Multifunctional adhesive polymers: Preactivated thiolated chitosan-EDTA conjugates.

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Chitosan-based materials are widely explored for biomedical applications due to their biocompatibility and biodegradability.
• Enhancing mucoadhesion and chelating properties of chitosan conjugates is crucial for effective mucosal drug delivery.

Purpose of the Study:

• To synthesize and characterize preactivated thiolated chitosan-EDTA (Ch-EDTA-cys-2MNA) conjugates.
• To evaluate the mucoadhesive, cohesive, and chelating properties of the synthesized conjugates.

Main Methods:

• Chitosan was thiolated using carbodiimide reaction and preactivated with 2-mercaptonicotinic acid (2MNA) via disulfide bond formation.
• Sulfhydryl group quantification, cytotoxicity screening (resazurin assay in Caco-2 cells), and mucoadhesion tests on porcine intestinal mucosa were performed.
• Bivalent cation binding capacity (Mg2+, Ca2+) was assessed and compared to unmodified and thiolated chitosan-EDTA.

Main Results:

• 80% of thiol groups on chitosan were successfully preactivated with 2MNA.
• Ch-EDTA-cys-2MNA conjugates exhibited no cytotoxicity at 0.25% (w/v) concentration.
• Conjugates maintained approximately 50% of the chelating properties of chitosan-EDTA and demonstrated significantly enhanced mucoadhesion (up to 6 hours vs. 1 hour).

Conclusions:

• The synthesized Ch-EDTA-cys-2MNA conjugates possess a promising combination of mucoadhesive and chelating properties.
• These novel conjugates hold potential for application in various mucosal drug delivery systems.