1
|
Padmakumar S, D'Souza A, Parayath NN, Bleier BS, Amiji MM. Nucleic acid therapies for CNS diseases: Pathophysiology, targets, barriers, and delivery strategies. J Control Release 2022; 352:121-145. [PMID: 36252748 DOI: 10.1016/j.jconrel.2022.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 09/10/2022] [Accepted: 10/10/2022] [Indexed: 11/08/2022]
Abstract
Nucleic acid therapeutics have emerged as one of the very advanced and efficacious treatment approaches for debilitating health conditions, including those diseases affecting the central nervous system (CNS). Precise targeting with an optimal control over gene regulation confers long-lasting benefits through the administration of nucleic acid payloads via viral, non-viral, and engineered vectors. The current review majorly focuses on the development and clinical translational potential of non-viral vectors for treating CNS diseases with a focus on their specific design and targeting approaches. These carriers must be able to surmount the various intracellular and extracellular barriers, to ensure successful neuronal transfection and ultimately attain higher therapeutic efficacies. Additionally, the specific challenges associated with CNS administration also include the presence of blood-brain barrier (BBB), the complex pathophysiological and biochemical changes associated with different disease conditions and the existence of non-dividing cells. The advantages offered by lipid-based or polymeric systems, engineered proteins, particle-based systems coupled with various approaches of neuronal targeting have been discussed in the context of a variety of CNS diseases. The possibilities of rapid yet highly efficient gene modifications rendered by the breakthrough methodologies for gene editing and gene manipulation have also opened vast avenues of research in neuroscience and CNS disease therapy. The current review also underscores the extensive scientific efforts to optimize specialized, efficacious yet non-invasive and safer administration approaches to overcome the therapeutic delivery challenges specifically posed by the CNS transport barriers and the overall obstacles to clinical translation.
Collapse
Affiliation(s)
- Smrithi Padmakumar
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, MA 02115, USA
| | - Anisha D'Souza
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, MA 02115, USA; Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 20115, USA
| | - Neha N Parayath
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, MA 02115, USA
| | - Benjamin S Bleier
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 20115, USA
| | - Mansoor M Amiji
- Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, MA 02115, USA; Department of Chemical Engineering, College of Engineering, Northeastern University, Boston, MA 02115, USA.
| |
Collapse
|
2
|
Rodier JT, Tripathi R, Fink MK, Sharma A, Korampally M, Gangopadhyay S, Giuliano EA, Sinha PR, Mohan RR. Linear Polyethylenimine-DNA Nanoconstruct for Corneal Gene Delivery. J Ocul Pharmacol Ther 2020; 35:23-31. [PMID: 30699061 DOI: 10.1089/jop.2018.0024] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
PURPOSE This study investigated the efficiency and potential toxicity of a linear 22-kDa polyethylenimine (PEI)-DNA nanoconstruct for delivering genes to corneal cells and the effects of PEI nitrogen-to-DNA phosphate (N:P) ratio on gene transfer efficiency in vitro and in vivo. METHODS A gel retardation assay, zeta potential measurement, bright-field microscopy, transfection with green fluorescent protein (GFP), immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) were used to characterize the physicochemical and biological properties and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and reactive oxygen species (ROS) assay for cytotoxicity of the linear PEI-DNA nanoconstruct using in vitro cultured primary human corneal fibroblast and in vivo mouse models. RESULTS Of the several evaluated N:P ratios, the highest gene transfection efficiency achieved without any notable cytotoxicity was observed at an N:P ratio of 30:1 (N:P 30). In vivo gene transfer studies revealed substantial GFP gene delivery into the corneas of mice 3 days after a single 5-min topical application without any significant adverse ocular effects. Slit-lamp biomicroscope ophthalmic examination of the mouse exposed to the linear PEI-DNA nanoconstruct showed no evidence of hyperemia (redness), corneal edema, ocular inflammation, or epiphora (excessive tearing). CONCLUSIONS The 22-kDa linear PEI-DNA nanoconstruct is an efficient and well-tolerated vector for corneal gene therapy in vitro and in vivo and could be used as a platform for developing novel gene-based nanomedicine approaches for corneal diseases.
Collapse
Affiliation(s)
- Jason T Rodier
- 1 Research Divison, Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri
- 2 Mason Eye Institute, School of Medicine & Vision, University of Missouri, Columbia, Missouri
| | - Ratnakar Tripathi
- 1 Research Divison, Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri
- 3 One-Health One-Medicine Ophthalmology Research Center, University of Missouri, Columbia, Missouri
| | - Michael K Fink
- 1 Research Divison, Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri
- 3 One-Health One-Medicine Ophthalmology Research Center, University of Missouri, Columbia, Missouri
| | - Ajay Sharma
- 1 Research Divison, Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri
- 3 One-Health One-Medicine Ophthalmology Research Center, University of Missouri, Columbia, Missouri
| | - Madhuri Korampally
- 1 Research Divison, Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri
- 4 Department of Electrical and Computer Engineering, University of Missouri, Columbia, Missouri
| | - Shubhra Gangopadhyay
- 4 Department of Electrical and Computer Engineering, University of Missouri, Columbia, Missouri
| | - Elizabeth A Giuliano
- 1 Research Divison, Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri
- 3 One-Health One-Medicine Ophthalmology Research Center, University of Missouri, Columbia, Missouri
| | - Prashant R Sinha
- 1 Research Divison, Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri
- 3 One-Health One-Medicine Ophthalmology Research Center, University of Missouri, Columbia, Missouri
| | - Rajiv R Mohan
- 1 Research Divison, Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri
- 2 Mason Eye Institute, School of Medicine & Vision, University of Missouri, Columbia, Missouri
- 3 One-Health One-Medicine Ophthalmology Research Center, University of Missouri, Columbia, Missouri
| |
Collapse
|
3
|
Cwetsch AW, Pinto B, Savardi A, Cancedda L. In vivo methods for acute modulation of gene expression in the central nervous system. Prog Neurobiol 2018; 168:69-85. [PMID: 29694844 PMCID: PMC6080705 DOI: 10.1016/j.pneurobio.2018.04.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 04/17/2018] [Accepted: 04/20/2018] [Indexed: 12/17/2022]
Abstract
Accurate and timely expression of specific genes guarantees the healthy development and function of the brain. Indeed, variations in the correct amount or timing of gene expression lead to improper development and/or pathological conditions. Almost forty years after the first successful gene transfection in in vitro cell cultures, it is currently possible to regulate gene expression in an area-specific manner at any step of central nervous system development and in adulthood in experimental animals in vivo, even overcoming the very poor accessibility of the brain. Here, we will review the diverse approaches for acute gene transfer in vivo, highlighting their advantages and disadvantages with respect to the efficiency and specificity of transfection as well as to brain accessibility. In particular, we will present well-established chemical, physical and virus-based approaches suitable for different animal models, pointing out their current and future possible applications in basic and translational research as well as in gene therapy.
Collapse
Affiliation(s)
- Andrzej W Cwetsch
- Local Micro-environment and Brain Development Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genova, Italy; Università degli Studi di Genova, Via Balbi, 5, 16126 Genova, Italy
| | - Bruno Pinto
- Local Micro-environment and Brain Development Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genova, Italy; Bio@SNS, Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126, Pisa, Italy
| | - Annalisa Savardi
- Local Micro-environment and Brain Development Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genova, Italy; Università degli Studi di Genova, Via Balbi, 5, 16126 Genova, Italy
| | - Laura Cancedda
- Local Micro-environment and Brain Development Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genova, Italy; DulbeccoTelethon Institute, Italy.
| |
Collapse
|
4
|
Simion V, Nadim WD, Benedetti H, Pichon C, Morisset-Lopez S, Baril P. Pharmacomodulation of microRNA Expression in Neurocognitive Diseases: Obstacles and Future Opportunities. Curr Neuropharmacol 2017; 15:276-290. [PMID: 27397479 PMCID: PMC5412696 DOI: 10.2174/1570159x14666160630210422] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 05/31/2016] [Accepted: 06/28/2016] [Indexed: 12/21/2022] Open
Abstract
Given the importance of microRNAs (miRNAs) in modulating brain functions and their implications in neurocognitive disorders there are currently significant efforts devoted in the field of miRNA-based therapeutics to correct and/or to treat these brain diseases. The observation that miRNA 29a/b-1 cluster, miRNA 10b and miRNA 7, for instance, are frequently deregulated in the brains of patients with neurocognitive diseases and in animal models of Alzheimer, Huntington's and Parkinson's diseases, suggest that correction of miRNA expression using agonist or antagonist miRNA oligonucleotides might be a promising approach to correct or even to cure such diseases. The encouraging results from recent clinical trials allow envisioning that pharmacological approaches based on miRNAs might, in a near future, reach the requirements for successful therapeutic outcomes and will improve the healthcare of patients with brain injuries or disorders. This review will focus on the current strategies used to modulate pharmacological function of miRNA using chemically modified oligonucleotides. We will then review the recent literature on strategies to improve nucleic acid delivery across the blood-brain barrier which remains a severe obstacle to the widespread application of miRNA therapeutics to treat brain diseases. Finally, we provide a state-of-art of current preclinical research performed in animal models for the treatment of neurocognitive disorders using miRNA as therapeutic agents and discuss future developments of miRNA therapeutics.
