Evaluation of functional characteristics of preactivated thiolated chitosan as potential therapeutic agent for dry mouth syndrome.

Abstract

The objective of this study was to investigate preactivated thiomers for their potential in the treatment of dry mouth syndrome. Chitosan-thioglycolic-mercaptonicotinamide conjugates (chitosan-TGA-MNA) were synthesized by the oxidative S-S coupling of chitosan-thioglycolic acid (chitosan-TGA) with 6-mercaptonicotinamide (MNA). Test disks were compressed out of unmodified chitosan, chitosan-TGA (thiomers) and chitosan-TGA-MNA conjugates to investigate cohesive properties, cytotoxicity assays and mucoadhesion studies. Immobilizing the MNA achieved higher swelling and cohesive properties of chitosan-TGA-MNA conjugates compared to unmodified chitosan. Rotating cylinder studies displayed a 3.1-fold improvement of mucoadhesiveness of chitosan-TGA-MNA conjugates compared to thiolated polymers. Findings in tensile strength were in good agreement with rotating cylinder ones. Furthermore, preactivated thiomers exhibit higher stability. All conjugates were found non-toxic against Caco-2 cells. Preactivated thiolated chitosan could be a promising system for the treatment of dry mouth syndrome where mucosa requires lubrication and mucoadhesiveness.