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Williams-Fegredo T, Davies L, Knevelman C, Mitrophanous K, Miskin J, Rafiq QA. Development of novel lipoplex formulation methodologies to improve large-scale transient transfection for lentiviral vector manufacture. Mol Ther Methods Clin Dev 2024; 32:101260. [PMID: 38745895 PMCID: PMC11092396 DOI: 10.1016/j.omtm.2024.101260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 04/24/2024] [Indexed: 05/16/2024]
Abstract
Large-scale transient transfection has advanced significantly over the last 20 years, enabling the effective production of a diverse range of biopharmaceutical products, including viral vectors. However, a number of challenges specifically related to transfection reagent stability and transfection complex preparation times remain. New developments and improved transfection technologies are required to ensure that transient gene expression-based bioprocesses can meet the growing demand for viral vectors. In this paper, we demonstrate that the growth of cationic lipid-based liposomes, an essential step in many cationic lipid-based transfection processes, can be controlled through adoption of low pH (pH 6.40 to pH 6.75) and in low salt concentration (0.2× PBS) formulations, facilitating improved control over the nanoparticle growth kinetics and enhancing particle stability. Such complexes retain the ability to facilitate efficient transfection for prolonged periods compared with standard preparation methodologies. These findings have significant industrial applications for the large-scale manufacture of lentiviral vectors for two principal reasons. First, the alternative preparation strategy enables longer liposome incubation times to be used, facilitating effective control in a good manufacturing practices setting. Second, the improvement in particle stability facilitates the setting of wider process operating ranges, which will significantly improve process robustness and maximise batch-to-batch control and product consistency.
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Affiliation(s)
- Thomas Williams-Fegredo
- Oxford Biomedica (UK) Limited, Windrush Court, Transport Way, Oxford OX4 6LT, UK
- Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London WC1E 6BT, UK
| | - Lee Davies
- Oxford Biomedica (UK) Limited, Windrush Court, Transport Way, Oxford OX4 6LT, UK
| | - Carol Knevelman
- Oxford Biomedica (UK) Limited, Windrush Court, Transport Way, Oxford OX4 6LT, UK
| | | | - James Miskin
- Oxford Biomedica (UK) Limited, Windrush Court, Transport Way, Oxford OX4 6LT, UK
| | - Qasim A. Rafiq
- Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London WC1E 6BT, UK
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2
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Hu Y, Eder BA, Lin J, Li S, Zhu Y, Wang TH, Guo T, Mao HQ. Liter-scale manufacturing of shelf-stable plasmid DNA/PEI transfection particles for viral vector production. Mol Ther Methods Clin Dev 2024; 32:101194. [PMID: 38352269 PMCID: PMC10863326 DOI: 10.1016/j.omtm.2024.101194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 01/18/2024] [Indexed: 02/16/2024]
Abstract
The transfection efficiency and stability of the delivery vehicles of plasmid DNA (pDNA) are critical metrics to ensure high-quality and high-yield production of viral vectors. We previously identified that the optimal size of pDNA/poly(ethylenimine) (PEI) transfection particles is 400-500 nm and developed a bottom-up assembly method to construct stable 400-nm pDNA/PEI particles and benchmarked their transfection efficiency in producing lentiviral vectors (LVVs). Here, we report scale-up production protocols for such transfection particles. Using a two-inlet confined impinging jet (CIJ) mixer with a dual syringe pump set-up, we produced a 1-L batch at a flow rate of 100 mL/min, and further scaled up this process with a larger CIJ mixer and a dual peristaltic pump array, allowing for continuous production at a flow rate of 1 L/min without a lot size limit. We demonstrated the scalability of this process with a 5-L lot and validated the quality of these 400-nm transfection particles against the target product profile, including physical properties, shelf and on-bench stability, transfection efficiency, and LVV production yield in both 15-mL bench culture and 2-L bioreactor runs. These results confirm the potential of this particle assembly process as a scalable manufacturing platform for viral vector production.
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Affiliation(s)
- Yizong Hu
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21218, USA
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | | | - Jinghan Lin
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sixuan Li
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Yining Zhu
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21218, USA
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Tza-Huei Wang
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21218, USA
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Ting Guo
- 2seventy bio, Inc., Cambridge, MA 02142, USA
| | - Hai-Quan Mao
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21218, USA
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
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3
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Protopapa G, Bono N, Visone R, D'Alessandro F, Rasponi M, Candiani G. A new microfluidic platform for the highly reproducible preparation of non-viral gene delivery complexes. LAB ON A CHIP 2022; 23:136-145. [PMID: 36477137 DOI: 10.1039/d2lc00744d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Transfection describes the delivery of exogenous nucleic acids (NAs) to cells utilizing non-viral means. In the last few decades, scientists have been doing their utmost to design ever more effective transfection reagents. These are eventually mixed with NAs to give rise to gene delivery complexes, which must undergo characterization, testing, and further refinement through the sequential reiteration of these steps. Unfortunately, although microfluidics offers distinct advantages over the canonical approaches to preparing particles, the systems available do not address the most frequent and practical quest for the simultaneous generation of multiple polymer-to-NA ratios (N/Ps). Herein, we developed a user-friendly microfluidic cartridge to repeatably prepare non-viral gene delivery particles and screen across a range of seven N/Ps at once or significant volumes of polyplexes at a given N/P. The microchip is equipped with a chaotic serial dilution generator for the automatic linear dilution of the polymer to the downstream area, which encompasses the NA divider to dispense equal amounts of DNA to the mixing area, enabling the formation of particles at seven N/Ps eventually collected in individual built-in tanks. This is the first example of a stand-alone microfluidic cartridge for the fast and repeatable preparation of non-viral gene delivery complexes at different N/Ps and their storage.