Collapse
Affiliation(s)
- Viorel Simion
- Centre de Biophysique Moléculaire, CNRS UPR4301, Université d’Orléans France, 45071 Orléans Cedex, France
| | - Wissem Deraredj Nadim
- Centre de Biophysique Moléculaire, CNRS UPR4301, Université d’Orléans France, 45071 Orléans Cedex, France
| | - Hélène Benedetti
- Centre de Biophysique Moléculaire, CNRS UPR4301, Université d’Orléans France, 45071 Orléans Cedex, France
| | - Chantal Pichon
- Centre de Biophysique Moléculaire, CNRS UPR4301, Université d’Orléans France, 45071 Orléans Cedex, France
| | - Severine Morisset-Lopez
- Centre de Biophysique Moléculaire, CNRS UPR4301, Université d’Orléans France, 45071 Orléans Cedex, France
| | - Patrick Baril
- Centre de Biophysique Moléculaire, CNRS UPR4301, Université d’Orléans France, 45071 Orléans Cedex, France
| |
Collapse
|
5
|
Lopes CD, Oliveira H, Estevão I, Pires LR, Pêgo AP. In vivo targeted gene delivery to peripheral neurons mediated by neurotropic poly(ethylene imine)-based nanoparticles. Int J Nanomedicine 2016; 11:2675-83. [PMID: 27354797 PMCID: PMC4907712 DOI: 10.2147/ijn.s104374] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A major challenge in neuronal gene therapy is to achieve safe, efficient, and minimally invasive transgene delivery to neurons. In this study, we report the use of a nonviral neurotropic poly(ethylene imine)-based nanoparticle that is capable of mediating neuron-specific transfection upon a subcutaneous injection. Nanoparticles were targeted to peripheral neurons by using the nontoxic carboxylic fragment of tetanus toxin (HC), which, besides being neurotropic, is capable of being retrogradely transported from neuron terminals to the cell bodies. Nontargeted particles and naked plasmid DNA were used as control. Five days after treatment by subcutaneous injection in the footpad of Wistar rats, it was observed that 56% and 64% of L4 and L5 dorsal root ganglia neurons, respectively, were expressing the reporter protein. The delivery mediated by HC-functionalized nanoparticles spatially limited the transgene expression, in comparison with the controls. Histological examination revealed no significant adverse effects in the use of the proposed delivery system. These findings demonstrate the feasibility and safety of the developed neurotropic nanoparticles for the minimally invasive delivery of genes to the peripheral nervous system, opening new avenues for the application of gene therapy strategies in the treatment of peripheral neuropathies.
Collapse
Affiliation(s)
- Cátia Df Lopes
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto (UPorto), Porto, Portugal; i3S - Instituto de Investigação e Inovação em Saúde, NanoBiomaterials for Targeted Therapies Group, UPorto, Porto, Portugal; FMUP - Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - Hugo Oliveira
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto (UPorto), Porto, Portugal
| | - Inês Estevão
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto (UPorto), Porto, Portugal
| | - Liliana Raquel Pires
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto (UPorto), Porto, Portugal
| | - Ana Paula Pêgo
- INEB - Instituto de Engenharia Biomédica, Universidade do Porto (UPorto), Porto, Portugal; i3S - Instituto de Investigação e Inovação em Saúde, NanoBiomaterials for Targeted Therapies Group, UPorto, Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, UPorto, Porto, Portugal; FEUP - Faculdade de Engenharia da Universidade do Porto, Porto, Portugal
| |
Collapse
|
6
|
Tokatlian T, Cam C, Segura T. Non-viral DNA delivery from porous hyaluronic acid hydrogels in mice. Biomaterials 2014; 35:825-35. [PMID: 24210142 DOI: 10.1016/j.biomaterials.2013.10.014] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 10/02/2013] [Indexed: 01/08/2023]
Abstract
The lack of vascularization within tissue-engineered constructs remains the primary cause of construct failure following implantation. Porous constructs have been successful in allowing for vessel infiltration without requiring extensive matrix degradation. We hypothesized that the rate and maturity of infiltrating vessels could be enhanced by complementing the open pore structure with the added delivery of DNA encoding for angiogenic growth factors. Both 100 and 60 μm porous and non-porous hyaluronic acid hydrogels loaded with pro-angiogenic (pVEGF) or reporter (pGFPluc) plasmid nanoparticles were used to study the effects of pore size and DNA delivery on angiogenesis in a mouse subcutaneous implant model. GFP-expressing transfected cells were found inside all control hydrogels over the course of the study, although transfection levels peaked by week 3 for 100 and 60 μm porous hydrogels. Transfection in non-porous hydrogels continued to increase over time corresponding with continued surface degradation. pVEGF transfection levels were not high enough to enhance angiogenesis by increasing vessel density, maturity, or size, although by 6 weeks for all pore size hydrogels more hydrogel implants were positive for vascularization when pVEGF polyplexes were incorporated compared to control hydrogels. Pore size was found to be the dominant factor in determining the angiogenic response with 60 μm porous hydrogels having more vessels/area present than 100 μm porous hydrogels at the initial onset of angiogenesis at 3 weeks. The results of this study show promise for the use of polyplex loaded porous hydrogels to transfect infiltrating cells in vivo and guide tissue regeneration and repair.
Collapse
|
7
|
Lai WF. In vivonucleic acid delivery with PEI and its derivatives: current status and perspectives. Expert Rev Med Devices 2014; 8:173-85. [DOI: 10.1586/erd.10.83] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|
8
|
Adolph EJ, Nelson CE, Werfel TA, Guo R, Davidson JM, Guelcher SA, Duvall CL. Enhanced Performance of Plasmid DNA Polyplexes Stabilized by a Combination of Core Hydrophobicity and Surface PEGylation. J Mater Chem B 2014; 2:8154-8164. [PMID: 25530856 DOI: 10.1039/c4tb00352g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nonviral gene therapy has high potential for safely promoting tissue restoration and for treating various genetic diseases. One current limitation is that conventional transfection reagents such as polyethylenimine (PEI) form electrostatically stabilized plasmid DNA (pDNA) polyplexes with poor colloidal stability. In this study, a library of poly(ethylene glycol-b-(dimethylaminoethyl methacrylate-co-butyl methacrylate)) [poly(EG-b-(DMAEMA-co-BMA))] polymers were synthesized and screened for improved colloidal stability and nucleic acid transfection following lyophilization. When added to pDNA in the appropriate pH buffer, the DMAEMA moieties initiate formation of electrostatic polyplexes that are internally stabilized by hydrophobic interactions of the core BMA blocks and sterically stabilized against aggregation by a PEG corona. The BMA content was varied from 0% to 60% in the second polymer block in order to optimally tune the balance of electrostatic and hydrophobic interactions in the polyplex core, and polymers with 40 and 50 mol% BMA achieved the highest transfection efficiency. Diblock copolymers were more stable than PEI in physiologic buffers. Consequently, diblock copolymer polyplexes aggregated more slowly and followed a reaction-limited colloidal aggregation model, while fast aggregation of PEI polyplexes was governed by a diffusion-limited model. Polymers with 40% BMA did not aggregate significantly after lyophilization and produced up to 20-fold higher transfection efficiency than PEI polyplexes both before and after lyophilization. Furthermore, poly(EG-b-(DMAEMA-co-BMA)) polyplexes exhibited pH-dependent membrane disruption in a red blood cell hemolysis assay and endosomal escape as observed by confocal microscopy.Lyophilized polyplexes made with the lead candidate diblock copolymer (40% BMA) also successfully transfected cells in vitro following incorporation into gas-foamed polymeric scaffolds. In summary, the enhanced colloidal stability, endosomal escape, and resultant high transfection efficiency of poly(EG-b-(DMAEMA-co-BMA))-pDNA polyplexes underscores their potential utility both for local delivery from scaffolds as well as systemic, intravenous delivery.
Collapse
Affiliation(s)
- Elizabeth J Adolph
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN
| | | | - Thomas A Werfel
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN
| | - Ruijing Guo
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN
| | - Jeffrey M Davidson
- Department of Pathology, Vanderbilt University Medical Center, Nashville, TN ; Research Service, VA Tennessee Valley Healthcare System, Nashville, TN
| | - Scott A Guelcher
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN ; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN ; Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN
| | - Craig L Duvall
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN
| |
Collapse
|
9
|
Newland B, Dowd E, Pandit A. Biomaterial approaches to gene therapies for neurodegenerative disorders of the CNS. Biomater Sci 2013; 1:556-576. [DOI: 10.1039/c3bm60030k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
10
|
Design and characterization of microporous hyaluronic acid hydrogels for in vitro gene transfer to mMSCs. Acta Biomater 2012; 8:3921-31. [PMID: 22820309 DOI: 10.1016/j.actbio.2012.07.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2012] [Revised: 07/11/2012] [Accepted: 07/12/2012] [Indexed: 01/08/2023]
Abstract
The effective and sustained delivery of DNA locally could increase the applicability of gene therapy in tissue regeneration and therapeutic angiogenesis. One promising approach is to use porous hydrogel scaffolds to encapsulate and deliver nucleotides in the form of nanoparticles to the affected sites. We have designed and characterized microporous (μ-pore) hyaluronic acid hydrogels which allow for effective cell seeding in vitro post-scaffold fabrication and allow for cell spreading and proliferation without requiring high levels of degradation. These factors, coupled with high loading efficiency of DNA polyplexes using a previously developed caged nanoparticle encapsulation (CnE) technique, then allowed for long-term sustained transfection and transgene expression of incorporated mMSCs. In this study, we examined the effect of pore size on gene transfer efficiency and the kinetics of transgene expression. For all investigated pore sizes (30, 60, and 100 μm), encapsulated DNA polyplexes were released steadily, starting by day 4 for up to 10 days. Likewise, transgene expression was sustained over this period, although significant differences between different pore sizes were not observed. Cell viability was also shown to remain high over time, even in the presence of high concentrations of DNA polyplexes. The knowledge acquired through this in vitro model can be utilized to design and better predict scaffold-mediated gene delivery for local gene therapy in an in vivo model where host cells infiltrate the scaffold over time.
