Reversal of multidrug resistance in breast cancer MCF-7/ADR cells by h-R3-siMDR1-PAMAM complexes

T7 peptide-mediated co-delivery platform overcoming multidrug-resistant breast cancer: In vitro and in vivo evaluation

P-glycoprotein (P-gp) overexpressed mutidrug resistance (MDR) is currently a key factor limiting the effectiveness of breast cancer chemotherapy. Systemic administration based on P-gp-associated mechanism leads to severe toxic side effects. Here, we designed a T7 peptide-modified mixed liposome (T7-MLP@DTX/SchB) that, by active targeting co-delivering chemotherapeutic agents and P-gp inhibitors, harnessed synergistic effects to improve the treatment of MDR breast cancer. This study established drug-resistant cell models and animal models. Subsequently, comprehensive evaluations involving cell uptake, cell apoptosis, cellular toxicity assays, in vivo tumor-targeting capability, and anti-tumor activity assays were conducted to assess the drug resistance reversal effects of T7-MLP@DTX/SchB. Additionally, a systematic assessment of the biosafety profile of T7-MLP@DTX/SchB was executed, including blood profiles, biochemical markers, and histopathological examination. It was found that this co-delivery strategy successfully exerted the synergistic effects, since there was a significant tumor growth inhibitory effect on multidrug-resistant breast cancer. Targeted modification with T7 peptide enhanced the therapeutic efficacy remarkably, while vastly ameliorating the biocompatibility compared to free drugs. The intriguing results supported the promising potential use of T7-MLP@DTX/SchB in overcoming MDR breast cancer treatment.

Bacteria and Bacterial Components as Natural Bio-Nanocarriers for Drug and Gene Delivery Systems in Cancer Therapy

Bacteria and bacterial components possess multifunctional properties, making them attractive natural bio-nanocarriers for cancer diagnosis and targeted treatment. The inherent tropic and motile nature of bacteria allows them to grow and colonize in hypoxic tumor microenvironments more readily than conventional therapeutic agents and other nanomedicines. However, concerns over biosafety, limited antitumor efficiency, and unclear tumor-targeting mechanisms have restricted the clinical translation and application of natural bio-nanocarriers based on bacteria and bacterial components. Fortunately, bacterial therapies combined with engineering strategies and nanotechnology may be able to reverse a number of challenges for bacterial/bacterial component-based cancer biotherapies. Meanwhile, the combined strategies tend to enhance the versatility of bionanoplasmic nanoplatforms to improve biosafety and inhibit tumorigenesis and metastasis. This review summarizes the advantages and challenges of bacteria and bacterial components in cancer therapy, outlines combinatorial strategies for nanocarriers and bacterial/bacterial components, and discusses their clinical applications.

Recent advances in multifunctional dendrimer-based nanoprobes for breast cancer theranostics

Breast cancer (BC) undoubtedly is one of the most common type of cancers amongst women, which causes about 5 million deaths annually. The treatments and diagnostic therapy choices currently available for Breast Cancer is very much limited . Advancements in novel nanocarrier could be a promising strategy for diagnosis and treatments of this deadly disease. Dendrimer nanoformulation could be functionalized and explored for efficient targeting of overexpressed receptors on Breast Cancer cells to achieve targeted drug delivery, for diagnostics and to overcome the resistance of the cells towards particular chemotherapeutic. Additionally, the dendrimer have shown promising potential in the improvement of therapeutic value for Breast Cancer therapy by achieving synergistic co-delivery of chemotherapeutics and genetic materials for multidirectional treatment. In this review, we have highlighted the application of dendrimer as novel multifunctional nanoplatforms for the treatment and diagnosis of Breast Cancer.

Organic/Inorganic Self-Assembled Hybrid Nano-Architectures for Cancer Therapy Applications

Since the conceptualization of nanomedicine, numerous nanostructure-mediated drug formulations have progressed into clinical trials for treating cancer. However, recent clinical trial results indicate such kind of drug formulations has a limited improvement on the antitumor efficacy. This is due to the biological barriers associated with those formulations, for example, circulation stability, extravasation efficiency in tumor, tumor penetration ability, and developed multi-drug resistance. When employing for nanomedicine formulations, pristine organic-based and inorganic-based nanostructures have their own limitations. Accordingly, organic/inorganic (O/I) hybrids have been developed to integrate the merits of both, and to minimize their intrinsic drawbacks. In this context, the recent development in O/I hybrids resulting from a self-assembly strategy will be introduced. Through such a strategy, organic and inorganic building blocks can be self-assembled via either chemical covalent bonds or physical interactions. Based on the self-assemble procedure, the hybridization of four organic building blocks including liposomes, micelles, dendrimers, and polymeric nanocapsules with five functional inorganic nanoparticles comprising gold nanostructures, magnetic nanoparticles, carbon-based materials, quantum dots, and silica nanoparticles will be highlighted. The recent progress of these O/I hybrids in advanced modalities for combating cancer, such as, therapeutic agent delivery, photothermal therapy, photodynamic therapy, and immunotherapy will be systematically reviewed.

