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Gupta S, Aggarwal S, Munde M. New Insights into the Role of Ligand-Binding Modes in GC-DNA Condensation through Thermodynamic and Spectroscopic Studies. ACS OMEGA 2023; 8:4554-4565. [PMID: 36777612 PMCID: PMC9909821 DOI: 10.1021/acsomega.2c01557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 09/20/2022] [Indexed: 06/18/2023]
Abstract
In biological systems, the unprompted assembly of DNA molecules by cationic ligands into condensed structures is ubiquitous. The ability of ligands to provoke DNA packaging is crucial to the molecular organization and functional control of DNA, yet their underlined physical roles have remained elusive. Here, we have examined the DNA condensation mechanism of four cationic ligands, including their primary DNA-binding modes through extensive biophysical studies. We observed contrasting changes for these ligands binding to poly[dGdC]:poly[dGdC] (GC-DNA) and poly[dAdT]:poly[dAdT] (AT-DNA). Based on a CD spectroscopic study, it was confirmed that only GC-DNA undergoes B- to Ψ-type DNA transformation in the presence of ligands. In the fluorescence displacement assay (FDA), the ability of ligands to displace GC-DNA-bound EtBr follows the order: protamine21+ > cohex3+ > Ni2+ > spermine4+, which indicates that there is no direct correlation between the ligand charge and its ability to displace the drug from the DNA, indicating that GC-DNA condensation is not just influenced by electrostatic interaction but ligand-specific interactions may also have played a crucial role. Furthermore, the detailed ITC-binding studies suggested that DNA-ligand interactions are generally driven by unfavorable enthalpy and favorable entropy. The correlations from various studies insinuate that cationic ligands show major groove binding as one of the preferred binding modes during GC-DNA condensation.
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Affiliation(s)
- Sakshi Gupta
- School
of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
- Department
of Applied Science, The NorthCap University, Sector 23-A, Gurgaon, Haryana 122017, India
| | - Soumya Aggarwal
- School
of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Manoj Munde
- School
of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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2
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Qiu C, Wu Y, Guo Q, Shi Q, Zhang J, Meng Y, Xia F, Wang J. Preparation and application of calcium phosphate nanocarriers in drug delivery. Mater Today Bio 2022; 17:100501. [DOI: 10.1016/j.mtbio.2022.100501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/05/2022] [Accepted: 11/20/2022] [Indexed: 11/24/2022] Open
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3
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Zhang M, Liu Q, Zhang M, Cao C, Liu X, Zhang M, Li G, Xu C, Zhang X. Enhanced antitumor effects of follicle-stimulating hormone receptor-mediated hexokinase-2 depletion on ovarian cancer mediated by a shift in glucose metabolism. J Nanobiotechnology 2020; 18:161. [PMID: 33160373 PMCID: PMC7648390 DOI: 10.1186/s12951-020-00720-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/24/2020] [Indexed: 01/10/2023] Open
Abstract
Background Most cancers favor glycolytic-based glucose metabolism. Hexokinase-2 (HK2), the first glycolytic rate-limiting enzyme, shows limited expression in normal adult tissues but is overexpressed in many tumor tissues, including ovarian cancer. HK2 has been shown to be correlated with the progression and chemoresistance of ovarian cancer and could be a therapeutic target. However, the systemic toxicity of HK2 inhibitors has limited their clinical use. Since follicle-stimulating hormone (FSH) receptor (FSHR) is overexpressed in ovarian cancer but not in nonovarian healthy tissues, we designed FSHR-mediated nanocarriers for HK2 shRNA delivery to increase tumor specificity and decrease toxicity. Results HK2 shRNA was encapsulated in a polyethylene glycol-polyethylenimine copolymer modified with the FSH β 33–53 or retro-inverso FSH β 33–53 peptide. The nanoparticle complex with FSH peptides modification effectively depleted HK2 expression and facilitated a shift towards oxidative glucose metabolism, with evidence of increased oxygen consumption rates, decreased extracellular acidification rates, and decreased extracellular lactate and glucose consumption in A2780 ovarian cancer cells and cisplatin-resistant A2780CP counterpart cells. Consequently, cell proliferation, invasion and migration were significantly inhibited, and tumor growth was suppressed even in cisplatin-resistant ovarian cancer. No obvious systemic toxicity was observed in mice. Moreover, the nanoparticle complex modified with retro-inverso FSH peptides exhibited the strongest antitumor effects and effectively improved cisplatin sensitivity by regulating cisplatin transport proteins and increasing apoptosis through the mitochondrial pathway. Conclusions These results established HK2 as an effective therapeutic target even for cisplatin-resistant ovarian cancer and suggested a promising targeted therapeutic approach. ![]()
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Affiliation(s)
- Meng Zhang
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China
| | - Qiyu Liu
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China
| | - Mingxing Zhang
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China
| | - Cong Cao
- School of Materials Science & Engineering, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Xiaoxia Liu
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China
| | - Mengyu Zhang
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China
| | - Guiling Li
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China
| | - Congjian Xu
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China. .,Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Shanghai, 200011, China.