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Affiliation(s)
- Giovanni Protopapa
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Milan, Italy.
| | - Nina Bono
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Milan, Italy.
| | - Roberta Visone
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Fabio D'Alessandro
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Milan, Italy.
| | - Marco Rasponi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Gabriele Candiani
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Milan, Italy.
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Kumar R, Santa Chalarca CF, Bockman MR, Bruggen CV, Grimme CJ, Dalal RJ, Hanson MG, Hexum JK, Reineke TM. Polymeric Delivery of Therapeutic Nucleic Acids. Chem Rev 2021; 121:11527-11652. [PMID: 33939409 DOI: 10.1021/acs.chemrev.0c00997] [Citation(s) in RCA: 128] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The advent of genome editing has transformed the therapeutic landscape for several debilitating diseases, and the clinical outlook for gene therapeutics has never been more promising. The therapeutic potential of nucleic acids has been limited by a reliance on engineered viral vectors for delivery. Chemically defined polymers can remediate technological, regulatory, and clinical challenges associated with viral modes of gene delivery. Because of their scalability, versatility, and exquisite tunability, polymers are ideal biomaterial platforms for delivering nucleic acid payloads efficiently while minimizing immune response and cellular toxicity. While polymeric gene delivery has progressed significantly in the past four decades, clinical translation of polymeric vehicles faces several formidable challenges. The aim of our Account is to illustrate diverse concepts in designing polymeric vectors towards meeting therapeutic goals of in vivo and ex vivo gene therapy. Here, we highlight several classes of polymers employed in gene delivery and summarize the recent work on understanding the contributions of chemical and architectural design parameters. We touch upon characterization methods used to visualize and understand events transpiring at the interfaces between polymer, nucleic acids, and the physiological environment. We conclude that interdisciplinary approaches and methodologies motivated by fundamental questions are key to designing high-performing polymeric vehicles for gene therapy.
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Affiliation(s)
- Ramya Kumar
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | | | - Matthew R Bockman
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Craig Van Bruggen
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Christian J Grimme
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Rishad J Dalal
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Mckenna G Hanson
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Joseph K Hexum
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Theresa M Reineke
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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Controlling Nanoparticle Formulation: A Low-Budget Prototype for the Automation of a Microfluidic Platform. Processes (Basel) 2021. [DOI: 10.3390/pr9010129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Active pharmaceutical ingredients (API) with suboptimal pharmacokinetic properties may require formulation into nanoparticles. In addition to the quality of the excipients, production parameters are crucial for producing nanoparticles which reliably deliver APIs to their target. Microfluidic platforms promise increased control over the formulation process due to the decreased degrees of freedom at the micro- and nanoscale. Publications about these platforms usually provide only limited information about the soft- and hardware required to integrate the microfluidic chip seamlessly into an experimental set-up. We describe a modular, low-budget prototype for microfluidic mixing in detail. The prototype consists of four modules. The control module is a raspberry pi executing customizable python scripts to control the syringe pumps and the fraction collector. The feeding module consists of up to three commercially available, programable syringe pumps. The formulation module can be any macro- or microfluidic chip connectable to syringe pumps. The collection module is a custom-built fraction collector. We describe each feature of the working prototype and demonstrate its power with polyplexes formulated from siRNA and two different oligomers that are fed to the chip at two different stages during the assembly of the nanoparticles.
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Hu H, Yang C, Li M, Shao D, Mao HQ, Leong KW. Flash Technology-Based Self-Assembly in Nanoformulation: From Fabrication to Biomedical Applications. MATERIALS TODAY (KIDLINGTON, ENGLAND) 2021; 42:99-116. [PMID: 34421329 PMCID: PMC8375602 DOI: 10.1016/j.mattod.2020.08.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Advances in nanoformulation have driven progress in biomedicine by producing nanoscale tools for biosensing, imaging, and drug delivery. Flash-based technology, the combination of rapid mixing technique with the self-assembly of macromolecules, is a new engine for the translational nanomedicine. Here, we review the state-of-the-art in flash-based self-assembly including theoretical and experimental principles, mixing device design, and applications. We highlight the fields of flash nanocomplexation (FNC) and flash nanoprecipitation (FNP), with an emphasis on biomedical applications of FNC, and discuss challenges and future directions for flash-based nanoformulation in biomedicine.
