Huang / Liu / Wagner Nonviral Vectors for Gene Therapy

Lipid- and Polymer-based Gene Transfer
1. Auflage 2014
ISBN: 978-0-12-800367-1
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, Band Volume 88, 428 Seiten

Reihe: Advances in Genetics

The field of genetics is rapidly evolving, and new medical breakthroughs are occurring as a result of advances in our knowledge of genetics. Advances in Genetics continually publishes important reviews of the broadest interest to geneticists and their colleagues in affiliated disciplines. - Includes methods for testing with ethical, legal, and social implications - Critically analyzes future directions - Written and edited by recognized leaders in the field

Autoren/Hrsg.

Huang, Leaf

Liu, Dexi

Wagner, Ernst

Inhaltsverzeichnis

1;Front Cover;1
2;Advances in
Genetics Nonviral Vectors for Gene Therapy;4
3;Copyright;5
4;DEDICATION;6
5;CONTENTS;8
6;CONTRIBUTORS;12
7;Chapter 1 - Nonviral Vectors: We Have Come a Long Way;16
7.1;1. INTRODUCTION;17
7.2;2. CHEMICAL METHODS;17
7.3;3. PHYSICAL METHODS;23
7.4;4. PERSPECTIVES;26
7.5;ACKNOWLEDGMENTS;26
7.6;REFERENCES;26
8;Chapter 2 - Lipid Nanoparticles for Gene Delivery;28
8.1;1. INTRODUCTION;29
8.2;2. RATIONAL DESIGNS TO OVERCOME EXTRACELLULAR AND INTRACELLULAR BARRIERS;30
8.3;3. CURRENT LIPIDIC VECTORS FOR GENE DELIVERY;33
8.4;4. GENE THERAPY APPLICATIONS;39
8.5;5. PHARMACOKINETICS, BIODISTRIBUTION AND TOXICITY OF LNPS;41
8.6;6. CLINICAL TRIALS;43
8.7;7. CONCLUSIONS;45
8.8;ACKNOWLEDGMENTS;45
8.9;REFERENCES;45
9;Chapter 3 - Nanotechnology for In vivo Targeted siRNA Delivery;52
9.1;1. RNA POTENTLY MODIFIES GENE EXPRESSION;53
9.2;2. TARGETING STRATEGIES;55
9.3;3. TARGETING THE LIVER;61
9.4;4. TARGETING PRIMARY TUMORS AND METASTASIS;71
9.5;5. ENDOTHELIAL CELL TARGETING;75
9.6;6. FUTURE PERSPECTIVES;77
9.7;REFERENCES;79
10;Chapter 4 - Lipid Nanoparticles for Short Interfering RNA Delivery;86
10.1;1. INTRODUCTION;87
10.2;2. CHALLENGES AND STRATEGIES FOR DELIVERY OF SIRNA;88
10.3;3. LIPID-BASED DELIVERY SYSTEMS;93
10.4;4. LNP-SIRNA FORMULATIONS IN CLINICAL TRIALS;110
10.5;5. FUTURE PROSPECTS;112
10.6;REFERENCES;117
11;Chapter 5 - Composite Nanoparticles for Gene Delivery;126
11.1;1. NANOMEDICINE AND GENE THERAPY;127
11.2;2. COMPOSITE NANOPARTICLES;128
11.3;3. FABRICATION METHODS OF COMPOSITE NANOPARTICLES;128
11.4;4. COMPOSITE NANOPARTICLES FOR TARGETED GENE DELIVERY;134
11.5;5. CONCLUSION;146
11.6;ACKNOWLEDGMENTS;146
11.7;REFERENCES;146
12;Chapter 6 - Multifunctional Enveloped Nanodevices (MENDs);154
12.1;1. INTRODUCTION;155
12.2;2. R8-MEND;157
12.3;3. KALA-MEND;169
12.4;4. MITO-PORTER;174
12.5;5. YSK-MEND;187
