Cellular uptake and antitumor activity of DOX-hyd-PEG-FA nanoparticles

Combined Photothermal Therapy and Cancer Immunotherapy by Immunogenic Hollow Mesoporous Silicon-Shelled Gold Nanorods

Hyperthermia can be integrated with tumor-killing chemotherapy, radiotherapy and immunotherapy to give rise to an anti-tumor response. To this end, a nano-delivery system is built, which can connect hyperthermia and immunotherapy. On this basis, the impact of such a combination on the immune function of dendritic cells (DCs) is explored. The core of this system is the photothermal material gold nanorod (GNR), and its surface is covered with a silica shell. Additionally, it also forms a hollow mesoporous structure using the thermal etching approach, followed by modification of targeted molecule folic acid (FA) on its surface, and eventually forms a hollow mesoporous silica gold nanorod (GNR@void@mSiO2) modified by FA. GNR@void@mSiO2-PEG-FA (GVS-FA) performs well in photothermal properties, drug carriage and release and tumor targeting performance. Furthermore, the thermotherapy of tumor cells through in vitro NIR irradiation can directly kill tumor cells by inhibiting proliferation and inducing apoptosis. GVS-FA loaded with imiquimod (R837) can be used as a adjuvant to enhance the immune function of DCs through hyperthermia.

Cancer cell membrane-camouflaged paclitaxel/PLGA nanoparticles for targeted therapy against lung cancer

Paclitaxel (PTX) is a first-line drug for the treatment of lung cancer, but its targeting and therapeutic effect are unsatisfactory. Herein, lung cancer cell (A549) membrane biomimetic PTX-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles (AM@PTX-NPs) were constructed to eliminate the shortcomings of PTX. The AM@PTX-NPs were successfully prepared with a high drug loading efficiency (10.90±0.06 %). Moreover, transmission electron microscopy, SDS-PAGE, and western blotting proved that AM@PTX-NPs were spherical nanoparticles camouflaged by the A549 cell membrane. Both in vitro and in vivo assays revealed that the AM@PTX-NPs displayed outstanding targeting capacity due to A549 membrane modification. The cytotoxicity experiment showed that the developed biomimetic formulation was able to effectively reduce the proliferation of A549 cells. Moreover, AM@PTX-NPs exhibited a significant tumor growth inhibition rate (73.00 %) with good safety in the tumor-bearing mice, which was higher than that of the PTX-NPs without A549 membrane coating (37.39 %). Overall, the constructed bioinspired vector could provide a novel platform for the PTX delivery and demonstrated a promising strategy for the targeted cancer treatment.

Free drug and ROS-responsive nanoparticle delivery of synergistic doxorubicin and olaparib combinations to triple negative breast cancer models

Combinations of the topoisomerase II inhibitor doxorubicin and the poly (ADP-ribose) polymerase inhibitor olaparib offer potential drug-drug synergy for the treatment of triple negative breast cancers (TNBC). In this study we performed in vitro screening of combinations of these drugs, administered directly or encapsulated within polymer nanoparticles, in both 2D and in 3D spheroid models of breast cancer. A variety of assays were used to evaluate drug potency, and calculations of combination index (CI) values indicated that synergistic effects of drug combinations occurred in a molar-ratio dependent manner. It is suggested that the mechanisms of synergy were related to enhancement of DNA damage as shown by the level of double-strand DNA breaks, and mechanisms of antagonism associated with mitochondrial mediated cell survival, as indicated by reactive oxygen species (ROS) generation. Enhanced drug delivery and potency was observed with nanoparticle formulations, with a greater extent of doxorubicin localised to cell nuclei as evidenced by microscopy, and higher cytotoxicity at the same time points compared to free drugs. Together, the work presented identifies specific combinations of doxorubicin and olaparib which were most effective in a panel of TNBC cell lines, explores the mechanisms by which these combined agents might act, and shows that formulation of these drug combinations into polymeric nanoparticles at specific ratios conserves synergistic action and enhanced potency in vitro compared to the free drugs.

