Oxidized sodium alginate cross-linked calcium alginate/antarctic krill protein composite fiber for improving strength and water resistance

Oxidation Sodium alginate is a naturally derived cross-linking agent. It has the advantages of high biocompatibility, no precipitation, and low toxicity that small-molecule aldehydes do not possess. Herein, we employed sodium periodate for the oxidation of sodium alginate (SA) to produce oxidized sodium alginate (OSA) aldehydebased crosslinker, which was used to crosslink calcium alginate (CA)/Antarctic krill protein (AKP) composite fibers to obtain OSA-co-CA/AKP composite fibers with multiple crosslinking networks. FT-IR was used to analyze the multiple cross-linked network construction and the hydrogen bonding mechanisms. The composite fibers' crystallinity, morphological structure, and thermal and mechanical properties were analyzed by XRD, SEM, DSC, TGA, and a single fiber strength meter, respectively. The results showed that the composite fibers possessed a multi-network structure of covalent bonding-ionic complexation-hydrogen bonding. And the inclusion of OSA enhanced the composite fibers' thermal stability, crystallinity, and mechanical properties. When the OSA was 1.64 wt%, the fracture strength and salt resistance increased by 16.58 % and 44.2 %, respectively. Cell Counting Kit-8 cytotoxicity test also verified its good biocompatibility and confirmed its potential as a biomedical material.

Automated summary

In this study, oxidized sodium alginate (OSA) was successfully prepared by the oxidation of sodium alginate (SA) using sodium periodate. The OSA was used as a crosslinker to crosslink calcium alginate (CA)/Antarctic krill protein (AKP) composite fibers, resulting in the formation of OSA-co-CA/AKP composite fibers with multiple crosslinking networks. The analysis of FT-IR, XRD, SEM, DSC, TGA, and a single fiber strength meter revealed that the composite fibers possessed a multi-network structure of covalent bonding-ionic complexation-hydrogen bonding. The inclusion of OSA enhanced the thermal stability, crystallinity, and mechanical properties of the composite fibers. Moreover, the Cell Counting Kit-8 cytotoxicity test confirmed the good biocompatibility of the composite fibers, indicating their potential as biomedical materials.