Femtosecond laser treatment enhances DNA transfection efficiency in vivo

In this report, we employed a very low power, near-infrared femtosecond laser technique to enhance the transfection efficiency of intradermally and intratumorally administered DNA plasmid.We found that femtosecond laser treatment can significantly enhance the delivery of DNA into the skin and into established tumors in mice. In addition, we found that both laser power density as well as duration of laser treatment are critical parameters for augmenting DNA transfection efficiency. The femtosecond laser technique employs a relatively unfocused laser beam that maximizes the transfected area, minimizes damage to tissue and simplifies its implementation.This femtosecond new laser technology represents a safe and innovative technology for enhancing DNA gene transfer in vivo.Gene therapy continues to evolve as an attractive approach for the treatment of many diseases (for reviews, see [1-11]). In particular, the use of plasmid DNA for gene therapy has several advantages which can circumvent the limitations and potential risks associated with viral vector-based DNA delivery. It is relatively safe, stable, and inexpensive to manufacture, making it attractive for application in the clinical arena. Furthermore, in contrast to viral vectors, DNA vaccines do not elicit anti-vector immune responses in the vaccinated patient, and, therefore, are well suited for indications likely to require multiple administrations in order to achieve and maintain target immune responses.The ideal approach for enhancing DNA vaccine potency is by improving the transfection efficiency with minimal tissue damage. Several physical techniques including electroporation and ultrasound have been employed in an effort to improve gene transfection efficiency. However, several safety concerns have been raised with the application of these approaches in humans (for reviews, see [12,13]). Therefore, continued exploration for new methods of enhancing DNA transfection efficiency while minimizing side effects is