Molecular Docking, Synthesis, And Characterization Of Chitosan-Graft-2-Mercaptobenzoic Acid Derivative As Potential Drug Carrier

Chitosan is a hydrophilic polymer with prominent mucoadhesive properties. However, it forms weak hydrogen bonds with mucin thus limiting its mucoadhesion and exhibit reduced bioavailability due to its short retention time in the body. The aim of the present study was to synthesize and characterize novel thiolated chitosan with improved functional property. A unique approach of using molecular docking to select ligand to chemically modify chitosan has been employed in the present research. A set of ligands were screened virtually using docking analysis and 2-mercapto benzoic acid showed the lowest glide score of -4.31 Kcal/Mol thus displayed better binding interaction with chitosan. Based on the docking results, the best-fit ligand was selected for wet lab synthesis. 2-Mercapto benzoic acid was covalently attached to chitosan via formation of an amide bond and the reaction was mediated by carbodiimide andN-hydroxysuccinimide. The synthesized polymer was in turn evaluated for zeta potential, Fourier transformed infrared, differential scanning calorimetry, molecular weight that confirmed conjugation of chitosan with the thiol ligand. The prepared thiomer was further subjected to mucoadhesion studies and displayed better mucoadhesion properties as compared to unmodified chitosan. Thus, the potential of the novel thiomer can be further explored as an excipient for drug delivery system with an emphasis on mucoadhesion.