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Issman L, Talmon Y. Cryo-SEM specimen preparation under controlled temperature and concentration conditions. J Microsc 2012; 246:60-9. [PMID: 22268668 DOI: 10.1111/j.1365-2818.2011.03587.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cryogenic temperature scanning electron microscopy (cryo-SEM) is an excellent technique for imaging liquid and semi-liquid materials of high vapour pressure, which are highly viscous or contain large (>0.5 μm) aggregates, in which nanometric details are to be studied. However, so far there have been no adequate tools for controlled cryo-specimen preparation. The specimen preparation stage is critical, because most of those samples are very sensitive to concentration and temperature changes, leading to nanostructural artefacts in the specimens. We designed and built a system for easy and reliable cryo-SEM specimen preparation under controlled conditions of fixed temperature and humidity. We describe this new methodology, and demonstrate its applicability, by showing imaging data of three liquid material systems. We have studied carbon nanotubes (CNTs) dispersions in superacid. We also characterized a number of systems made of water/isooctane/nonionic and cationic surfactant that showed different microemulsion phases as function of the system composition and temperature. In all of the examples given, we demonstrate artefact- and contamination-free specimens, which have preserved their native nanostructure. Our new system paves the way for a new methodology for the newly emerging field of cryo-SEM.
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Affiliation(s)
- L Issman
- Department of Chemical Engineering, Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa, Israel
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Kim J, Hwang I, Britain D, Chung TD, Sun Y, Kim DH. Microfluidic approaches for gene delivery and gene therapy. LAB ON A CHIP 2011; 11:3941-8. [PMID: 22027752 DOI: 10.1039/c1lc20766k] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Recent advances in microfluidics have created new and exciting prospects for gene delivery and therapy. The micro-scaled environment within microfluidic systems enables precise control and optimization of multiple processes and techniques used in gene transfection and the production of gene and drug transporters. Traditional non-viral gene transfection methods, such as electroporation, microinjection and optical gene transfection, are improved from the use of innovative microfluidic systems. Additionally, microfluidic systems have also made the production of many viral and non-viral vectors controlled, automated, and reproducible. In summary, the development and application of microfluidic systems are producing increased efficiency in gene delivery and promise improved gene therapy results.
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Affiliation(s)
- Jungkyu Kim
- Department of Chemistry and Electrical Engineering, University of California, Berkeley, CA, USA
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Yu B, Zhu J, Xue W, Wu Y, Huang X, Lee LJ, Lee RJ. Microfluidic assembly of lipid-based oligonucleotide nanoparticles. Anticancer Res 2011; 31:771-776. [PMID: 21498694 PMCID: PMC3791325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
BACKGROUND Oligonucleotides (ONs) have shown great promise as therapeutic agents for various diseases. It is necessary to provide a protocol for preparation of ON-loaded lipid nanoparticles (LNPs) in a reproducible manner on a laboratory scale. MATERIALS AND METHODS A 3-inlet microfluidic (MF) chip-based device was used to synthesize LNPs at the lipid/ON ratio of 10/1 (w/w) and at flow rates ranging from 50 to 1100 μl/min. A series of LNPs containing either antisense oligodeoxyribonucleotide (AS-ODN) or small-interfering RNA (siRNA) were synthesized. Bulk mixing was used as control. RESULTS The MF method was shown to be particularly useful for synthesis of LNPs loaded with AS-ODN. The optimal range of flow rates for AS-ODN LNPs was found to be 100 to 200 μl/min. MF synthesis produced LNPs with lower polydispersity values. However, the MF was less effective in preparing LNPs loaded with siRNA, which may have been due to greater rigidity of double-stranded siRNA comparing to single-stranded AS-ODN. CONCLUSION MF technology is a simple, affordable and reproducible method for production of ON-LNPs.