Nano-induced endothelial leakiness-reversing nanoparticles for targeting, penetration and restoration of endothelial cell barrier

Nano-induced endothelial leakiness (NanoEL) can improve the ability of nanoparticles (NPs) to enter the tumor environment, nevertheless, it can inadvertently trigger adverse effects such as tumor metastasis. To overcome these concerns, it becomes important to develop a NPs design strategy that capitalizes on the NanoEL effect while averting unwanted side effects during the drug delivery process. Herein, we introduce the PLGA-ICG-PEI-Ang1@M NP which has a core comprising poly (lactic-co-glycolic acid) (PLGA) and the inner shell with a highly positively charged polyethyleneimine (PEI) and the anti-permeability growth factor Angiopoietin 1 (Ang1), while the outer shell is camouflaged with a Jurkat cell membrane. During the drug delivery process, our NPs exhibit their capability to selectively target and penetrate endothelial cell layers. Once the NPs penetrate the endothelial layer, the proton sponge effect triggered by PEI in the acidic environment surrounding the tumor site can rupture the cell membrane on the NPs' surface. This rupture, in turn, enables the positively charged Ang1 to be released due to the electrostatic repulsion from PEI and the disrupted endothelial layer can be restored. Consequently, the designed NPs can penetrate endothelial layers, promote the cell layer recovery, restrict the tumor metastasis, and facilitate efficient cancer therapy. STATEMENT OF SIGNIFICANCE.

Synthesis, characterization, and in vitro anti-tumor activity studies of the hyaluronic acid-mangiferin-methotrexate nanodrug targeted delivery system

In this study, to increase the accumulation of MTX in the tumor site and reduce the toxicity to normal tissues by MA, a novel nano-drug delivery system comprised of hyaluronic acid (HA)-mangiferin (MA)-methotrexate (MTX) (HA-MA-MTX) was developed by a self-assembly strategy. The advantage of the nano-drug delivery system is that MTX can be used as a tumor-targeting ligand of the folate receptor (FA), HA can be used as another tumor-targeting ligand of the CD44 receptor, and MA serves as an anti-inflammatory agent. ¹HNMR and FT-IR results confirmed that HA, MA, and MTX were well coupled together by the ester bond. DLS and AFM images revealed that the size of HA-MA-MTX nanoparticles was about ~138 nm. In vitro cell experiments proved that HA-MA-MTX nanoparticles have a positive effect on inhibiting K7 cancer cells while having relatively lower toxicity to normal MC3T3-E1 cells than MTX does. All these results indicated that the prepared HA-MA-MTX nanoparticles can be selectively ingested by K7 tumor cells through FA and CD44 receptor-mediated endocytosis, thus inhibiting the growth of tumor tissues and reducing the nonspecific uptake toxicity caused by chemotherapy. Therefore, these self-assembled HA-MA-MTX NPs could be a potential anti-tumor drug delivery system.

Epigallocatechin-3-gallate Delivered in Nanoparticles Increases Cytotoxicity in Three Breast Carcinoma Cell Lines

The anticancer activity of epigallocatechin-3-gallate (EGCG), orally administrated, is limited by poor bioavailability, absorption, and unpredictable distribution in human tissues. EGCG charged nanoparticles may represent an opportunity to overcome these limitations. We assayed two different kinds of lipid nanoparticles (LNPs and LNPs functionalized with folic acid) charged with EGCG on three breast carcinoma cell lines (MCF-7, MDA-MB-231, and MCF-7TAM) and the human normal MCF10A mammary epithelial cells. Both LNPs loaded with EGCG, at low concentrations, induced a significant cytotoxicity in the three breast carcinoma cells but not in MCF10A cells. In view of a future application, both LNPs and LNPs-FA were found to be very suitable for in vitro studies and useful to improve EGCG administration in vivo. Since they are produced by inexpensive procedures using bioavailable, biocompatible, and biodegradable molecules, they represent an applicable tool for a more rationale use of EGCG as an anti-cancer agent.

Biopolymeric Prodrug Systems as Potential Antineoplastic Therapy

Nowadays, cancer represents a major public health issue, a substantial economic issue, and a burden for society. Limited by numerous disadvantages, conventional chemotherapy is being replaced by new strategies targeting tumor cells. In this context, therapies based on biopolymer prodrug systems represent a promising alternative for improving the pharmacokinetic and pharmacologic properties of drugs and reducing their toxicity. The polymer-directed enzyme prodrug therapy is based on tumor cell targeting and release of the drug using polymer–drug and polymer–enzyme conjugates. In addition, current trends are oriented towards natural sources. They are biocompatible, biodegradable, and represent a valuable and renewable source. Therefore, numerous antitumor molecules have been conjugated with natural polymers. The present manuscript highlights the latest research focused on polymer–drug conjugates containing natural polymers such as chitosan, hyaluronic acid, dextran, pullulan, silk fibroin, heparin, and polysaccharides from Auricularia auricula.