| | - Xiaoyan Zhang
- Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China.
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Tuning with Phosphorylcholine Grafts Improves the Physicochemical Properties of PLL/pDNA Nanoparticles at Neutral pH. Macromol Res 2019. [DOI: 10.1007/s13233-020-8019-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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5
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Gupta S, Tiwari N, Munde M. A Comprehensive Biophysical Analysis of the Effect of DNA Binding Drugs on Protamine-induced DNA Condensation. Sci Rep 2019; 9:5891. [PMID: 30971720 PMCID: PMC6458161 DOI: 10.1038/s41598-019-41975-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 03/13/2019] [Indexed: 11/21/2022] Open
Abstract
DNA condensation is a ubiquitous phenomenon in biology, yet the physical basis for it has remained elusive. Here, we have explored the mechanism of DNA condensation through the protamine-DNA interaction, and by examining on it the influence of DNA binding drugs. We observed that the DNA condensation is accompanied by B to Ψ-DNA transition as a result of DNA base pair distortions due to protamine binding, bringing about the formation of toroidal structure through coil-globule transition. The binding energetics suggested that electrostatic energy, bending energy and hydration energy must play crucial roles in DNA condensation. EtBr intercalation interferes with the protamine-DNA interaction, challenging the distortion of the DNA helix and separation of DNA base pairs by protamine. Thus, EtBr, by competing directly with protamine, resists the phenomenon of DNA condensation. On the contrary, netropsin impedes the DNA condensation by an allosteric mechanism, by resisting the probable DNA major groove bending by protamine. In summary, we demonstrate that drugs with distinct binding modes use different mechanism to interfere with DNA condensation.
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Affiliation(s)
- Sakshi Gupta
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Neha Tiwari
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Manoj Munde
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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6
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Liu C, Kou Y, Zhang X, Dong W, Cheng H, Mao S. Enhanced oral insulin delivery via surface hydrophilic modification of chitosan copolymer based self-assembly polyelectrolyte nanocomplex. Int J Pharm 2019; 554:36-47. [DOI: 10.1016/j.ijpharm.2018.10.068] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/16/2018] [Accepted: 10/29/2018] [Indexed: 12/12/2022]
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7
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Urnauer S, Klutz K, Grünwald GK, Morys S, Schwenk N, Zach C, Gildehaus FJ, Rödl W, Ogris M, Wagner E, Spitzweg C. Systemic tumor-targeted sodium iodide symporter (NIS) gene therapy of hepatocellular carcinoma mediated by B6 peptide polyplexes. J Gene Med 2018; 19. [PMID: 28423213 DOI: 10.1002/jgm.2957] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 04/03/2017] [Accepted: 04/16/2017] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Nonviral polymer-based gene transfer represents an adaptable system for tumor-targeted gene therapy because various design strategies of shuttle systems, together with the mechanistic concept of active tumor targeting, lead to improved gene delivery vectors resulting in higher tumor specificity, efficacy and safety. METHODS Using the sodium iodide symporter (NIS) as a theranostic gene, nonviral gene delivery vehicles based on linear polyethylenimine (LPEI), polyethylene glycol (PEG) and coupled to the synthetic peptide B6 (LPEI-PEG-B6), which specifically binds to tumor cells, were investigated in a hepatocellular carcinoma xenograft model for tumor selectivity and transduction efficiency. RESULTS In vitro incubation of three different tumor cell lines with LPEI-PEG-B6/NIS resulted in significant increase in iodide uptake activity compared to untargeted and empty vectors. After establishment of subcutaneous HuH7 tumors, NIS-conjugated nanoparticles were injected intravenously followed by analysis of radioiodide biodistribution using 123 I-scintigraphy showing significant perchlorate-sensitive iodide accumulation in tumors of LPEI-PEG-B6/NIS-treated mice (8.0 ± 1.5% ID/g 123 I; biological half-life of 4 h). After four cycles of repetitive polyplex/131 I applications, a significant delay of tumor growth was observed, which was associated with markedly improved survival in the therapy group. CONCLUSIONS These results clearly demonstrate that systemic in vivo NIS gene transfer using nanoparticle vectors coupled to B6 tumor targeting ligand is capable of inducing tumor-specific radioiodide uptake. This promising gene therapy approach opens the exciting prospect of NIS-mediated radionuclide therapy in metastatic cancer, together with the possibility of combining several targeting ligands to enhance selective therapeutic efficacy in a broad field of cancer types with various receptor expression profiles.