Collapse
|
11
|
Kurita A, Matsunobu T, Satoh Y, Ando T, Sato S, Obara M, Shiotani A. Targeted gene transfer into rat facial muscles by nanosecond pulsed laser-induced stress waves. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:098002. [PMID: 21950944 DOI: 10.1117/1.3628313] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We investigate the feasibility of using nanosecond pulsed laser-induced stress waves (LISWs) for gene transfer into rat facial muscles. LISWs are generated by irradiating a black natural rubber disk placed on the target tissue with nanosecond pulsed laser light from the second harmonics (532 nm) of a Q-switched Nd:YAG laser, which is widely used in head and neck surgery and proven to be safe. After injection of plasmid deoxyribose nucleic acid (DNA) coding for Lac Z into rat facial muscles, pulsed laser is used to irradiate the laser target on the skin surface without incision or exposure of muscles. Lac Z expression is detected by X-gal staining of excised rat facial skin and muscles. Strong Lac Z expression is observed seven days after gene transfer, and sustained for up to 14 days. Gene transfer is achieved in facial muscles several millimeters deep from the surface. Gene expression is localized to the tissue exposed to LISWs. No tissue damage from LISWs is observed. LISW is a promising nonviral target gene transfer method because of its high spatial controllability, easy applicability, and minimal invasiveness. Gene transfer using LISW to produce therapeutic proteins such as growth factors could be used to treat nerve injury and paralysis.
Collapse
Affiliation(s)
- Akihiro Kurita
- National Defense Medical College, Department of Otolaryngology, Namiki 3-2, Tokorozawa, Saitama 359-8513 Japan
| | | | | | | | | | | | | |
Collapse
|
12
|
Gojgini S, Tokatlian T, Segura T. Utilizing cell-matrix interactions to modulate gene transfer to stem cells inside hyaluronic acid hydrogels. Mol Pharm 2011; 8:1582-91. [PMID: 21823632 DOI: 10.1021/mp200171d] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effective delivery of DNA locally would increase the applicability of gene therapy in tissue regeneration, where diseased tissue is to be repaired in situ. One promising approach is to use hydrogel scaffolds to encapsulate and deliver plasmid DNA in the form of nanoparticles to the diseased tissue, so that cells infiltrating the scaffold are transfected to induce regeneration. This study focuses on the design of a DNA nanoparticle-loaded hydrogel scaffold. In particular, this study focuses on understanding how cell-matrix interactions affect gene transfer to adult stem cells cultured inside matrix metalloproteinase (MMP) degradable hyaluronic acid (HA) hydrogel scaffolds. HA was cross-linked to form a hydrogel material using a MMP degradable peptide and Michael addition chemistry. Gene transfer inside these hydrogel materials was assessed as a function of polyplex nitrogen to phosphate ratio (N/P = 5 to 12), matrix stiffness (100-1700 Pa), RGD (Arg-Gly-Asp) concentration (10-400 μM), and RGD presentation (0.2-4.7 RGDs per HA molecule). All variables were found to affect gene transfer to mouse mensenchymal stem cells culture inside the DNA loaded hydrogels. As expected, higher N/P ratios lead to higher gene transfer efficiency but also higher toxicity; softer hydrogels resulted in higher transgene expression than stiffer hydrogels, and an intermediate RGD concentration and RGD clustering resulted in higher transgene expression. We believe that the knowledge gained through this in vitro model can be utilized to design better scaffold-mediated gene delivery for local gene therapy.
Collapse
Affiliation(s)
- Shiva Gojgini
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
| | | | | |
Collapse
|
13
|
Lei Y, Ng QKT, Segura T. Two and three-dimensional gene transfer from enzymatically degradable hydrogel scaffolds. Microsc Res Tech 2010; 73:910-7. [PMID: 20232458 DOI: 10.1002/jemt.20840] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The ability to genetically modify mesenchymal stem cells (MSCs) seeded inside synthetic hydrogel scaffolds would offer an alternative approach to guide MSC differentiation. In this report, we explored gene transfer to MSCs seeded on top or inside matrix metalloproteinase (MMP) degradable hydrogels that were loaded with DNA/poly(ethylene imine) (PEI) polyplexes. DNA/PEI polyplexes were encapsulated inside poly(ethylene glycol) (PEG) hydrogels crosslinked with MMP degradable peptides via Michael Addition chemistry. Gene transfer was visualized and quantified through using a vector encoding for green fluorescent protein and luciferase. We found that gene transfer to MSCs was possible for cells seeded both in two and three dimensions. The amount of luciferase expression was similar for cells seeded in two and three dimensions even though the number of cells in three dimensions is significantly higher, indicating that gene transfer to cells seeded in two dimensions is more efficient than for cells seeded in three dimensions. The use of hydrogel scaffolds that allow cellular infiltration to deliver DNA may result in long-lasting signals in vivo, which are essential for the regeneration of functional tissues.
Collapse
Affiliation(s)
- Yuguo Lei
- Chemical and Biomolecular Engineering Department, University of California, Los Angeles, California, USA
| | | | | |
Collapse
|
14
|
Okabayashi T, Nakanishi K, Tsuchihara T, Arino H, Yoshihara Y, Tominaga S, Uenoyama M, Suzuki S, Asagiri M, Nemoto K. Axonal-transport-mediated gene transduction in the interior of rat bone. PLoS One 2010; 5. [PMID: 20927397 PMCID: PMC2946924 DOI: 10.1371/journal.pone.0013034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 09/06/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Gene transduction has been considered advantageous for the sustained delivery of proteins to specific target tissues. However, in the case of hard tissues, such as bone, local gene delivery remains problematic owing to anatomical accessibility limitations of the target sites. METHODOLOGY/PRINCIPAL FINDINGS Here, we evaluated the feasibility of exogenous gene transduction in the interior of bone via axonal transport following intramuscular administration of a nonviral vector. A high expression level of the transduced gene was achieved in the tibia ipsilateral to the injected tibialis anterior muscle, as well as in the ipsilateral sciatic nerve and dorsal root ganglia. In sciatic transection rats, the gene expression level was significantly lowered in bone. CONCLUSIONS/SIGNIFICANCE These results suggest that axonal transport is critical for gene transduction. Our study may provide a basis for developing therapeutic methods for efficient gene delivery into hard tissues.
Collapse
Affiliation(s)
- Toshitaka Okabayashi
- Department of Orthopaedic Surgery, National Defense Medical College, Saitama, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Lei Y, Huang S, Sharif-Kashani P, Chen Y, Kavehpour P, Segura T. Incorporation of active DNA/cationic polymer polyplexes into hydrogel scaffolds. Biomaterials 2010; 31:9106-16. [PMID: 20822811 DOI: 10.1016/j.biomaterials.2010.08.016] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Accepted: 08/07/2010] [Indexed: 01/08/2023]
Abstract
The effective and sustained delivery of DNA and siRNAs locally would increase the applicability of gene therapy in tissue regeneration and cancer therapy. One promising approach is to use hydrogel scaffolds to encapsulate and deliver nucleotides in the form of nanoparticles to the disease sites. However, this approach is currently limited by the inability to load concentrated and active gene delivery nanoparticles into the hydrogels due to the severe nanoparticle aggregation during the loading process. Here, we present a process to load concentrated and un-aggregated non-viral gene delivery nanoparticles, using DNA/polyethylene imine (PEI) polyplexes as an example, into neutral polyethylene glycol (PEG), negatively charged hyaluronic acid (HA) and protein fibrin hydrogels crosslinked through various chemistries. The encapsulated polyplexes are highly active both in vitro and in vivo. We believe this process will significantly advance the applications of hydrogel scaffold mediated non-viral gene delivery in tissue regeneration and cancer therapy.
