Antibacterial composite cellulose fibers modified with silver nanoparticles and nanosilica

In the present research, nanocomposite antibacterial cellulose fibers of Lyocell type modified with nanosilver particles and nanosilica were obtained. Nanosilver particles were generated by the chemical reduction of silver nitrate (AgNO3) in 50% water solution of N-methylmorpholine N-oxide (NMMO), which was applied as a direct cellulose solvent for the production of Lyocell fibers. The main aim of this study has been to obtain antibacterial cellulose fibers modified with silver nanoparticles, which are entirely safe for contact with human tissue. Taking into account the potential medical applications of the obtained fibers, the antibacterial activity and cytotoxicity of silver nanoparticles enclosed in fibers were examined in human and mouse cells. Considering the size of the silver nanoparticles with nanosilica in NMMO and their physical properties, the time of generation was the subject of a thorough analysis. The basic physical properties of the nanoparticles introduced in the fibers were tested using the UV/VIS, DLS and TEM methods. The basic properties of the fibers, namely the mechanical and hydrophilic ones, and the average degree of polymerisation of the cellulose fibers were estimated. The conditions of the synthesis of nanoparticles in NMMO with nanosilica were optimised. The results have confirmed that fibers with high-quality antibacterial properties, safe for human tissue and suitable for medical purposes, could be obtained.