Recent Advances in Preclinical Research Using PAMAM Dendrimers for Cancer Gene Therapy

Carriers of genetic material are divided into vectors of viral and non-viral origin. Viral carriers are already successfully used in experimental gene therapies, but despite advantages such as their high transfection efficiency and the wide knowledge of their practical potential, the remaining disadvantages, namely, their low capacity and complex manufacturing process, based on biological systems, are major limitations prior to their broad implementation in the clinical setting. The application of non-viral carriers in gene therapy is one of the available approaches. Poly(amidoamine) (PAMAM) dendrimers are repetitively branched, three-dimensional molecules, made of amide and amine subunits, possessing unique physiochemical properties. Surface and internal modifications improve their physicochemical properties, enabling the increase in cellular specificity and transfection efficiency and a reduction in cytotoxicity toward healthy cells. During the last 10 years of research on PAMAM dendrimers, three modification strategies have commonly been used: (1) surface modification with functional groups; (2) hybrid vector formation; (3) creation of supramolecular self-assemblies. This review describes and summarizes recent studies exploring the development of PAMAM dendrimers in anticancer gene therapies, evaluating the advantages and disadvantages of the modification approaches and the nanomedicine regulatory issues preventing their translation into the clinical setting, and highlighting important areas for further development and possible steps that seem promising in terms of development of PAMAM as a carrier of genetic material.

HER-2/neu and MYC gene silencing in breast cancer: therapeutic potential and advancement in nonviral nanocarrier systems

Globally, breast cancer is the second leading cause of cancer-related mortality among women, with approximately 1.4 million new cases diagnosed annually. Associated genetic perturbations are emerging in the face of intense scientific enquiry, facilitating its classification, prognostication and treatment. RNAi, utilizing siRNA, is a powerful treatment strategy to silence disease-causing genes. However, therapeutic siRNA instability and poor cellular uptake have limited its clinical application, necessitating the use of nanocarriers. In this review, we highlight the RNAi mechanism, HER-2/neu and MYC as breast cancer gene targets, and nonviral nanocarriers as potentially safe and efficient delivery systems.

Rising horizon in circumventing multidrug resistance in chemotherapy with nanotechnology

Multidrug resistance (MDR) is one of the key barriers in chemotherapy, leading to the generation of insensitive cancer cells towards administered therapy. Genetic and epigenetic alterations of the cells are the consequences of MDR, resulted in drug resistivity, which reflects in impaired delivery of cytotoxic agents to the cancer site. Nanotechnology-based nanocarriers have shown immense shreds of evidence in overcoming these problems, where these promising tools handle desired dosage load of hydrophobic chemotherapeutics to facilitate designing of safe, controlled and effective delivery to specifically at tumor microenvironment. Therefore, encapsulating drugs within the nano-architecture have shown to enhance solubility, bioavailability, drug targeting, where co-administered P-gp inhibitors have additionally combat against developed MDR. Moreover, recent advancement in the stimuli-sensitive delivery of nanocarriers facilitates a tumor-targeted release of the chemotherapeutics to reduce the associated toxicities of chemotherapeutic agents in normal cells. The present article is focused on MDR development strategies in the cancer cell and different nanocarrier-based approaches in circumventing this hurdle to establish an effective therapy against deadliest cancer disease.

