Gene therapy involves introducing genetic material into host cells for therapeutic purposes. Initially focused on genetic disorders, gene therapy now targets diverse diseases. This therapy can be classified into germline gene therapy and somatic gene therapy, with the latter being the current focus due to ethical restrictions on germline alterations. Various viral and nonviral delivery systems have been developed, each with unique advantages and limitations, hindering a universal system for all cell types in vitro and in vivo. This review explores the history of gene therapy, different gene delivery systems, and their practical applications.
Viral vectors, such as retroviruses and adenoviruses, have been extensively used in gene delivery. Retroviruses are effective for dividing cells, while adenoviruses can deliver large DNA particles but do not integrate into the host genome. Adeno-associated vectors offer safer delivery options with limited transgene capacity. Lentiviruses, a subclass of retroviruses, can integrate with nondividing cells, making them suitable for certain applications. Poxvirus vectors are known for high-level cytoplasmic expression, while herpes simplex virus shows potential for gene delivery to the nervous system.
Nonviral delivery systems, including physical and chemical methods, offer alternatives to viral vectors. Physical methods like electroporation and hydrodynamic delivery facilitate DNA entrance into cells by creating transient membrane penetrations. Chemical methods, such as cationic lipids and polymers, form stable complexes with DNA for cellular uptake. Cationic liposomes and polymers have shown promise in gene delivery, with modifications to improve efficiency and reduce toxicity. Lipid-polymer systems combine DNA precondensation with lipid or polymer coatings for enhanced delivery.
Despite advancements in gene delivery systems, challenges remain in achieving universal, efficient, and safe gene therapy across all cell types. Enhancing extracellular targeting, improving intracellular delivery, and minimizing toxicity are critical areas for further development. Clinical successes in recent years have spurred optimism in the potential of gene therapy for treating a wide range of diseases. Continued research and innovation are essential to overcome current limitations and unlock the full therapeutic potential of gene delivery systems.
Key Takeaways:
– Gene therapy encompasses introducing genetic material for therapeutic benefits.
– Viral vectors like retroviruses and adenoviruses offer effective gene delivery but have limitations.
– Nonviral delivery systems, including physical and chemical methods, provide alternatives with lower toxicity.
– Advancements in gene delivery systems are crucial for improving therapeutic outcomes and expanding the scope of gene therapy.
Tags: secretion, drug delivery, viral vectors, cell therapy, gene therapy
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