Collapse
Affiliation(s)
- Yuguo Lei
- Chemical and Biomolecular Engineering Department, University of California, Los Angeles, 420 Westwood Plaza, 5531 Boelter Hall, Los Angeles, CA 90095, USA
| | | | | | | | | | | |
Collapse
|
16
|
Rakkhithawatthana V, Sanitrum P, Sajomsang W, Na Ubon P, Tencomnao T, Saengkrit N. Investigation of gene transferring efficacy through nano-polyplex consisting of methylated N-(4-pyridinylmethyl) chitosan chloride and poly(ethylenimine) in human cell lines. Carbohydr Polym 2010. [DOI: 10.1016/j.carbpol.2009.11.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
17
|
Arulmuthu ER, Williams DJ, Versteeg HK. The arrival of genetic engineering. ACTA ACUST UNITED AC 2009; 28:40-54. [PMID: 19150770 DOI: 10.1109/memb.2008.931015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Eugene R Arulmuthu
- Healthcare Engineering Group, Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK
| | | | | |
Collapse
|
18
|
Di Gioia S, Conese M. Polyethylenimine-mediated gene delivery to the lung and therapeutic applications. DRUG DESIGN DEVELOPMENT AND THERAPY 2009; 2:163-88. [PMID: 19920904 PMCID: PMC2761186 DOI: 10.2147/dddt.s2708] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Nonviral gene delivery is now considered a promising alternative to viral vectors. Among nonviral gene delivery agents, polyethylenimine (PEI) has emerged as a potent candidate for gene delivery to the lung. PEI has some advantages over other polycations in that it combines strong DNA compaction capacity with an intrinsic endosomolytic activity. However, intracellular (mainly the nuclear membrane) and extracellular obstacles still hamper its efficiency in vitro and in vivo, depending on the route of administration and the type of PEI. Nuclear delivery has been increased by adding nuclear localization signals. To overcome nonspecific interactions with biological fluids, extracellular matrix components and nontarget cells, strategies have been developed to protect polyplexes from these interactions and to increase target specificity and gene expression. When gene delivery into airway epithelial cells of the conducting airways is necessary, aerosolization of complexes seems to be better suited to guarantee higher transgene expression in the airway epithelial cells with lower toxicity than observed with either intratracheal or intravenous administration. Aerosolization, indeed, is useful to target the alveolar epithelium and pulmonary endothelium. Proof-of-principle that PEI-mediated gene delivery has therapeutic application to some genetic and acquired lung disease is presented, using as genetic material either plasmidic DNA or small-interfering RNA, although optimization of formulation and delivery protocols and limitation of toxicity need further studies.
Collapse
Affiliation(s)
- Sante Di Gioia
- Department of Biomedical Sciences, University of Foggia, Viale L. Pinto 1, Foggia, Italy
| | | |
Collapse
|
19
|
Li W, Ma N, Ong LL, Kaminski A, Skrabal C, Ugurlucan M, Lorenz P, Gatzen HH, Lützow K, Lendlein A, Pützer BM, Li RK, Steinhoff G. Enhanced thoracic gene delivery by magnetic nanobead-mediated vector. J Gene Med 2008; 10:897-909. [PMID: 18481827 DOI: 10.1002/jgm.1208] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Systemic gene delivery is limited by the adverse hydrodynamic conditions on the collection of gene carrier particles to the specific area. In the present study, a magnetic field was employed to guide magnetic nanobead (MNB)/polymer/DNA complexes after systemic administration to the left side of the mouse thorax in order to induce localized gene expression. METHODS Nonviral polymer (poly ethyleneimine, PEI) vector-gene complexes were conjugated to MNBs with the Sulfo-NHS-LC-Biotin linker. In vitro transfection efficacy of MNB/PEI/DNA was compared with PEI/DNA in three different cell lines as well as primary endothelial cells under magnetic field stimulation. In vivo, MNB/PEI/DNA complexes were injected into the tail vein of mice and an epicardial magnet was employed to attract the circulating MNB/PEI/DNA complexes. RESULTS Endocytotic uptake of MNB/PEI/DNA complexes and intracellular gene release with nuclear translocation were observed in vitro, whereas the residues of MNB/PEI complexes were localized at the perinuclear region. Compared with PEI/DNA complexes alone, MNB/PEI/DNA complexes had a 36- to 85-fold higher transfection efficiency under the magnetic field. In vivo, the epicardial magnet effectively attracted MNB/PEI/DNA complexes in the left side of the thorax, resulting in strong reporter and therapeutic gene expression in the left lung and the heart. Gene expression in the heart was mainly within the endothelium. CONCLUSIONS MNB-mediated gene delivery could comprise a promising method for gene delivery to the lung and the heart.
Collapse
Affiliation(s)
- Wenzhong Li
- Department of Cardiac Surgery, University of Rostock, Rostock, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Lei Y, Segura T. DNA delivery from matrix metalloproteinase degradable poly(ethylene glycol) hydrogels to mouse cloned mesenchymal stem cells. Biomaterials 2008; 30:254-65. [PMID: 18838159 DOI: 10.1016/j.biomaterials.2008.09.027] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Accepted: 09/10/2008] [Indexed: 10/21/2022]
Abstract
The ability to genetically modify mesenchymal stem cells (MSCs) seeded inside synthetic hydrogel scaffolds would offer an alternative approach to guide MSC differentiation and to study molecular pathways in three dimensions than protein delivery. In this report, we explored gene transfer to infiltrating MSCs into matrix metalloproteinase (MMP) degradable hydrogels that were loaded with DNA/poly(ethylene imine) (PEI) polyplexes. DNA/PEI polyplexes were encapsulated inside poly(ethylene glycol) (PEG) hydrogels crosslinked with MMP-degradable peptides via Michael addition chemistry. A large fraction of encapsulated polyplexes remained active after encapsulation (65%) and the mechanical properties of the hydrogels were unchanged by the encapsulation of the polyplexes. Cells were seeded inside the hydrogel scaffolds using two different approaches: clustered and homogeneous. The viability of MSCs was similar in hydrogels with and without polyplexes. Transgene expression was characterized with time using a secreted reporter gene and showed different profiles for clustered and homogeneously seeded cells. Clustered cells resulted in cumulative transgene expression that increased through the 21-day incubation, while homogeneously seeded cells resulted in cumulative transgene expression that plateaued after 7 days of culture. The use of hydrogel scaffolds that allow cellular infiltration to deliver DNA may result in long lasting signals in vivo, which are essential for the regeneration of functional tissues.
Collapse
Affiliation(s)
- Yuguo Lei
- University of California, Los Angeles, Chemical and Biomolecular Engineering Department, Los Angeles, CA, United States
| | | |
Collapse
|
21
|
Poly (lactide-co-glycolide)-Polymethacrylate Nanoparticles for Intramuscular Delivery of Plasmid Encoding Interleukin-10 to Prevent Autoimmune Diabetes in Mice. Pharm Res 2008; 26:72-81. [DOI: 10.1007/s11095-008-9710-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Accepted: 08/12/2008] [Indexed: 12/16/2022]
|
22
|
Huang SW, Zhuo RX. Recent Advances in Polyphosphoester and Polyphosphoramidate-Based Biomaterials. PHOSPHORUS SULFUR 2008. [DOI: 10.1080/10426500701734620] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Shi-Wen Huang
- a Key Laboratory of Biomedical Polymers, Ministry of Education, College of Chemistry and Molecular Sciences , Wuhan University , Wuhan, P. R. China
| | - Ren-Xi Zhuo
- a Key Laboratory of Biomedical Polymers, Ministry of Education, College of Chemistry and Molecular Sciences , Wuhan University , Wuhan, P. R. China
| |
Collapse
|
23
|
Bergen JM, Pun SH. Analysis of the intracellular barriers encountered by nonviral gene carriers in a model of spatially controlled delivery to neurons. J Gene Med 2008; 10:187-97. [PMID: 18064730 DOI: 10.1002/jgm.1137] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Neuron-specific, nonviral gene delivery vehicles are useful tools for the potential treatment of neurological disease and spinal cord injury. For minimally invasive, peripheral administration, gene carriers must efficiently mediate uptake at axon terminals, retrograde axonal transport, vesicular escape, and nuclear entry. The design of improved vehicles will benefit from an understanding of the barriers that limit nonviral delivery to neurons. Here, we demonstrate a detailed analysis of intracellular trafficking of both a lipid-based and a polymer-based delivery vehicle following site-specific exposure to neuron-like cells. METHODS Site-specific exposure of gene carriers to soma or neurites of neuron-like PC-12 cells was accomplished using a microfluidic, compartmented culture chamber. Binding and internalization of vehicles at neurites and soma were quantified using an environmentally sensitive fluorescent marker. The intracellular transport of gene carriers was analyzed by time-lapse particle tracking in live cells, and transfection efficiencies were measured using green fluorescent protein (GFP) as a reporter gene. RESULTS While the lipid-based carrier mediated measurable transfection when delivered to neuronal soma, neuritic delivery of this formulation failed to produce reporter gene expression due to limited internalization and transport. In contrast, the polymeric nanoparticles displayed active retrograde transport toward neuronal soma, but failed to produce measurable reporter gene expression. CONCLUSIONS These results highlight distinct intracellular barriers preventing efficient neuronal transfection by the nonviral carriers examined, and provide a basis for the rational improvement of existing nonviral systems.
