The present proposal will optimize and apply a method for non-viral gene transfer to the salivary glands. This method utilizes low frequency ultrasound pulses to destroy microbubbles, causing local cavitation and opening transient pores in cell membranes enabling non-viral vectors to enter cells of the salivary gland. This proposed method is derived from existing ultrasound-assisted gene transfer (UAGT) techniques that our group has recently shown is capable of robust, stable, and long-lasting gene transfer to the salivary glands. UAGT has several important advantages over other gene transfer methods, in particular a presumed lack of immunogenicity and therefore the theoretical option to re-dose. Gene transfer to the salivary glands presents the opportunity to achieve endogenous production and salivary secretion of peptide therapeutics. Endogenous production overcomes many of the challenges that have thus far limited the utility of emerging anti-biofilm peptide molecules for targeting individual bad actors in the periodontal flora. Chief among these limitations are manufacturing, stability and delivery of the therapeutics itself, as well as the challenge of achieving a steady-state, sustained concentration of the therapeutic in the saliva. The long-term goal of this research therefore is to lay the pre-clinical groundwork for UAGT to the salivary glands for application in dental medicine. In order to achieve this goal, we will first apply what is already known regarding UAGT to the salivary gland and undertake a careful histopathological evaluation of the effect of this technique on salivary gland architecture and viability. Secondly, we will endeavor an initial proof-of-principle study wherein we will introduce genes with known anti-biofilm activity in model microorganisms (S. mutans and P. aeruginosa) to the salivary glands and assay in vitro the biofilm-inhibiting properties of saliva produced by treated animals. Once this technology has been proven to be reliable, safe and effective in the rodent model, we speculate that it may be an attractive adjuvant or even a primary approach to dealing with destructive microbial pathogens in the periodontium, particularly in vulnerable patients physically incapable of routine oral hygiene.
In this application, we propose to use a non-viral gene therapy approach to address the public health issue of chronic periodontal inflammation and tissue destruction by a subset of oral flora. Specifically, we propose a method of inhibiting biofilm formation, a natural process that is accelerated in the most vulnerable to of dental patients who are unable to maintain routine oral hygiene (i.e. tooth brushing). The immediate application of this technology to public health is to provide a gene therapy-based treatment that may bridge vulnerable patients between episodic periodontal treatments.
|Geguchadze, Ramaz; Wang, Zhimin; Zourelias, Lee et al. (2014) Proteomic profiling of salivary gland after nonviral gene transfer mediated by conventional plasmids and minicircles. Mol Ther Methods Clin Dev 1:14007|