12.6;6. SS-CLEAVABLE PROTON-ACTIVATED LIPID-LIKE MATERIAL (SSPALM);199
12.7;7. PERSPECTIVES;206
12.8;ACKNOWLEDGMENTS;207
12.9;REFERENCES;207
13;Chapter 7 - Lipid-Coated Calcium Phosphate Nanoparticles for Nonviral Gene Therapy;220
13.1;1. RECENT PROGRESS OF NONVIRAL GENE THERAPY AND IN VITRO/IN VIVO DELIVERY SYSTEMS;221
13.2;2. LCP NANOPARTICLES AS A MULTIFUNCTIONAL PLATFORM FOR GENE DELIVERY;225
13.3;3. POTENTIAL THERAPEUTIC APPLICATIONS OF LCP: CANCER, CHRONIC LIVER DISEASE, AND GENE THERAPY;234
13.4;4. LCP NANOPARTICLES: CONCLUSIONS;238
13.5;REFERENCES;238
14;Chapter 8 - Polymers for Nucleic Acid Transfer—An Overview;246
14.1;1. FIVE DECADES IN POLYPLEXES: CHALLENGES AND BREAKTHROUGHS;247
14.2;2. OPTIMIZING THE CORE: BIODEGRADABLE AND BIOCOMPATIBLE POLYMERS;250
14.3;3. OPTIMIZING THE SHELL: BIOINSPIRED SMART POLYPLEXES;256
14.4;4. NEXT STEPS: MULTIFUNCTIONAL AND SEQUENCE-DEFINED POLYMERS;260
14.5;5. PERSPECTIVES;264
14.6;REFERENCES;264
15;Chapter 9 - Recent Developments in Nucleic Acid Delivery with Polyethylenimines;278
15.1;1. INTRODUCTION;279
15.2;2. MECHANISM OF PEI-MEDIATED DNA TRANSFECTION;280
15.3;3. PROTON SPONGE: MYTH OR REALITY?;283
15.4;4. PEI FOR GENE DELIVERY;288
15.5;5. PEI DERIVATIVES FOR THE DELIVERY OF EXON SKIPPING OLIGONUCLEOTIDES;292
15.6;6. PEIS FOR SIRNA DELIVERY;293
15.7;7. CONCLUSION;297
15.8;REFERENCES;297
16;Chapter 10 - Bioresponsive Polymer-Based Nucleic Acid Carriers;304
16.1;1. INTRODUCTION;305
16.2;2. POLYMER SELF-ASSEMBLIES FOR NUCLEIC ACID DELIVERY;307
16.3;3. REDUCTIVE ENVIRONMENT-RESPONSIVE NUCLEIC ACID DELIVERY;311
16.4;4. ACIDIC PH-RESPONSIVE NUCLEIC ACID DELIVERY;317
16.5;5. OTHER STIMULI-RESPONSIVE NUCLEIC ACID DELIVERY;325
16.6;6. CONCLUSION AND FUTURE PERSPECTIVES;329
16.7;REFERENCES;329
17;Chapter 11 - Chitosan-Based Nanoparticles for Mucosal Delivery of RNAi Therapeutics;340
17.1;1. INTRODUCTION;341
17.2;2. RNA INTERFERENCE;342
17.3;3. THE MUCOSAL BARRIER;345
17.4;4. MUCOADHESIVE BIOMATERIALS;348
17.5;5. CHITOSAN;350
17.6;6. CHITOSAN/SIRNA NANOPARTICLES;351
17.7;7. CHITOSAN/SIRNA NANOPARTICLES FOR DELIVERY ACROSS MUCOSAL BARRIERS;355
17.8;8. CONSIDERATIONS AND FUTURE PERSPECTIVES;357
17.9;REFERENCES;360
18;Chapter 12 - Polycation-Mediated Integrated Cell Death Processes;368
18.1;1. INTRODUCTION: CELL DEATH DEFINITIONS, GUIDELINES, AND PROCESSES;369
18.2;2. LYSOSOMAL-RELATED CELL DEATH;382
18.3;3. ER-RELATED CELL DEATH;388
18.4;4. MITOCHONDRION-RELATED CELL DEATH ON POLYCATION TREATMENT;391
18.5;5. CELL DEATH-ASSAY DESIGN, CONSIDERATIONS, AND INTERPRETATIONS;395
18.6;6. SAFER DESIGN OF POLYCATIONIC SYSTEMS;399
18.7;7. CONCLUSIONS;402
18.8;REFERENCES;402
19;INDEX;414
20;COLOR PLATES;424

