Transfection of large plasmids in primary human myoblasts

Non-viral gene delivery in skeletal muscle: a protein factory

“…68,69 The commonly used cationic polymers, poly-(L)-ornithine (PLO), polyamidoamine and branched polyethylemine (PEI) and its analogues mediate highly efficient plasmid delivery in vitro into many types of cells, including myoblasts. [70][71][72] In vivo, however, these polymers did not improve transfection efficiency in skeletal muscle. The reason(s) for the failure in vivo may again be the interaction between the positively charged polymers and negatively charged ECM components within skeletal muscle.…”

“…Indeed, whole inactive viral particles or viral proteins, particularly those derived from adenoviruses, have been shown to enhance transgene expression. 72,76,77 Although the results are encouraging, the amount of viral protein required presents an impediment to therapeutic usage of this approach for in vivo transfection. However, it may have some applicability for ex vivo gene therapy.…”

“…For example, Campeau et al used this principle for delivery of the fulllength dystrophin gene (12 kb in size) into myoblasts, which were then transplanted into muscle. 72 Intensive effort has been focused therefore on the design of short synthetic peptides that would mimic the useful functions of viral proteins, while avoiding the disadvantages associated with virus infection, namely, induction of inflammation, immunogenicity and toxicity. 78 Most peptides designed and tested so far have either originated from earlier studies on drug delivery or have been modified from viral protein sequences.…”

“…However, little or no benefit over plasmid alone was reported when NLS was used in combination with adenovirus/PEI for gene transfer into myoblasts. 72 The limited benefit of simply adding NLS to a plasmid DNA delivery system suggests the need for a more stable linkage of NLS to plasmid DNA either directly or indirectly through DNA-condensing and membranedestabilizing polymers. Again the success of this type of approach has, so far, been limited (see review by Bremener et al 78 ).…”

Microbubble ultrasound improves the efficiency of gene transduction in skeletal muscle in vivo with reduced tissue damage

“…PEI has been proved to be highly efficient for plasmid DNA delivery in many cell types including myoblasts in vitro. 21,22 Unfortunately, the use of PEI in combination with naked plasmid delivery in vivo has been reported not to improve the efficiency of transgene expression in skeletal muscle, and furthermore is associated with increased muscle damage. Our finding that Optison both reduced the amount of muscle damage and potentiated the effect of plasmid DNA gave us the idea that the microbubbles might also have similar effects on PEI/plasmid complexes.…”