In vitro and in vivo study of novel antimicrobial gellan–polylysine polyion complex fibers as suture materials

Abstract

Gellan gumand gellan-derived materials have never been used for suture materials due to their lack of strength and toughness. In this study, gellan and ε-polylysine formed a polyion complex in water solution, and the complex was transformed into fibers via wet-spinning. The fibers were bundled, twisted, and elongated, and the resultant twisted and elongated yarn (GPF) had a diameter of 97.53–103.76 μm and tensile strength of 4 N. The swelling ratio of GPF was 165.55%–183.23% in weight in normal saline, and the linear density was 2.84–3.31 g/km. GPF was tested using agar diffusion tests and it was found that the fibers had good antibacterial activity against Escherichia coli and Staphylococcus epidermidis. In weight loss experiments, GPF was found to be undegradable in normal saline and slightly degradable (residual weight ratio was 83.2 ± 1.2%) in simulated body fluid with trypsin within 7 days. Moreover, GPF showed no cytotoxicity toward BV-2 cells in cytotoxity tests with CCK8 and no hemolysis in hemolytic tests with fresh C57 mice blood. Finally, GPF was assessed using mouse dorsal cross-cutting model, and none of the mice that were tested with GPF showed infection or rejection reaction. Therefore, GPF is a promising suture material, and this study provides a new development direction for the application of gellan materials with improved mechanical properties.