Abstracts from the 20th International Symposium on Signal Transduction at the Blood-Brain Barriers

https://deepblue.lib.umich.edu/bitstream/2027.42/138963/1/12987_2017_Article_71.pd

Kanser tedavisinde, ilaç hedeflenmesi için kullanılacak dendrimer kaplı manyetik nanoparçacıkların sentezi ve ilaç taşıma özelliklerinin incelenmesi.

Nanotechnology is a promising alternative to overcome the limitations of classical chemotherapy. This technology has enabled the development of particles with nano sizes that can be fabricated from a multitude of materials in a variety of compositions. These nanoparticles include; quantum dots (QDs), polymeric nanoparticles, gold nanoparticles, magnetic nanoparticles and dendrimeric nanoparticles. In first section of this study, superparamagnetic iron oxide nanoparticles were synthesized by coprecipitation method. The nanoparticles were modified with aminopropyltrimethoxysilane and then were coated with PAMAM dendrimer. The detailed characterization of synthesized nanoparticles was performed by X-ray diffraction, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering, and vibrating sample magnetometer (VSM) analyses. TEM images demonstrated that the DcMNPs have mono-disperse size distribution with an average particle diameter of 16 ± 5 nm. DcMNPs were found to be superparamagnetic through VSM analysis. The synthesis, aminosilane modification, and dendrimer coating of iron oxide nanoparticles were validated by FTIR and XPS analyses. Cellular internalization of nanoparticles was studied by inverted light scattering microscopy, and cytotoxicity was determined by XTT analysis. Results demonstrated that the synthesized DcMNPs, with their functional groups, symmetry perfection, size distribution, magnetic properties, and nontoxic characteristics could be suitable nano-carriers for targeted cancer therapy upon loading with various anticancer agents. Poly (I: C), which is a synthetic double-stranded RNA, have significant toxicity on tumor cells. In the second part of this study, Poly (I:C) for the first time was efficiently bound onto the surface of different generations of newly synthesized PAMAM dendrimer coated magnetic nanoparticles (DcMNPs) which can be targeted to the tumor site under magnetic field. Poly (I:C) activation was achieved in the presence of EDC and 1-Methylimidazole. Binding of Poly (I:C) onto DcMNPs was followed by agarose gel electrophoresis. Acidic reaction conditions were found as superior to basic and neutral for binding of Poly (I:C). In addition, having more functional groups at the surface, higher generations (G7, G6, G5) of PAMAM DcMNPs were found more suitable as a delivery system for Poly (I:C). In vitro cytotoxicity study on different breast-cancer cell lines demonstrated that Poly (I:C)-bound DcMNPs are more effective than free Poly (I:C). However, highest cytotoxicity of Poly (I:C)-bound DcMNPs was observed in Doxorubicin resistant MCF7 cells. Therefore, Poly (I:C)-bound DcMNPs seem to be a suitable for the treatment of Doxorubicin resistant cells. In the third part of the study, Doxorubicin loading, release, and stability on nanoparticles (NPs) were analyzed. Doxorubicin could be loaded on G2, G3 and G4DcMNPs with 97% efficiency. The release studies demonstrated that low-generation NPs obtained in this study have pH-sensitive drug release characteristics. G4DcMNPs, which released most of the drug in lower pH, seems to be the most suitable generation for efficient Doxorubicin delivery. In vitro cytotoxicity study on Doxorubicin resistant MCF7 cells demonstrated that application of Doxorubicin-loaded DcMNPs are five times more effective than free Doxorubicin. Therefore, application of Doxorubicin-loaded G4DcMNPs may help to overcome Doxorubicin resistance in MCF7/Dox cells. On the contrary, G2 and G3DcMNPs would be suitable for the delivery of drugs such as Vinca alkaloids and Taxenes, which show their effects in cytoplasm. The results also provide new insights in the development of pH-sensitive targeted drug delivery systems to overcome drug resistance during cancer therapy. In the last section of the research Poly (I:C) binding on Doxorubicin-loaded G4DcMNPs at pH 6 and pH 6.5 were studied. Results demonstrated that Doxorubicin loading on lower generation of DcMNPs make them more suitable for Poly (I:C) binding. Loading of Doxorubicin into the cavities of G4DcMNPs increases the binding efficiency of Poly (I:C) to the surface functional groups up to ten fold. Amine groups at the surface of DcMNPs are the main reasons for the toxicity of these nanoparticles in blood. Binding of Poly (I:C) to amine groups on the surface of Doxorubicin-loaded DcMNPs will decrease the cytotoxicity of the system in the blood and increase its biocompatibility. TEM results demonstrated that Poly (I:C) binding on DcMNPs increases their dispersivity too. When we compared the in vitro cytotoxicity of Doxorubicin, Poly (I:C) and Poly (I:C)-bound Doxorubicin-loaded DcMNPs, it was observed that Poly (I:C)-bound Doxorubicin-loaded DcMNPs show the highest cytotoxic effect on Doxorubicin resistant cells. The results demonstrated that Poly (I:C)-bound, Doxorubicin loaded- G4DcMNPs may be a useful delivery system by the biocompatibility of the complex in blood stream, and by their high toxicity inside tumor cells. These nanoparticles can also be a suitable targeted system to overcome the Doxorubicin resistance in cancer cells.Ph.D. - Doctoral Progra

