Gene therapy being the primary objective of molecular biology experiments, especially siRNA transfection to induce RNAi in animals, where the ability to deliver foreign genetic constructs (also known as in vivo transfection) is one of the goals. Transfection reagents and kits that promote in vivo delivery of exogenous DNA/RNA have become a complicated research problem because each individual cancer cell line requires optimized transfection reagent, and similar – targeted tissue delivery of therapeutic cargo molecule require in vivo transfection reagent. There are commercially available tissue-targeted in vivo transfection kits such as Pancreas In Vivo Transfection Kit, Liver-targeted and Kidney-targeted in vivo reagents.

Studies have pointed towards lipid-based and polymer-based reagents to be the likely candidates for successful in vivo transfection. With general discomfort about using viruses as a means of delivering therapeutic molecules within the body, non-viral approaches are being considered as a safer option. The chemical tools for such approach include polymer and lipid transfection carriers. Several biotechnology companies including Altogen Biosystems have developed in vivo transfection reagents and kits.

Some of in vivo transfection reagents are based on nanotechnology involving the use of nanoparticles. These nanoparticles in combination with cationic lipids and polymers form complexes, lipoplexes and polyplexes, with nucleic acids to be inserted (siRNA, plasmid DNA, or proteins). Thereafter, genetic material and lipid/polymer complexes enter the cell through endocytosis.

Some transfection reagents are even optimized to promote intracellular separation of nucleic acid molecules from endosomes. Further, they may even advance entry of exogenous genetic material past the nuclear membrane. A polymer based in vivo transfection reagents contain PEG (see PEG-Liposome Transfection Kit) and polyethylenimine (PEI), stated to be an enhancer for in vivo delivery as well as reducing immune response.

In vivo transfection reagents offers life scientists with an opportunity to test their in vitro gene expression or knocked down genetic model in living organisms. Many times, what seems plausible in vitro may or may not actually be feasible in living systems. In vivo tests are therefore essential for testing new medicines – such approaches often include xenograft cancer animal models and pharmacology and tox IND studies performed by preclinical CROs.

In vivo transfection is set to help the field of medical science and the way doctors treat patients. Hopefully, no more cancer patients will have to go through the painful side effects of traditional chemotherapy and radiation. Scientists hope that a simple in vivo intratumoral administration of therapeutic genetic material will be efficient against tumors.

Scientists are working on development of new medicines to cure autoimmune and degenerative diseases using gene delivery (in vivo transfection) through systemic or local delivery of therapeutic siRNA, miRNA, shRNA and/or DNA.