22 research outputs found

    Non-viral eNOS gene delivery and transfection with stents for the treatment of restenosis

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    Background: In this study, we have examined local non-viral gene delivery, transfection, and therapeutic efficacy of endothelial nitric oxide synthase (eNOS) encoding plasmid DNA administered using coated stents in a rabbit iliac artery restenosis model.Methods: Lipopolyplexes (LPPs) with eNOS expressing plasmid DNA were immobilized on stainless steel stents using poly(D,L-lactide-co-glycolide) (PLGA) and type B gelatin coatings. The gene-eluting stents were implanted bilaterally in the denuded iliac arteries and eNOS transfection and therapeutic efficacy were examined 14 days after implantation.Results: The results show that non-viral lipopolyplex-coated stents can efficiently tranfect eNOS locally in the arterial lumen assessed by PCR and ELISA. Human eNOS ELISA levels were significantly raised 24 hours after transfection compared to controls (125 pg eNOS compared to <50 pg for all controls including naked DNA). Local eNOS production suppressed smooth muscle cell proliferation and promoted re-endothelialization of the artery showing a significant reduction in restenosis of 1.75 neointima/media ratio for stents with lipoplexes encoding eNOS compared with 2.3 neointima/media ratio for stents with lipoplexes encosing an empty vector.Conclusions: These results support the hypothesis that a potent non-viral gene vector encoding for eNOS coated onto a stent can inhibit restenosis through inhibition of smooth muscle cell growth and promotion of a healthy endothelium. © 2010 Brito et al; licensee BioMed Central Ltd

    Barium Titanate Nanoparticles: Highly Cytocompatible Dispersions in Glycol-chitosan and Doxorubicin Complexes for Cancer Therapy

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    In the latest years, innovative nanomaterials have attracted a dramatic and exponentially increasing interest, in particular for their potential applications in the biomedical field. In this paper, we reported our findings on the cytocompatibility of barium titanate nanoparticles (BTNPs), an extremely interesting ceramic material. A rational and systematic study of BTNP cytocompatibility was performed, using a dispersion method based on a non-covalent binding to glycol-chitosan, which demonstrated the optimal cytocompatibility of this nanomaterial even at high concentration (100 ÎŒg/ml). Moreover, we showed that the efficiency of doxorubicin, a widely used chemotherapy drug, is highly enhanced following the complexation with BTNPs. Our results suggest that innovative ceramic nanomaterials such as BTNPs can be realistically exploited as alternative cellular nanovectors

    Inhibition of hexokinase-2 with targeted liposomal 3-bromopyruvate in an ovarian tumor spheroid model of aerobic glycolysis

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    Srujan Kumar Gandham, Meghna Talekar, Amit Singh, Mansoor M Amiji Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, MA,&nbsp;USA Background: The objective of this study was to evaluate the expression levels of glycolytic markers, especially hexokinase-2 (HK2), using a three-dimensional multicellular spheroid model of human ovarian adenocarcinoma (SKOV-3) cells and to develop an epidermal growth factor receptor-targeted liposomal formulation for improving inhibition of HK2 and the cytotoxicity of 3-bromopyruvate (3-BPA). Methods: Multicellular SKOV-3 tumor spheroids were developed using the hanging drop method and expression levels of glycolytic markers were examined. Non-targeted and epidermal growth factor receptor-targeted liposomal formulations of 3-BPA were formulated and characterized. Permeability and cellular uptake of the liposomal formulations in three-dimensional SKOV-3 spheroids was evaluated using confocal microscopy. The cytotoxicity and HK2 inhibition potential of solution form of 3-BPA was compared to the corresponding liposomal formulation by using cell proliferation and HK2 enzymatic assays. Results: SKOV-3 spheroids were reproducibly developed using the 96-well hanging drop method, with an average size of 900 &micro;m by day 5. HK2 enzyme activity levels under hypoxic conditions were found to be higher than under normoxic conditions (P&lt;0.0001, Student&rsquo;s t-test, unpaired and two-tailed). Liposomal formulations (both non-targeted and targeted) of 3-BPA showed a more potent inhibitory effect (P&lt;0.001, Student&rsquo;s t-test, unpaired and two-tailed) at a dose of 50 &micro;M than the aqueous solution form at 3, 6, and 24 hours post administration. Similarly, the cytotoxic activity 3-BPA at various concentrations (10 &micro;M&ndash;100 &micro;M) showed that the liposomal formulations had an enhanced cytotoxic effect of 2&ndash;5-fold (P&lt;0.0001, Student&rsquo;s t-test, unpaired and two-tailed) when compared to the aqueous solution form for both 10 &micro;M and 25 &micro;M concentrations. Conclusion: SKOV-3 spheroids developed by the hanging drop method can be used as a tumor aerobic glycolysis model for evaluation of therapies targeting the glycolytic pathway in cancer cells. Encapsulation of 3-BPA in a liposomal formulation improved permeability, HK2 inhibition, and cytotoxicity in the multicellular spheroid model.Keywords: ovarian cancer, aerobic glycolysis, hexokinase-2, 3-bromopyruvate, epidermal growth factor receptor-targeted liposome