Carbosilane dendrimers with phosphonium terminal groups are low toxic non-viral transfection vectors for siRNA cell delivery

Non-viral gene delivery vectors studied in the gene therapy applications are often designed with the cationic nitrogen containing groups necessary for binding and cell release of nucleic acids. Disadvantage is a relatively high toxicity which restricts the in vivo use of such nanoparticles. Here we show, that the 3rd generation carbosilane dendrimers possessing (trimethyl)phosphonium (PMe₃) groups on their periphery were able to effectively deliver the functional siRNA into the cells (B14, Cricetulus griseus), release it into the cytosol and finally to achieve up to 40% gene silencing of targeted gene (glyceraldehyde-3-phosphate dehydrogenase (GAPDH)) with the comparable or, in some cases, even better effectivity as their ammonium counterparts. Moreover, such cationic dendrimers show relatively low in vivo toxicity as compared to their ammonium analogues when analyzed by standard fish embryo test (FET) on Danio rerio in vivo model, with LD₅₀ = 6.26 µM after 48 h of incubation. This is more than 10-fold improvement as compared to published values for various other types of cationic dendrimers. We discuss the potential of further increase of the transfection efficiency, endosomal escape and decrease of toxicity of such non-viral vectors, based on the systematic screening of different types of substituents on central phosphonium atom.

A chemoenzymatically synthesized cholesterol-g-poly(amine-co-ester)-mediated p53 gene delivery for achieving antitumor efficacy in prostate cancer

BACKGROUND

An amphiphilic cationic copolymer cholesterol-g-poly(amine-co-ester), namely Chol-g-PMSC-PPDL synthesized in a chemoenzymatic route has been utilized as a carrier for p53 gene delivery to check its antitumor efficacy, using human prostate cancer cell line PC-3 (p53 null) as a model.

MATERIALS AND METHODS

The transfection efficiency was measured by quantitative PCR and Western blotting assay. The anti-proliferative effect was detected using MTT method, colony formation assay and Live/Dead staining. The anti-migration effect was evaluated through wound healing and Transwell migration assays.

RESULTS

The transfection efficiency assay indicated that the carrier-mediated p53 gene transfection could dramatically enhance the intracellular p53 expression level. Through p53 gene delivery, obvious anti-proliferative effect could be detected which was elucidated to be associated with the simultaneous activation of mitochondrial-dependent apoptosis pathway and cell cycle arrest at G1 phase. Meanwhile, the anti-migration effect could be obtained after p53 gene transfection.

CONCLUSION

Chol-g-PMSC-PPDL-mediated p53 gene transfection could potentially be employed as a promising strategy for achieving effective anti-tumor response.

Peptidylarginine deiminase 4 overexpression resensitizes MCF-7/ADR breast cancer cells to adriamycin via GSK3β/p53 activation

Background

Adriamycin (ADR) is widely used in the clinical chemotherapy against breast cancer. But its efficacy is strongly limited due to the acquisition of multidrug resistance (MDR). Therefore, acquisition of the resistance to ADR is still a major cause of chemotherapy failure in breast cancer patients. Peptidylarginine deiminase IV (PAD4) is reported to target non-histone proteins for citrullination, regulate their substrate activities, and thereby play critical roles in maintaining cell phenotype in breast cancer cells. However, whether PAD4 is involved in the development of MDR in breast cancer is poorly understood.

Materials and methods

We examined the expression of PAD family members, including PAD4 in ADR-resistant MCF-7 cells compared with the parental control cells by real-time PCR and Western blotting analyses. Rescue of PAD4 expression in MCF-7/ADR cells was performed to assess whether PAD4 could restore the sensitivity of MCF-7/ADR cells to ADR treatment with cell counting kit-8, flow cytometry, TUNEL, nuclear and cytoplasmic extract preparations, and immunofluorescence staining analyses.

Results

Both PAD2 and PAD4 were significantly decreased in ADR-resistant cells. However, only PAD4 overexpression can increase the sensitivity of MCF-7/ADR cells to ADR treatment and decrease MDR1 gene expression. Overexpression of PAD4 in MCF-7/ADR cells inhibited cell proliferation by inducing cell apoptosis. Under ADR treatment, overexpression of PAD4 promoted nuclear accumulation of glycogen synthase kinase-3β and p53, which further activated proapoptotic gene expression and downregulated MDR1 expression. Moreover, PAD4 activity was required for activating proapoptotic gene transcripts.

Conclusion

We demonstrate the previously unappreciated role of PAD4 in reversing ADR resistance in MCF-7/ADR cells and help establish PAD4 as a candidate biomarker of prognosis and chemotherapy target for MDR in breast cancers.

Lobaplatin inhibits breast cancer progression, cell proliferation while it induces cell apoptosis by downregulating MTDH expression

Objective

Lobaplatin shows antitumor activity against a wide range of tumors, including metastatic breast cancer (BCa). The overexpression of metadherin (MTDH) is associated with poor prognosis of BCa patients. This study was designed to investigate the effect of lobaplatin on MCF-7 cell proliferation and its association with MTDH expression.