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Affiliation(s)
- Hanze Hu
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Chao Yang
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
- Institutes of Life Sciences, School of Biomedical Sciences and Engineering, Guangzhou International Campus, National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, Guangdong 510630, China
| | - Mingqiang Li
- Laboratory of Biomaterials and Translational Medicine, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, 510630, China
| | - Dan Shao
- Institutes of Life Sciences, School of Biomedical Sciences and Engineering, Guangzhou International Campus, National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, Guangdong 510630, China
| | - Hai-Quan Mao
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Kam W. Leong
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
- Department of Systems Biology, Columbia University Medical Center, New York, NY 10032, USA
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7
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Hao Y, Seo JH, Hu Y, Mao HQ, Mittal R. Flow physics and mixing quality in a confined impinging jet mixer. AIP ADVANCES 2020; 10:045105. [PMID: 32266109 PMCID: PMC7124763 DOI: 10.1063/5.0002125] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 03/16/2020] [Indexed: 05/16/2023]
Abstract
Due to their ability to provide efficient mixing at small scales, confined impinging jet mixers (CIJMs) are employed widely in nanoparticle assembly processes such as flash nanoprecipitation and flash nanocomplexation, which require rapid mixing. In this mixing device, two jets from opposite directions impinge directly on each other forming a thin shear layer that breaks down rapidly into small flow structures. This enables effective mixing of the species transported by each jet by drastically reducing the diffusion distance. In the present study, the mixing performance of a commonly used cylindrical CIJM is examined by direct numerical simulations. Analysis of the simulation results indicates that the interaction of the shear layer with the inner walls of the CIJM is critical in inducing a range of instabilities in the impinging jet flow. By examining flow structures, statistical quantities, and metrics, we have characterized and quantified the mixing quality of a binary mixture in the CIJM. Product uniformity in processes such as precipitation and complexation is expected to depend on the residence time of the constituents, and this quantity is also calculated and compared for the cases with different jet Reynolds numbers. The jet Reynolds numbers of Re = 200, 600, and 1000 are considered, and the simulation results show that the CIJM achieves very good mixing for the Re = 600 and Re = 1000 cases. It is also found that the Re = 600 case performs slightly better than the other cases in terms of uniformity of the residence time. These quantitative analyses offer useful insights into the mechanism of nanoparticle size control and uniformity afforded by the unique flow physics and mixing characteristics in the CIJMs.
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Affiliation(s)
- Yue Hao
- Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Jung-Hee Seo
- Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | | | | | - Rajat Mittal
- Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
- Author to whom correspondence should be addressed:
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8
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Soliman OY, Alameh MG, De Cresenzo G, Buschmann MD, Lavertu M. Efficiency of Chitosan/Hyaluronan-Based mRNA Delivery Systems In Vitro: Influence of Composition and Structure. J Pharm Sci 2019; 109:1581-1593. [PMID: 31891675 DOI: 10.1016/j.xphs.2019.12.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/22/2019] [Accepted: 12/23/2019] [Indexed: 12/25/2022]
Abstract
Messenger RNA (mRNA)-containing nanoparticles were produced by electrostatic complexation with a library of pharmaceutical grade chitosans with different degrees of deacetylation and hyaluronic acids (HAs) (native vs. sulfated). Polymer length (Mn), HA degree of sulfation (DS), and amine to phosphate to carboxyl + sulfate (from HA) ratio (N:P:C) were controlled. In vitro transfections were performed in the presence/absence of trehalose and at different pH. Particle size and ζ-potential were correlated with transfection efficiency. Polymer length and charge densities (degree of deacetylation, degree of sulfation) of both HA and chitosan had a direct influence on transfection efficiency through modulation of avidity to mRNA. N:P:C ratio, trehalose, mixing concentration, and nucleic acid dose influenced transfection efficiency with optimized formulations reaching ∼60%-65% transfection efficiency relative to commercially available lipid control with no apparent toxicity for transfection at slightly acidic pH 6.5.
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Affiliation(s)
| | - Mohamad Gabriel Alameh
- Infectious Disease Division, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Gregory De Cresenzo
- Institute of Biomedical Engineering, Polytechnique Montréal, Montreal, Quebec, Canada; Department of Chemical Engineering, Polytechnique Montréal, Montreal, Quebec, Canada
| | - Michael D Buschmann
- Department of Bioengineering, Volgenau School of Engineering, George Mason University, Fairfax, Virginia 22030
| | - Marc Lavertu
- Institute of Biomedical Engineering, Polytechnique Montréal, Montreal, Quebec, Canada; Department of Chemical Engineering, Polytechnique Montréal, Montreal, Quebec, Canada.