    Hyaluronic acid based self-assembling nanosystems for CD44 target mediated siRNA delivery to solid tumors

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    Anticancer therapeutics employing RNA interference mechanism holds promising potentials for sequence-specific silencing of target genes. However targeted delivery of siRNAs to tumor tissues and cells and more importantly, their intracellular release at sites of interest still remains a major challenge that needs to be addressed before this technique could become a clinically viable option. In the current study, we have engineered and screened a series of CD44 targeting hyaluronic acid (HA) based self-assembling nanosystems for targeted siRNA delivery. The HA polymer was functionalized with lipids of varying carbon chain lengths/nitrogen content, as well as polyamines for assessing siRNA encapsulation. From the screens, several HA-derivatives were identified that could stably encapsulate/complex siRNAs and form self-assembled nanosystems, as determined by gel retardation assays and dynamic light scattering. Many HA derivatives could transfect siRNAs into cancer cells overexpressing CD44 receptors. Interestingly, blocking the CD44 receptors on the cells using free excess soluble HA prior to incubation of cy3-labeled-siRNA loaded HA nano-assemblies resulted in >90% inhibition of the receptor mediated uptake, confirming target specificity. In addition, SSB/PLK1 siRNA encapsulated in HA-PEI/PEG nanosystems demonstrated dose dependent and target specific gene knockdown in both sensitive and resistant A549 lung cancer cells overexpressing CD44 receptors. More importantly, these siRNA encapsulated nanosystems demonstrated tumor selective uptake and target specific gene knock down in vivo in solid tumors as well as in metastatic tumors. The HA based nanosystems thus portend to be promising siRNA delivery vectors for systemic targeting of CD44 overexpressing cancers including tumor initiating (stem-) cells and metastatic lesions

    In vivo biodistribution of siRNA and cisplatin administered using CD44-targeted hyaluronic acid nanoparticles

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    Multidrug resistance (MDR) is a significant problem in the clinical management of several cancers. Overcoming MDR generally involves multi-modal therapeutic approaches that integrate enhancement of delivery efficiency using targeted nano-platforms as well as strategies that can sensitize cancer cells to drug treatments. We recently demonstrated that tandem delivery of siRNAs that downregulate anti-apoptotic genes overexpressed in cisplatin resistant tumors followed by therapeutic challenge using cisplatin loaded CD44 targeted hyaluronic acid (HA) nanoparticle (NP) induced synergistic antitumor response CD44 expressing tumors that are resistant to cisplatin. In the current study, a near infrared (NIR) dye-loaded HA NP was employed to image the whole body localization of NPs after intravenous (i.v.) injection into live mice bearing human lung tumors that were sensitive and resistant to cisplatin. In addition, we quantified the siRNA duplexes and cisplatin dose distribution in various tissues and organs using an ultra-sensitive quantitative PCR method and inductively coupled plasma-mass spectrometry (ICP-MS), respectively, after i.v. injection of the payload loaded HA NPs in tumor bearing mice. Our findings demonstrate that the distribution pattern of the siRNA and cisplatin using specifically engineered CD44 targeting HA NPs correlated well with the tumor targeting capability as well as the activity and efficacy obtained with combination treatments. (C) 2013 Elsevier B.V. All rights reserve

    Polymeric nanoparticle-based delivery of microRNA-199a-3p inhibits proliferation and growth of osteosarcoma cells