Patients and methods

Clinical treatment for BCa using lobaplatin, in combination with other general chemotherapy drugs, was administered to 32 BCa patients. The safety, effectiveness, and prognosis in lobaplatin-treated BCa patients were compared with those in controls (n=32). In vitro experiments were performed in MCF-7 cells to investigate the effect of lobaplatin on cell proliferation, apoptosis, and MTDH expression.

Results

We found the intraoperative local chemotherapy using lobaplatin was safe and effective for BCa treatment, in comparison with the patients administered general chemotherapy drugs. Treatment of MCF-7 cell cultures with lobaplatin significantly reduced cell proliferation and increased cell apoptotic percentage. The expression of MTDH and Bcl-2 was inhibited by lobaplatin and that of Bax was increased by lobaplatin. Moreover, we observed the inhibition of MTDH by shRNA reduced cell proliferation and enhanced cell apoptosis.

Conclusion

Lobaplatin was a safe and effective adjuvant chemotherapy for BCa. The effect of lobaplatin on inhibiting MCF-7 cell proliferation and inducing cell apoptosis might be, as least in part, mediated by suppressing the expression of oncogene MTDH.

Using LC-MS/MS-based targeted proteomics to monitor the pattern of ABC transporters expression in the development of drug resistance

Purpose

The overexpression of ATP-binding cassette transporters (ABC transporters), mainly including permeability glycoproteins (P-gp), multidrug resistance (MDR)-related protein 1 (MRP1), and breast cancer resistance proteins (BCRP), is one of the main reasons for the development of MDR which directly leads to chemotherapy failure. However, most of the currently used detection methods in MDR-related studies are qualitative or semiquantitative, but not quantitative. As a result, the measurement criteria of different experiments are not unified. Moreover, there are many contradictory results of the studies of the induction effect of drugs on ABC transporters. So, it is necessary to establish a quantitative assay for the quantification of P-gp, MRP1, and BCRP to study the mechanism of drug resistance.

Methods

In this paper, a novel and advanced liquid chromatography/mass spectrometry (MS)/MS-based targeted proteomics method for the quantification of P-gp, MRP1, and BCRP was developed and validated. Then, the cell lines MCF-7, HepG-2, and SMMC-7721 were, respectively, induced by different concentrations of doxorubicin (adriamycin [ADM]), mitoxantrone (MX), and methotrexate (MTX), to establish resistance cell lines. The method established was used to quantify the expression of P-gp, MRP1, and BCRP.

Results

The result showed that the induction effects of drugs on protein were relatively stable and selective. ADM, MX, and MTX could induce overexpression of P-gp, MRP1, and BCRP. And, the induction effect of different drugs on proteins was selective. The pattern of overexpression of ABC transporters in the three types of resistance cell lines was different.

Conclusion

During the development of drug resistance, the cell type and patch, but not drug type, were the most important determinant factors of the overexpression level of ABC transporters in resistance cell lines. This study provides a good foundation for understanding the development of drug resistance in cell lines and can be used to explain the contradictory results in other published studies as described above.

Recent advances in "smart" delivery systems for extended drug release in cancer therapy

Advances in nanomedicine have become indispensable for targeted drug delivery, early detection, and increasingly personalized approaches to cancer treatment. Nanoparticle-based drug-delivery systems have overcome some of the limitations associated with traditional cancer-therapy administration, such as reduced drug solubility, chemoresistance, systemic toxicity, narrow therapeutic indices, and poor oral bioavailability. Advances in the field of nanomedicine include “smart” drug delivery, or multiple levels of targeting, and extended-release drug-delivery systems that provide additional methods of overcoming these limitations. More recently, the idea of combining smart drug delivery with extended-release has emerged in hopes of developing highly efficient nanoparticles with improved delivery, bioavailability, and safety profiles. Although functionalized and extended-release drug-delivery systems have been studied extensively, there remain gaps in the literature concerning their application in cancer treatment. We aim to provide an overview of smart and extended-release drug-delivery systems for the delivery of cancer therapies, as well as to introduce innovative advancements in nanoparticle design incorporating these principles. With the growing need for increasingly personalized medicine in cancer treatment, smart extended-release nanoparticles have the potential to enhance chemotherapy delivery, patient adherence, and treatment outcomes in cancer patients.

Overcoming multidrug resistance through inhalable siRNA nanoparticles-decorated porous microparticles based on supercritical fluid technology

BACKGROUND

In recent times, the co-delivery therapeutics have garnered enormous interest from researchers in the treatment of cancers with multidrug resistance (MDR) due to their efficient delivery of multiple agents, which result in synergistic effects and capable of overcoming all the obstacles of MDR in cancer. However, an efficient delivery platform is required for the conveyance of diverse agents that can successfully devastate MDR in cancer.