Collapse
Affiliation(s)
- Jamie M Bergen
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | | |
Collapse
|
24
|
Quantitative comparison of intracellular unpacking kinetics of polyplexes by a model constructed from quantum dot-FRET. Mol Ther 2008; 16:324-32. [PMID: 18180773 DOI: 10.1038/sj.mt.6300392] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A major challenge for non-viral gene delivery is gaining a mechanistic understanding of the rate-limiting steps. A critical barrier in polyplex-mediated gene delivery is the timely unpacking of polyplexes within the target cell to liberate DNA for efficient gene transfer. In this study, the component plasmid DNA and polymeric gene carrier were individually labeled with quantum dots (QDs) and Cy5 dyes, respectively, as a donor and acceptor pair for fluorescence resonance energy transfer (FRET). The high signal-to-noise ratio in QD-mediated FRET enabled sensitive detection of discrete changes in polyplex stability. The intracellular uptake and dissociation of polyplexes through QD-FRET was captured over time by confocal microscopy. From quantitative image-based analysis, distributions of released plasmid within the endo/lysosomal, cytosolic, and nuclear compartments formed the basis for constructing a three-compartment first-order kinetics model. Polyplex unpacking kinetics for chitosan, polyethylenimine, and polyphosphoramidate were compared and found to correlate well with transfection efficiencies. Thus, QD-FRET-enabled detection of polyplex stability combined with image-based quantification is a valuable method for studying mechanisms involved in polyplex unpacking and trafficking within live cells. We anticipate that this method will also aid the design of more efficient gene carriers.
Collapse
|
25
|
Park IK, Lasiene J, Chou SH, Horner PJ, Pun SH. Neuron-specific delivery of nucleic acids mediated by Tet1-modified poly(ethylenimine). J Gene Med 2007; 9:691-702. [PMID: 17582226 PMCID: PMC2633605 DOI: 10.1002/jgm.1062] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The development of minimally invasive, non-viral gene delivery vehicles for the central nervous system (CNS) is an important technology goal in the advancement of molecular therapies for neurological diseases. One approach is to deliver materials peripherally that are recognized and retrogradely transported by motor neurons toward the CNS. Tet1 is a peptide identified by Boulis and coworkers to possess the binding characteristics of tetanus toxin, which interacts specifically with motor neurons and undergoes fast, retrograde delivery to cell soma. In this work, Tet1-poly(ethylenimine) (Tet1-PEI) was synthesized and evaluated as a neurontargeted delivery vehicle. METHODS Tet1-PEI and NT-PEI (neurotensin-PEI) were synthesized and complexed with plasmid DNA to form polyplexes. Polyplexes were assessed for binding and uptake in differentiated neuron-like PC-12 cells by flow cytometry and confocal microscopy. In order to determine gene delivery efficiency, polyplexes were exposed to PC-12 cells at various stages of differentiation. Targeted binding of polyplexes with primary neurons was studied using dorsal root ganglion cells. RESULTS Tet1-PEI and NT-PEI polyplexes bound specifically to differentiated PC-12 cells. The specificity of the interaction was confirmed by delivery to non-neuronal cells and by competition studies with free ligands. Tet1-PEI polyplexes preferentially transfected PC-12 cells undergoing NGF-induced differentiation. Finally, neuron-specific binding of Tet1-PEI polyplexes was confirmed in primary neurons. CONCLUSIONS These studies demonstrate the potential of Tet1-PEI as a neuron-targeted material for non-invasive CNS delivery. Tet1-PEI binds specifically and is internalized by neuron-like PC-12 cells and primary dorsal root ganglion. Future work will include evaluation of siRNA delivery with these vectors.
Collapse
Affiliation(s)
- In-Kyu Park
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Jurate Lasiene
- Department of Neurological Surgery, University of Washington, Seattle, WA 98195, USA
| | - Shinn-Huey Chou
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Philip J. Horner
- Department of Neurological Surgery, University of Washington, Seattle, WA 98195, USA
| | - Suzie H. Pun
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
- Correspondence to: Suzie H. Pun, Department of Bioengineering, University of Washington, Seattle, WA 98195, USA. E-mail:
| |
Collapse
|
26
|
Bergen JM, Park IK, Horner PJ, Pun SH. Nonviral approaches for neuronal delivery of nucleic acids. Pharm Res 2007; 25:983-98. [PMID: 17932730 PMCID: PMC2292496 DOI: 10.1007/s11095-007-9439-5] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Accepted: 08/20/2007] [Indexed: 12/23/2022]
Abstract
The delivery of therapeutic nucleic acids to neurons has the potential to treat neurological disease and spinal cord injury. While select viral vectors have shown promise as gene carriers to neurons, their potential as therapeutic agents is limited by their toxicity and immunogenicity, their broad tropism, and the cost of large-scale formulation. Nonviral vectors are an attractive alternative in that they offer improved safety profiles compared to viruses, are less expensive to produce, and can be targeted to specific neuronal subpopulations. However, most nonviral vectors suffer from significantly lower transfection efficiencies than neurotropic viruses, severely limiting their utility in neuron-targeted delivery applications. To realize the potential of nonviral delivery technology in neurons, vectors must be designed to overcome a series of extra- and intracellular barriers. In this article, we describe the challenges preventing successful nonviral delivery of nucleic acids to neurons and review strategies aimed at overcoming these challenges.
Collapse
Affiliation(s)
- Jamie M Bergen
- Bioengineering, University of Washington, Seattle, WA 98195, USA
| | | | | | | |
Collapse
|
27
|
Thakor D, Spigelman I, Tabata Y, Nishimura I. Subcutaneous peripheral injection of cationized gelatin/DNA polyplexes as a platform for non-viral gene transfer to sensory neurons. Mol Ther 2007; 15:2124-31. [PMID: 17622241 DOI: 10.1038/sj.mt.6300256] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Selective modulation of sensory neuron gene expression could have numerous applications for the peripheral nervous system. Here, we report that subcutaneous peripheral injection of plasmid DNA complexed with a non-viral cationized gelatin (CG) vector led to transgene expression in rat lumbar dorsal root ganglia (DRGs). CG/DNA polyplexes appeared to undergo rapid retrograde transport through sciatic and spinal nerves, with reporter gene messenger RNA (mRNA) expression detectable in L4 and L5 DRGs within 60 hours. Maximum transgene expression was observed for polyplexes formed at 7.5:1 CG-to-DNA weight ratio under salt-free conditions, which generated 615 +/- 112 nm nanoparticles with zeta-potential of 9.4 +/- 0.19 mV. Six days after injection of the CG/DNA polypex, reporter gene protein immunofluorescence was observed in 1,164 +/- 176 DRG neurons, representing an estimated transfection rate of 47% of targeted neurons. Reporter gene expression was not detected in heart, lung, or liver tissues, suggesting a lack of systemic uptake. Measurements of tactile sensitivity indicate that CG/DNA injection did not cause behavioral toxicity. The injection platform was further used for plasmid-driven short hairpin RNA-mediated suppression of glyceraldehyde-3-phosphate dehydrogenase. This non-invasive gene delivery system could be used for the mechanistic study and targeted molecular evaluation of peripheral nervous system pathologies such as neuropathic pain.
Collapse
Affiliation(s)
- Devang Thakor
- Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials, and Hospital Dentistry, School of Dentistry, University of California, Los Angeles, California 90095, USA
| | | | | | | |
Collapse
|
28
|
Liu BH, Yang Y, Paton JFR, Li F, Boulaire J, Kasparov S, Wang S. GAL4-NF-kappaB fusion protein augments transgene expression from neuronal promoters in the rat brain. Mol Ther 2006; 14:872-82. [PMID: 16904943 DOI: 10.1016/j.ymthe.2006.05.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2005] [Revised: 04/10/2006] [Accepted: 05/21/2006] [Indexed: 11/27/2022] Open
Abstract
Targeted gene expression mediated by a mammalian cellular promoter is desirable for gene therapy in the brain, where there are a variety of different neuronal phenotypes, several types of supportive cells, and blood vessels. However, this approach can be hampered by weak activity of some cellular promoters. In view of the potency of the transcription factor NF-kappaB in regulating neuronal gene expression, we have assessed whether it can be used to enhance the strength of neuron-specific promoters. Our approach was to use a neuronal promoter to drive expression of a chimeric transactivator, which consisted of a part of the transcriptional activation domain of the NF-kappaB p65 protein fused to the DNA-binding domain of GAL4 protein from yeast. The second copy of the neuronal promoter was modified by introducing the unique GAL4 binding sequences at its 5' end and used to drive the expression of a transgene. Binding of the chimeric transcriptional activator upstream of the second promoter was expected to potentiate its transcriptional activity. In this study, the approach was applied to the platelet-derived growth factor beta chain and synapsin-1 neuron-specific promoters and tested in vitro and in vivo using plasmid, lentiviral, and baculoviral vectors. We observed up to a 100-fold improvement in reporter gene expression in cultured neurons and 20-fold improvement in the rat brain in vivo. Moreover, the cell-type specificity of the two tested promoters was well preserved and restricted to neurons. Finally, the expression driven by the new lentiviral vectors with the p65-potentiated synapsin-1 promoter showed no signs of decline or cell damage 4 weeks after injection. This approach should be suitable for constructing powerful and stable gene expression systems based on weak cell-specific promoters in neuronal phenotypes.
