Poly (I:C)- and doxorubicin-loaded magnetic dendrimeric nanoparticles affect the apoptosis-related gene expressions in MCF-7 cells.

Use of nanoparticles as drug carrier vectors has great potential to circumvent the limitations associated with chemotherapy, including drug resistance and destructive side effects. For this purpose, magnetic generation 4 dendrimeric nanoparticles were prepared to carry chemotherapeutic agent doxorubicin (G4-DOX) and immune modulator polyinosinic:polycytidylic acid [Poly(I:C)]. As previously reported, DOX and Poly(I:C) was loaded onto G4 nanoparticles (PIC-G4-DOX). Cellular internalization study using confocal microscopy demonstrated high levels of cellular internalization of PIC-G4-DOX nanoparticles by MCF-7 cells. This resulted in higher efficacy of PIC-G4-DOX nanoparticles in killing MCF-7 breast cancer cells. Alteration in the expression levels of selected genes was determined by RT-qPCR analyses. Proapoptotic NOXA, PUMA, and BAX genes were upregulated, and SURVIVIN, APOLLON, and BCL-2 genes were downregulated, indicating the cell-killing effectiveness of PIC-G4-DOX nanoparticles. Gene expression analysis provided some insights into the possible molecular mechanisms on cytotoxicity of DOX and Poly(I:C) delivered through G4 magnetic nanoparticles. The results demonstrated that PIC-G4-DOX can be useful for targeted delivery affecting apoptotic pathways, resulting in an advanced degree of cancer-cell-killing. They are promising for targeting cancer-cells because of their stability, biocompatibility, higher internalization, and toxicity.

Smart Drug Delivery Systems in Cancer Therapy.

BACKGROUND: Smart nanocarriers have been designed for tissue-specific targeted drug delivery, sustained or triggered drug release and co-delivery of synergistic drug combinations to develop safer and more efficient therapeutics. OBJECTIVE: Advances in drug delivery systems provide reduced side effects, longer circulation half-life and improved pharmacokinetics. RESULTS: Smart drug delivery systems have been achieved successfully in the case of cancer. These nanocarriers can serve as an intelligent system by considering the differences of tumor microenvironment from healthy tissue, such as low pH, low oxygen level, or high enzymatic activity of matrix metalloproteinases. CONCLUSION: The performance of anti-cancer agents used in cancer diagnosis and therapy is improved by enhanced cellular internalization of smart nanocarriers and controlled drug release. Here, we review targeting, cellular internalization; controlled drug release and toxicity of smart drug delivery systems. We are also emphasizing the stimulus responsive controlled drug release from smart nanocarriers.

Loading of Gemcitabine on chitosan magnetic nanoparticles increases the anti-cancer efficacy of the drug.

Targeted delivery of anti-cancer drugs increase the efficacy, while decreasing adverse effects. Among various delivery systems, chitosan coated iron oxide nanoparticles (CsMNPs) gained attention with their biocompatibility, biodegradability, low toxicity and targetability under magnetic field. This study aimed to increase the cellular uptake and efficacy of Gemcitabine. CsMNPs were synthesized by in situ co-precipitation and Gemcitabine was loaded onto the nanoparticles. Nanoparticle characterization was performed by TEM, FTIR, XPS, and zeta potential. Gemcitabine release and stability was analyzed. The cellular uptake was shown. Cytotoxicity of free-Gemcitabine and Gem-CsMNPs were examined on SKBR and MCF-7 breast cancer cells by XTT assay. Gemcitabine loading was optimized as 30µM by spectrophotometric analyses. Drug release was highest (65%) at pH 4.2, while it was 8% at pH 7.2. This is a desired release characteristic since pH of tumor-tissue and endosomes are acidic, while the blood-stream and healthy-tissues are neutral. Peaks reflecting the presence of Gemcitabine were observed in FTIR and XPS. At neutral pH, zeta potential increased after Gemcitabine loading. TEM images displayed, Gem-CsMNPs were 4nm with uniform size-distribution and have spherical shape. The cellular uptake and targetability of CsMNPs was studied on MCF-7 breast cancer cell lines. IC50 value of Gem-CsMNPs was 1.4 fold and 2.6 fold lower than free-Gem on SKBR-3 and MCF-7 cell lines respectively, indicating the increased efficacy of Gemcitabine when loaded onto nanoparticles. Targetability by magnetic field, stability, size distribution, cellular uptake and toxicity characteristics of CsMNPs in this study provides a useful targeted delivery system for Gemcitabine in cancer therapy.

Targeted silencing of Survivin in cancer cells by siRNA loaded chitosan magnetic nanoparticles.

