1
|
Malfanti A, Sami H, Balasso A, Marostica G, Arpac B, Mastrotto F, Mantovani G, Cola E, Anton M, Caliceti P, Ogris M, Salmaso S. Control of cell penetration enhancer shielding and endosomal escape-kinetics crucial for efficient and biocompatible siRNA delivery. J Control Release 2023; 363:101-113. [PMID: 37722420 DOI: 10.1016/j.jconrel.2023.09.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 07/21/2023] [Accepted: 09/14/2023] [Indexed: 09/20/2023]
Abstract
Although cationic liposomes are efficient carriers for nucleic acid delivery, their toxicity often hampers the clinical translation. Polyethylene glycol (PEG) coating has been largely used to improve their stability and reduce toxicity. Nevertheless, it has been found to decrease the transfection process. In order to exploit the advantages of cationic liposomes and PEG decoration for nucleic acid delivery, liposomes decorated with tetraArg-[G-1]-distearoyl glycerol (Arg4-DAG) dendronic oligo-cationic lipid enhancer (OCE) and PEG-lipid have been investigated. Non decorated or OCE-decorated lipoplexes (OCEfree-LPX and OCE-LPX, respectively) were obtained by lipid film hydration using oligonucleotide (ON) solutions. PEG and OCE/PEG decorated lipoplexes (PEG-OCEfree-LPX and PEG-OCE-LPX, respectively) were obtained by post-insertion of 2 or 5 kDa PEG-DSPE on preformed lipoplexes. The OCE decoration yielded lipoplexes with size of about 240 nm, 84% loading efficiency at 10 N/P ratio, ten times higher than OCEfree-LPX, and prevented the ON release when incubated with physiological heparin concentration or with plasma. The PEG decoration reduced the zeta potential, enhanced the lipoplex stability in serum and decreased both hemolysis and cytotoxicity, while it did not affect the lipoplex size and ON loading. With respect to OCEfree-LPX, the OCE-LPX remarkably associated with cells and were taken up by different cancer cell lines (HeLa and MDA-MB-231). Interestingly, 2 or 5 kDa PEG decoration did not reduce either the cell interaction or the cell up-take of the cationic lipoplexes. With siRNA as a payload, OCE enabled efficient internalization, but endosomal release was hampered. Post-transfection treatment with the lysosomotropic drug chloroquine allowed to identify the optimal time point for endosomal escape. Chloroquine treatment after 12 to 20 h of LPX pre-incubation enabled siRNA mediated target knockdown indicating that this is the time window of endo-lysosomal processing. This indicates that OCE can protect siRNA from lysosomal degradation for up to 20 h, as shown by these rescue experiments.
Collapse
Affiliation(s)
- Alessio Malfanti
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo 5, Padova 35131, Italy
| | - Haider Sami
- University of Vienna, Faculty of Life Sciences, Department of Pharmaceutical Sciences, Laboratory of Macromolecular Cancer Therapeutics (MMCT), Josef-Holaubek-Platz 2, Vienna 1090, Austria
| | - Anna Balasso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo 5, Padova 35131, Italy
| | - Giulia Marostica
- University of Vienna, Faculty of Life Sciences, Department of Pharmaceutical Sciences, Laboratory of Macromolecular Cancer Therapeutics (MMCT), Josef-Holaubek-Platz 2, Vienna 1090, Austria
| | - Busra Arpac
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo 5, Padova 35131, Italy
| | - Francesca Mastrotto
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo 5, Padova 35131, Italy
| | | | - Elisa Cola
- University of Vienna, Faculty of Life Sciences, Department of Pharmaceutical Sciences, Laboratory of Macromolecular Cancer Therapeutics (MMCT), Josef-Holaubek-Platz 2, Vienna 1090, Austria
| | - Martina Anton
- Institute of Molecular Immunology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Paolo Caliceti
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo 5, Padova 35131, Italy
| | - Manfred Ogris
- University of Vienna, Faculty of Life Sciences, Department of Pharmaceutical Sciences, Laboratory of Macromolecular Cancer Therapeutics (MMCT), Josef-Holaubek-Platz 2, Vienna 1090, Austria.
| | - Stefano Salmaso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Via F. Marzolo 5, Padova 35131, Italy.