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9
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Hu Y, He Z, Hao Y, Liu HW, Gong L, Howard G, Ahn HH, Brummet M, Ke X, Anderson C, Seo JH, Zhu J, Chen K, Pang Wan Rion M, Cui H, Ullman CG, Carrington CA, Pomper MG, Mittal R, Minn I, Mao HQ. Kinetic Control in Assembly of Plasmid DNA/Polycation Complex Nanoparticles. ACS NANO 2019; 13:10161-10178. [PMID: 31503450 PMCID: PMC7293580 DOI: 10.1021/acsnano.9b03334] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Polyelectrolyte complex (PEC) nanoparticles assembled from plasmid DNA (pDNA) and polycations such as linear polyethylenimine (lPEI) represent a major nonviral delivery vehicle for gene therapy tested thus far. Efforts to control the size, shape, and surface properties of pDNA/polycation nanoparticles have been primarily focused on fine-tuning the molecular structures of the polycationic carriers and on assembly conditions such as medium polarity, pH, and temperature. However, reproducible production of these nanoparticles hinges on the ability to control the assembly kinetics, given the nonequilibrium nature of the assembly process and nanoparticle composition. Here we adopt a kinetically controlled mixing process, termed flash nanocomplexation (FNC), that accelerates the mixing of pDNA solution with polycation lPEI solution to match the PEC assembly kinetics through turbulent mixing in a microchamber. This achieves explicit control of the kinetic conditions for pDNA/lPEI nanoparticle assembly, as demonstrated by the tunability of nanoparticle size, composition, and pDNA payload. Through a combined experimental and simulation approach, we prepared pDNA/lPEI nanoparticles having an average of 1.3 to 21.8 copies of pDNA per nanoparticle and average size of 35 to 130 nm in a more uniform and scalable manner than bulk mixing methods. Using these nanoparticles with defined compositions and sizes, we showed the correlation of pDNA payload and nanoparticle formulation composition with the transfection efficiencies and toxicity in vivo. These nanoparticles exhibited long-term stability at -20 °C for at least 9 months in a lyophilized formulation, validating scalable manufacture of an off-the-shelf nanoparticle product with well-defined characteristics as a gene medicine.
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Affiliation(s)
- Yizong Hu
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Zhiyu He
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Yue Hao
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Heng-wen Liu
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Like Gong
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Gregory Howard
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Hye-Hyun Ahn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Mary Brummet
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Xiyu Ke
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Caleb Anderson
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jung-Hee Seo
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jinchang Zhu
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Kuntao Chen
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Marion Pang Wan Rion
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Honggang Cui
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | | | - Martin G. Pomper
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Rajat Mittal
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Hai-Quan Mao
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
- Correspondence should be addressed to Dr. Hai-Quan Mao: 3400 N. Charles Street, Croft Hall 100, Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, 21218, USA.
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10
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Kasper JC, Hedtrich S, Friess W. Lyophilization of Synthetic Gene Carriers. Methods Mol Biol 2019; 1943:211-225. [PMID: 30838619 DOI: 10.1007/978-1-4939-9092-4_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Lyophilization, also known as freeze drying, is a widely used method for stabilization, improvement of long-term storage stability, and simplification of handling of drugs and/or carrier systems. Lyophilization is time-consuming and energy-consuming, and hence optimized processes are required to avoid time loss and higher costs without compromising product stability. Beginning from the last decade, nonviral, synthetic carriers for gene delivery have been of increasing interest. However, these systems suffer from poor physical stability in aqueous solution or suspension. Hence, to ensure long-term storage stability lyophilization of the gene carrier systems is favored. This chapter gives an overview of the basic steps and troubleshooting for successful lyophilization of synthetic gene carriers. Furthermore, the required excipients and their mechanism of action are summarized.
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Affiliation(s)
- Julia Christina Kasper
- Bioprocess and Pharmaceutical Development Biologicals, Boehringer Ingelheim Pharma GmbH and Co. KG, Biberach, Germany
| | - Sarah Hedtrich
- Institute for Pharmacy, Pharmacology & Toxicology, Freie Universität Berlin, Berlin, Germany
| | - Wolfgang Friess
- Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-Universität, Munich, Germany.
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11
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Rödl W, Taschauer A, Schaffert D, Wagner E, Ogris M. Synthesis of Polyethylenimine-Based Nanocarriers for Systemic Tumor Targeting of Nucleic Acids. Methods Mol Biol 2019; 1943:83-99. [PMID: 30838611 DOI: 10.1007/978-1-4939-9092-4_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Nucleic acid-based therapies offer the option to treat tumors in a highly selective way, while toxicity towards healthy tissue can be avoided when proper delivery vehicles are used. We have recently developed carrier systems based on linear polyethylenimine, which after chemical coupling of protein- or peptide-based ligands can form nanosized polyplexes with plasmid DNA (pDNA) or RNA and deliver their payload into target cells by receptor-mediated endocytosis. This chapter describes the synthesis of LPEI from a precursor polymer and the current coupling techniques and purification procedure for peptide conjugates with linear polyethylenimine. A protocol is also given for the formation and characterization of polyplexes formed with LPEI conjugate and pDNA.
