Biocompatible and antibacterial poly(lactic acid)/cellulose nanofiber‑silver nanoparticle biocomposites prepared via Pickering emulsion method

Developing biocompatible and antibacterial materials with biodegradable polymers is an ideal strategy to improve public health problems and plastic pollution simultaneously. In the present study, novel biocompatible and antibacterial poly ( -lactic acid) (PLLA, coded as P)/TEMPO-oxidized cellulose nanofiber (TOCNF, coded as T)‑silver nanoparticle (AgNP, coded as A) films were first developed. The core/shell PT Pickering emulsion was prepared by sonication treatment. The TOCNF shells with -COO Na groups (∼1.5 mmol/g cellulose) were used as the support to in situ synthesize and immobilize AgNPs on the PT emulsion droplets. Silver nitrate (AgNO ) (1.5, 3.0, 4.5, and 6.0 mmol/g cellulose) was added to the PT emulsions. Then, ion-exchange reaction and hydrothermal reduction were conducted to form PTA (PTA1-PTA4) emulsions. After centrifugation to remove the excess Ag , filtration, oven-drying, and hot-pressing, the PTA composite films were successfully prepared. The PTA3 film contained AgNPs 12.4 ± 2.8 nm in diameter and exhibited the highest antibacterial activities against the E. coli (85.2%) and S. aureus (80.1%) at 37 °C, where the initial bacterial suspension concentrations were approximately 2 × 10 CFU mL . Therefore, the biocompatible and antibacterial PTA3 film is a promising candidate for biomedical applications, in particular as an antibacterial bioactive packaging material.