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. (C) 2014 Elsevier Masson SAS. All rights reserved

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 (G 4-DOX) and immune modulator polyinosinic:polycytidylic acid [Poly(I:C)]. As previously reported, DOX and Poly(I:C) was loaded onto G 4 nanoparticles (PIC-G 4-DOX). Cellular internalization study using confocal microscopy demonstrated high levels of cellular internalization of PIC-G 4-DOX nanoparticles by MCF-7 cells. This resulted in higher efficacy of PIC-G 4-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-G 4-DOX nanoparticles. Gene expression analysis provided some insights into the possible molecular mechanisms on cytotoxicity of DOX and Poly(I:C) delivered through G 4 magnetic nanoparticles. The results demonstrated that PIC-G 4-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.Publisher's Versio

Polyinosinic: polycytidylic acid loading onto different generations of PAMAM dendrimer-coated magnetic nanoparticles

WOS: 000322593200053Poly (I:C), which is a synthetic double-stranded RNA, have significant toxicity on tumor cells. The immobilization of Poly (I:C) onto nanoparticles is important for the fabrication of targeted delivery systems. In this study, different generations of newly synthesized PAMAM dendron-coated magnetic nanoparticles (DcMNP) which can be targeted to the tumor site under magnetic field were efficiently loaded for the first time with Poly (I:C). Different generations of DcMNPs (G(2), G(3), G(4), G(5), G(6), and G(7)) were synthesized. Poly (I:C) activation was achieved in the presence of EDC and 1-methylimidazole. Loading of Poly (I:C) onto DcMNPs was followed by agarose gel electrophoresis. Acidic reaction conditions were found as superior to basic and neutral for binding of Poly (I:C). In addition, having more functional groups at the surface, higher generations (G(7), G(6), and G(5)) of PAMAM DcMNPs were found more suitable as a delivery system for Poly (I:C). Further in vitro and in vivo analyses of Poly (I:C)/PAMAM magnetic nanoparticles may provide new opportunities for the selective targeting and killing of tumor cells.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-109T949, TBAG-2215]; Middle East Technical UniversityMiddle East Technical University [BAP-07-02-2010-06]This study was supported by TUBITAK (TBAG-109T949 and TBAG-2215), and Middle East Technical University (BAP-07-02-2010-06)

Synthesis and Characterization of PEGylated Near-IR-Emitting Ag2S Quantum Dots for Tumor Imaging and Therapy

