In recent years, core-shell filaments with the unique structure and properties have been employed to prepare many kinds of functional materials in the fields of drug delivery, wound dressings, tissue engineering, etc. As known, interfacial polyelectrolyte complexation (IPC) spinning was an easy and facile method to obtain the core-shell filaments. In this work, anionic cellulose nanofibrils (ACNF) and cationic guar gum (CGG) as non-toxic charged polyelectrolytes were employed to produce composite filaments with core-shell structure via IPC spinning. The comprehensive characterization of the resultant CGG/ACNF filament was performed, and the application performance of CGG/ACNF filament as surgical suture were fully investigated in comparison with silk suture and PGLA (90% glycolide and 10% L-lactide) absorbable suture in vitro and in vivo, respectively. Results showed that the CGG/ACNF filament with the typical core-shell structure and nervation pattern surface exhibited good mechanical properties (tensile strength of 105 MPa) and high orientation index (0.74). Moreover, the tensile strength and knotting strength of the CGG/ACNF suture prepared by twisting CGG/ACNF filaments were significantly increased, and the CGG/ACNF suture had a similar friction coefficient with PGLA suture. Also, the CGG/ACNF suture could inhibit the bacterial growth (Escherichia coli and Bacillus subtilis) because the positive charges on CGG could absorb on the cell wall of bacteria and then break the membrane. The cytocompatibility of CGG/ACNF suture was better than that of silk suture for Homo sapiens cells and Buffalo rat liver cells, and also better compared to PGLA suture for Buffalo rat liver cells. In addition, the wound of rat skin sewed with CGG/ACNF suture exhibited better healing properties, and there was no serious inflammatory reaction after implanted the CGG/ACNF suture in rats. Hence, the CGG/ACNF suture could aid the wound healing mainly due to the wound immobilization of the suture and the wound adhesion and antibacterial properties of CGG. Therefore, the CGG/ACNF suture with high strength and better cytocompatibility has great potential to be used in surgical operation, and the CGG/ACNF filament with the unique core-shell structure also has a promising prospect in many advanced fields.

cellulose nanofibrils;guar gum;interfacial polyelectrolyte complexation;surgical suture;wound healing