Spinning solutions of cellulose in N-methylmorpholine N-oxide were modified by addition of colloidal silicate (Ludox SM30) and silver-zirconium phosphate (AlphaSan@) and Triclosan (irgrasan DP300) antibacterial agents to obtain functional cellulosic fibers with antibacterial activity. The solutions were tested rheologically and analyzed by differential scanning calorimetry. The addition of nanosilica resulted in a substantial improvement of the rheological properties of the spinning solutions. The simultaneous addition of nanosilica and antibacterial agents did not result in any modification of the properties of the original solution. The modifiers affected, however, the dynamics of the crystallization of the spinning solutions.