PEGylated DOX-coated nano graphene oxide as pH-responsive multifunctional nanocarrier for targeted drug delivery

Nano graphene oxide (NGO) has high drug-loading capacity due to its huge surface area. However, the limited stability and the poor biocompatibility of NGO hampered its application as drug delivery carrier under physiological conditions. Thereby, a new strategy of using chemical conjugation on NGO with hydrophilic polymers was adopted but currently was too complicated, low yield and costly. In this study, doxorubicin-hyd-PEG-folic acid (DOX-hyd-PEG-FA) polymers were coated on the surface of NGO via π-π stocking and the hydrophobic effect between DOX and NGO. With the PEG shell protection, the biocompatibility of NGO was significantly improved. The drug-loading capacity of nanoparticles was more than 100%. FA ligands on the nanoparticle could guide the nanoparticles actively targeting to tumour cells. The hydrazone bond between DOX and PEG was decomposed spontaneously in the weakly acidic environment, which made PEG layer dissociated from NGO. Furthermore, DOX was easily protonized at low pH conditions, which weakened the interaction between DOX and NGO. Thus, DOX could be released rapidly from the nanoparticles in tumour cells. In summary, NGO@DOX-hyd-PEG-FA is an easy-prepared nanoparticle with excellent biocompatibility, high pH-sensitivity and active tumour targeting. Therefore, it is a promising multifunctional nanocarrier effective for targeted drug delivery.

Overexpression of human ATP-binding cassette transporter ABCG2 contributes to reducing the cytotoxicity of GSK1070916 in cancer cells

The emergence of multidrug resistance (MDR) is one of the main factors that impair therapeutic outcome in cancer therapy. Among all the factors that contribute to MDR, overexpression of ABCG2 transporter has been described as a key factor. GSK1070916 is a potent Aurora kinase inhibitor with broad anticancer effects. The robust efficacy shown in preclinical studies allowed the drug progress to clinical investigation. However, the potential mechanisms of acquired resistance to GSK1070916 remain inconclusive. Since several Aurora kinase inhibitors were reported to be transported substrates of ABCG2, we aimed to identify the potential interaction of GSK1070916 with ABCG2. Our data showed that ABCG2-overexpressing cells demonstrated high resistance-fold to GSK1070916 compared to the parental cells. In addition, combination of GSK1070916 with an ABCG2 inhibitor was able to restore its sensitivity. The multicellular tumor spheroid assay supported this finding by demonstrating attenuated growth inhibition in ABCG2-overexpressing tumor spheroids. In addition, the ABCG2 ATPase assay and computational modeling suggested that GSK1070916 could bind to ABCG2 substrate-binding site. The HPLC assay provided another direct evidence that ABCG2-overexpressing cells showed attenuated intracellular accumulation of GSK1070916, and such phenomenon was abolished by Ko143, a known ABCG2 inhibitor. Furthermore, GSK1070916 was able to hinder the efflux activity of ABCG2, indicating possible drug-drug interactions with other ABCG2 substrate drugs. In summary, we revealed that overexpression of ABCG2 can cause GSK1070916 resistance in cancer cells. The combination of an ABCG2 inhibitor with GSK1070916 may be a rational strategy to overcome the drug resistance and should be considered for clinical investigation.

Redox-Responsive Heparin-Chlorambucil Conjugate Polymeric Prodrug for Improved Anti-Tumor Activity

Polymeric prodrug-based delivery systems have been extensively studied to find a better solution for the limitations of a single drug and to improve the therapeutic and pharmacodynamics properties of chemotherapeutic agents, which can lead to efficient therapy. In this study, redox-responsive disulfide bond-containing amphiphilic heparin-chlorambucil conjugated polymeric prodrugs were designed and synthesized to enhance anti-tumor activities of chlorambucil. The conjugated prodrug could be self-assembled to form spherical vesicles with 61.33% chlorambucil grafting efficiency. The cell viability test results showed that the prodrug was biocompatible with normal cells (HaCaT) and that it selectively killed tumor cells (HeLa cells). The uptake of prodrugs by HeLa cells increased with time. Therefore, the designed prodrugs can be a better alternative as delivery vehicles for the chlorambucil controlled release in cancer cells.