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Bonarek P, Polit A. Systematic calorimetric studies of proton exchange associated with binding of beta-lactoglobulin with ligand. Int J Biol Macromol 2018; 120:128-134. [DOI: 10.1016/j.ijbiomac.2018.08.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 08/03/2018] [Accepted: 08/04/2018] [Indexed: 01/05/2023]
|
4
|
Suga K, Akizaki K, Umakoshi H. Quantitative Monitoring of Microphase Separation Behaviors in Cationic Liposomes Using HHC, DPH, and Laurdan: Estimation of the Local Electrostatic Potentials in Microdomains. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:3630-3636. [PMID: 27022833 DOI: 10.1021/acs.langmuir.5b04682] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Microphase separation behaviors of cationic liposomes have been investigated using a pH-sensitive fluorescent probe with 4-heptadecyl-7-hydroxycoumarin (HHC), 1,6-diphenyl-1,3,5-hexatriene, and 6-lauroyl-2-dimethylaminonaphthalene, and to estimate localized electrostatic potentials. Shifts of the apparent pKa values of HHC were observed in cationic liposomes in proportion to the amount of cationic lipids. Two pKa values were obtained with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/3β-[N(N',N'-dimethylaminoethane)-carbamoyl] cholesterol hydrochloride (DC-Ch) liposomes, while only one pKa value was generated with either DOPC/1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) or DOPC/dimethyldioctadecylammonium-bromide (DODAB) liposomes. The physicochemical membrane property analyses, focusing on membrane fluidity and membrane polarity, revealed heterogeneity among DOPC/DC-Ch liposomes. By analyzing the pH titration curves using sigmoidal fitting, the localized electrostatic potentials were estimated. For DOPC/DOTAP = (7/3), the membrane was in the liquid-disordered phase and the density of cationic molecules was 0.41 cation/nm(2). For DOPC/DC-Ch = (7/3), the membrane was heterogeneous and the densities of cationic molecules in liquid-disordered and liquid-ordered phases were 0.25 and 1.24 cation/nm(2), respectively. We thereby conclude that the DC-Ch molecules can form nanodomains when these molecules are concentrated to 59%.
Collapse
Affiliation(s)
- Keishi Suga
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , 1-3 Machikaneyamacho, Toyonaka, Osaka 560-8531, Japan
| | - Kei Akizaki
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , 1-3 Machikaneyamacho, Toyonaka, Osaka 560-8531, Japan
| | - Hiroshi Umakoshi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , 1-3 Machikaneyamacho, Toyonaka, Osaka 560-8531, Japan
| |
Collapse
|
5
|
Nascimento TL, Hillaireau H, Noiray M, Bourgaux C, Arpicco S, Pehau-Arnaudet G, Taverna M, Cosco D, Tsapis N, Fattal E. Supramolecular Organization and siRNA Binding of Hyaluronic Acid-Coated Lipoplexes for Targeted Delivery to the CD44 Receptor. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:11186-11194. [PMID: 26375384 DOI: 10.1021/acs.langmuir.5b01979] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The dynamics of the formation of siRNA-lipoplexes coated with hyaluronic acid (HA) and the parameters influencing their supramolecular organization were studied. The insertion of a HA-dioleylphosphatidylethanolamine (DOPE) conjugate in the liposome structure as well as subsequent complexation with siRNA increased the liposome size. Lipoplexes were around 110 nm at high ± charge ratios with a zeta potential around +50 mV and around 230 nm at low ± ratios, with a zeta potential that decreased to negative values, reaching -45 mV. The addition of the conjugate did not compromise siRNA binding to liposomes, although these nucleic acids induced a displacement of part of the HA-DOPE conjugate upon lipoplex formation, as confirmed by capillary electrophoresis. Isothermal titration calorimetry, X-ray diffraction studies, and cryo-TEM microscopy demonstrated that in addition to electrostatic interactions with siRNA a rearrangement of the lipid bilayers takes place, resulting in condensed oligolamellar vesicles. This phenomenon is dependent on the number of siRNA molecules and the degree of modification with HA. Finally, the suitable positioning of HA on the lipoplex surface and its ability to bind specifically to the CD44 receptors in a concentration-dependent manner was demonstrated by surface plasmon resonance analysis.