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Affiliation(s)
- Wolfgang Rödl
- Pharmaceutical Biotechnology, Center for System Based Drug Research, Ludwig-Maximilians-University, Munich, Germany
| | - Alexander Taschauer
- Laboratory of MacroMolecular Cancer Therapeutics (MMCT), Department of Pharmaceutical Chemistry, Center of Pharmaceutical Sciences, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - David Schaffert
- Department of Molecular Biology, Aarhus University, Aarhus, Denmark
| | - Ernst Wagner
- Pharmaceutical Biotechnology, Center for System Based Drug Research, Ludwig-Maximilians-University, Munich, Germany
- Center for NanoScience (CeNS), Ludwig-Maximilians-University, Munich, Germany
| | - Manfred Ogris
- Laboratory of MacroMolecular Cancer Therapeutics (MMCT), Department of Pharmaceutical Chemistry, Center of Pharmaceutical Sciences, Faculty of Life Sciences, University of Vienna, Vienna, Austria.
- Center for NanoScience (CeNS), Ludwig-Maximilians-University, Munich, Germany.
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12
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Feldmann DP, Xie Y, Jones SK, Yu D, Moszczynska A, Merkel OM. The impact of microfluidic mixing of triblock micelleplexes on in vitro / in vivo gene silencing and intracellular trafficking. NANOTECHNOLOGY 2017; 28:224001. [PMID: 28488596 PMCID: PMC5539944 DOI: 10.1088/1361-6528/aa6d15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The triblock copolymer polyethylenimine-polycaprolactone-polyethylene glycol (PEI-PCL-PEG) has been shown to spontaneously assemble into nano-sized particulate carriers capable of complexing with nucleic acids for gene delivery. The objective of this study was to investigate micelleplex characteristics, their in vitro and in vivo fate following microfluidic preparation of siRNA nanoparticles compared to the routinely used batch reactor mixing technique. Herein, PEI-PCL-PEG nanoparticles were prepared with batch reactor or microfluidic mixing techniques and characterized by various biochemical assays and in cell culture. Microfluidic nanoparticles showed a reduction of overall particle size as well as a more uniform size distribution when compared to batch reactor pipette mixing. Confocal microscopy, flow cytometry and qRT-PCR displayed the subcellular delivery of the microfluidic formulation and confirmed the ability to achieve mRNA knockdown. Intratracheal instillation of microfluidic formulation resulted in a significantly more efficient (p < 0.05) knockdown of GAPDH compared to treatment with the batch reactor formulation. The use of microfluidic mixing techniques yields an overall smaller and more uniform PEG-PCL-PEI nanoparticle that is able to more efficiently deliver siRNA in vivo. This preparation method may prove to be useful when a scaled up production of well-defined polyplexes is required.
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Affiliation(s)
- Daniel P Feldmann
- Department of Oncology, Wayne State University School of Medicine, 4100 John R St, Detroit, MI 48201, United States of America
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13
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Automated in-line mixing system for large scale production of chitosan-based polyplexes. J Colloid Interface Sci 2017; 500:253-263. [PMID: 28411432 DOI: 10.1016/j.jcis.2017.04.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 04/05/2017] [Accepted: 04/05/2017] [Indexed: 01/28/2023]
Abstract
Chitosan (CS)-based polyplexes are efficient non-viral gene delivery systems that are most commonly prepared by manual mixing. However, manual mixing is not only poorly controlled but also restricted to relatively small preparation volumes, limiting clinical applications. In order to overcome these drawbacks and to produce clinical quantities of CS-based polyplexes, a fully automated in-line mixing platform was developed for production of large batches of small-size and homogeneous CS-based polyplexes. Operational conditions to produce small-sized homogeneous polyplexes were identified. Increasing mixing concentrations of CS and nucleic acid was directly associated with an increase in size and polydispersity of both CS/pDNA and CS/siRNA polyplexes. We also found that although the speed of mixing has a negligible impact on the properties of CS/pDNA polyplexes, the size and polydispersity of CS/siRNA polyplexes are strongly influenced by the mixing speed: the higher the speed, the smaller the size and polydispersity. While in-line and manual CS/pDNA polyplexes had similar size and PDI, CS/siRNA polyplexes were smaller and more homogenous when prepared in-line in the non-laminar flow regime compared to manual method. Finally, we found that in-line mixed CS/siRNA polyplexes have equivalent or higher silencing efficiency of ApoB in HepG2 cells, compared to manually prepared polyplexes.
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14
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Reinhard S, Wagner E. How to Tackle the Challenge of siRNA Delivery with Sequence-Defined Oligoamino Amides. Macromol Biosci 2016; 17. [PMID: 27328447 DOI: 10.1002/mabi.201600152] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 05/24/2016] [Indexed: 12/31/2022]
Abstract
RNA interference (RNAi) as a mechanism of gene regulation provides exciting opportunities for medical applications. Synthetic small interfering RNA (siRNA) triggers the knockdown of complementary mRNA sequences in a catalytic fashion and has to be delivered into the cytosol of the targeted cells. The design of adequate carrier systems to overcome multiple extracellular and intracellular roadblocks within the delivery process has utmost importance. Cationic polymers form polyplexes through electrostatic interaction with negatively charged nucleic acids and present a promising class of carriers. Issues of polycations regarding toxicity, heterogeneity, and polydispersity can be overcome by solid-phase-assisted synthesis of sequence-defined cationic oligomers. These medium-sized highly versatile nucleic acid carriers display low cytotoxicity and can be modified and tailored in multiple ways to meet specific requirements of nucleic acid binding, polyplex size, shielding, targeting, and intracellular release of the cargo. In this way, sequence-defined cationic oligomers can mimic the dynamic and bioresponsive behavior of viruses.