Folic acid conjugated polymeric drug delivery vehicle for targeted cancer detection in hepatocellular carcinoma

Targeted therapies provide increased efficiency for the detection and treatment of cancer with reduced side effects. Folate receptor (alpha subunit) is overexpressed in multiple tumors including liver cancer. In this study, we evaluated the specificity and toxicity of a folic acid-containing drug delivery vehicle (DDV) in a hepatocellular carcinoma (HCC) model. The DDV was prepared with two units each of folic acid (FA) and fluorescein isothiocyanate (FITC) molecules and conjugated to a central poly (ethylene glycol) (PEG) core via a modified chemo-enzymatic synthetic process. Rat hepatoma (N1S1) and human monocytic (U937) cell lines were used for cell culture-based assays and tested for DDV uptake and toxicity. Folate receptor expressions in liver tissues and cell lines were verified using standard immunohistochemistry techniques. Rat HCC model was used for in vivo assessment. The DDV was injected via intra-arterial or intravenous methods and imaged with IVIS spectrum in vivo imaging system. Strong signals of FITC in the liver tumor region correlated to targeted DDV uptake. The use of PEG enhanced water-solubility and provided flexibility for the interaction of FA ligands with multiple cell surface folate receptors that resulted in increased specific uptake. Our study suggested that PEG incorporation and folate targeting via intra-arterial approach is an efficient strategy for targeted delivery in HCC therapy.

Doxorubicin and Anti-PD-L1 Antibody Conjugated Gold Nanoparticles for Colorectal Cancer Photochemotherapy

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. The prognosis and overall survival of CRC are known to be significantly correlated with the overexpression of PD-L1. Since combination therapies can significantly improve therapeutic efficacy, we constructed doxorubicin (DOX) conjugated and anti-PD-L1 targeting gold nanoparticles (PD-L1-AuNP-DOX) for the targeted chemo-photothermal therapy of CRC. DOX and anti-PD-L1 antibody were conjugated to the α-terminal end group of lipoic acid polyethylene glycol N-hydroxysuccinimide (LA-PEG-NHS) using an amide linkage, and PD-L1-AuNP-DOX was constructed by linking LA-PEG-DOX, LA-PEG-PD-L1, and a short PEG chain on the surface of AuNP using thiol-Au covalent bonds. Physicochemical characterizations and biological studies of PD-L1-AuNP-DOX were performed in the presence of near-infrared (NIR) irradiation (biologic studies were conducted using cellular uptake, apoptosis, and cell cycle assays in CT-26 cells). PD-L1-AuNP-DOX (40.0 ± 3.1 nm) was successfully constructed and facilitated the efficient intracellular uptake of DOX as evidenced by pronounced apoptotic effects (66.0%) in CT-26 cells. PD-L1-AuNP-DOX treatment plus NIR irradiation significantly and synergistically suppressed the in vitro proliferation of CT-26 cells by increasing apoptosis and cell cycle arrest. The study demonstrates that PD-L1-AuNP-DOX in combination with synergistic targeted chemo-photothermal therapy has a considerable potential for the treatment of localized CRC.

Application of active targeting nanoparticle delivery system for chemotherapeutic drugs and traditional/herbal medicines in cancer therapy: a systematic review

Patients treated with conventional cancer chemotherapy suffer from side effects of the drugs due to non-selective action of chemotherapeutic drugs to normal cells. Active targeting nanoparticles that are conjugated to targeting ligands on the surface of nanoparticles play an important role in improving drug selectivity to the cancer cell. Several chemotherapeutic drugs and traditional/herbal medicines reported for anticancer activities have been investigated for their selective delivery to cancer cells by active targeting nanoparticles. This systematic review summarizes reports on this application. Literature search was conducted through PubMed database search up to March 2017 using the terms nanoparticle, chemotherapy, traditional medicine, herbal medicine, natural medicine, natural compound, cancer treatment, and active targeting. Out of 695 published articles, 61 articles were included in the analysis based on the predefined inclusion and exclusion criteria. The targeting ligands included proteins/peptides, hyaluronic acid, folic acid, antibodies/antibody fragments, aptamer, and carbohydrates/polysaccharides. In vitro and in vivo studies suggest that active targeting nanoparticles increase selectivity in cellular uptake and/or cytotoxicity over the conventional chemotherapeutic drugs and non-targeted nanoparticle platform, particularly enhancement of drug efficacy and safety. However, clinical studies are required to confirm these findings.

