For patients with more extensive gland damage there is currently no conventional therapy to enhance salivary secretion. The initial goal of these studies was to re-engineer the function of the surviving nonfluid secreting ductal cells in damaged glands to a secretory phenotype. The first peer-reviewed publication on gene transfer to salivary glands was published in 1994. Since then, several laboratories have reported that gene transfer to salivary glands can readily be accomplished. Most of these studies have utilized viral vectors to mediate gene transfer.
Viral vectors can be extremely efficient in transferring genes, but can pose a safety risk.
An alternative means of gene transfer is to use nonviral methods. Perhaps the most successful form of nonviral gene transfer involves the use of cationic liposomes. This method is much less efficient than preferred viral vectors, but poses relatively little safety risk. Gene transfer was accomplished using a replication-deficient, first generation, recombinant adenovirus. Conversely, when animals were administered the aquaporin 1-encoding adenovirus 4 months after irradiation, salivary flow rates were indistinguishable from control levels at 3 days postadministration.