BACKGROUND: The aim of this study was to silence Survivin expression, related with drug-resistance, via siRNA-loaded CS-MNPs. METHODS AND RESULTS: The highest siRNA-loading efficiency was achieved at siRNA:CS-MNP ratio of 1:2. Nanoparticles had spherical morphology and homogenous size distribution in TEM. After siRNA loading, core sizes (3-5 nm) of CS-MNPs didn't change significantly, however hydrodynamic diameters increased ~10 nm, indicating swelling of chitosan coat due to efficient siRNA loading. 73% of siRNA was pH-dependently released at 24hours, after 30% burst release at first 3.5hours. Stability was high enough to keep siRNAs in CS-MNPs at pH7.2. Cellular-internalization of Survivin-siRNA-CS-MNPs was high and localized in cytoplasm of cells. CONCLUSION: Although, mock-siRNA loaded/unloaded CS-MNPs weren't cytotoxic, cell-death of breast cancer cells was significantly increased, after the treatment of Survivin-siRNA-loaded CS-MNPs. This reveals, successful loading of Survivin-siRNA on CS-MNPs and significant silencing of Survivin expression by triggering cell-death. Consequently, CS-MNPs are highly efficient delivery systems for intact siRNAs.

Detection of XRCC1 gene polymorphisms in Turkish head and neck squamous cell carcinoma patients: a comparative analysis with different populations.

PURPOSE: X-ray repair cross-complementing (XRCC1) is one of the most important genes for the maintenance of genomic integrity and protection of cells from DNA damage. Although tobacco and alcohol consumption are the major risk factors for the development of head and neck squamous cell carcinoma (HNSCC), sequence variation in XRCC1 gene may alter HNSCC susceptibility. Reports on the relationship between HNSCC and polymorphisms in XRCC1 gene have been inconsistent so far. The aim of this study was to investigate the association of XRCC1 Arg194Trp and Arg399Gln single nucleotide polymorphisms (SNP), smoking and alcohol consumption with the risk of HNSCC in Turkish population and also to compare to these results with the ones from both Turkish and different populations in the literature. The frequencies of Arg194Trp and Arg399Gln SNPs were studied in 55 HNSCC and 69 healthy individuals. METHODS: Genomic DNA was isolated from peripheral blood and SNP was genotyped by PCR-RFLP method. RESULTS: The genotype and allele frequencies of both polymorphisms were not statistically different between the HNSCC and control groups. On the other hand, smoking and chronic alcohol consumption were associated with risk of HNSCC, but there was no association between Arg194Trp, Arg399Gln polymorphisms, smoking and alcohol consumption in HNSCC cases. CONCLUSION: These results indicate that both Arg194Trp and Arg399Gln polymorphisms were not associated with the development of HNSCC in Turkish population. In addition, the allele frequencies of polymorphisms were in line with other Turkish population results that were studied previously. However, compared to different populations, there were marked differences in allele frequencies.

Magnetite: from synthesis to applications.

In this review the synthesis, functionalization and some applications of magnetite nanoparticles (MNPs) were highlighted. It is our intention to highlight the correlations between the synthesis routes, related synthesis parameters, functionalization strategies and the properties expected for the materials containing MNPs. The uses of MNPs are strongly influenced by the properties of the materials. Therefore this review is trying to discuss the applications of the magnetite and magnetite based nanomaterials by taking into account all the factors that can influence the properties of the final materials and consequently their potential applications.

Association between XRCC3 Thr241Met polymorphism and laryngeal cancer susceptibility in Turkish population.

DNA repair systems are essential for normal cell function. Genetic alterations in the DNA repair genes such as X-ray repair cross-complementing group 3 (XRCC3), can cause a change in protein activity which results in cancer susceptibility. The aim of this study was to investigate the association of XRCC3 Thr241Met single nucleotide polymorphism (SNP), smoking and alcohol consumption with the risk of laryngeal cancer in Turkish population. The frequencies of Thr241Met SNP were studied in 58 laryngeal cancer cases (SSC) and 67 healthy individuals. Genomic DNA was isolated from peripheral blood samples of both controls and laryngeal cancer cases. Thr241Met SNP was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The genotype and allele frequencies of Thr241Met polymorphism were not statistically significant between the laryngeal cancer and control groups. Carrying mutant allele was not associated with the risk of laryngeal cancer. On the other hand, smoking and chronic alcohol consumption were associated with the risk of laryngeal cancer but there is no association between Thr241Met, smoking and alcohol consumption in laryngeal cancer cases. These results indicate that Thr241Met polymorphism was not associated with the development of laryngeal cancer in Turkish population. However, it should be kept in mind that the association of a polymorphism with cancer susceptibility can differ due to several factors such as cancer type, selection criteria, ethnic differences and size of the studied population.