Charge reversible calcium phosphate lipid hybrid nanoparticle for siRNA delivery

Bcl-2 gene is an important target to treat lung cancer. The small interference RNA (siRNA) of Bcl-2 gene (siBcl-2) can specifically silence Bcl-2 gene. However, naked siBcl-2 is difficult to accumulate in the tumor tissue to exert its activity. In this paper, a calcium phosphate lipid hybrid nanoparticle that possessed charge reversible property was prepared to enhance the activity of siBcl-2 in vivo. The average diameter and zeta potential of siBcl-2 loaded calcium phosphate lipid hybrid nanoparticles (LNPS@siBcl-2) were 80 nm and −13 mV at pH7.4 whereas the diameter and zeta potential changed to 1506 nm and +9 mV at pH5.0. LNPS@siBcl-2 could efficiently deliver siBcl-2 to the cytoplasm and significantly decreased the expression of Bcl-2 in A549 cells. Moreover, the in vivo experimental results showed that most of the Cy5-siBcl-2 accumulated in tumor tissue after LNPS@Cy5-siBcl-2 was administered to tumor-bearing mice by tail vein injection. Meanwhile, the expression of Bcl-2 was decreased but the expression of the BAX and Caspase-3 was increased in tumor tissue. LNPS@siBcl-2 significantly inhibited the growth of tumor in tumor-bearing mice without any obvious systemic toxicity. Thus, the charge reversible calcium phosphate lipid hybrid nanoparticle was an excellent siBcl-2 delivery carrier to improve the activity of siBcl-2 in vivo. LNPS@siBcl-2 has potential in the treatment of lung cancer.

Detecting the functional complexities between high-density lipoprotein mimetics

High-density lipoprotein (HDL) is a key regulator of lipid homeostasis through its native roles like reverse cholesterol transport. The reconstitution of this natural nanoparticle (NP) has become a nexus between nanomedicine and multi-disease therapies, for which a major portion of HDL functionality is attributed to its primary scaffolding protein, apolipoprotein A1 (apoA1). ApoA1-mimetic peptides were formulated as cost-effective alternatives to apoA1-based therapies; reverse-4F (r4F) is one such peptide used as part of a nanoparticle platform. While similarities between r4F- and apoA1-based HDL-mimetic nanoparticles have been identified, key functional differences native to HDL have remained undetected. In the present study, we executed a multidisciplinary approach to uncover these differences by exploring the form, function, and medical applicability of engineered HDL-mimetic NPs (eHNPs) made from r4F (eHNP-r4F) and from apoA1 (eHNP-A1). Comparative analyses of the eHNPs through computational molecular dynamics (MD), advanced microfluidic NP synthesis and screening technologies, and in vivo animal model studies extracted distinguishable eHNP characteristics: the eHNPs share identical structural and compositional characteristics with distinct differences in NP stability and organization; eHNP-A1 could more significantly stimulate anti-inflammatory responses characteristic of the scavenger receptor class B type 1 (SR-B1) mediated pathways; and eHNP-A1 could outperform eHNP-r4F in the delivery of a model hydrophobic drug to an in vivo tumor. The biomimetic microfluidic technologies and MD simulations uniquely enabled our comparative analysis through which we determined that while eHNP-r4F is a capable NP with properties mimicking natural eHNP-A1, challenges remain in reconstituting the full functionality of NPs naturally derived from humans.