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Affiliation(s)
- Bo Yu
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, U.S.A
- NSF Nanoscale Science and Engineering Center (NSEC), The Ohio State University, Columbus, OH, U.S.A
| | - Jing Zhu
- Division of Pharmaceutics, College of Pharmacy, The Ohio State University, Columbus, OH, U.S.A
| | - Weiming Xue
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, U.S.A
- School of Chemical Engineering, Northwest University, Xian, P.R. China
| | - Yun Wu
- NSF Nanoscale Science and Engineering Center (NSEC), The Ohio State University, Columbus, OH, U.S.A
| | - Xiaomeng Huang
- NSF Nanoscale Science and Engineering Center (NSEC), The Ohio State University, Columbus, OH, U.S.A
- Division of Pharmaceutics, College of Pharmacy, The Ohio State University, Columbus, OH, U.S.A
| | - L. James Lee
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, U.S.A
- NSF Nanoscale Science and Engineering Center (NSEC), The Ohio State University, Columbus, OH, U.S.A
- Division of Pharmaceutics, College of Pharmacy, The Ohio State University, Columbus, OH, U.S.A
| | - Robert J. Lee
- NSF Nanoscale Science and Engineering Center (NSEC), The Ohio State University, Columbus, OH, U.S.A
- Division of Pharmaceutics, College of Pharmacy, The Ohio State University, Columbus, OH, U.S.A
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Phua K, Leong KW. Microscale oral delivery devices incorporating nanoparticles. Nanomedicine (Lond) 2010; 5:161-3. [PMID: 20148626 DOI: 10.2217/nnm.09.113] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Jin Y, Liu S, Yu B, Golan S, Koh CG, Yang J, Huynh L, Yang X, Pang J, Muthusamy N, Chan KK, Byrd JC, Talmon Y, Lee LJ, Lee RJ, Marcucci G. Targeted delivery of antisense oligodeoxynucleotide by transferrin conjugated pH-sensitive lipopolyplex nanoparticles: a novel oligonucleotide-based therapeutic strategy in acute myeloid leukemia. Mol Pharm 2010; 7:196-206. [PMID: 19852511 DOI: 10.1021/mp900205r] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Therapeutic use of oligodeoxynucleotides (ODNs) that hybridize to and downregulate target mRNAs encoding proteins that contribute to malignant transformation has a sound rationale, but has had an overall limited clinical success in cancer due to insufficient intracellular delivery. Here we report a development of formulations capable of promoting targeted delivery and enhanced pharmacologic activity of ODNs in acute myeloid leukemia (AML) cell lines and patient primary cells. In this study, transferrin (Tf) conjugated pH-sensitive lipopolyplex nanoparticles (LPs) were prepared to deliver GTI-2040, an antisense ODN against the R2 subunit of ribonucleotide reductase that has been shown to contribute to chemoresistance in AML. LPs had an average particle size around 110 nm and a moderately positive zeta potential at approximately 10 mV. The ODN encapsulation efficiency of LPs was >90%. These nanoparticles could release ODNs at acidic endosomal pH and facilitate the cytoplasmic delivery of ODNs after endocytosis. In addition, Tf-mediated targeted delivery of GTI-2040 was achieved. R2 downregulation at both mRNA and protein levels was improved by 8-fold in Kasumi-1 cells and 2- to 20-fold in AML patient primary cells treated with GTI-2040-Tf-LPs, compared to free GTI-2040 treatment. Moreover, Tf-LPs were more effective than nontargeted LPs, with 10 to 100% improvement at various concentrations in Kasumi-1 cells and an average of 45% improvement at 3 microM concentration in AML patient primary cells. Treatment with 1 microM GTI-2040-Tf-LPs sensitized AML cells to the chemotherapy agent cytarabine, by decreasing its IC(50) value from 47.69 nM to 9.05 nM. This study suggests that the combination of pH sensitive LP formulation and Tf mediated targeting is a promising strategy for antisense ODN delivery in leukemia therapy.
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Affiliation(s)
- Yan Jin
- NSF Nanoscale Science and Engineering Center, Division of Pharmaceutics, College of Pharmacy, Department of Chemical and Biomolecular Engineering, The Comprehensive Cancer Center, and Division of Hematology and Oncology, Department of Internal Medicine, The Ohio State University, Columbus, Ohio, USA
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Galasso M, Sana ME, Volinia S. Non-coding RNAs: a key to future personalized molecular therapy? Genome Med 2010; 2:12. [PMID: 20236487 PMCID: PMC2847703 DOI: 10.1186/gm133] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Continual discoveries on non-coding RNA (ncRNA) have changed the landscape of human genetics and molecular biology. Over the past ten years it has become clear that ncRNAs are involved in many physiological cellular processes and contribute to molecular alterations in pathological conditions. Several classes of ncRNAs, such as small interfering RNAs, microRNAs, PIWI-associated RNAs, small nucleolar RNAs and transcribed ultra-conserved regions, are implicated in cancer, heart diseases, immune disorders, and neurodegenerative and metabolic diseases. ncRNAs have a fundamental role in gene regulation and, given their molecular nature, they are thus both emerging therapeutic targets and innovative intervention tools. Next-generation sequencing technologies (for example SOLiD or Genome Analyzer) are having a substantial role in the high-throughput detection of ncRNAs. Tools for non-invasive diagnostics now include monitoring body fluid concentrations of ncRNAs, and new clinical opportunities include silencing and inhibition of ncRNAs or their replacement and re-activation. Here we review recent progress on our understanding of the biological functions of human ncRNAs and their clinical potential.
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Affiliation(s)
- Marco Galasso
- Data Mining for Analysis of Microarrays, Department of Morphology and Embryology, Università Degli Studi di Ferrara, 44100 Ferrara, Italy.
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Fuchs S, Coester C. Protein-based nanoparticles as a drug delivery system: chances, risks, perspectives. J Drug Deliv Sci Technol 2010. [DOI: 10.1016/s1773-2247(10)50056-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Liposomes are composed of lipid bilayer membranes that encapsulate an aqueous volume. A major challenge in the development of liposomes for drug delivery is the control of size and size distribution. In conventional methods, lipids are spontaneously assembled into heterogeneous bilayers in a bulk phase. Additional processing by extrusion or sonication is required to obtain liposomes with small size and a narrow size distribution. Microfluidics is an emerging technology for liposome synthesis, because it enables precise control of the lipid hydration process. Here, we describe a number of microfluidic methods that have been reported to produce micro/nanosized liposomes with narrower size distribution in a reproducible manner, focusing on the use of continuous-flow microfluidics. The advantages of liposome formation using the microfluidic approach over traditional bulk-mixing approaches are discussed.
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Affiliation(s)
- Bo Yu
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, USA
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