METHODS

Initially, short-interfering RNA-loaded chitosan (siRNA-CS) nanoparticles were synthesized using the ionic gelation method. Further, the siRNA-CS nanoparticles and doxorubicin hydrochloride (DOX) were co-loaded in poly-L-lactide porous microparticles (PLLA PMs) (nano-embedded porous microparticles, [NEPMs]) by the supercritical anti-solvent (SAS) process.

RESULTS AND DISCUSSION

The NEPM formulation exhibited an excellent aerodynamic performance and sustained release of DOX, which displayed higher anticancer efficacy in drug-resistant cells (human small cell lung cancer, H69AR cell line) than those treated with either free DOX and DOX-PLLA PMs due to the siRNA from CS nanoparticles silenced the MDR gene to DOX therapy.

CONCLUSION

This eco-friendly process provides a convenient way to fabricate such innovative NEPMs co-loaded with a chemotherapeutic agent and a gene, which can devastate MDR in cancer through the co-delivery system.

Codelivery of doxorubicin and JIP1 siRNA with novel EphA2-targeted PEGylated cationic nanoliposomes to overcome osteosarcoma multidrug resistance

Purpose

Osteosarcoma (OS) mostly affects children and young adults, and has only a 20%–30% 5-year survival rate when metastasized. We aimed to create dual-targeted (extracellular against EphA2 and intracellular against JNK-interacting protein 1 [JIP1]), doxorubicin (DOX)-loaded liposomes to treat OS metastatic disease.

Materials and methods

Cationic liposomes contained N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium methyl-sulfate (DOTAP), cholesterol, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and distearoyl-phosphatidylethanolamine–methyl-poly(ethylene glycol) (DSPE–mPEG) conjugate. EphA2 targeting was accomplished by conjugating YSA peptide to DSPE–mPEG. Vesicles were subsequently loaded with DOX and JIP1 siRNA.

Results

Characteristics assessment showed that 1) size of the bilayered particles was 109 nm; 2) DOX loading efficiency was 87%; 3) siRNA could be successfully loaded at a liposome:siRNA ratio of >24:1; and 4) the zeta potential was 18.47 mV. Tumor-mimicking pH conditions exhibited 80% siRNA and 50.7% DOX sustained release from the particles. Stability studies ensured the protection of siRNA against degradation in serum. OS cell lines showed increased and more pericellular/nuclear localizations when using targeted vesicles. Nontargeted and targeted codelivery caused 70.5% and 78.6% cytotoxicity in OS cells, respectively (free DOX: 50%). Targeted codelivery resulted in 42% reduction in the siRNA target, JIP1 mRNA, and 46% decrease in JIP1 levels.

Conclusion

Our dual-targeted, DOX-loaded liposomes enhance toxicity toward OS cells and may be effective for the treatment of metastatic OS.

Poly (amidoamine) (PAMAM) dendrimer mediated delivery of drug and pDNA/siRNA for cancer therapy

Poly (amidoamine) (PAMAM) dendrimers are well-defined, highly branched macromolecules with numerous active amine groups on the surface. Because of their unique properties, PAMAM dendrimers have steadily grown in popularity in drug delivery, gene therapy, medical imaging and diagnostic application. This review focuses on the recent developments on the application in PAMAM dendrimers as effective carriers for drug and gene (pDNA, siRNA) delivery in cancer therapy, including: a) PAMAM for anticancer drug delivery; b) PAMAM and gene therapy; c) PAMAM used in overcoming tumor multidrug resistance; d) PAMAM used for hybrid nanoparticles; and e) PAMAM linked or loaded in other nanoparticles.