Core-shell drug carrier from folate conjugated chitosan obtained from prawn shell for targeted doxorubicin delivery

A multifunctional drug carrier with dual targeting (magnetic and folate-receptor) and pH sensitive core-shell hybrid nanomaterial has been developed to carry an anticancer drug doxorubicin.Superparamagnetic iron oxide nanoparticles (IONPs) were used as core of the carrier and cross-linked folate conjugated chitosan (FA-CS) was acted as shell in which doxorubicin was physically entrapped. Transmission electron microscopy (TEM) analysis confirmed the average particle size of IONPs and FA-CS coated IONPs 8.2 and 15.4 nm respectively. Magnetic measurement indicated that both the IONPs and FA-CS coated IONPs were superparamagnetic at room temperature with a magnetization value 57.72 and 37.44 emu/g respectively. At pH 5.8 (malignant tissue) showed a burst release of 30.05% of the doxorubicin in the first 4 h followed by a sustained release of 88.26% of drug over 72 h. From these results it is expected that doxorubicin loaded nanoparticles can be a promising drug carrier for the treatment of solid tumors with the ability to reduce toxic side effects of drugs by selective targeting and sustained release.

Photothermal-triggered control of sub-cellular drug accumulation using doxorubicin-loaded single-walled carbon nanotubes for the effective killing of human breast cancer cells

Single-walled carbon nanotubes (SWNTs) are often the subject of investigation as effective photothermal therapy (PTT) agents owing to their unique strong optical absorption. Doxorubicin (DOX)-loaded SWNTs (SWNTs-DOX) can be used as an efficient therapeutic agent for combined near infrared (NIR) cancer photothermal and chemotherapy. However, SWNTs-DOX-mediated induction of cancer cell death has not been fully investigated, particularly the reaction of DOX inside cancer cells by PTT. In this study, we examined how the SWNTs-DOX promoted effective MDA-MB-231 cell death compared to DOX and PTT alone. We successfully synthesized the SWNTs-DOX. The SWNTs-DOX exhibited a slow DOX release, which was accelerated by NIR irradiation. Furthermore, DOX released from the SWNTs-DOX accumulated inside the cells at high concentration and effectively localized into the MDA-MB-231 cell nucleus. A combination of SWNTs-DOX and PTT promoted an effective MDA-MB-231 cell death by mitochondrial disruption and ROS generation. Thus, SWNTs-DOX can be utilized as an excellent anticancer agent for early breast cancer treatment.

Folate-conjugated dually responsive micelles for targeted anticancer drug delivery

Folate-conjugated dual-responsive micelles were developed, sustained and sensitive drug release from the drug loaded micelles was observed. Folate-targeted micelles showed higher anticancer activity and enhanced cellar uptake than non-targeted ones.

Hemocompatibility of folic-acid-conjugated amphiphilic PEG-PLGA copolymer nanoparticles for co-delivery of cisplatin and paclitaxel: treatment effects for non-small-cell lung cancer

In this study, we used folic-acid-modified poly(ethylene glycol)-poly(lactic-co-glycolic acid) (FA-PEG-PLGA) to encapsulate cisplatin and paclitaxel (separately or together), and evaluated their antitumor effects against lung cancer; this study was conducted in order to investigate the antitumor effects of the co-delivery of cisplatin and paclitaxel by a targeted drug delivery system. Blood compatibility assays and complement activation tests revealed that FA-PEG-PLGA nanoparticles did not induce blood hemolysis, blood clotting, or complement activation. The results also indicated that FA-PEG-PLGA nanoparticles had no biotoxic effects, the drug delivery system allowed controlled release of the cargo molecules, and the co-delivery of cisplatin and paclitaxel efficiently induces cancer cell apoptosis and cell cycle retardation. In addition, co-delivery of cisplatin and paclitaxel showed the ability to suppress xenograft lung cancer growth and prolong the survival time of xenografted mice. These results implied that FA-PEG-PLGA nanoparticles can function as effective carriers of cisplatin and paclitaxel, and that co-delivery of cisplatin and paclitaxel by FA-PEG-PLGA nanoparticles results in more effective antitumor effects than the combination of free-drugs or single-drug-loaded nanoparticles.

