The objective of this work to functionalize polylactic acid (PLA/nano silica) composite to produce environmentally ‎friendly filament using it in Polylactic acid (PLA) and nanosilica with different concentrations (1, 2%) were prepared to produce PLA/nanocomposites. PLA, PLA/nanosilica (1% and 2%) filaments were produced using a single screw extruder. Tensile, flexural, and thermal properties were investigated; a Scanning Electron Microscopy (SEM) test was also used to verify PLA and PLA/nanosilica structure. Finally antibacterial properties of the produced nanocomposites were investigated to evaluate their performance against Staphylococcus aureus (S. Aureus) and Gram-negative Escherichia coli (E. Coli). The results revealed that PLA/nanosilica (1%) had the better mechanical and thermal properties.  The PLA/nanosilica (1%) filament sample was used in 3D printing (3DP) applications for producing different samples (tooth brush case and pill organizer).