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Affiliation(s)
- Sarah Urnauer
- Department of Internal Medicine IV, University Hospital of Munich, LMU Munich, Germany
| | - Kathrin Klutz
- Department of Internal Medicine IV, University Hospital of Munich, LMU Munich, Germany
| | - Geoffrey K Grünwald
- Department of Internal Medicine IV, University Hospital of Munich, LMU Munich, Germany
| | - Stephan Morys
- Department of Pharmacy, Center of Drug Research, Pharmaceutical Biotechnology and Center for Nanoscience (CeNS), LMU Munich, Germany
| | - Nathalie Schwenk
- Department of Internal Medicine IV, University Hospital of Munich, LMU Munich, Germany
| | - Christian Zach
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Germany
| | | | - Wolfgang Rödl
- Department of Pharmacy, Center of Drug Research, Pharmaceutical Biotechnology and Center for Nanoscience (CeNS), LMU Munich, Germany
| | - Manfred Ogris
- Department of Pharmacy, Center of Drug Research, Pharmaceutical Biotechnology and Center for Nanoscience (CeNS), LMU Munich, Germany.,Division of Clinical Pharmacy and Diagnostics, University of Vienna, Austria
| | - Ernst Wagner
- Department of Pharmacy, Center of Drug Research, Pharmaceutical Biotechnology and Center for Nanoscience (CeNS), LMU Munich, Germany
| | - Christine Spitzweg
- Department of Internal Medicine IV, University Hospital of Munich, LMU Munich, Germany
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8
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Hong SS, Zhang MX, Zhang M, Yu Y, Chen J, Zhang XY, Xu CJ. Follicle-stimulating hormone peptide-conjugated nanoparticles for targeted shRNA delivery lead to effective gro-α silencing and antitumor activity against ovarian cancer. Drug Deliv 2018; 25:576-584. [PMID: 29461120 PMCID: PMC6058603 DOI: 10.1080/10717544.2018.1440667] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The distinct hormone molecules and receptors, such as follicle-stimulating hormone receptor (FSHR) in ovarian cancer, provide opportunities for more precisely targeted therapy. We previously developed FSHR-mediated nanoparticles and found that FSH peptides on the surface of nanoparticles improved the delivery of short interfering RNA (siRNA) into ovarian cancer cells. However, the high toxicity of the nanoparticles and the transient silencing of the siRNA in vivo limited further study. Here, we developed FSH peptide-conjugated nanoparticles with an increased amount of polyethylene glycol (PEG) grafting and encapsulated short hairpin RNA (shRNA) to silence the target gene, growth-regulated oncogene α (gro-α). The nanoparticle complexes exhibited good stability over three weeks. Expression of the target gene, gro-α, was significantly down-regulated by gro-α shRNA-loaded nanoparticles conjugated with FSH peptides (FSH33-G-NP) in FSHR-positive HEY cells. Cell proliferation, migration, and invasion were also inhibited by FSH33-G-NP. Tumor growth was delayed significantly in the mice treated with FSH33-G-NP. No significant loss of body weight or severe toxic effects were observed in any groups. In conclusion, gro-α shRNA-loaded nanoparticles conjugated with FSH peptides overcame the drawbacks of the in vivo application of RNAi therapeutics and polymer-based nanocarriers and showed safe antitumor efficacy. Our study might contribute to the application of FSHR-based targeted therapy and imaging in cancer.