Near-infrared (NIR) emitting semiconductor quantum dots (QDs) have emerged as a new class of fluorescent probes in recent years due to better penetration depth into thetissue and elimination or significant reduction of tissue autofluorescence.Ag2S quantum dots are the most popular NIR emitting quantum dots in recent years becausedramatically improved cytocompatibility compared to heavy metal containing, more traditional QDs such as PbS, PbSe, CdHgTe.Previously, we have developed cationic polyethyleneimine (PEI)-25 kDa and 2MPA coated Ag2S QDs with high quantum yields.However, cationic QDs show some toxicity. Inorder to reduce such toxicity and prevent adsorption of blood components, we pegylated the cationic Ag2S QDs. PEGylation also enabled Doxorubicin® (Dox) loading tothese NIR QDs. Hence, PEG-PEI/2MPA coated aqueous Ag2S NIRQDs showed enhanced cytocompatability, theranostic and diagnostic potential.MaterialsBranched polyethyleneimine (PEI) (Mw 25 kDa) and N,N’-carbonyldiimidazole (CDI) were obtained from Aldrich. Methoxy polyethylene glycol (mPEG-OH, 2 kD) and chloroformwere purchased from Rapp Polymere and Merck Millipore, respectively.MethodsPEI and 2-MPA coated Ag2S QDs have been synthesized according to our previos report [5]. PEGylation was performed using CDI chemistry by activation of hydroxyl terminalgroups of the mPEG with CDI and conjugation of activated mPEG to QDs. Finally, washed samples were loaded with Dox. All cytotoxicity and optical imaging studies wereperformed with HeLa cells.ResultsPEI/2MPA Ag2S QDs have been conjugated with mPEG using CDI chemistry. NMR proved the conjugation. Particles were stable and highly luminescent even after PEGylation(Figure 1 a). Doxorubicin was loaded in PEGylated particles in high efficiency (Figure 1b). PEGylation improved the viability of HeLa cells especially at high doses (Figure 1c).Yet, Dox reduced viability.DiscussionIn this study, PEI and 2MPA coated and PEGylated Ag2S QDs have been developed as new theranostic nanoparticles which allows optical imaging at the NIR window andeffective delivery of a cancer drug into cells. Particles were stable in aqueous medium and luminesce strongly around 820 nm. Dox which is mostly used cancer drug wasloaded to the PEGylated particles to evaluate the QDs as a cancer drug delivery agent. In addition to increased viability of cells after PEGylation, Dox loading increased thetoxicty, provin g effcient delivery of Dox into the cells which was confirmed by confocal microscopy (Figure 1d). The drug release and apoptosis/necrosis studies will beperformed as next steps.ConclusionAs a conclusion, we have developed PEGylated cationic Ag2S QDs with high stability and strong luminesence in the NIR region. Such particles have high cytocompatability tobe used as safe optical imaging and drug delivery agents. This was demonstrated with Dox loading and delivery into HeLa cells.Figure 1. Photoluminescence and absorbance spectra of PEI/2MPA and PEG-PEI/2MPA Ag2S QDs (a), fluorescence intensity of Dox loaded PEG-QDs (b), cytotoxicityevaluation (c) and cell internalization of the nanoparticles (Arrows and red color show PEG-QDs in the HeLa cells) (d)

Synthesis and Characterization of PEGylated Near-IR-Emitting Ag2S Quantum Dots for Tumor Imaging and Therapy

Near-infrared (NIR) emitting semiconductor quantum dots (QDs) have emerged as a new class of fluorescent probes in recent years due to better penetration depth into thetissue and elimination or significant reduction of tissue autofluorescence.Ag2S quantum dots are the most popular NIR emitting quantum dots in recent years becausedramatically improved cytocompatibility compared to heavy metal containing, more traditional QDs such as PbS, PbSe, CdHgTe.Previously, we have developed cationic polyethyleneimine (PEI)-25 kDa and 2MPA coated Ag2S QDs with high quantum yields.However, cationic QDs show some toxicity. Inorder to reduce such toxicity and prevent adsorption of blood components, we pegylated the cationic Ag2S QDs. PEGylation also enabled Doxorubicin® (Dox) loading tothese NIR QDs. Hence, PEG-PEI/2MPA coated aqueous Ag2S NIRQDs showed enhanced cytocompatability, theranostic and diagnostic potential.MaterialsBranched polyethyleneimine (PEI) (Mw 25 kDa) and N,N’-carbonyldiimidazole (CDI) were obtained from Aldrich. Methoxy polyethylene glycol (mPEG-OH, 2 kD) and chloroformwere purchased from Rapp Polymere and Merck Millipore, respectively.MethodsPEI and 2-MPA coated Ag2S QDs have been synthesized according to our previos report [5]. PEGylation was performed using CDI chemistry by activation of hydroxyl terminalgroups of the mPEG with CDI and conjugation of activated mPEG to QDs. Finally, washed samples were loaded with Dox. All cytotoxicity and optical imaging studies wereperformed with HeLa cells.ResultsPEI/2MPA Ag2S QDs have been conjugated with mPEG using CDI chemistry. NMR proved the conjugation. Particles were stable and highly luminescent even after PEGylation(Figure 1 a). Doxorubicin was loaded in PEGylated particles in high efficiency (Figure 1b). PEGylation improved the viability of HeLa cells especially at high doses (Figure 1c).Yet, Dox reduced viability.DiscussionIn this study, PEI and 2MPA coated and PEGylated Ag2S QDs have been developed as new theranostic nanoparticles which allows optical imaging at the NIR window andeffective delivery of a cancer drug into cells. Particles were stable in aqueous medium and luminesce strongly around 820 nm. Dox which is mostly used cancer drug wasloaded to the PEGylated particles to evaluate the QDs as a cancer drug delivery agent. In addition to increased viability of cells after PEGylation, Dox loading increased thetoxicty, provin g effcient delivery of Dox into the cells which was confirmed by confocal microscopy (Figure 1d). The drug release and apoptosis/necrosis studies will beperformed as next steps.ConclusionAs a conclusion, we have developed PEGylated cationic Ag2S QDs with high stability and strong luminesence in the NIR region. Such particles have high cytocompatability tobe used as safe optical imaging and drug delivery agents. This was demonstrated with Dox loading and delivery into HeLa cells.Figure 1. Photoluminescence and absorbance spectra of PEI/2MPA and PEG-PEI/2MPA Ag2S QDs (a), fluorescence intensity of Dox loaded PEG-QDs (b), cytotoxicityevaluation (c) and cell internalization of the nanoparticles (Arrows and red color show PEG-QDs in the HeLa cells) (d)

