Chitosan (CHS) and chitin (CHT) biopolymers have found many applications in the field of controlled-release drug delivery systems. Herein, molecular dynamics (MD) simulation and binding free energy calculations were used to investigate the potentials of CHS and CHT polymers for the controlled release of follicle-stimulating hormone (FSH). The results indicated that FSH conformation did not change in the presence of CHS and CHT. In addition, FSH-polymer interactions caused stability of the 310-helix structure of the alpha subunits of FSH (FSHα). Both the biopolymers interacted with the protein mainly through the hydrophobic forces. CHS has more affinity for FSH when compared with CHT. Furthermore, in both systems, the affinity of polymers for FSHα was more than that for beta subunits of FSH (FSHβ). The results suggested that the polysaccharides might improve the controlled-release FSH delivery.