Collapse
Affiliation(s)
- B H Liu
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, 138669, Singapore
| | | | | | | | | | | | | |
Collapse
|
29
|
Huynh GH, Deen DF, Szoka FC. Barriers to carrier mediated drug and gene delivery to brain tumors. J Control Release 2006; 110:236-259. [PMID: 16318895 DOI: 10.1016/j.jconrel.2005.09.053] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Accepted: 09/29/2005] [Indexed: 01/18/2023]
Abstract
Brain tumor patients face a poor prognosis despite significant advances in tumor imaging, neurosurgery and radiation therapy. Potent chemotherapeutic drugs fail when used to treat brain tumors because biochemical and physiological barriers limit drug delivery into the brain. In the past decade a number of strategies have been introduced to increase drug delivery into the brain parenchyma. In particular, direct drug administration into the brain tumor has shown promising results in both animal models and clinical trials. This technique is well suited for the delivery of liposome and polymer drug carriers, which have the potential to provide a sustained level of drug and to reach cellular targets with improved specificity. We will discuss the current approaches that have been used to increase drug delivery into the brain parenchyma in the context of fluid and solute transport into, through and from the brain, with a focus on liposome and polymer drug carriers.
Collapse
Affiliation(s)
- Grace H Huynh
- Joint Graduate Group in Bioengineering, University of California at San Francisco and Berkeley San Francisco, CA 94143-0446, United States
| | - Dennis F Deen
- Brain Tumor Research Center of the Department of Neurological Surgery, University of California at San Francisco, San Francisco, CA 94143-0520, United States
| | - Francis C Szoka
- Joint Graduate Group in Bioengineering, University of California at San Francisco and Berkeley San Francisco, CA 94143-0446, United States; Departments of Pharmaceutical Chemistry and Biopharmaceutical Sciences, University of California at San Francisco, San Francisco, CA 94143-0446, United States.
| |
Collapse
|
30
|
Park IK, Cook SE, Kim YK, Kim HW, Cho MH, Jeong HJ, Kim EM, Nah JW, Bom HS, Cho CS. Glucosylated polyethylenimine as a tumor-targeting gene carrier. Arch Pharm Res 2005; 28:1302-10. [PMID: 16350859 DOI: 10.1007/bf02978216] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glucosylated polyethylenimine (GPEI) was synthesized as a tumor-targeting gene carrier through facilitative glucose metabolism by tumor glucose transporter. Particle sizes of GPEI/DNA complex increased in proportion to glucose content of GPEI, whereas surface charge of the complex was not dependent on glucosylation, partially due to inefficient shielding of the short hydrophilic group introduced. GPEI with higher glucosylation (36 mol-%) had no cytotoxic effect on cells even at polymer concentrations higher than 200 microg/mL. Compared to unglucosylated PEI, glucosylation induced less than one-order decrease of transfection efficiency. Transfection of GPEI/DNA complex into tumor cells possibly occurred through specific interaction between glucose-related cell receptors and glucose moiety of GPEI. Gamma imaging technique revealed GPEI/DNA complex was distributed in liver, spleen, and tumors.
Collapse
Affiliation(s)
- In-Kyu Park
- School of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Lungwitz U, Breunig M, Blunk T, Göpferich A. Polyethylenimine-based non-viral gene delivery systems. Eur J Pharm Biopharm 2005; 60:247-66. [PMID: 15939236 DOI: 10.1016/j.ejpb.2004.11.011] [Citation(s) in RCA: 719] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2004] [Revised: 11/02/2004] [Accepted: 11/02/2004] [Indexed: 10/25/2022]
Abstract
Gene therapy has become a promising strategy for the treatment of many inheritable or acquired diseases that are currently considered incurable. Non-viral vectors have attracted great interest, as they are simple to prepare, rather stable, easy to modify and relatively safe, compared to viral vectors. Unfortunately, they also suffer from a lower transfection efficiency, requiring additional effort for their optimization. The cationic polymer polyethylenimine (PEI) has been widely used for non-viral transfection in vitro and in vivo and has an advantage over other polycations in that it combines strong DNA compaction capacity with an intrinsic endosomolytic activity. Here, we give some insight into strategies developed for PEI-based non-viral vectors to overcome intracellular obstacles, including the improvement of methods for polyplex preparation and the incorporation of endosomolytic agents or nuclear localization signals. In recent years, PEI-based non-viral vectors have been locally or systemically delivered, mostly to target gene delivery to tumor tissue, the lung or liver. This requires strategies to efficiently shield transfection polyplexes against non-specific interaction with blood components, extracellular matrix and untargeted cells and the attachment of targeting moieties, which allow for the directed gene delivery to the desired cell or tissue. In this context, materials, facilitating the design of novel PEI-based non-viral vectors are described.
Collapse
Affiliation(s)
- U Lungwitz
- Department of Pharmacy and Chemistry, Pharmaceutical Technology Unit, University of Regensburg, Regensburg, Germany
| | | | | | | |
Collapse
|
32
|
Wang X, Wang C, Zeng J, Xu X, Hwang PYK, Yee WC, Ng YK, Wang S. Gene Transfer to Dorsal Root Ganglia by Intrathecal Injection: Effects on Regeneration of Peripheral Nerves. Mol Ther 2005; 12:314-20. [PMID: 15925545 DOI: 10.1016/j.ymthe.2005.03.032] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2004] [Revised: 03/02/2005] [Accepted: 03/19/2005] [Indexed: 11/24/2022] Open
Abstract
Gene delivery to sensory neurons of the dorsal root ganglion (DRG) offers the prospect of developing new clinical interventions against peripheral nerve diseases and disorders. Here we show that genes can be transferred to rat DRG through lumbar intrathecal injection of delivery vectors into the cerebrospinal fluid. Genes could be transferred to DRG using polyethylenimine (PEI)/DNA complexes, Lipofectamine 2000/DNA complexes, adeno-associated virus vectors, or baculovirus vectors. We also show that nerve growth factor cDNA, delivered through lumbar intrathecal injection of PEI complexes, was able to improve regeneration of transected rat sciatic nerves. These data demonstrate the viability of using an intrathecal gene delivery approach for treating peripheral neuropathies.
Collapse
Affiliation(s)
- Xu Wang
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos No. 04-41, Singapore 138669
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
Nucleic acid delivery has many applications in basic science, biotechnology, agriculture, and medicine. One of the main applications is DNA or RNA delivery for gene therapy purposes. Gene therapy, an approach for treatment or prevention of diseases associated with defective gene expression, involves the insertion of a therapeutic gene into cells, followed by expression and production of the required proteins. This approach enables replacement of damaged genes or expression inhibition of undesired genes. Following two decades of research, there are two major methods for delivery of genes. The first method, considered the dominant approach, utilizes viral vectors and is generally an efficient tool of transfection. Attempts, however, to resolve drawbacks related with viral vectors (e.g., high risk of mutagenicity, immunogenicity, low production yield, limited gene size, etc.), led to the development of an alternative method, which makes use of non-viral vectors. This review describes non-viral gene delivery vectors, termed "self-assembled" systems, and are based on cationic molecules, which form spontaneous complexes with negatively charged nucleic acids. It introduces the most important cationic polymers used for gene delivery. A transition from in vitro to in vivo gene delivery is also presented, with an emphasis on the obstacles to achieve successful transfection in vivo.
Collapse
Affiliation(s)
- H. Eliyahu
- Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Jerusalem, Israel
- Laboratory of Membrane and Liposome Research, Department of Biochemistry, The Hebrew University – Hadassah Medical School, Jerusalem, Israel
| | - Y. Barenholz
- Laboratory of Membrane and Liposome Research, Department of Biochemistry, The Hebrew University – Hadassah Medical School, Jerusalem, Israel
| | - A. J. Domb
- Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Jerusalem, Israel
| |
Collapse
|
34
|
Abstract
Since the first edition of this book in 1999 the field of gene therapy has been the arena both for major advances that justified the early hopes placed in the concept, and for ever-present impatience with the slowness of overall progress. On the positive side, gene therapy obtained its first brilliant success, though not where most efforts were invested and not with a synthetic vector (Cavazzana-Calvo et al., 2000). Yet the search for efficient molecules is still very active, in part because the negative consequences of using viral vectors somewhat shadow the brilliant picture (Hacein-Bey-Abina et al., 2003). Clinical trial reports using the first generation of non-viral vectors, that is, cationic lipids, emphasize safety more than efficacy. The next generation, namely cationic polymers, is coming to maturity. This is illustrated in Fig. 8.1 by a literature survey that compares the most used "open source" vector in each category, the lipid DOTAP and polymer PEI. This "coming of age" is also highlighted by the number of planned clinical trials using PEI, trials we shall discuss in the last paragraph of this chapter. Advances have not only been made toward therapy, but also toward a better understanding of the mechanisms underlying gene delivery. Finally, PEI has become one of the most popular reagents for transfection of cells in culture, on a fast-growing market that is boosted by human and animal genome sequencing.
