Date Published: December 9, 2019
Publisher: Springer International Publishing
Author(s): Chinyang Chang, Jiao Sun, Hiroki Hayashi, Ayano Suzuki, Yuko Sakaguchi, Hiroshi Miyazaki, Tomoyuki Nishikawa, Hironori Nakagami, Kunihiko Yamashita, Yasufumi Kaneda.
DNA vaccination can be applied to the treatment of various infectious diseases and cancers; however, technical difficulties have hindered the development of an effective delivery method. The efficacy of a DNA vaccine depends on optimal antigen expression by the injected plasmid DNA. The pyro-drive jet injector (PJI) is a novel system that allows for adjustment of injection depth and may, thus, provide a targeted delivery approach for various therapeutic or preventative compounds. Herein, we investigated its potential for use in delivering DNA vaccines. This study evaluated the optimal ignition powder dosage, as well as its delivery effectiveness in both rat and mouse models, while comparing the results of the PJI with that of a needle syringe delivery system. We found that the PJI effectively delivered plasmid DNA to intradermal regions in both rats and mice. Further, it efficiently transfected plasmid DNA directly into the nuclei, resulting in higher protein expression than that achieved via needle syringe injection. Moreover, results from animal ovalbumin (OVA) antigen induction models revealed that animals receiving OVA expression plasmids (pOVA) via PJI exhibited dose-dependent (10 μg, 60 μg, and 120 μg) production of anti-OVA antibodies; while only low titers (< 1/100) of OVA antibodies were detected when 120 μg of pOVA was injected via needle syringe. Thus, PJI is an effective, novel method for delivery of plasmid DNA into epidermal and dermal cells suggesting its promise as a tool for DNA vaccination.
Technology is constantly changing and advancing with many novel devices being discovered with potential to serve as preventative or therapeutic strategies for various diseases. For more than two centuries, vaccination has been widely employed as an effective medical technology. However, although many types of vaccines have proven effective, a need remains for the modification and creation of simpler and more effective injection technologies .
Recently developed DNA vaccines have been proposed as a promising new vaccination method [18–20]. In traditional vaccine production, antigen preparation has required the cultivation of pathogenic bacteria or viruses to obtain the appropriate bacterial or viral strains. Compared to traditional vaccines, the DNA vaccine manufacturing process is simple. With the progress made in DNA analysis techniques, DNA vaccines are easier to design and produce; however, the DNA vaccine injection device requires further optimization. Herein, we not only highlight the novel adjustable PJI but also demonstrate the ability of this device to effectively deliver DNA vaccines. Animal models are required to test the effectiveness and ensure safety of newly developed medical therapeutic and prevention strategies.
We evaluated the efficacy of the PJI system as an intradermal DNA vaccination device, and the results show that PJI effectively delivers plasmid DNA into the nuclei of the dermal region and induces efficient gene expression. Furthermore, a model DNA vaccination study showed dose-dependent and stable antibody production. Thus, PJI should be considered as a novel DNA vaccination device for larger animals; however, further testing must be performed prior to large animal application. Overall, this study clearly demonstrates that the PJI system is a promising new DNA vaccine delivery device.