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    Linlin Zhang,1,2,* Arun K lyer,3,4,* Xiaoqian Yang,1 Eisuke Kobayashi,1 Yuqi Guo,1,2 Henry Mankin,1 Francis J Hornicek,1 Mansoor M Amiji,3 Zhenfeng Duan1 1Sarcoma Biology Laboratory, Center for Sarcoma and Connective Tissue Oncology, Massachusetts General Hospital, Boston, Massachusetts, USA; 2Department of Pathology, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, People&rsquo;s Republic of China; 3Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, Massachusetts, USA; 4Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI,&nbsp;USA *These authors contributed equally to this work Abstract: Our prior screening of microRNAs (miRs) identified that miR-199a-3p expression is reduced in osteosarcoma cells, one of the most common types of bone tumor. miR-199a-3p exhibited functions of tumor cell growth inhibition, suggesting the potential application of miR-199a-3p as an anticancer agent. In the study reported here, we designed and developed a lipid-modified dextran-based polymeric nanoparticle platform for encapsulation of miRs, and determined the efficiency and efficacy of delivering miR-199a-3p into osteosarcoma cells. In addition, another potent miR, let-7a, which also displayed tumor suppressive ability, was selected as a candidate miR for evaluation. Fluorescence microscopy studies and real-time polymerase chain reaction results showed that dextran nanoparticles could deliver both miR-199a-3p and let-7a into osteosarcoma cell lines (KHOS and U-2OS) successfully. Western blotting analysis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays demonstrated that dextran nanoparticles loaded with miRs could efficiently downregulate the expression of target proteins and effectively inhibit the growth and proliferation of osteosarcoma cells. These results demonstrate that a lipid-modified dextran-based polymeric nanoparticle platform may be an effective nonviral carrier for potential miR-based anticancer therapeutics. Keywords: bone tumor, dextran nanoparticles, miR-199a-3p, let-7a, RNA

    Informatics and Standards for Nanomedicine Technology

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    There are several issues to be addressed concerning the management and effective use of information (or data), generated from nanotechnology studies in biomedical research and medicine. These data are large in volume, diverse in content, and are beset with gaps and ambiguities in the description and characterization of nanomaterials. In this work, we have reviewed three areas of nanomedicine informatics: information resources; taxonomies, controlled vocabularies, and ontologies; and information standards. Informatics methods and standards in each of these areas are critical for enabling collaboration, data sharing, unambiguous representation and interpretation of data, semantic (meaningful) search and integration of data; and for ensuring data quality, reliability, and reproducibility. In particular, we have considered four types of information standards in this review, which are standard characterization protocols, common terminology standards, minimum information standards, and standard data communication (exchange) formats. Currently, due to gaps and ambiguities in the data, it is also difficult to apply computational methods and machine learning techniques to analyze, interpret and recognize patterns in data that are high dimensional in nature, and also to relate variations in nanomaterial properties to variations in their chemical composition, synthesis, characterization protocols, etc. Progress towards resolving the issues of information management in nanomedicine using informatics methods and standards discussed in this review will be essential to the rapidly growing field of nanomedicine informatics

    Stomach-Specific Controlled Release Gellan Beads of Acid-Soluble Drug Prepared by Ionotropic Gelation Method

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    The purpose of the present work was the development and evaluation of stomach-specific controlled release mucoadhesive drug delivery system prepared by ionotropic gelation of gellan beads, containing acid-soluble drug amoxicillin trihydrate, using 32 factorial design with concentration of gellan gum and quantity of drug as variables. The study showed that beads prepared in alkaline cross-linking medium have higher entrapment efficiency than the acidic cross-linking medium. The entrapment efficiency was in the range of 32% to 46% w/w in acidic medium, which increased up to 60% to 90% w/w in alkaline medium. Batches with lowest, medium, and highest drug entrapment were subjected to chitosan coating to form a polyelectrolyte complex film. As polymer concentration increases, entrapment efficiency and particle size increases. Scanning electron microscopy revealed spherical but rough surface due to leaching of drug in acidic cross-linking solution, dense spherical structure in alkaline cross-linking solution, and rough surface of chitosan-coated beads with minor wrinkles. The in vitro drug release up to 7 h in a controlled manner following the Peppas model (r = 0.9998). In vitro and in vivo mucoadhesivity study showed that beads have good mucoadhesivity and more than 85% beads remained adhered to stomach mucosa of albino rat even after 7 h. In vitro growth inhibition study showed complete eradication of Helicobacter pylori. These results indicate that stomach-specific controlled release mucoadhesive system of amoxicillin gellan beads may be useful in H. pylori treatment
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