Collapse
Affiliation(s)
- Barbara Demeneix
- Evolution des Régulations Endocriniennes, Muséum National d'Histoire Naturelle, 7, rue Cuvier, 75231 Paris; Chimie Génétique, Faculté de Pharmacie, route du Rhin 67401 Illkirch, France
| | | |
Collapse
|
35
|
Kim SW, Ogawa T, Tabata Y, Nishimura I. Efficacy and cytotoxicity of cationic-agent-mediated nonviral gene transfer into osteoblasts. ACTA ACUST UNITED AC 2004; 71:308-15. [PMID: 15372469 DOI: 10.1002/jbm.a.30160] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Ex vivo gene transfer into osteoblastic cells is an advantageous strategy for bone tissue engineering. This study investigated the efficacy and cytotoxicity of in vitro cationic-agent-mediated nonviral gene transfer into osteoblasts. Various cationic agents, lipid, gelatin, and polyethylenimine (PEI) were tested. Each was formulated in various concentrations to form a complex with plasmid DNA encoding red fluorescent protein. The cationic agent/DNA complexes were transfected into human fetal osteoblastic cell line and rat bone-marrow-derived primary osteoblasts, as well as NIH 3T3 fibroblast controls. Rat primary osteoblasts were transfected more with cationic lipid and PEI agents than with gelatin carrier, yielding transfection efficacy up to 18.1% and 12.7 %, respectively. In contrast, human fetal osteoblastic cell line was transfected more with cationic lipid and gelatin than with PEI. There was a positive correlation between the lipid and PEI doses and cytotoxicity. When the lipid and PEI were used to transfect the rat primary osteoblasts in a dose that yielded the highest transfection efficacy, cell survival rates decreased as low as 40%. When their transfection efficacies into primary osteoblasts were compromised at two thirds of the highest value, that is, 12.6% and 8.3% for the lipid and PEI, respectively, the cell survival rate was nearly 80%. Cationic gelatin was associated with cell survival rates over 60 % in any cell type, regardless of the doses tested. These results suggest that different types of osteoblastic cells may possess different ability to the uptake and expression of cationic-agent-bound DNA. There seemed to be agent-specific threshold doses that dropped the cell survival rate. Cationic-agent-mediated nonviral gene transfer into osteoblastic cells may be successful when the agent- and dose-dependent transfection efficacy and cytotoxicity are optimized.
Collapse
Affiliation(s)
- Soo-Woo Kim
- The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, 10833 Le Conte Avenue, CHS, B3-087, Los Angeles, CA, USA
| | | | | | | |
Collapse
|
36
|
Li Y, Wang J, Lee CGL, Wang CY, Gao SJ, Tang GP, Ma YX, Yu H, Mao HQ, Leong KW, Wang S. CNS gene transfer mediated by a novel controlled release system based on DNA complexes of degradable polycation PPE-EA: a comparison with polyethylenimine/DNA complexes. Gene Ther 2003; 11:109-14. [PMID: 14681704 DOI: 10.1038/sj.gt.3302135] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Nonviral gene delivery systems based upon polycation/plasmid DNA complexes are quickly gaining recognition as an alternative to viral gene vectors for their potential in avoiding immunogenicity and toxicity problems inherent in viral systems. We investigated in this study the feasibility of using a controlled release system based on DNA complexed with a recently developed polymeric gene carrier, polyaminoethyl propylene phosphate (PPE-EA), to achieve gene transfer in the brain. A unique feature of this gene delivery system is the biodegradability of PPE-EA, which can provide a sustained release of DNA at different rates depending on the charge ratio of the polymer to DNA. PPE-EA/DNA complexes, naked DNA, and DNA complexed with polyethylenimine (PEI), a nondegradable cationic polymer known to be an effective gene carrier, were injected intracisternally into the mouse cerebrospinal fluid. Transgene expression mediated by naked DNA was mainly detected in the brain stem, a region close to the injection site. With either PPE-EA or PEI as a carrier, higher levels of gene expression could be detected in the cerebral cortex, basal ganglia, and diencephalons. Transgene expression in the brain mediated by PPE-EA/DNA complexes at an N/P ratio of 2 persisted for at least 4 weeks, with a significant higher level than that produced by either naked plasmid DNA or PEI/DNA at the 4-week time point. Furthermore, PPE-EA displayed much lower toxicity in cultured neural cells as compared to PEI and did not cause detectable pathological changes in the central nervous system (CNS). The results established the potential of PPE-EA as a new and biocompatible gene carrier to achieve sustained gene expression in the CNS.
Collapse
Affiliation(s)
- Y Li
- Institute of Bioengineering and Nanotechnology, Singapore
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Wang J, Huang SW, Zhang PC, Mao HQ, Leong KW. Effect of side-chain structures on gene transfer efficiency of biodegradable cationic polyphosphoesters. Int J Pharm 2003; 265:75-84. [PMID: 14522120 DOI: 10.1016/j.ijpharm.2003.07.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Cationic polyphosphoesters (PPEs) with different side-chain charge groups were designed and synthesized as biodegradable gene carriers. Poly(N-methyl-2-aminoethyl propylene phosphate) (PPE-MEA), with a secondary amino group (-CH(2)CH(2)NHCH3) side chain released DNA in several hours at N/P (amino group of polymer to phosphate group of DNA) ratios from 0.5 to 5; whereas PPE-HA, bearing -CH(2)(CH2)(4)CH(2)NH(2) groups in the side chain, did not release DNA at the same ratio range for 30 days. Hydrolytic degradation and DNA binding results suggested that side chain cleavage, besides the polymer degradation, was the predominant factor affected the DNA release and transfection efficiencies. The side chain of PPE-MEA was cleaved faster than that of PPE-HA, resulting poor cellular uptake and no transgene expression for PPE-MEA/DNA complexes in COS-7 cells at charge ratios from 4 to 12. In contrast, PPE-HA/DNA complexes were stable enough to be internalized by cells and effected gene transfection (3400 folds higher than background at a charge ratio of 12). Interestingly, gene expression levels mediated by PPE-MEA and PPE-HA in mouse muscle following intramuscular injection of complexes showed a reversed order: PPE-MEA/DNA complexes mediated a 1.5-2-fold higher luciferase expression in mouse muscle as compared with naked DNA injection, while PPE-HA/DNA complexes induced delayed and lowered luciferase expression than naked DNA. These results suggested that the side chain structure is a crucial factor determining the mechanism and kinetics of hydrolytic degradation of PPE carriers, which in turn influenced the kinetics of DNA release from PPE/DNA complexes and their transfection abilities in vitro and in vivo.
Collapse
Affiliation(s)
- Jun Wang
- Johns Hopkins Singapore, Tissue and Therapeutic Engineering Laboratory, Clinical Research Centre, Level 5, NUS, 10 Medical Drive, Singapore 117597, Singapore
| | | | | | | | | |
Collapse
|
38
|
Shi L, Tang GP, Gao SJ, Ma YX, Liu BH, Li Y, Zeng JM, Ng YK, Leong KW, Wang S. Repeated intrathecal administration of plasmid DNA complexed with polyethylene glycol-grafted polyethylenimine led to prolonged transgene expression in the spinal cord. Gene Ther 2003; 10:1179-88. [PMID: 12833127 DOI: 10.1038/sj.gt.3301970] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Gene delivery into the spinal cord provides a potential approach to the treatment of spinal cord traumatic injury, amyotrophic lateral sclerosis, and spinal muscular atrophy. These disorders progress over long periods of time, necessitating a stable expression of functional genes at therapeutic levels for months or years. We investigated in this study the feasibility of achieving prolonged transgene expression in the rat spinal cord through repeated intrathecal administration of plasmid DNA complexed with 25 kDa polyethylenimine (PEI) into the lumbar subarachnoid space. With a single injection, DNA/PEI complexes could provide transgene expression in the spinal cord 40-fold higher than naked plasmid DNA. The transgene expression at the initial level persisted for about 5 days, with a low-level expression being detectable for at least 8 weeks. When repeated dosing was tested, a 70% attenuation of gene expression was observed following reinjection at a 2-week interval. This attenuation was associated with apoptotic cell death and detected even using complexes containing a noncoding DNA that did not mediate any gene expression. When each component of the complexes, PEI polymer or naked DNA alone, were tested in the first dosing, no reduction was found. Using polyethylene glycol (PEG)-grafted PEI for DNA complexes, no attenuation of gene expression was detected after repeated intrathecal injections, even in those rats receiving three doses, administered 2 weeks apart. Lumbar puncture is a routine and relatively nontraumatic clinical procedure. Repeated administration of DNA complexed with PEG-grafted PEI through this less invasive route may prolong the time span of transgene expression when needed, providing a viable strategy for the gene therapy of spinal cord disorders.
Collapse
Affiliation(s)
- L Shi
- Molecular and Biomaterials Laboratory, Institute of Materials Research & Engineering, National University of Singapore, 3 Research Link, Singapore 117602, Republic of Singapore
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Abstract
Polymers with repeating phosphoester bonds in the backbone are structurally versatile, and biodegradable through hydrolysis, and possibly enzymatic digestion at the phosphoester linkages under physiological conditions. These biodegradable polyphosphoesters are appealing for biological and pharmaceutical applications because of their potential biocompatibility and similarity to bio-macromolecules such as nucleic acids. In the first part of this review, we will focus on one particular structure synthesized by extending oligomeric lactide prepolymers with ethylphosphate groups. This amorphous to semi-crystalline polymer is promising in delivering anti-cancer therapeutics in the form of microspheres. In the second half, we will discuss the conjugation of charged groups to the side chain of the phosphate, constituting one of the few biodegradable cationic polymers in the field for non-viral gene delivery. Capable of delivering exogenous genes to a cell nucleus or providing an extracellular sustained release of DNA, these cationic polyphosphoesters also serve as a valuable model to understand the important characteristics that render a polymer an effective gene carrier.
