Thiolated particles as effective intravesical drug delivery systems for treatment of bladder-related diseases

Abstract

Aim: To prove in vivo mucoadhesiveness of thiolated and well-established polymeric microparticles and nanoparticles (NPs) as a promising nanomedical tool for the treatment of bladder-related diseases. Materials & methods: Spray drying and ionic gelation were used in order to generate microparticles and NPs. For particle detection, the fluorescent marker, fluorescein diacetate, was incorporated in microparticles and NPs, respectively. Mucoadhesive properties of the particles were pre-evaluated via rheological measurements and ex vivo in the porcine urinary bladder model to identify the most appropriate particles for in vivo application in female Sprague Dawley rats. Results: Pretrials indicated that particles based on chitosan were most suitable as an intravesical drug delivery system for in vivo application. The retention time of thiolated chitosan NPs on the rat urinary bladder mucosa was approximately 170-fold higher in comparison with the pure fluorescent marker, fluorescein diacetate, having being applied as aqueous suspension without polymeric excipients. Conclusion: This advanced nanomedical tool based on thiolated chitosan seems to be a promising approach for the treatment of bladder-related diseases. Original submitted 20 January 2012; Revised submitted 20 April 2012; Published online 20 July 2012