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Affiliation(s)
- Sören Reinhard
- Pharmaceutical Biotechnology, Department of Pharmacy, Ludwig Maximilians University, 81377, Munich, Germany
| | - Ernst Wagner
- Pharmaceutical Biotechnology, Department of Pharmacy, Ludwig Maximilians University, 81377, Munich, Germany.,Nanosystems Initiative Munich (NIM), 80799, Munich, Germany
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15
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Taschauer A, Geyer A, Gehrig S, Maier J, Sami H, Ogris M. Up-Scaled Synthesis and Characterization of Nonviral Gene Delivery Particles for TransientIn VitroandIn VivoTransgene Expression. Hum Gene Ther Methods 2016; 27:87-97. [DOI: 10.1089/hgtb.2016.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Alexander Taschauer
- MMCT Laboratory of Macromolecular Cancer Therapeutics, Department for Pharmaceutical Chemistry, Faculty Center for Pharmacy, University of Vienna, Vienna, Austria
| | - Antonia Geyer
- MMCT Laboratory of Macromolecular Cancer Therapeutics, Department for Pharmaceutical Chemistry, Faculty Center for Pharmacy, University of Vienna, Vienna, Austria
| | - Sebastian Gehrig
- MMCT Laboratory of Macromolecular Cancer Therapeutics, Department for Pharmaceutical Chemistry, Faculty Center for Pharmacy, University of Vienna, Vienna, Austria
| | - Julia Maier
- MMCT Laboratory of Macromolecular Cancer Therapeutics, Department for Pharmaceutical Chemistry, Faculty Center for Pharmacy, University of Vienna, Vienna, Austria
| | - Haider Sami
- MMCT Laboratory of Macromolecular Cancer Therapeutics, Department for Pharmaceutical Chemistry, Faculty Center for Pharmacy, University of Vienna, Vienna, Austria
| | - Manfred Ogris
- MMCT Laboratory of Macromolecular Cancer Therapeutics, Department for Pharmaceutical Chemistry, Faculty Center for Pharmacy, University of Vienna, Vienna, Austria
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16
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Lu M, Ho YP, Grigsby CL, Nawaz AA, Leong KW, Huang TJ. Three-dimensional hydrodynamic focusing method for polyplex synthesis. ACS NANO 2014; 8:332-9. [PMID: 24341632 PMCID: PMC3999362 DOI: 10.1021/nn404193e] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Successful intracellular delivery of nucleic acid therapeutics relies on multiaspect optimization, one of which is formulation. While there has been ample innovation on chemical design of polymeric gene carriers, the same cannot be said for physical processing of polymer-DNA nanocomplexes (polyplexes). Conventional synthesis of polyplexes by bulk mixing depends on the operators' experience. The poorly controlled bulk mixing process may also lead to batch-to-batch variation and consequent irreproducibility. Here, we synthesize polyplexes by using a three-dimensional hydrodynamic focusing (3D-HF) technique in a single-layered, planar microfluidic device. Without any additional chemical treatment or postprocessing, the polyplexes prepared by the 3D-HF method show smaller size, slower aggregation rate, and higher transfection efficiency, while exhibiting reduced cytotoxicity compared to the ones synthesized by conventional bulk mixing. In addition, by introducing external acoustic perturbation, mixing can be further enhanced, leading to even smaller nanocomplexes. The 3D-HF method provides a simple and reproducible process for synthesizing high-quality polyplexes, addressing a critical barrier in the eventual translation of nucleic acid therapeutics.
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Affiliation(s)
- Mengqian Lu
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, USA
| | - Yi-Ping Ho
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Denmark
| | - Christopher L. Grigsby
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Ahmad Ahsan Nawaz
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, USA
| | - Kam W. Leong
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Tony Jun Huang
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, USA
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17
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Formulation development of lyophilized, long-term stable siRNA/oligoaminoamide polyplexes. Eur J Pharm Biopharm 2013; 85:294-305. [DOI: 10.1016/j.ejpb.2013.05.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Revised: 05/12/2013] [Accepted: 05/21/2013] [Indexed: 11/18/2022]
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18
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Buschmann MD, Merzouki A, Lavertu M, Thibault M, Jean M, Darras V. Chitosans for delivery of nucleic acids. Adv Drug Deliv Rev 2013; 65:1234-70. [PMID: 23872012 PMCID: PMC7103275 DOI: 10.1016/j.addr.2013.07.005] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 05/22/2013] [Accepted: 07/05/2013] [Indexed: 01/19/2023]
Abstract
Alternatives to efficient viral vectors in gene therapy are desired because of their poor safety profiles. Chitosan is a promising non-viral nucleotide delivery vector because of its biocompatibility, biodegradability, low immunogenicity and ease of manufacturing. Since the transfection efficiency of chitosan polyplexes is relatively low compared to viral counterparts, there is an impetus to gain a better understanding of the structure-performance relationship. Recent progress in preparation and characterisation has enabled coupling analysis of chitosans structural parameters that has led to increased TE by tailoring of chitosan's structure. In this review, we summarize the recent advances that have lead to a more rational design of chitosan polyplexes. We present an integrated review of all major areas of chitosan-based transfection, including preparation, chitosan and polyplexes physicochemical characterisation, in vitro and in vivo assessment. In each, we present the obstacles to efficient transfection and the strategies adopted over time to surmount these impediments.
