Preparation of cellulosic fibers with biological activity by immobilization of trypsin on periodate oxidized viscose fibers

In this study, a biologically active fibrous material was designed by immobilizing trypsin on viscose fibers. The viscose yarn was first oxidized with sodium periodate to produce aldehyde groups and then employed as a support for subsequent immobilization of trypsin through bovine serum albumin. The oxidation by sodium periodate caused changes in the chemical and physical properties of the modified yarn samples, which were evaluated by determining the aldehyde group content, fineness and tensile strength of yarn. The viscose fibers oxidized under the most severe conditions (0.4 % NaIO₄, 360 min) exhibited the maximum amount of introduced aldehyde groups (1.284 mmol/g), but also the highest decrease in tensile strength. The trypsin activity was assayed with N-α-benzoyl-DL-arginine p-nitroanilide hydrochloride, whereas the amount of bound trypsin was determined by Bradford method. Trypsin immobilized on oxidized viscose yarn retained 97.3 and 83.8 % of the initial activity over 60 days of storage at 4 and 25 °C, respectively, and remained firmly attached to the carrier. The potential application of obtained bioactive fibers is in the treatment of wounds.