Gene therapy continues to hold promise in treating a variety of inherited and acquired diseases. Although viral vectors are popular for many gene therapy applications because of their high transduction efficiency, they are not without limitations.

“This paper presents a comprehensive investigation of chitosan as a gene carrier in terms of synthesis, and also in terms of physical, chemical, and biological characterization.”

Non-viral vectors present an attractive alternative, particularly because of their non-immunogenicity. They can also satisfy many of the pharmaceutical issues better than the viral vectors, such as ease of scale-up, storage stability, and quality control. The field of nonviral gene delivery has been growing and may be one reason this paper has attracted attention.

Earlier we have described the possibility of delivering DNA through the oral route using chitosan, a natural biopolymer, as the gene carrier. This paper presents a comprehensive investigation of chitosan as a gene carrier in terms of synthesis, and also in terms of physical, chemical, and biological characterization. It sets the foundation for applying and optimizing this new gene carrier.

The significance of chitosan as a gene carrier lies in its potential efficacy of delivering genes through the oral route. Although nonviral gene therapy is attractive because of long-term safety issues, the gene expression level achievable by nonviral gene transfer is low and transient. For gene medicine applications, where high expression levels are needed to be therapeutic, frequent administration would be required.

Intravenous or intramuscular injection, being invasive, is unattractive and may not be better than protein replacement therapy. Oral delivery, being patient-compliant and economic, is the best administration route that can render gene therapy practical.