Poly(acrylamide) hydrogel composites with microsized β-chitin fiber and the properties of mechanical and drug release

Microsized β-chitin fibers were prepared, and PAAm /β-chitin composited hydrogels were synthesized by situ free radical polymerization. The morphology, mechanical properties, swelling ratio, transparency and drug release capabilities of the composited PAAm hydrogels were studied systematically. The results showed that the microsized β-chitin fibers were evenly dispersed in the PAAm hydrogels, and the tensile and compressive strength of PAAm hydrogels were increased by 2.1 folds and 4.4 folds respectively by adding with 15 phr microsized β-chitin fibers, while water absorbency and transparency of the hydrogels were decreased with higher microsized β-chitin fibers content. The drug release behaviors of diclofenac sodium in the hydrogel followed the Fickian diffusion mechanism with n value of 0.099 and 0.147 for PAAm hydrogels and PAAm/β-chitin composite hydrogels respectively, and the release time of 60 % drug were extended from 1 h to 5 h by the addition of 5 phr microsized β-chitin fibers. The results indicate that microsized β-chitin fibers can improve the mechanical properties and decrease the drug release rate of PAAm hydrogel, and the composited hydrogels may find potential applications in the field of transdermal drug delivery system. [Display omitted] •Microsized natural β-chitin fiber is dispersed into PAAm hydrogel with high content.•The compressive strength of PAAm/β-chitin composite hydrogels is improved 4.4-fold.•PAAm/β-chitin composite hydrogel can extend the release time of diclodenac sodium.•Hydrogen bonding and electrostatic interaction play main role in drug slow release.