Synthesis and Characterization of Folate-Targeted Poly(ethylene glycol) Coated Cationic Ag2S QDs for Tumor Targeted Gene Delivery

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PAMAM dendrimer-coated iron oxide nanoparticles: synthesis and characterization of different generations

This study focuses on the synthesis and characterization of different generations (G(0)-G(7)) of polyamidoamine (PAMAM) dendrimer-coated magnetic nanoparticles (DcMNPs). In this study, superparamagnetic iron oxide nanoparticles were synthesized by co-precipitation method. The synthesized nanoparticles were modified with aminopropyltrimethoxysilane for dendrimer coating. Aminosilane-modified MNPs were coated with PAMAM dendrimer. The characterization of synthesized nanoparticles was performed by X-ray diffraction, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering, and vibrating sample magnetometry (VSM) analyses. TEM images demonstrated that the DcMNPs have monodisperse size distribution with an average particle diameter of 16 +/- 5 nm. DcMNPs were found to be superparamagnetic through VSM analysis. The synthesis, aminosilane modification, and dendrimer coating of iron oxide nanoparticles were validated by FTIR and XPS analyses. Cellular internalization of nanoparticles was studied by inverted light scattering microscopy, and cytotoxicity was determined by XTT analysis. Results demonstrated that the synthesized DcMNPs, with their functional groups, symmetry perfection, size distribution, improved magnetic properties, and nontoxic characteristics could be suitable nanocarriers for targeted cancer therapy upon loading with various anticancer agents

Doxorubicin loading, release, and stability of polyamidoamine dendrimer-coated magnetic nanoparticles

WOS: 000319071200016PubMed ID: 23558592Nanotechnology is a promising alternative to overcome the limitations of classical chemotherapy. As a novel approach, dendrimer-coated magnetic nanoparticles (DcMNPs) maintain suitable drug delivery system because of their buildup of functional groups, symmetry perfection, nanosize, and internal cavities. They can also be targeted to the tumor site in a magnetic field. The aim of this study is to obtain an effective targeted delivery system for doxorubicin, using polyamidoamine (PAMAM) DcMNPs. Different generations (G2, G3, G4, and G7) of PAMAM DcMNPs were synthesized. Doxorubicin loading, release, and stability efficiencies in these nanoparticles (NPs) were studied. The results showed that low-generation NPs obtained in this study have pH-sensitive drug release characteristics. G4DcMNP, which releases most of the drug in lower pH, seems to be the most suitable generation for efficient Doxorubicin delivery. Furthermore, application of doxorubicin-loaded G4DcMNPs may help to overcome doxorubicin resistance in MCF-7 cells. On the contrary, G2 and G3DcMNPs would be suitable for the delivery of drugs such as vinca alkaloids (Johnson IS, Armstrong JG, Gorman M, Burnett JP. 1963. Cancer Res 23:13901427.) and taxenes (Clarke SJ, Rivory LP. 1999. Clin Pharmacokinet 36(2):99114.), which show their effects in cytoplasm. The results of this study can provide new insights in the development of pH-sensitive targeted drug delivery systems to overcome drug resistance during cancer therapy. (c) 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:18251835, 2013TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-109T949, TBAG-2215]; Middle East Technical UniversityMiddle East Technical University [BAP-07-02-2010-06]This study was supported by TUBITAK (TBAG-109T949 and TBAG-2215) and Middle East Technical University (BAP-07-02-2010-06)