Collapse
Affiliation(s)
- Zhong Zhao
- Stent Therapeutics, Cordis Corporation, Warren, NJ 07059, USA
| | | | | | | |
Collapse
|
40
|
Wang J, Zhang PC, Lu HF, Ma N, Wang S, Mao HQ, Leong KW. New polyphosphoramidate with a spermidine side chain as a gene carrier. J Control Release 2002; 83:157-68. [PMID: 12220847 DOI: 10.1016/s0168-3659(02)00180-3] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A new cationic polymer (PPA-SP), polyphosphoramidate bearing spermidine side chain, was prepared as a non-viral vector for gene delivery. PPA-SP was synthesized from poly(1,2-propylene H-phosphonate) by the Atherton-Todd reaction. The weight average molecular weight of PPA-SP was 3.44x10(4) with a number average degree of polymerization of 90, as determined by GPC/LS/RI method. The average net positive charge per polymer chain was 102. PPA-SP was able to condense plasmid DNA efficiently and formed complexes at an N/P ratio (free amino groups in polymer to phosphate groups in DNA) of 2 and above, as determined by agarose gel electrophoresis. This new gene carrier offered significant protection to DNA against nuclease degradation at N/P ratios above 2, and showed lower cytotoxicity than PLL and PEI in cell culture. The LD(50) of PPA-SP was 85 microg/ml in COS-7 cells, in contrast to 20 and 42 microg/ml for PLL and PEI, respectively. The complexes prepared in saline at N/P ratios of 5 approximately 10 had an average size of 250 nm and zeta-potential of 26 mV. PPA-SP mediated efficient gene transfection in a number of cell lines, and the transfection protocol was optimized in HEK293 cells using a luciferase plasmid as a marker gene. Gene expression mediated by PPA-SP was greatly enhanced when chloroquine was used in conjunction at a concentration of 100 microM. Under the optimized condition, PPA-SP/DNA complexes yield a luciferase expression level closed to PEI/DNA complexes or Transfast mediated transfection. In a non-invasive CNS gene delivery model, PPA-SP/DNA complexes yielded comparable bcl-2 expression as PEI/DNA complexes in mouse brain stem following injection of the complexes in the tongue.
Collapse
Affiliation(s)
- Jun Wang
- Johns Hopkins Singapore Biomedical Centre, Tissue and Therapeutic Engineering Laboratory, 10 Medical Drive, Singapore 117597, Singapore
| | | | | | | | | | | | | |
Collapse
|
41
|
Merdan T, Kopecek J, Kissel T. Prospects for cationic polymers in gene and oligonucleotide therapy against cancer. Adv Drug Deliv Rev 2002; 54:715-58. [PMID: 12204600 DOI: 10.1016/s0169-409x(02)00046-7] [Citation(s) in RCA: 645] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Gene and antisense/ribozyme therapy possesses tremendous potential for the successful treatment of genetically based diseases, such as cancer. Several cancer gene therapy strategies have already been realized in vitro, as well as in vivo. A few have even reached the stage of clinical trials, most of them phase I, while some antisense strategies have advanced to phase II and III studies. Despite this progress, a major problem in exploiting the full potential of cancer gene therapy is the lack of a safe and efficient delivery system for nucleic acids. As viral vectors possess toxicity and immunogenicity, non-viral strategies are becoming more and more attractive. They demonstrate adequate safety profiles, but their rather low transfection efficiency remains a major drawback. This review will introduce the most important cationic polymers used as non-viral vectors for gene and oligonucleotide delivery and will summarize strategies for the targeting of these agents to cancer tissues. Since the low efficiency of this group of vectors can be attributed to specific systemic and subcellular obstacles, these hurdles, as well as strategies to circumvent them, will be discussed. Local delivery approaches of vector/DNA complexes will be summarized and an overview of the principles of anticancer gene and antisense/ribozyme therapy as well as an outline of ongoing clinical trials will be presented.
Collapse
Affiliation(s)
- Thomas Merdan
- Department of Pharmaceutics and Biopharmacy, Philipps University, Ketzerbach 63, 35032 Marburg, Germany
| | | | | |
Collapse
|
42
|
Wang J, Zhang PC, Mao HQ, Leong KW. Enhanced gene expression in mouse muscle by sustained release of plasmid DNA using PPE-EA as a carrier. Gene Ther 2002; 9:1254-61. [PMID: 12215893 DOI: 10.1038/sj.gt.3301794] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2002] [Accepted: 04/29/2002] [Indexed: 11/09/2022]
Abstract
Delivery of plasmid DNA by nanoparticles improves the DNA bioavailability, for instance in intramuscular administration, by localizing the DNA in the muscle tissue. Extracellular sustained release of the DNA may lead to more prolonged transgene expression. The present study describes a novel controlled gene delivery system based on a water soluble and biodegradable polyphosphoester, poly(2-aminoethyl propylene phosphate) (PPE-EA). The polymer degraded in PBS at 37 degrees C through the cleavage of the backbone phosphate bonds, and it was synthesized with a relative high molecular weight to ensure a suitable hydrolytic stability as a gene carrier. The tissue response and cytotoxicity study demonstrated a better tissue compatibility of PPE-EA in mouse muscle compared with commonly used polyethylenimine and poly-L-lysine. PPE-EA condensed DNA efficiently and protected DNA from nuclease and serum degradation. Sustained release of plasmid was achieved from PPE-EA/DNA complexes as a result of PPE-EA degradation. The DNA release profiles appear to be predominantly controlled by carrier degradation and the release rate of plasmid could be adjusted by varying the charge ratio of PPE-EA to DNA. At an N/P (amino to phosphate groups) ratio of 1, a 46% burst was observed for the first day, followed by about 4% release per day (24 microg DNA/day/mg of complex) for 12 days. Higher charge ratios reduced both the DNA release rate and the burst effect. The released DNA retained its structural and functional integrity. Intramuscular injection of PPE-EA-p43-LacZ complexes at N/P ratios of 0.5 and 1 resulted in enhanced beta-galactosidase expression in anterior tibialis muscle in Balb/c mice, as compared with naked DNA injections. Similarly, PPE-EA/IFN(alpha)2b DNA complexes generated an increased systemic level of interferon-alpha2b in mouse serum following intramuscular injection, as compared with naked DNA injection.
Collapse
Affiliation(s)
- J Wang
- Tissue and Therapeutic Engineering Laboratory, Johns Hopkins Singapore, Singapore
| | | | | | | |
Collapse
|
43
|
Dolivet G, Merlin JL, Barberi-Heyob M, Ramacci C, Erbacher P, Parache RM, Behr JP, Guillemin F. In vivo growth inhibitory effect of iterative wild-type p53 gene transfer in human head and neck carcinoma xenografts using glucosylated polyethylenimine nonviral vector. Cancer Gene Ther 2002; 9:708-14. [PMID: 12136433 DOI: 10.1038/sj.cgt.7700485] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2002] [Indexed: 11/08/2022]
Abstract
Polyethylenimine (PEI) derivatives are polycationic nonviral vectors for gene transfer. Previous results achieved in vitro in head and neck cancer cells demonstrated that glucosylated PEI yields higher gene transfer efficiency and longer transgene expression than unsubstituted PEI. Using glucosylated PEI, p53 gene transfer was successfully achieved with subsequent recovery of P53 protein expression and induction of spontaneous apoptosis. The present study reports in vivo data achieved in human head and neck squamous cell carcinoma xenografted mice. Using biotinylated PEI and histochemistry analysis, the vector was found to diffuse in the proliferating cells of the tumor tissue, sparing necrotic areas. No diffusion was observed inside keratinized area composed of nonproliferating, mature differentiated cells. Using green fluorescent protein (GFP) transfection and fluorescence microscopy, the transgene expression was mainly observed at the periphery of the tumor containing proliferating cells. GFP expression appeared lower inside the tumor depth. Quantitative transgene expression kinetics was then determined using luciferase as reporter gene. The maximal transgene expression was achieved 48 hours after intratumoral injection of glucosylated PEI/DNA complexes. The highest gene transfer efficacy was achieved 48 hours after two intratumoral injection. After transfection of wild-type p53, tumor growth inhibition was observed in tumor-bearing mice receiving intratumoral injection of glucosylated PEI/DNA complexes repeated twice weekly. Tumor growth inhibition was maintained under continuous treatment using the same schedule. In all experiments, no noticeable toxicity was observed. The present results demonstrate the feasibility and the tumor growth inhibition potency of nonviral gene transfer using glucosylated polyethylenimine.
Collapse
Affiliation(s)
- Gilles Dolivet
- Centre Alexis Vautrin, Avenue de Bourgogne, Vandoeuvre-Nancy, France
| | | | | | | | | | | | | | | |
Collapse
|