Physically crosslinked chitosan/αβ-glycerophosphate hydrogels enhanced by surface-modified cyclodextrin: An efficient strategy for controlled drug release

Abstract

This study reports physically crosslinked chitosan/αβ-glycerophosphate (CS/GP) hydrogels containing surface-modified cyclodextrin for efficient controlled drug release. Highly water-soluble β-cyclodextrin-grafted L-serine (CD-g-Ser) compounds were synthesized, and employed as an effective carrier of berberine hydrochloride (Ber) for CS/GP hydrogels. Various characterizations, including gelation time determination, scanning electron microscopy, and viscosity measurement, indicated that the introduction of CD-g-Ser led to increased crosslinking degree, improved temperature sensitivity, and shortened sol-gel phase transition time of the hydrogel. Meanwhile, the sustained release ability for Ber was achieved due to the hydrophobic association between cyclodextrin and Ber. It was observed that within 4 h, the hydrogel containing CD-g-Ser released 40 % of Ber, while the CS/GP hydrogel without CD-g-Ser released 65 % of Ber. Furthermore, in vitro bacteriostasis experiments confirmed the drug-loaded hydrogel had an excellent antibacterial effect against E. coli and S. aureus (diameter of the inhibition zone up to (16.4 and 34.7) mm, respectively), low hemolysis rate (<2 %), and high cell viability (>90 %). The findings indicate that the physical crosslinked CS hydrogel can be used as a new drug delivery system, and its excellent antibacterial effect makes it a potential wound dressing candidate.

Keywords: Chitosan hydrogel; Controlled drug release; Physically crosslink.