Preparation of hydrogel containing Angelica dahurica coumarin by radiation crosslinking and its properties

A polyvinyl alcohol/sodium carboxymethylcellulose hydrogel material containing Angelica dahurica coumarin was prepared by radiation crosslinking and freeze/thraw cycles. The effects of coumarin content and combination of menthol and low-molecular-weight collagen on the structure and properties of the hydrogel were studied through bacteriostatic tests as well as tensile strength, water absorption, and scanning electron microscope observation. The results showed irradiation stability for angelica dahurica coumarin. The minimum inhibitory concentrations (MICs) of angelica dahurica coumarin to E. coli were 3.13, 3.13, and 1.56 mg/mL at absorbed doses of 0, 10, and 20 kGy, respectively, thereby proving that the antibacterial property increased with dosage. The MIC of angelica dahurica coumarin to S. aureus was 6.25 mg/mL. The bacteriostasis rate of the composite hydrogels increased rapidly at first and then slowed down with the increasing coumarin contents although their tensile strength decreased. The bacteriostasis rate of the hydrogel reached 100% on introducing menthol at a mass fraction of 1%; the tensile strength reached a value of 0.7 MPa showing no obvious change. Low-molecular-weight collagen improved the dispersibility and bacteriostasis rate of coumarin. The tensile strength of the hydrogels decreased slightly; the water absorption of the hydrogels reached 800% and 1100% in 2 and 24 h, respectively. (authors)