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Affiliation(s)
- Michael D Buschmann
- Dept. Chemical Engineering and Inst. Biomedical Engineering, Ecole Polytechnique, Montreal, QC, Canada.
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Kasper JC, Pikal MJ, Friess W. Investigations on Polyplex Stability During the Freezing Step of Lyophilization Using Controlled Ice Nucleation—The Importance of Residence Time in the Low-Viscosity Fluid State. J Pharm Sci 2013; 102:929-46. [DOI: 10.1002/jps.23419] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 11/16/2012] [Accepted: 11/28/2012] [Indexed: 02/01/2023]
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Kasper JC, Küchler S, Friess W. Lyophilization of synthetic gene carriers. Methods Mol Biol 2013; 948:133-147. [PMID: 23070768 DOI: 10.1007/978-1-62703-140-0_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Lyophilization, also known as freeze-drying, is a widely used method for stabilization, improvement of long-term storage stability, and simplification of the handling of drugs and/or carrier systems. Lyophilization is time- and energy-consuming; hence, optimized processes are required to avoid time loss and higher costs without compromising product stability. Since the last decade nonviral, synthetic carriers for gene delivery are of increasing interest. However, these systems suffer from poor physical stability in aqueous solution or suspension. Hence, to ensure long-term storage stability lyophilization of the gene carrier systems is favored. Though, lyophilized products retrieving original carrier size and transfection efficiency after reconstitution are mandatory. This chapter gives an overview of the basic steps and troubleshooting for successful lyophilization of synthetic gene carriers. Furthermore the required excipients and their mechanism of action are summarized.
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Affiliation(s)
- Julia Christina Kasper
- Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-Universität, Munich, Germany
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21
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Rödl W, Schaffert D, Wagner E, Ogris M. Synthesis of polyethylenimine-based nanocarriers for systemic tumor targeting of nucleic acids. Methods Mol Biol 2013; 948:105-20. [PMID: 23070766 DOI: 10.1007/978-1-62703-140-0_8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Nucleic acid-based therapies offer the option to treat tumors in a highly selective way, while toxicity towards healthy tissue can be avoided when proper delivery vehicles are used. We have recently developed carrier systems based on linear polyethylenimine, which after chemical coupling of proteinous or peptidic ligands can form nanosized polyplexes with plasmid DNA or RNA and deliver their payload into target cells by receptor-mediated endocytosis. This chapter describes the synthesis of linear PEI (LPEI) from a precursor polymer and the current coupling techniques and purification procedure for peptide conjugates with linear polyethylenimine. A protocol is also given for the formation and characterization of polyplexes formed with LPEI conjugate and plasmid DNA.
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Affiliation(s)
- Wolfgang Rödl
- Department of Pharmacy, Center for System Based Drug Research, Pharmaceutical Biotechnology, Ludwig-Maximilians-University, Munich, Germany
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22
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Abstract
Nonviral vector technology is attracting increasing importance in the biomedical community owing to unique advantages and prospects for the treatment of severe diseases by gene therapy. In this review, synthetic vectors that allow the controlled design of efficient and biocompatible carriers are highlighted. The current benefits, potentials, problems and unmet needs of synthetic gene delivery systems, as well as the strategies to overcome the obstacles are also discussed. Common design principles and structure–activity trends have been established that are important for stable and targeted transport to regions of interest in the body, efficient uptake into cells as well as controlled release of drugs inside the cells, for example, in specialized compartments. The status quo of the use of these systems in preclinical and clinical trials is also considered.
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Debus H, Beck-Broichsitter M, Kissel T. Optimized preparation of pDNA/poly(ethylene imine) polyplexes using a microfluidic system. LAB ON A CHIP 2012; 12:2498-2506. [PMID: 22552347 DOI: 10.1039/c2lc40176b] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Poly(ethylene imine) (PEI) is an established non-viral vector system for the delivery of various nucleic acids in gene therapy applications. Polyelectrolyte complexes between both compounds, so called polyplexes, are formed by electrostatic interactions of oppositely charged macromolecules and are thought to facilitate uptake into cells. Such complexes form spontaneously and on lab scale they are usually prepared by mixing solutions through pipetting. Hence, an optimized preparation procedure allowing the scale-up of well-defined polyplexes would be of general interest. We developed a new method for microfluidic polyplex preparation on a chip. The mixing behaviour within the microfluidic channels was evaluated. Polyplexes with PEI and plasmid DNA were prepared using this method, in comparison to the standard pipetting procedure. Sizes and polydispersity indices of these complexes were examined. The influence of various parameters on the polyplex characteristics and the suitability of this production procedure for other PEI-based complexes were also evaluated. It was shown that polyplexes could easily be prepared by microfluidics. The ratio of PEI to DNA was most important for the formation of small polyplexes, whereas other parameters had minor influence. The size of polyplexes prepared with this new method was observed to be relatively constant between 140 nm and 160 nm over a wide range of complex concentrations. In comparison, the size of polyplexes prepared by pipetting (approximately 90 nm to 160 nm) varied considerably. The versatility of this system was demonstrated with different (targeted) PEI-based vectors for the formation of complexes with pDNA and siRNA. In conclusion, polyplex preparation using microfluidics could be a promising alternative to the standard pipetting method due to its suitability for preparation of well-defined complexes with different compositions over a wide range of concentrations.