Development of poly (I:C) modified doxorubicin loaded magnetic dendrimer nanoparticles for targeted combination therapy.

The objective of this study was to develop and evaluate the anticancer activity and the safety of a combinational drug delivery system using polyamidoamine (PAMAM) dendrimer-coated iron oxide nanoparticles for doxorubicin and poly I:C delivery in vitro. Dendrimer-coated magnetic nanoparticles (DcMNPs) are suitable for drug delivery system as nanocarriers with their following properties, such as surface functional groups, symmetry perfection, internal cavities, nano-size and magnetization. These nanoparticles could be targeted to the tumor site under a magnetic field since they have a magnetic core. DcMNPs were found as a convenient vehicle for targeted doxorubicin delivery in cancer therapy. Poly (I:C) binding on doxorubicin loaded DcMNPs (DcMNPs-Dox) was reported for the first time in the literature. It was also demonstrated that loading of doxorubicin into the cavities of DcMNPs increases the binding efficiency of poly (I:C) to the surface functional groups of dendrimer up to 10 times. When we compare the in vitro cytotoxic properties of doxorubicin, poly (I:C) and poly (I:C) bound doxorubicin loaded DcMNPs (PIC-DcMNPs-Dox), it was observed that PIC-DcMNPs-Dox show the highest cytotoxic effect by passing the cell resistance mechanisms on doxorubicin resistant MCF7 (MCF7/Dox) cells. Results demonstrated that applying PIC-DcMNPs-Dox would improve the efficacy by increasing the biocompatibility of system in blood stream and the toxicity inside tumor cells. These results provide invaluable information and new insight for the design and optimization of a novel combinational drug delivery system for targeted cancer therapy.

Idarubicin-loaded folic acid conjugated magnetic nanoparticles as a targetable drug delivery system for breast cancer.

Conventional cancer chemotherapies cannot differentiate between healthy and cancer cells, and lead to severe side effects and systemic toxicity. Another major problem is the drug resistance development before or during the treatment. In the last decades, different kinds of controlled drug delivery systems have been developed to overcome these shortcomings. The studies aim targeted drug delivery to tumor site. Magnetic nanoparticles (MNP) are potentially important in cancer treatment since they can be targeted to tumor site by an externally applied magnetic field. In this study, MNPs were synthesized, covered with biocompatible polyethylene glycol (PEG) and conjugated with folic acid. Then, anti-cancer drug idarubicin was loaded onto the nanoparticles. Shape, size, crystal and chemical structures, and magnetic properties of synthesized nanoparticles were characterized. The characterization of synthesized nanoparticles was performed by dynamic light scattering (DLS), Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) analyses. Internalization and accumulation of MNPs in MCF-7 cells were illustrated by light and confocal microscopy. Empty MNPs did not have any toxicity in the concentration ranges of 0-500µg/mL on MCF-7 cells, while drug-loaded nanoparticles led to significant toxicity in a concentration-dependent manner. Besides, idarubicin-loaded MNPs exhibited higher toxicity compared to free idarubicin. The results are promising for improvement in cancer chemotherapy.

Polyhydroxybutyrate-coated magnetic nanoparticles for doxorubicin delivery: cytotoxic effect against doxorubicin-resistant breast cancer cell line.

In this study, polyhydroxybutyrate (PHB)-coated magnetic nanoparticles (MNPs) were prepared by coprecipitation of iron salts (Fe and Fe) by ammonium hydroxide. Characterizations of PHB-coated MNPs were performed by Fourier transform infrared spectroscopy, x-ray diffraction, dynamic light scattering, thermal gravimetric analysis, vibrating sample magnetometry, and transmission electron microscopy analyses. Doxorubicin was loaded onto PHB-MNPs, and the release efficiencies at different pHs were studied under in vitro conditions. The most efficient drug loading concentration was found about 87% at room temperature in phosphate-buffered saline (pH 7.2). The drug-loaded MNPs were stable up to 2 months in neutral pH for mimicking physiological conditions. The drug release studies were performed with acetate buffer (pH 4.5) that mimics endosomal pH. Doxorubicin (60%) released from PHB-MNPs within 65 hours. Doxorubicin-loaded PHB-MNPs were about 2.5-fold more cytotoxic as compared with free drug on resistant Michigan Cancer Foundation-7 (human breast adenocarcinoma, MCF-7) cell line (1 µM doxorubicin) in vitro. Therefore, doxorubicin-loaded PHB-MNPs lead to overcome the drug resistance.