Collapse
Affiliation(s)
- Thais L Nascimento
- Faculté de Pharmacie, Institut Galien Paris-Sud. Université Paris-Sud , LabEx LERMIT, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
- CNRS, UMR 8612, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
- CAPES Foundation, Ministry of Education of Brazil, Brasília DF 70040-020, Brazil
| | - Hervé Hillaireau
- Faculté de Pharmacie, Institut Galien Paris-Sud. Université Paris-Sud , LabEx LERMIT, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
- CNRS, UMR 8612, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
| | - Magali Noiray
- Faculté de Pharmacie, Institut Galien Paris-Sud. Université Paris-Sud , LabEx LERMIT, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
- CNRS, UMR 8612, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
| | - Claudie Bourgaux
- Faculté de Pharmacie, Institut Galien Paris-Sud. Université Paris-Sud , LabEx LERMIT, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
- CNRS, UMR 8612, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
| | - Silvia Arpicco
- Dipartemento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Facoltà di Farmacia , Via Pietro Giuria 9, 10125 Torino, Italy
| | - Gérard Pehau-Arnaudet
- Institut Pasteur, Plate-Forme de Microscopie Ultrastructurale, 25-28 rue du Docteur Roux, 75015 Paris, France
| | - Myriam Taverna
- Faculté de Pharmacie, Institut Galien Paris-Sud. Université Paris-Sud , LabEx LERMIT, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
- CNRS, UMR 8612, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
| | - Donato Cosco
- Department of Health Sciences, University "Magna Græcia" of Catanzaro, Campus Universitario "S. Venuta" , Viale S. Venuta, Germaneto, I-88100 Catanzaro, Italy
| | - Nicolas Tsapis
- Faculté de Pharmacie, Institut Galien Paris-Sud. Université Paris-Sud , LabEx LERMIT, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
- CNRS, UMR 8612, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
| | - Elias Fattal
- Faculté de Pharmacie, Institut Galien Paris-Sud. Université Paris-Sud , LabEx LERMIT, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
- CNRS, UMR 8612, 5 rue JB Clément, 92296 Châtenay-Malabry Cedex, France
| |
Collapse
|
6
|
Ohno M, Toyota T, Nomoto T, Fujinami M. Changes in Interfacial Tension of a Lipid Membrane Formed at the Water/Chloroform Interface upon DNA Complex Formation. ANAL SCI 2015; 31:979-86. [PMID: 26460361 DOI: 10.2116/analsci.31.979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Changes in the interfacial tension of a lipid monolayer membrane formed at the water/chloroform interface upon DNA addition were measured using the quasi-elastic laser scattering (QELS) method. A cationic lipid, N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTAP), as well as zwitterionic lipids, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), were used to form lipid monolayer membranes at different calcium ion concentrations. A rapid decrease of the interfacial tension resulting from electrostatic interactions between DOTAP and DNA was observed within 10 s. However, such rapid decreases were not observed for DOPE or DOPC. A decrease in the interfacial tension was exhibited by DOPE after 1000 s from the addition of DNA, which may be due to an overall structural change in the DOPE membrane. A DOTAP/DOPE complex system showed behaviors attributable to both DOTAP and DOPE, whereas the behavior of the DOTAP/DOPC system resembled that of DOPC alone. The current results provide a model for the so-called lipoplex carriers used in gene therapy.
Collapse
Affiliation(s)
- Masashi Ohno
- Department of Applied Chemistry and Biotechnology, Chiba University
| | | | | | | |
Collapse
|
7
|
Baoum AA, Middaugh CR, Berkland C. DNA complexed with TAT peptide and condensed using calcium possesses unique structural features compared to PEI polyplexes. Int J Pharm 2014; 465:11-7. [DOI: 10.1016/j.ijpharm.2014.01.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 12/17/2013] [Accepted: 01/29/2014] [Indexed: 11/29/2022]
|
8
|
Physicochemical characterization techniques for lipid based delivery systems for siRNA. Int J Pharm 2012; 427:35-57. [DOI: 10.1016/j.ijpharm.2011.09.032] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Revised: 09/20/2011] [Accepted: 09/21/2011] [Indexed: 01/24/2023]
|
9
|
Raudino A, Sarpietro MG, Pannuzzo M. The thermodynamics of simple biomembrane mimetic systems. JOURNAL OF PHARMACY AND BIOALLIED SCIENCES 2011; 3:15-38. [PMID: 21430953 PMCID: PMC3053513 DOI: 10.4103/0975-7406.76462] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 10/09/2010] [Accepted: 12/15/2010] [Indexed: 11/04/2022] Open
Abstract
