Exploring the Potential of Tail Vein pDNA Delivery for Gene Therapy

A Simple and Effective Method for Transfecting Liver Cells

The tail vein pDNA delivery is an efficient method of transfusing liver cells in mice and rats, achieving high levels of gene transfer. This technique involves injecting a large bolus of pDNA into the tail vein, which then predominantly drains into the liver via the vena cava. The procedure appears harsh, but it is well-tolerated by almost all animals, with minimal damage that resolves within a week.

Procedure and Optimal Volume for Delivery

The best volume for delivery equates to approximately 10% of a mouse or rat's body weight. The delivery time varies between species - it should be between 5-7 seconds for mice and 15-20 seconds for rats. Temporary elevation of liver enzymes is observed post-procedure, but levels normalize within a few days.

Wide Adoption in Gene Therapy Research

This method is now widely used in the gene therapy field, both for basic research and gene therapy evaluation. It is beneficial for testing novel expression vectors quickly. Although the liver is the primary organ transfected, the method also shows potential for diseases where liver transgene expression is appropriate, and for ectopic expression of secreted proteins. It also has potential for situations where hepatocytes can replace the function of other cells.

Transgene Expression and Potential Translation to Humans

Apart from liver cells, this method also allows transgene expression in other organs, albeit at lower levels. The tail vein pDNA delivery technique shows promise for translation to the human situation, as evidenced by studies in large animals and rabbits using catheters for intravascular delivery to the liver.

Degradable Cationic Polycarbamates for Nonviral Gene Therapy

Recent studies have explored the use of degradable cationic polycarbamates (CPCs) for nonviral gene therapy, particularly against metastatic lung cancer. These CPCs, designed to mimic the chemical structure of PEIs for nonviral gene transfection, degrade under physiological conditions and display favorable gene delivery properties with less cytotoxicity.

Non-Viral Plasmid DNA for Gene Therapy

Non-viral plasmid DNA has traditionally been used as ancillary products for viral vectors' production. Recent developments have focused on creating antibiotic-free gene vectors, which have shown increased transfection efficiency and prolonged transgene expression due to their reduced size. Combining non-viral gene vectors with DNA transposons has yielded a significantly higher yield of genetically engineered T and Natural Killer cells for adoptive immunotherapies.

Advancements in Nme2Cas9 Adenine Base Editors

Advancements in gene therapy have also been seen in the development of domain inlaid Nme2Cas9 adenine base editors, which have improved activity and targeting scope. The engineering of Nme2Cas9 base editors has expanded the editing scope and improved the efficacy, targeting scope, and delivery capabilities of base editing systems in vivo.

Overcoming Challenges in rAAV Gene Therapy

While there are several challenges in rAAV gene therapy, a novel chemical tyrosine bioconjugation strategy has been proposed to improve gene transfer efficiency in the liver and retina. This non-genetic method for rAAV vector engineering aims to overcome issues such as immune responses and off-targeting. The study shows that the modification of tyrosine residues on AAV capsids improved the in vivo transduction efficiency of rAAV2 vectors in both liver and retinal targets.