Effect of gemcitabine and retinoic acid loaded PAMAM dendrimer-coated magnetic nanoparticles on pancreatic cancer and stellate cell lines.

Gemcitabine is an anticancer drug used in the treatment of different cancer types, including pancreatic ductal adenocarcinoma. The maximum tolerated dose in humans is restricted by its side effects on healty cells. Furthermore, the fibrotic stroma produced by the pancreatic stellate cells prevents effective delivery of chemotherapeutic agents providing a safe-haven for the cancer cells. This becomes more of a problem considering the short half-life of this drug. Magnetic nanoparticle-based targeted drug delivery systems are a promising alternative to overcome the limitations of classical chemotherapies. The aim of this study is to obtain an effective targeted delivery system for gemcitabine using magnetic nanoparticles (MNPs) and all-trans retinoic acid (ATRA). This dual approach targets the tumor cells and its infrastructure - stellate cells - simultaneously. Gemcitabine and ATRA were loaded onto the PAMAM dendrimer-coated magnetic nanoparticles (DcMNPs), which were synthesized and characterized previously. Drug loading and release characteristics, and stability of the nanoparticles were investigated. Gemcitabine and ATRA loaded MNPs are efficiently taken up by pancreatic cancer and stellate cells successfully targeting and eliminating both cells. Results of this study can provide new insights on pancreatic cancer therapy where tumor is seen as a system with its stroma insead of epithelial cells alone.

Chitosan magnetic nanoparticles for pH responsive Bortezomib release in cancer therapy.

The use of nanotechnology in cancer treatment offers exciting opportunities, including the possibility of destroying tumors with minimal damage to healthy tissue by novel targeted drug delivery systems. pH differences between healthy and tumor microenvironment provide pH responsive release of drugs at tumor site via smart nanoparticles. In this study, chitosan coated superparamagnetic iron oxide nanoparticles (CS MNPs) were in situ synthesized by ionic crosslinking method as nanocarrier systems and loaded with the drug Bortezomib (Velcade(®)). The drug loading capacity, drug release and stability of CS MNPs were analyzed. CS MNPs were visualized inside the cells by fluorescence microscopy. The cytotoxicity of Bortezomib, CS MNPs and Bortezomib loaded CS MNPs were tested by XTT analyses in vitro. Gene expression analyses revealed that pro-apoptotic PUMA and NOXA genes were upregulated while anti-apoptotic BCL-2, SURVIVIN and cIAP-2 genes were downregulated at Bortezomib loaded CS MNP treated cells. Immunocytochemical analyses demonstrated an increase in p53 tumor suppressor protein levels at treated cells, which supports the upregulation of PUMA and NOXA genes, while Survivin protein level did not significantly change. This study points out that the pH responsive magnetic targeting of Bortezomib is more efficacious than free drug treatment. Moreover, targeted delivery of Bortezomib would reduce the frequency of drug administration by lowering the required amount of drug dose.

Synthesis of Doxorubicin loaded magnetic chitosan nanoparticles for pH responsive targeted drug delivery.

Targeted drug delivery is a promising alternative to overcome the limitations of classical chemotherapy. In an ideal targeted drug delivery system carrier nanoparticles would be directed to the tumor tissue and selectively release therapeutic molecules. As a novel approach, chitosan coated magnetic nanoparticles (CS MNPs) maintain a pH dependent drug delivery which provides targeting of drugs to the tumor site under a magnetic field. Among various materials, chitosan has a great importance as a pH sensitive, natural, biodegradable, biocompatible and bioadhesive polymer. The aim of this study was to obtain an effective targeted delivery system for Doxorubicin, using chitosan coated MNPs. Different sized CS MNPs were produced by in situ synthesis method. The anti-cancer agent Doxorubicin was loaded onto CS MNPs which were characterized previously. Doxorubicin loading was confirmed by FTIR. Drug loading and release characteristics, and stability of the nanoparticles were investigated. Our results showed that the CS MNPs have pH responsive release characteristics. The cellular internalization of Doxorubicin loaded CS MNPs were visualized by fluorescent microscopy. Doxorubicin loaded CS MNPs are efficiently taken up by MCF-7 (MCF-7/S) and Doxorubicin resistant MCF-7 (MCF-7/1 µM) breast cancer cells, which increases the efficacy of drug and also maintains overcoming the resistance of Doxorubicin in MCF-7/Dox cells. Consequently, CS MNPs synthesized at various sizes can be effectively used for the pH dependent release of Doxorubicin in cancer cells. Results of this study can provide new insights in the development of pH responsive targeted drug delivery systems to overcome the side effects of conventional chemotherapy.