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Affiliation(s)
- Heiko Debus
- Philipps-Universität Marburg, Department of Pharmaceutics and Biopharmacy, Ketzerbach 63, 35032, Marburg, Germany
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Optimising the self-assembly of siRNA loaded PEG-PCL-lPEI nano-carriers employing different preparation techniques. J Control Release 2012; 160:583-91. [DOI: 10.1016/j.jconrel.2012.04.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 04/02/2012] [Accepted: 04/04/2012] [Indexed: 11/17/2022]
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25
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Raymond C, Tom R, Perret S, Moussouami P, L’Abbé D, St-Laurent G, Durocher Y. A simplified polyethylenimine-mediated transfection process for large-scale and high-throughput applications. Methods 2011; 55:44-51. [DOI: 10.1016/j.ymeth.2011.04.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 04/12/2011] [Accepted: 04/15/2011] [Indexed: 12/13/2022] Open
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26
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Invading target cells: multifunctional polymer conjugates as therapeutic nucleic acid carriers. Front Chem Sci Eng 2011. [DOI: 10.1007/s11705-011-1203-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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27
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How to screen non-viral gene delivery systems in vitro? J Control Release 2011; 154:218-32. [PMID: 21600249 DOI: 10.1016/j.jconrel.2011.05.001] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 03/31/2011] [Accepted: 05/01/2011] [Indexed: 11/21/2022]
Abstract
Screening of new gene delivery candidates regarding transfection efficiency and toxicity is usually performed by reading out transgene expression levels relative to a reference formulation after in vitro transfection. However, over the years and among different laboratories, this screening has been performed in a variety of cell lines, using a variety of conditions and read-out systems, and by comparison to a variety of reference formulations. This makes a direct comparison of results difficult, if not impossible. Reaching a consensus would enable placing new results into context of previous findings and estimate the overall contribution to the improvement of non-viral gene delivery. In this paper we illustrate the sensitivity of transfection outcomes on testing conditions chosen, and propose a screening protocol with the aim of standardization within the field.
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Kasper JC, Schaffert D, Ogris M, Wagner E, Friess W. Development of a lyophilized plasmid/LPEI polyplex formulation with long-term stability--A step closer from promising technology to application. J Control Release 2011; 151:246-55. [PMID: 21223985 DOI: 10.1016/j.jconrel.2011.01.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 12/22/2010] [Accepted: 01/04/2011] [Indexed: 10/18/2022]
Abstract
Cationic polymer/DNA complexes are limited by their instability in aqueous suspensions and usually have to be freshly prepared prior to administration. Thus, the development of isotonic lyophilized polyplex formulations with long-term stability is a desirable goal. Polyplexes based on 22kDa linear polyethylenimine were prepared using a micro-mixer method. Freeze-thawing and lyophilization were performed on a pilot scale freeze-drier. Several excipients (trehalose, sucrose, lactosucrose, dextran, hydroxypropylbetadex or povidone and combinations thereof) at varying concentrations were evaluated for their stabilizing potential against freezing and dehydration induced stresses. For stability testing the lyophilized samples were stored for 6 weeks at 2-8°C, 20°C and 40°C, respectively. Polyplex samples were characterized for particle size, zeta potential, their in vitro transfection efficiency and metabolic activity in Neuro2A cells. In addition, liquid samples were investigated for turbidity and number of sub-visible particles and solid samples were analyzed for residual moisture content, glass transition temperature and sample morphology. L-histidine buffer pH 6.0 was selected as effective buffer. In isotonic formulations with 14% lactosucrose, 10% hydroxypropylbetadex/6.5% sucrose or 10% povidone/6.3% sucrose, particle size was <170nm for all formulations and did not change after storage for 6weeks at 40°C. Polyplexes formulated with lactosucrose or hydroxypropylbetadex/sucrose showed high transfection efficiencies and cellular metabolic activities. Absence of large aggregates was indicated by turbidity and subvisible particle number measurements. The current standard limits for particulate contamination for small volume parenterals were met for all formulations. All samples were amorphous with low residual moisture levels (<1.3%) and high glass transition temperatures (>90°C).
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Affiliation(s)
- Julia Christina Kasper
- Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-University, Butenandtstrasse 5, 81377 Munich, Germany.
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