Leseproben

Chapter One

Nonviral Vectors

We Have Come a Long Way

Tyler Goodwin and Leaf Huang1     Division of Molecular Pharmaceutics and Center for Nanotechnology in Drug Delivery, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
1 Corresponding author: E-mail: [e-mail] 

Abstract

Gene therapy, once thought to be the future of medicine, has reached the beginning stages of exponential growth. Many types of diseases are now being studied and treated in clinical trials through various gene delivery vectors. It appears that the future is here, and gene therapy is just beginning to revolutionize the way patients are treated. However, as promising as these ongoing treatments and clinical trials are, there are many more barriers and challenges that need to be addressed and understood in order to continue this positive growth. Our knowledge of these challenging factors such as gene uptake and expression should be expanded in order to improve existing delivery systems. This chapter will provide a brief overview on recent advances in the field of nonviral vectors for gene therapy as well as point out some novel vectors that have assisted in the extraordinary growth of nonviral gene therapy as we know it today.

Keywords

Cationic lipids; Cationic polymers; Electroporation; Genetic material; Hydrodynamic injection

1. Introduction

The past several decades have shown immense growth in the knowledge of the ability to create and improve nonviral vectors for the delivery of genetic material. This genetic material has great promise as a therapeutic agent against numerous aliments including genetic disorders, chronic and acute diseases, and cancer. Within this field of nonviral vectors, we have produced promising physical methods and chemical vectors for gene delivery consisting of electroporation techniques, cationic lipids, cationic polymers, hybrid lipid polymers, as well as many others. An increased understanding of the field has catalyzed efficiency to new levels in which delivery of plasmid DNA or oligonucleotide into cells can be well characterized and has yielded promising results in preclinical and clinical trials. These vectors have shown to be a promising alternative to viral vectors due to their safety, adaptability, and efficiency in large-scale production. Nonviral vectors have demonstrated their potential to be the next delivery systems of genetic material. They have been shown to exhibit cell specificity through addition of targeting ligands, minimal immune toxicities through addition of inflammatory suppressor molecules, as well as sufficient genetic material release into the cytoplasm of the cell through endosomal destabilization via proton sponge effect or other mechanisms. However, even with these strides, the field of nonviral gene therapy has many areas that need to be addressed, particularly in gene release, nuclear uptake, and expression, which are lagging behind viral vector capabilities. With each vector comes advantages and disadvantages, which will be addressed throughout Part I and Part II of this book.

2. Chemical Methods

The chemical methods which deliver genetic material via a vector consisting of cationic lipids (lipoplex), cationic polymers (polyplex), or lipid-polymer hybrids (lipopolyplex) have shown promise. These vectors are being used as a systemic approach to delivering genetic material. Therefore, many challenges need to be addressed in order to improve and generate ideal nonviral vectors. These vectors must overcome barriers which consist of extracellular stability, specific cell targeting, internalization, endosomal escape, nucleotide release, nuclear envelope entry, and genome integration (Figure 1.1) (Hu, Haynes, Wang, Liu, & Huang, 2013). These first few barriers mentioned seem to have been accomplished to a reasonable level. Multiple vectors have become efficient at achieving long circulation half-life with stable carrier molecules and the addition of hydrophilic moieties such as polyethylene glycol (PEG). The improved cell specificity and internalization with the conjugation of targeting ligands, as well as endosomal escape through the proton sponge effect, have also been achieved with moderate success. By overcoming these initial barriers and being able to deliver genetic material into the cytoplasm of the diseased cell, numerous oligonucleotides, mainly siRNA, are reaching new levels in clinical trials. However, in order to truly reach clinical efficiency in DNA delivery, we must improve intracellular nucleotide release, nuclear entry, and genome integration.

