Gene transfer in skeletal muscle by systemic injection of DODAC lipopolyplexes

Flexible cyclic siloxane core enhances the transfection efficiency of polyethylenimine-based non-viral gene vectors

cD₄^H–AGE–PEI conjugates, with a favorable balance between hydrophilic and hydrophobic moieties, are promising carriers for gene delivery.

In vivo delivery of naked antisense oligos in aged mdx mice: analysis of dystrophin restoration in skeletal and cardiac muscle

Antisense-mediated exon skipping holds great potential for the treatment of DMD. In mdx mice, functional recovery of skeletal muscle has been obtained upon systemic delivery of "naked" oligonucleotides or viral vectors encoding for antisense snRNAs. However, amongst the studies reported so far, which used either neonatal or young adult animals--only one achieved dystrophin restoration in cardiac muscle, using an adeno-associated vector. Here we report the in vivo delivery of morpholino oligos in aged mdx mice, both in skeletal muscle, via intra-arterial injection, and in cardiac muscle, via intra-muscular injection. Localized intra-arterial delivery yielded high levels of dystrophin restoration and just two doses of 100 microg each resulted into detectable force recovery in the EDL muscles of treated limbs. On the other hand, upon intra-cardiac injections in the left ventricle wall the skipping effect was much lower than what obtained in tibialis anterior muscles injected with comparable amounts of oligos. This latter finding suggests that even upon direct delivery antisense-mediated dystrophin restoration in cardiac muscle might suffer from limitations that do not exist in skeletal muscle.

An overview of condensing and noncondensing polymeric systems for gene delivery

INTRODUCTIONSelf-assembling synthetic vectors for DNA delivery are designed to fulfill several biological functions. They must be able to deliver their genetic payload specifically to the target tissue/cells in a site-specific manner, while protecting the genetic material from degradation by metabolic or immune pathways. Furthermore, they must exhibit minimal toxicity and be proven safe enough for therapeutic use. Ultimately, they must have the capability to express a therapeutic gene for a finite period of time in an appropriate, regulated fashion. The DNA encapsulated in these vectors may be in a condensed or noncondensed form, depending on the nature of the polymer and the technique used for formulating the vector system. The whole process presents many barriers at both tissue and cellular levels. Overcoming these hurdles is the principal objective for efficient polymer-based DNA therapeutics.

Comparing reagents for efficient transfection of human primary myoblasts: FuGENE 6, Effectene and ExGen 500

This study compared three different synthetic reagents (FuGENE 6, Effectene and ExGen 500) for the transfection of human primary myoblasts. We examined the efficiency, cytotoxicity and size of the complexes formed in the presence of different amounts of vector and DNA and with variable amounts of serum. Transfection rates were relatively high for primary cells, especially with FuGENE 6 (20%), which appeared to be the best transfection reagent for these cells, even in the presence of 10% serum. Cultured human myoblasts are an interesting tool for studying neuromuscular diseases and are potentially useful for myoblast transfer therapy studies. Moreover, the efficiency of these transfection reagents in a medium containing 10% serum is promising for possible gene therapy protocols for muscle diseases.

Biochemical and biophysical characteristics of lipoplexes pertinent to solid tumour gene therapy

Cationic liposomes have become the reagent of choice for transfer of nucleic acids such as plasmids and oligodeoxynucleotides to cells in culture and in vivo. Whilst these reagents have several advantages over other forms of nucleic acid transfer methods, toxicity remains a significant problem, especially in vivo. Recent studies have also highlighted the immunostimulatory nature of these cationic vesicles when complexed to plasmid DNA, a phenomenon that may be harnessed for efficacious usage against tumours. Current research in this dynamic technological field is aimed at the development of cationic lipids that have negligible toxic effects and enhanced transfection capabilities.