. Results indicate that Angiopep-conjugated dual targeting PEG-PCL nanoparticle is a potential brain targeting drug delivery system for glioma treatment.

The targeted delivery of anticancer drugs to brain glioma by PEGylated oxidized multi-walled carbon nanotubes modified with angiopep-2

In this study, a dual-targeting drug delivery system based on PEGylated oxidized multi-walled carbon nanotubes (O-MWNTs) modified with angiopep-2 (O-MWNTs-PEG-ANG) was successfully developed for treatment of brain glioma. O-MWNTs can not only distribute in brains but also accumulate in tumors, and have ultrahigh surface area with remarkably high loading anticancer drug of doxorubicin (DOX), which was selected as drug carrier. Angiopep-2 can specifically combine to the low-density lipoprotein receptor-related protein (LRP) receptor overexpressed on the blood–brain barrier (BBB) and glioma cells, which was selected as targeting ligand. The cooperative dual-targeting to brain glioma by O-MWNTs-PEG-ANG was evaluated by intracellular tracking in vitro and fluorescence imaging in vivo, which demonstrated that the combination of O-MWNTs-PEG and angiopep-2 constituted an ideal dual-targeting drug delivery system. The anti-glioma effect of DOX-loaded O-MWNTs-PEG-ANG (DOX-O-MWNTs-PEG-ANG) was assessed by C6 cytotoxicity and median survival time of glioma bearing mice, which showed a better anti-glioma effect than DOX. The biological safety of O-MWNTs-PEG-ANG was evaluated by BCEC and C6 cytotoxicity, hematology analysis and CD68 immunohistochemical analysis, which proved O-MWNTs-PEG-ANG was good biocompatibility and low toxicity. The biological safety of DOX-O-MWNTs-PEG-ANG was evaluated by histopathological analysis, which suggested a lower cardiac toxicity than DOX. In conclusion, O-MWNTs-PEG-ANG is a promising dual-targeting carrier to deliver DOX for the treatment of brain tumor.

Angiopep-conjugated poly(ethylene glycol)-co-poly(ε-caprolactone) nanoparticles as dual-targeting drug delivery system for brain glioma

Dual-targeting nanoparticle drug delivery system was developed by conjugating Angiopep with PEG–PCL nanoparticles (ANG-NP) through bifunctional PEG to overcome the limitations of low transport of chemotherapeutics across the Blood–brain barrier (BBB) and poor penetration into tumor tissue. ANG-NP can target the low-density lipoprotein receptor-related protein (LRP) which is over-expressed on the BBB and glioma cells. Compared with non-targeting nanoparticles, a significantly higher amount of rhodamine isothiocyanate-labeled dual-targeting nanoparticles were endocytosed by U87 MG cells. The antiproliferative and cell apoptosis assay of paclitaxel-loaded ANG-NP (ANG-NP-PTX) demonstrated that ANG-NP-PTX resulted in enhanced inhibitory effects to U87 MG glioma cells. The transport ratios across the BBB model in vitro were significantly increased and the cell viability of U87 MG glioma cells after crossing the BBB was obviously decreased by ANG-NP-PTX. Enhanced accumulation of ANG-NP in the glioma bed and infiltrating margin of intracranial U87 MG glioma tumor-bearing in vivo model were observed by real time fluorescence image. In conclusion, Angiopep-conjugated PEG–PCL nanoparticles were prospective in dual-targeting drug delivery system for targeting therapy of brain glioma.

Multi-functionalized graphene oxide based anticancer drug-carrier with dual-targeting function and pH-sensitivity

A dual-targeting drug delivery and pH-sensitive controlled release system based on multi-functionalized graphene oxide (GO) was established in order to enhance the effect of targeted drug delivery and realize intelligently controlled release. A superparamagnetic GO–Fe3O4 nanohybrid was firstly prepared via a simple and effective chemical precipitation method. Then folic acid, a targeting agent toward some tumor cells, was conjugated onto Fe3O4 nanoparticlesvia the chemical linkage with amino groups of the 3-aminopropyl triethoxysilane (APS) modified superparamagnetic GO–Fe3O4 nanohybrid, to give the multi-functionalized GO. Doxorubicin hydrochloride (Dox) as an anti-tumor drug model was loaded onto the surface of this multi-functionalized GO via π–π stacking. The drug loading capacity of this multi-functionalized GO is as high as 0.387 mg mg−1 and the drug release depends strongly on pH values. Cell uptake studies were carried out using fluorescein isothiocyanate labeled or Dox loaded multi-functionalized GO to evaluate their targeted delivery property and toxicity to tumor cells. The results show that this multi-functionalized GO has potential applications for targeted delivery and the controlled release of anticancer drugs.