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Affiliation(s)
- Shan-Shan Hong
- a Obstetrics and Gynecology Hospital , Fudan University , Shanghai , China
| | - Ming-Xing Zhang
- a Obstetrics and Gynecology Hospital , Fudan University , Shanghai , China
| | - Meng Zhang
- a Obstetrics and Gynecology Hospital , Fudan University , Shanghai , China
| | - Yi Yu
- a Obstetrics and Gynecology Hospital , Fudan University , Shanghai , China
| | - Jun Chen
- b Departments of Pharmaceutics, School of Pharmacy , Fudan University , Shanghai , China
| | - Xiao-Yan Zhang
- a Obstetrics and Gynecology Hospital , Fudan University , Shanghai , China.,c Department of Obstetrics and Gynecology of Shanghai Medical School , Fudan University , Shanghai , China.,d Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases , Shanghai , China
| | - Cong-Jian Xu
- a Obstetrics and Gynecology Hospital , Fudan University , Shanghai , China.,c Department of Obstetrics and Gynecology of Shanghai Medical School , Fudan University , Shanghai , China.,d Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases , Shanghai , China
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9
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Influence of Defined Hydrophilic Blocks within Oligoaminoamide Copolymers: Compaction versus Shielding of pDNA Nanoparticles. Polymers (Basel) 2017; 9:polym9040142. [PMID: 30970822 PMCID: PMC6432433 DOI: 10.3390/polym9040142] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/07/2017] [Accepted: 04/11/2017] [Indexed: 01/07/2023] Open
Abstract
Cationic polymers are promising components of the versatile platform of non-viral nucleic acid (NA) delivery agents. For a successful gene delivery system, these NA vehicles need to comprise several functionalities. This work focuses on the modification of oligoaminoamide carriers with hydrophilic oligomer blocks mediating nanoparticle shielding potential, which is necessary to prevent aggregation or dissociation of NA polyplexes in vitro, and hinder opsonization with blood components in vivo. Herein, the shielding agent polyethylene glycol (PEG) in three defined lengths (12, 24, or 48 oxyethylene repeats) is compared with two peptidic shielding blocks composed of four or eight repeats of sequential proline-alanine-serine (PAS). With both types of shielding agents, we found opposing effects of the length of hydrophilic segments on shielding and compaction of formed plasmid DNA (pDNA) nanoparticles. Two-arm oligoaminoamides with 37 cationizable nitrogens linked to 12 oxyethylene units or four PAS repeats resulted in very compact 40⁻50 nm pDNA nanoparticles, whereas longer shielding molecules destabilize the investigated polyplexes. Thus, the balance between sufficiently shielded but still compact and stable particles can be considered a critical optimization parameter for non-viral nucleic acid vehicles based on hydrophilic-cationic block oligomers.
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10
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Bellettini IC, Fayad SJ, Machado VG, Minatti E. Properties of polyplexes formed through interaction between hydrophobically-modified poly(ethylene imine)s and calf thymus DNA in aqueous solution. SOFT MATTER 2017; 13:2609-2619. [PMID: 28327732 DOI: 10.1039/c6sm02835g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Polycationic polymers and DNA form soluble complexes in aqueous solution, which allows the transfer of genetic material into cells. Therefore, these chemically-modified polymers are of interest for use in studies aimed at better transfection efficiency and gene expression along with reduced cytotoxicity. In this study, branched poly(ethylene imine) (PEI) was modified by alkylation with n-alkyl groups (n = 4, 6, 8 and 12 carbons). The polyplexes formed through interaction of the modified PEIs and calf thymus DNA (ctDNA) were investigated using UV-Vis spectrophotometry, ethidium bromide fluorescence emission, circular dichroism spectroscopy, dynamic light scattering, and small-angle X-ray scattering techniques along with the determination of the zeta potential and viscosity. According to the results obtained, the formation of ctDNA-PEI polyplexes occurs in three steps. Firstly, when a small amount of polyelectrolyte is present the ctDNA chains are partially compacted. Subsequently, with the addition of more polyelectrolyte, the complexes have a null charge density and micrometric size. Lastly, with a higher concentration of PEI, the ctDNA is fully compacted by the PEI chains, leading to positively charged complexes with Rh values in the range of 52.0-86.0 nm. The viscosity and SAXS analysis suggested that the unmodified PEI exhibits the strongest interaction and promotes the best ctDNA condensation.