Figure 1.1 Proposed mechanism for intracellular delivery of DNA by lipid calcium phosphate (LCP).

Stepwise scheme for nonviral acid-sensitive vector (LCP), in which (a) the vector is internalized through receptor-mediated endocytosis, (b) PEG is shed from the vector, (c,d) vector and endosome further destabilized as endosome’s pH decreases and releases the DNA–peptide complex into the cytoplasm. The DNA–peptide complex enters the nucleus through the nuclear pore, where it dissociates and releases free DNA, which is transcribed to mRNA, migrates to the cytoplasm to be translated, and results in desired protein synthesis (Hu et al., 2013). Original figure was prepared by Bethany DiPrete. (See the color plate.)

2.1. Cationic Lipid-Based Nanoparticles (Lipoplex)

Cationic lipid-based gene delivery (lipofection) was first published by Felgner’s group in the late 1980s (Felgner et al., 1987). It has become the most studied and popular of all nonviral gene delivery methods and is discussed further in part I, chapters 2, 3, 4, and 7. The basis for using cationic lipids as a delivery system for negatively charged DNA is that the positively charged hydrophilic head group can condense with the DNA while the hydrophobic tail can form micellar or bilayer structures around the DNA. This complexation of lipids around the DNA has been termed a lipoplex and yields DNA protection against nucleases. There are numerous lipid structures that have been tested in order to find optimal lipids to form a lipoplex structure with DNA. The head groups can vary from primary, secondary, and tertiary amines, or quaternary ammonium salts as well as phosphorus, guanidino, arsenic, imidazole, and pyridinium groups. The hydrophobic tails consist of aliphatic chains which can be unsaturated or saturated and are connected to the hydrophilic head by a linker usually consisting of an ester, ether, carbamate, or amide. Cholesterol, as well as other steroids, is usually included in the formulation of these lipoplexes in order to increase the stability and flexibility of these vectors and have been shown to improve transfection in vivo. All of these components are critical in formulating promising nonviral gene delivery vectors. Varying these components can drastically change the transfection efficiency as well as improve uptake into the cell and release from the endosome. The electrostatic interaction between the negatively charged cellular membrane and the positively charged lipid head groups is vital in achieving higher levels of cellular uptake. The lipid fusion mechanism in which the positively charged vectors fuse with the cellular membrane ultimately resulting in cellular uptake of genetic material is promoted by vectors with increased flexibility as well as neutral or helper lipids (colipids) that can assist in this fusion with the cellular membrane (Li & Szoka, 2007). The fusogenic properties which facilitate cellular uptake are also valuable in the endosomal escape of lipoplexes through membrane destabilization followed by DNA release from the vector into the cytoplasm of the cell. Although the simple early lipoplexes have the capability to deliver genetic material to cells, they have drawbacks which include low transfection, an inability to target specific cells, short half-life, and toxicity due to the positively charged lipids used. Many more details and examples of cationic lipid vectors are discussed in part I, chapters 2, 3, 4, and 7.

To address the short circulation and toxicity issues with cationic lipid vectors, PEG has been introduced to the surface of these vectors in order to shield the positive charge and reduce opsonization from the reticuloendothelial system. The addition of PEG increased circulation time, allowing more time for these vectors to transfect cells (Harvie, Wong, & Bally, 2000); however, the surface PEG prevents an interaction between the cationic lipoplexes and anionic cell membrane, reducing the overall transfection efficiency. Therefore, in order to increase cellular uptake of these PEGylated lipoplexes, several strategies have been devised. The conjugation of cell-specific targeting ligands to the distal end of PEG, as well as the addition of PEG-lipid conjugates with shorter alkylated chains that can shed off the vector while in circulation over time, have shown promise. The incorporation of chemically sensitive bonds has also improved the shedding of PEG once inside an acidic or reducing environment such as the endosome or cytoplasm (Li & Szoka, 2007).

Prolonged circulation time and decreased toxicity due to surface modification makes targeted gene delivery to cells located in the interstitial regions possible. Improvements in these nonviral cationic lipid vectors have proved to be promising in gene transfer, especially in the field of siRNA delivery. In addition to its...