Insight into the forces governing a system is essential for understanding its behavior and function. Thermodynamic investigations provide a wealth of information that is not, or is hardly, available from other methods. This article reviews thermodynamic approaches and assays to measure collective properties such as heat adsorption / emission and volume variations. These methods can be successfully applied to the study of lipid vesicles (liposomes) and biological membranes. With respect to instrumentation, differential scanning calorimetry, pressure perturbation calorimetry, isothermal titration calorimetry, dilatometry, and acoustic techniques aimed at measuring the isothermal and adiabatic processes, two- and three-dimensional compressibilities are considered. Applications of these techniques to lipid systems include the measurement of different thermodynamic parameters and a detailed characterization of thermotropic, barotropic, and lyotropic phase behavior. The membrane binding and / or partitioning of solutes (proteins, peptides, drugs, surfactants, ions, etc.) can also be quantified and modeled. Many thermodynamic assays are available for studying the effect of proteins and other additives on membranes, characterizing non-ideal mixing, domain formation, bilayer stability, curvature strain, permeability, solubilization, and fusion. Studies of membrane proteins in lipid environments elucidate lipid-protein interactions in membranes. Finally, a plethora of relaxation phenomena toward equilibrium thermodynamic structures can be also investigated. The systems are described in terms of enthalpic and entropic forces, equilibrium constants, heat capacities, partial volume changes, volume and area compressibility, and so on, also shedding light on the stability of the structures and the molecular origin and mechanism of the structural changes.
Collapse
Affiliation(s)
- Antonio Raudino
- University of Catania, Department of Chemistry, Viale A. Doria 6-95125, Catania, Italy
| | | | - Martina Pannuzzo
- University of Catania, Department of Chemistry, Viale A. Doria 6-95125, Catania, Italy
| |
Collapse
|
10
|
Tros de Ilarduya C, Sun Y, Düzgüneş N. Gene delivery by lipoplexes and polyplexes. Eur J Pharm Sci 2010; 40:159-70. [DOI: 10.1016/j.ejps.2010.03.019] [Citation(s) in RCA: 468] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 03/17/2010] [Accepted: 03/23/2010] [Indexed: 11/28/2022]
|
11
|
Ma PL, Lavertu M, Winnik FM, Buschmann MD. New Insights into Chitosan−DNA Interactions Using Isothermal Titration Microcalorimetry. Biomacromolecules 2009; 10:1490-9. [DOI: 10.1021/bm900097s] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Pei Lian Ma
- Department of Chemical and Biomedical Engineering, Ecole Polytechnique de Montréal, P.O. 6079 Succ. Centre-Ville, Montreal, Quebec, H3C 3A7, Canada, and Department of Chemistry and Faculty of Pharmacy, Université de Montréal, P.O. 6128 Succ. Centre-Ville, Montreal, Quebec, H3C 3J7, Canada
| | - Marc Lavertu
- Department of Chemical and Biomedical Engineering, Ecole Polytechnique de Montréal, P.O. 6079 Succ. Centre-Ville, Montreal, Quebec, H3C 3A7, Canada, and Department of Chemistry and Faculty of Pharmacy, Université de Montréal, P.O. 6128 Succ. Centre-Ville, Montreal, Quebec, H3C 3J7, Canada
| | - Françoise M. Winnik
- Department of Chemical and Biomedical Engineering, Ecole Polytechnique de Montréal, P.O. 6079 Succ. Centre-Ville, Montreal, Quebec, H3C 3A7, Canada, and Department of Chemistry and Faculty of Pharmacy, Université de Montréal, P.O. 6128 Succ. Centre-Ville, Montreal, Quebec, H3C 3J7, Canada
| | - Michael D. Buschmann
- Department of Chemical and Biomedical Engineering, Ecole Polytechnique de Montréal, P.O. 6079 Succ. Centre-Ville, Montreal, Quebec, H3C 3A7, Canada, and Department of Chemistry and Faculty of Pharmacy, Université de Montréal, P.O. 6128 Succ. Centre-Ville, Montreal, Quebec, H3C 3J7, Canada
| |
Collapse
|
12
|
Spectroscopic methods for the physical characterization and formulation of nonviral gene delivery systems. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2008; 434:55-80. [PMID: 18470639 DOI: 10.1007/978-1-60327-248-3_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
Abstract
Currently, with the exception of naked DNA formulations, most pharmaceutical preparations of plasmid DNA employ some type of polycationic delivery vector such as synthetic cationic polymers and lipids to enhance delivery. A number of biophysical techniques are readily available for the structural characterization of plasmid DNA within synthetic gene delivery complexes. Here we present applications of ultraviolet (UV) absorption, circular dichroism (CD), infrared (IR), and fluorescence spectroscopies as well as dynamic light scattering to the structural analysis of the oligonucleotide component of nonviral gene delivery vectors. We also illustrate this approach for the investigation of the formulation of lipoplex and polyplex-based gene delivery systems. To summarize such data, we show how the macromolecular complexes can be represented as vectors in a highly dimensional space in which the components of the vector consist of normalized values of experimental parameters measured as a function of different solution conditions such as pH and ionic strength.