Crizotinib, a MET inhibitor, inhibits growth, migration, and invasion of breast cancer cells in vitro and synergizes with chemotherapeutic agents

MET is a receptor tyrosine kinase known for its pleiotropic effects in tumorigenesis. Dysregulations of MET expression and/or signaling have been reported and determined to be associated with inferior outcomes in breast cancer patients rendering MET a versatile candidate for targeted therapeutic intervention. Crizotinib is a multi-targeted small-molecule kinase inhibitor for MET, ALK, and ROS1 kinases. This study evaluated the anti-proliferative, cytotoxic, anti-migratory, and anti-invasive effects of crizotinib in breast cancer cells in vitro. Cell viability was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) colorimetric assay. In vitro wound-healing assay was used to examine the effect of crizotinib on breast cancer cell migration. The expressions of Ki-67, MET, and phospho-MET receptors were characterized using immunofluorescence staining. Results showed that crizotinib has significant anti-proliferative activity on all mammary tumor cells with IC₅₀ values of 5.16, 1.5, and 3.85 µM in MDA-MB-231, MCF-7, and SK-BR-3 cells, respectively. Crizotinib induced cytotoxic effects in all breast cancer cells examined. Combined treatment of small dose of crizotinib with paclitaxel or doxorubicin exhibited a highly synergistic inhibition of growth of MDA-MB-231 and MCF-7 cells with combination index values <1 while no significant effect was observed in SK-BR-3 cells compared with individual compounds. Treatment with crizotinib demonstrated a remarkable reduction in the expression of Ki-67 protein in all 3 tested cell lines. Crizotinib inhibited migration and invasion of MDA-MB-231 cells in a dose-dependent fashion. Crizotinib reduced MET receptor activation in MDA-MB-231 cells when treated at effective concentrations. In conclusion, crizotinib suppressed proliferation, migration, and invasion of breast cancer cells in vitro. The results of this study demonstrated that combined treatment of crizotinib with chemotherapeutic agents resulted in a synergistic growth inhibition of specific breast cancer cell lines.

Co-delivery of paclitaxel and anti-survivin siRNA via redox-sensitive oligopeptide liposomes for the synergistic treatment of breast cancer and metastasis

The overexpression of survivin in breast cancer cells is an important factor of paclitaxel (PTX) resistance in breast cancer. To overcome PTX resistance and improve the antitumor effect of PTX, we developed a novel liposome-based nanosystem (PTX/siRNA/SS-L), composed of a redox-sensitive cationic oligopeptide lipid (LHSSG2C₁₄) with a proton sponge effect, natural soybean phosphatidylcholine (SPC), and cholesterol for co-delivery of PTX and anti-survivin siRNA, which could specifically downregulate survivin overexpression. PTX/siRNA/SS-L exhibited high encapsulation efficiency and rapid redox-responsive release of both PTX and siRNA. Moreover, in vitro studies on the 4T1 breast cancer cells revealed that PTX/siRNA/SS-L offered significant advantages over other experimental groups, such as higher cellular uptake, successful endolysosomal escape, reduced survivin expression, the lowest cell viability and wound healing rate, as well as the highest apoptosis rate. In particular, in vivo evaluation of 4T1 tumor-bearing mice showed that PTX/siRNA/SS-L had lower toxicity and induced a synergistic inhibitory effect on tumor growth and pulmonary metastasis. Collectively, the collaboration of anti-survivin siRNA and PTX via redox-sensitive oligopeptide liposomes provides a promising strategy for the treatment of breast cancer and metastasis.

Novel PEI/Poly-γ-Gutamic Acid Nanoparticles for High Efficient siRNA and Plasmid DNA Co-Delivery

The efficient delivery of sufficient amounts of nucleic acids into target cells is critical for successful gene therapy and gene knockdown. The DNA/siRNA co-delivery system has been considered a promising approach for cancer therapy to simultaneously express and inhibit tumor suppressor genes and overexpressed oncogenes, respectively, triggering synergistic anti-cancer effects. Polyethylenimine (PEI) has been identified as an efficient non-viral vector for transgene expression. In this study, we created a very high efficient DNA/siRNA co-delivery system by incorporating a negatively-charged poly-γ-glutamic acid (γ-PGA) into PEI/nucleic acid complexes. Spherical nanoparticles with about 200 nm diameter were formed by mixing PEI/plasmid DNA/siRNA/γ-PGA (dual delivery nanoparticles; DDNPs) with specific ratio (N/P/C ratio) and the particles present positive surface charge under all manufacturing conditions. The gel retardation assay shows both nucleic acids were effectively condensed by PEI, even at low N/P ratios. The PEI-based DDNPs reveal excellent DNA/siRNA transfection efficiency in the human hepatoma cell line (Hep 3B) by simultaneously providing high transgene expression efficiency and high siRNA silencing effect. The results indicated that DDNP can be an effective tool for gene therapy against hepatoma.

Redox/pH dual-sensitive hybrid micelles for targeting delivery and overcoming multidrug resistance of cancer

A three-step approach was used to enhance anticancer activity via targeted delivery, intracellular drug burst release, and depressed drug efflux.