Dual subcellular compartment delivery of doxorubicin to overcome drug resistant and enhance antitumor activity

In order to overcome drug resistant and enhance antitumor activity of DOX, a new pH-sensitive micelle (DOX/DQA-DOX@DSPE-hyd-PEG-AA) was prepared to simultaneously deliver DOX to nucleus and mitochondria. Drug released from DOX/DQA-DOX@DSPE-hyd-PEG-AA showed a pH-dependent manner. DOX/DQA-DOX@DSPE-hyd-PEG-AA induced the depolarization of mitochondria and apoptosis in MDA-MB-231/ADR cells and A549 cells, which resulted in the high cytotoxicity of DOX/DQA-DOX@DSPE-hyd-PEG-AA against MDA-MB-231/ADR cells and A549 cells. Confocal microscopy confirmed that DOX/DQA-DOX@DSPE-hyd-PEG-AA simultaneously delivered DQA-DOX and DOX to the mitochondria and nucleus of tumor cell. After DOX/DQA-DOX@DSPE-hyd-PEG-AA was injected to the tumor-bearing nude mice by the tail vein, DOX was mainly found in tumor tissue. But DOX was widely distributed in the whole body after the administration of free DOX. Compared with free DOX, the same dose of DOX/DQA-DOX@DSPE-hyd-PEG-AA significantly inhibited the growth of DOX-resistant tumor in tumor-bearing mice without obvious systemic toxicity. Therefore, dual subcellular compartment delivery of DOX greatly enhanced the antitumor activity of DOX on DOX-resistant tumor. DOX/DQA-DOX@DSPE-hyd-PEG-AA has the potential in target therapy for DOX-resistant tumor.

Doxorubicin-poly (ethylene glycol)-alendronate self-assembled micelles for targeted therapy of bone metastatic cancer

In order to increase the therapeutic effect of doxorubicin (DOX) on bone metastases, a multifunctional micelle was developed by combining pH-sensitive characteristics with bone active targeting capacity. The DOX loaded micelle was self-assembled by using doxorubicin-poly (ethylene glycol)-alendronate (DOX-hyd-PEG-ALN) as an amphiphilic material. The size and drug loading of DOX loaded DOX-hyd-PEG-ALN micelle was 114 nm and 24.3%. In pH 5.0 phosphate buffer solution (PBS), the micelle released DOX significantly faster than in pH 7.4 PBS. In addition, with the increase of incubation time, more red DOX fluorescence was observed in tumor cells and trafficked from cytoplasm to nucleus. The IC₅₀ of DOX loaded DOX-hyd-PEG-ALN micelle on A549 cells was obviously lower than that of free DOX in 48 h. Furthermore, the in vivo image experimental results indicated that a larger amount of DOX was accumulated in the bone metastatic tumor tissue after DOX loaded DOX-hyd-PEG-ALN micelle was intravenously administered, which was confirmed by histological analysis. Finally, DOX loaded DOX-hyd-PEG-ALN micelle effectively delayed the tumor growth, decreased the bone loss and reduced the cardiac toxicity in tumor-bearing nude mice as compared with free DOX. In conclusion, DOX loaded DOX-hyd-PEG-ALN micelle had potential in treating bone metastatic tumor.

Folate-conjugated nanoparticles as a potent therapeutic approach in targeted cancer therapy

The selective and efficient drug delivery to tumor cells can remarkably improve different cancer therapeutic approaches. There are several nanoparticles (NPs) which can act as a potent drug carrier for cancer therapy. However, the specific drug delivery to cancer cells is an important issue which should be considered before designing new NPs for in vivo application. It has been shown that cancer cells over-express folate receptor (FR) in order to improve their growth. As normal cells express a significantly lower levels of FR compared to tumor cells, it seems that folate molecules can be used as potent targeting moieties in different nanocarrier-based therapeutic approaches. Moreover, there is evidence which implies folate-conjugated NPs can selectively deliver anti-tumor drugs into cancer cells both in vitro and in vivo. In this review, we will discuss about the efficiency of different folate-conjugated NPs in cancer therapy.

Active-targeted pH-responsive albumin–photosensitizer conjugate nanoparticles as theranostic agents

The objective of this study was to develop an active-targeted, pH-responsive albumin–photosensitizer conjugate as a theranostic agent.

Folate-mediated and doxorubicin-conjugated poly(ε-caprolactone)-g-chondroitin sulfate copolymers for enhanced intracellular drug delivery

The aim of this study was to conjugate an anticancer drug, doxorubicin (DOX) and a folate targeting moiety, folic acid (FA), to self-assembled polycaprolactone (PCL)-graft-chondroitin sulfate (CS) copolymers for enhanced chemotherapy.