Collapse
|
13
|
Ruponen M, Braun CS, Middaugh CR. Biophysical characterization of polymeric and liposomal gene delivery systems using empirical phase diagrams. J Pharm Sci 2006; 95:2101-14. [PMID: 16883552 DOI: 10.1002/jps.20621] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A major problem with the pharmaceutical use of nonviral gene delivery systems arises from their limited characterization due to their size and heterogeneity. In this study, we provide a more intuitive view of their structure and behavior employing an empirically based phase diagram approach. Complexes formed between plasmid DNA and four cationic carriers (a monovalent lipid, the same monovalent lipid combined with a helper lipid, polylysine, and a branched form of polyethyleneimine), at both positive and negative nitrogen/phosphorous ratios, are characterized employing dynamic light scattering, circular dichroism, and extrinsic dye fluorescence as methods sensitive to various aspects of the structure of the complexes. These measurements were performed as a function of pH and ionic strength to perturb the electrostatic contacts that are key to complex formation. Using a multidimensional eigenvalue approach, the data are presented in the form of a colored, five dimensional diagram. The resultant eight empirical phase diagrams display three to five variably resolved phases. In contrast, the phase diagram of the plasmid alone showed only two to three such phases. Each state is assigned to a particular form of the complex in terms of their size, extent of collapse and conformation of the associated DNA component. The utility of this approach is then briefly discussed.
Collapse
Affiliation(s)
- Marika Ruponen
- The Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, Kansas 66047, USA
| | | | | |
Collapse
|
14
|
Braun CS, Fisher MT, Tomalia DA, Koe GS, Koe JG, Middaugh CR. A stopped-flow kinetic study of the assembly of nonviral gene delivery complexes. Biophys J 2005; 88:4146-58. [PMID: 15805171 PMCID: PMC1305645 DOI: 10.1529/biophysj.104.055202] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Stopped-flow circular dichroism and fluorescence spectroscopy are used to characterize the assembly of complexes consisting of plasmid DNA bound to the cationic lipids dimethyldioctadecylammonium bromide and 1, 2-dioleoyl- 3-trimethylammonium-propane and a series of polyamidoamine dendrimers. The kinetics of complexation determined from the stopped-flow circular dichroism measurements suggests complexation occurs within 50 ms. Further analysis, however, was precluded by the presence of mixing (shear) artifacts. Stopped-flow fluorescence employing the high-affinity DNA dyes Hoechst 33258 and YOYO-1 was able to resolve two sequential steps in the assembly of complexes that are assigned to binding/dehydration and condensation events. The rates of each process were determined over the temperature range of 10-50 degrees C and activation energies were determined from the slope of Arrhenius plots. The behavior of polyamidoamine dendrimers can be separated into two classes based on their differing binding modes: generation 2 and the larger generations (G4, G7, and G9). The larger generations have activation energies for binding that follow the trend G4 > G7 > G9. The activation energies for condensation (compaction) of complexes composed of these same dendrimers have the opposite trend G9 > G7 > G4. It is postulated that a balance between a more energetically favorable condensation and less favorable binding may prove beneficial in enhancing gene delivery.
