Thiolated polysaccharides in drug delivery

Thiolation of Fenugreek Seed Polysaccharide; Utilization as a Novel Biomucoadhesive Agent in Drug Delivery

“…In addition, their diverse molecular structures and the availability of functional chemical moieties in their molecular structures facilitate chemical modifications or functionalization like cross-linking, carboxymethylation, esterification, sulfation, phosphorylation, thiolation, grafting, etc., in order to introduce or improve derived functional properties [6][7][8][9]. Amongst these chemical modifications, a thiolation is a well-recognized approach to polysaccharide modification that imparts improvement of mucoadhesion of polysaccharides [10,11]. Thus, the above-mentioned chemical modifications can improve the applicability of different plant polysaccharides.…”

“…In general, mucoadhesivity of the majority of polymers is associated with the formation of different kinds of non-covalent bonds like ionic interaction, hydrogen bonds, and Van der's Wall, which are weak bonds in nature [14,15]. Thus, these non-covalent bonds are not capable of providing high mucoadhesive contact and prolonging residence time [10,11]. As a result, the drug delivery system is unable to adhere to the mucous membrane of the target site over a prolonged period.…”

Thiolated Moringa Exudate Gum as Improved Bio-Mucoadhesive Agent in the Formulations of Dental Paste and Gel

“…Many researchers approached techniques like thiolation, carboxymethylation, grafting, cross-linking, etc., to alter or improve the usefulness of natural polysaccharides [8,10,11]. The thiolation technique among these techniques is very important to improve the mucoadhesive potential of these natural polysaccharides [12,13]. Many approaches were there to impart and improve mucoadhesive by forming hydrogen bonds, van der Waals force, ionic bonds, etc [14,15].…”

“…However, these bonds are weak and provide insufficient bonding strength, thereby decreasing the residence time of materials in the desired site(s). However, modification of polysaccharides by thiolation technique makes the derivatives a stronger mucoadhesive agent by forming covalent bonds [13]. Thiolated polysaccharides are also called thiomers, which have active thiol groups in the molecules [12].…”

“…These thiol groups form disulfide bonds with cysteine present in the glycoprotein of the mucus membrane [16]. Disulfide bond formation enhances the bioadhesion capability of the modified polysaccharide [12,13]. Many polysaccharides have been successfully modified to thiomers by various investigators to improve mucoadhesivity.…”