Non‐viral VEGF₁₆₅ gene therapy – magnetofection of acoustically active magnetic lipospheres (‘magnetobubbles’) increases tissue survival in an oversized skin flap model

Abstract

Adenoviral transduction of the VEGF gene in an oversized skin flap increases flap survival and perfusion. In this study, we investigated the potential of magnetofection of magnetic lipospheres containing VEGF165-cDNA on survival and perfusion of ischemic skin flaps and evaluated the method with respect to the significance of applied magnetic field and ultrasound. We prepared perfluoropropane-filled magnetic lipospheres (‘magnetobubbles’) from Tween60-coated magnetic nanoparticles, Metafectene, soybean-oil and cDNA and studied the effect in an oversized random-pattern-flap model in the rats (n= 46). VEGF-cDNA-magnetobubbles were administered under a magnetic field with simultaneously applied ultrasound, under magnetic field alone and with applied ultrasound alone. Therapy was conducted 7 days pre-operative. Flap survival and necrosis were measured 7 days post-operatively. Flap perfusion, VEGF-protein concentration in target and surrounding tissue, formation and appearance of new vessels were analysed additionally. Magnetofection with VEGF-cDNA-magnetobubbles presented an increased flap survival of 50% and increased flap perfusion (P < 0.05). Without ultrasound and without magnetic field, the effect is weakened. VEGF concentration in target tissue was elevated (P < 0.05), while underlying muscle was not affected. Our results demonstrate the successful VEGF gene therapy by means of magnetobubble magnetofection. Here, the method of magnetofection of magnetic lipospheres is equally efficient as adenoviral transduction, but has a presumable superior safety profile.

Magnetic Field-Assisted Gene Delivery: Achievements and Therapeutic Potential

“…Magnetic field-and ultrasound-aided delivery of the gene for VEGF 165 to oversized ischemic rat skin flaps was implemented using magnetic lipospheres (magnetobubbles) loaded with the corresponding cDNA. This approach increased the survival and perfusion of flaps grafted in rats [29].…”

Electroporation and ultrasound enhanced non-viral gene delivery in vitro and in vivo

“…Most agents are unable to cross the nuclear membrane and thus transfer of plasmid to the nucleus can only occur when there is breakdown of the nuclear membrane associated with cell division. As an alternative to the use of transfection reagents, plasmid delivery can be enhanced by a number of physical delivery methods that induce temporary permeabilisation of tissues by the formation of micropores (Wells (Xenariou et al 2006;Holzbach et al 2008), laser poration (Zeira et al 2007;Tsen et al 2009), ballistic delivery (Trimble et al 2003;Alvarez et al 2005), hydrodynamic delivery (Liu et al 1999;Zhang et al 1999;Hagstrom et al 2004;Zhang et al 2004), ultrasound (Newman and Bettinger 2007;Suzuki et al 2008) and electroporation (Mir 2008;McMahon and Wells 2004).…”

Increased interstitial pressure improves nucleic acid delivery to skin enabling a comparative analysis of constitutive promoters

“…injection [8][9][10][11] gene gun, 12,13 magnetofection, 14 electroporation [15][16][17][18][19][20] and topical formulations. [21][22][23][24][25][26] However, only limited success with sustainable gene expression has been observed over wide areas of the skin.…”