Collapse
Affiliation(s)
- Chad S Braun
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, 66047, USA
| | | | | | | | | | | |
Collapse
|
15
|
Braun CS, Vetro JA, Tomalia DA, Koe GS, Koe JG, Middaugh CR. Structure/Function Relationships of Polyamidoamine/DNA Dendrimers as Gene Delivery Vehicles. J Pharm Sci 2005; 94:423-36. [PMID: 15614818 DOI: 10.1002/jps.20251] [Citation(s) in RCA: 185] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PAMAM dendrimers are members of a class of polyamine polymers that demonstrate significant gene delivery ability. In this study, a selection of PAMAM dendrimers, spanning a range of sizes (generations 2, 4, 7, and 9) and transfection efficiencies, are characterized by various biophysical methods to search for structural properties that correlate with transfection. Measurements of colloidal properties (size and zeta potential) as a function of charge ratio reveal that highly transfecting dendrimer/DNA complexes have size/zeta potential values between 4 and 8. Circular dichroism (CD) and FTIR spectroscopy of complexes confirm the DNA component remains in B form when associated with all dendrimer generations up to a 5:1 charge ratio (+/-). Isothermal titration calorimetry and differential scanning calorimetry detect changes that are related to polymer structure and charge ratio but do not directly correlate with transfection efficiency. Despite DNA structural and stability changes detected by CD, FTIR, DSC, and ITC that are similar to those seen with other cationic delivery vehicles [e.g., cationic lipids, peptoids/lipitoids, peptides, polyethyleneimines (PEIs), etc.], clear correlations with transfection activity are not readily apparent. This may be due, at least in part, to the heterogeneity of the complexes.
Collapse
Affiliation(s)
- Chad S Braun
- Department of Pharmaceutical Chemistry, University of Kansas, 2095 Constant Ave., Lawrence, Kansas 66047, USA
| | | | | | | | | | | |
Collapse
|
16
|
Patel MM, Anchordoquy TJ. Contribution of hydrophobicity to thermodynamics of ligand-DNA binding and DNA collapse. Biophys J 2005; 88:2089-103. [PMID: 15653734 PMCID: PMC1305261 DOI: 10.1529/biophysj.104.052100] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The importance of understanding the dynamics of DNA condensation is inherent in the biological significance of DNA packaging in cell nuclei, as well as for gene therapy applications. Specifically, the role of ligand hydrophobicity in DNA condensation has received little attention. Considering that only multivalent cations can induce true DNA condensation, previous studies exploring monovalent lipids have been unable to address this question. In this study we have elucidated the contribution of the hydrophobic effect to multivalent cation- and cationic lipid-DNA binding and DNA collapse by studying the thermodynamics of cobalt hexammine-, spermine-, and lipospermine-plasmid DNA binding at different temperatures. Comparable molar heat capacity changes (DeltaC(p)) associated with cobalt hexammine- and spermine-DNA binding (-23.39 cal/mol K and -17.98 cal/mol K, respectively) suggest that upon binding to DNA, there are insignificant changes in the hydration state of the methylene groups in spermine. In contrast, the acyl chain contribution to the DeltaC(p) of lipospermine-DNA binding (DeltaC(p ) = DeltaC(p lipospermine) - DeltaC(p spermine)) is significant (-220.94 cal/mol K). Although lipopermine induces DNA ordering into "tubular" suprastructures, such structures do not assume toroidal dimensions as observed for spermine-DNA complexes. We postulate that a steric barrier posed by the acyl chains in lipospermine precludes packaging of DNA into dimensions comparable to those found in nature.
Collapse
Affiliation(s)
- Mayank M Patel
- Department of Pharmaceutical Sciences, C238 University of Colorado Health Sciences Center, 4200 E. Ninth Ave., Denver, CO 80262, USA.
| | | |
Collapse
|
17
|
Cliff MJ, Gutierrez A, Ladbury JE. A survey of the year 2003 literature on applications of isothermal titration calorimetry. J Mol Recognit 2004; 17:513-23. [PMID: 15384176 DOI: 10.1002/jmr.714] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Over the last decade isothermal titration calorimetry (ITC) has developed from a specialist method which was largely restricted in its use to dedicated experts, to a major, commercially available tool in the arsenal directed at understanding molecular interactions. The number of those proficient in this field has multiplied dramatically, as has the range of experiments to which this method has been applied. This has led to an overwhelming amount of new data and novel applications to be assessed. With the increasing number of publications in this field comes a need to highlight works of interest and impact. In this overview of the literature we have attempted to draw attention to papers and issues for which both the experienced calorimetrist and the interested dilettante hopefully will share our enthusiasm.
Collapse
Affiliation(s)
- Matthew J Cliff
- Department of Biochemistry and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | | | | |
Collapse
|
18
|
Protein–polysaccharide interactions: phase-ordering kinetics, thermodynamic and structural aspects. Curr Opin Colloid Interface Sci 2003. [DOI: 10.1016/s1359-0294(03)00093-1] [Citation(s) in RCA: 358] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|