Magnetofection Reagents

Magnetofection is a simple, versatile and efficient method for gene transfer, which uses magnetic force to promote gene vectors associated with cationic magnetic nanoparticles into target cells. The tool has high transfection and transduction efficiency and low toxicity to primary cells.

With the development of nanotechnology and molecular biology, nanoparticles with positively charged surfaces have shown a promising future as non-viral vectors for gene delivery. A class of nanoparticles that includes gold nanoshells and other metal nanoparticles can be designed to show superparamagnetic properties, allowing a targeted acceleration of this type of nanoparticles in a temporary magnetic field. Superparamagnetic nanoparticles can be functionalized by coating with polymers, preferentially with biocompatible or biodegradable polymers of synthetic or biological origin. Superparamagnetic nanoparticles have many advantages over other non-virus delivery systems including enhanced resistance to digestion, high DNA carrying capacity, powerful penetration, low cost, and the ability to drive stable and efficient expression of target genes when exposed to an external magnetic field.

Magnetofection is a unique technique suitable for viral and non-viral gene delivery applications. Magnetofection unites the advantages of popular biochemical and physical transfection methods in one system, while breaking through their limitations such as inefficiency, toxicity, and difficulty in handling.

Product Range

Magnetofection™ is the only versatile and universal technology applicable to all types of nucleic acids (such as DNA, siRNA, dsRNA, shRNA, mRNA, and ODN), non-viral transfection systems, and viruses. Amerigo Scientific offers Magnetofection™ reagents designed for defined applications.

• Non-Viral Applications - perfect for primary and hard-to-transfect adherent cells

• Viral Applications - ideal for any cells including adherent and suspension cells

• In vivo Applications

Principle

Magnetofection™ principle is to associate nucleic acids, transfection reagents or viruses with specific magnetic nanoparticles. The resulting molecular complexes are then concentrated and transported into cells supported by an appropriate magnetic field. In this way, the exploitation of a magnetic force exerted upon gene vectors allows a very rapid concentration of the entire applied vector dose on cells, so that 100% of the cells get in contact with a significant vector dose, and promotes cellular uptake.

The magnetic nanoparticles are made of iron oxyde, which is fully biodegradable, coated with specific proprietary cationic molecules varying upon applications. Their association with the gene vectors (DNA, siRNA, ODN, virus, etc.) is achieved by salt-induced colloidal aggregation and electrostatic interaction. The magnetic particles are then concentrated onto cells by the influence of an external magnetic field generated by a specific magnetic plate. The cellular uptake of the genetic material is accomplished by endocytosis and pinocytosis, two natural biological processes. Consequently, membrane architecture & structure stay intact in contrast to other physical transfection methods that damage, create hole or electroshock the cell membranes. The nucleic acids are then released into the cytoplasm by different mechanisms depending upon the formulation used.

• First is the proton sponge effect caused by cationic polymers coated on the nanoparticles that promotes endosome osmotic swelling, disruption of the endosomal membrane and intracellular release of DNA.
• Second is the destabilization of the endosome by cationic lipids coated on the particles that release the nucleic acid into cells by flip-flop of cell negative lipids and charged neutralization.
• Third one is the usual viral mechanism when virus is used.

Biodistribution

The biodegradable cationic magnetic nanoparticles are not toxic at the recommended doses and even higher. Gene vectors / magnetic nanoparticles complexes are internalized into cells after 10-15 minutes, much faster than any other transfection method. After 24, 48 or 72 hours, most of the particles are localized in the cytoplasm, in vacuoles (membranes surrounded structure into cells) and occasionally in the nucleus. In addition, magnetic nanoparticles do not influence cell function.

How to Use

The protocol is a very simple procedure:

1. Dilute nucleic acids or vectors in serum free medium or buffer and add Magnetofection™ reagent.
2. Incubate 20-30 minutes.
3. Add these complexes directly to cells.
4. Place the culture plate on the magnetic plate to apply a magnetic field.
5. Incubate 5-20 minutes, remove the magnetic plate, and culture the transfected cells until assay.

Support Equipment

The only equipment requirement of Magnetofection™ is a magnetic plate designed specifically for this application, without the need for expensive equipment such as electroporation or gene guns. The magnetic plates are reusable and are available in three types. Their design allows the generation of a heterogeneous magnetic field that magnetizes the nanoparticles in the solution, creating a very strong gradient to attract the nanoparticles and covering all the surfaces of the plate. The plate can be washed with 70% ethanol and used in incubators or robots.