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Affiliation(s)
- I C Bellettini
- Departamento de Química, Universidade Federal de Santa Catarina, UFSC, Florianópolis, SC 88040-900, Brazil.
| | - S J Fayad
- Departamento de Química, Universidade Federal de Santa Catarina, UFSC, Florianópolis, SC 88040-900, Brazil.
| | - V G Machado
- Departamento de Química, Universidade Federal de Santa Catarina, UFSC, Florianópolis, SC 88040-900, Brazil.
| | - E Minatti
- Departamento de Química, Universidade Federal de Santa Catarina, UFSC, Florianópolis, SC 88040-900, Brazil.
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11
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Lounis FM, Chamieh J, Leclercq L, Gonzalez P, Cottet H. The Effect of Molar Mass and Charge Density on the Formation of Complexes between Oppositely Charged Polyelectrolytes. Polymers (Basel) 2017; 9:polym9020050. [PMID: 30970728 PMCID: PMC6432040 DOI: 10.3390/polym9020050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 01/11/2017] [Accepted: 01/19/2017] [Indexed: 12/17/2022] Open
Abstract
The interactions between model polyanions and polycations have been studied using frontal continuous capillary electrophoresis (FACCE) which allows the determination of binding stoichiometry and binding constant of the formed polyelectrolyte complex (PEC). In this work, the effect of the poly(l-lysine) (PLL) molar mass on the interaction with statistical copolymers of acrylamide and 2-acrylamido-2-methyl-1-propanesulfonate (PAMAMPS) has been systematically investigated for different PAMAMPS chemical charge densities (15% and 100%) and different ionic strengths. The study of the ionic strength dependence of the binding constant allowed the determination of the total number of released counter-ions during the formation of the PEC, which can be compared to the total number of counter-ions initially condensed on the individual polyelectrolyte partners before the association. Interestingly, this fraction of released counter-ions, which was strongly dependent on the PLL molar mass, was almost independent of the PAMAMPS charge density. These findings are useful to predict the binding constant according to the molar mass and charge density of the polyelectrolyte partners.
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Affiliation(s)
- Feriel Meriem Lounis
- Institut des Biomolécules Max Mousseron, IBMM, UMR 5247 CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, Place Eugène Bataillon, CC 1706, 34095 Montpellier CEDEX 5, France.
| | - Joseph Chamieh
- Institut des Biomolécules Max Mousseron, IBMM, UMR 5247 CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, Place Eugène Bataillon, CC 1706, 34095 Montpellier CEDEX 5, France.
| | - Laurent Leclercq
- Institut des Biomolécules Max Mousseron, IBMM, UMR 5247 CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, Place Eugène Bataillon, CC 1706, 34095 Montpellier CEDEX 5, France.
| | - Philippe Gonzalez
- Institut des Biomolécules Max Mousseron, IBMM, UMR 5247 CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, Place Eugène Bataillon, CC 1706, 34095 Montpellier CEDEX 5, France.
| | - Hervé Cottet
- Institut des Biomolécules Max Mousseron, IBMM, UMR 5247 CNRS, Université de Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, Place Eugène Bataillon, CC 1706, 34095 Montpellier CEDEX 5, France.
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12
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Utsuno K, Kono H, Tanaka E, Jouna N, Kojima Y, Uludağ H. Low Molecular Weight Branched PEI Binding to Linear DNA. Chem Pharm Bull (Tokyo) 2017; 64:1484-1491. [PMID: 27725501 DOI: 10.1248/cpb.c16-00454] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Polyethylenimine (PEI) is one of the most versatile non-viral vectors used in gene therapy, especially for delivering plasmid DNA to human cells. However, a good understanding of PEI binding to DNA, the fundamental basis for the functioning of PEI as a vector, has been missing in the literature. In this study, PEI (branched, 600 Da) binding to DNA was examined by isothermal titration calorimetry (ITC), quartz crystal microbalance (QCM) and a complementary set of analysis tools. We demonstrated that a separation between the binding heat and the condensation heat is needed and that the excluded site model should be used for PEI binding stage in the ITC analysis. The equilibrium constant for PEI binding to DNA was determined to be 2.5×105 M-1 from the ITC analysis, and as 2.3×105 M-1 from the QCM analysis. Additionally, we suggested that the 600 Da branched PEI binds to the major groove of DNA and the rearrangement of PEI on DNA may be difficult to occur because of the small dissociation rate. The binding analysis presented here can be employed to improve our understanding of the functioning of PEI and PEI-like non-viral vectors.
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Affiliation(s)
- Kuniharu Utsuno
- Department of Science & Engineering for Materials, National Institute of Technology, Tomakomai College
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