Tannic Acid-Assisted Synthesis of Biodegradable and Antibacterial Mesoporous Organosilica Nanoparticles Decorated with Nanosilver

Metal/silica nanoparticles (NPs) have long been used as antibacterial substitutes; however, fabrication of a degradable carrier for achieving sustained release profile, high bactericidal efficacy, and good biocompatibility is still a challenge. Herein, we fabricated nanosilver-decorated biodegradable mesoporous organosilica nanoparticles (MONs) using a biocompatible natural polyphenol, tannic acid (TA), as not only a nonsurfactant template to form MONs but also a reducible agent to generate nanosilvers. Such a straightforward and green one-pot method does not need prior synthesis of silver NPs, removal of template, and use of toxic reducing agents. The resulting Ag-MONs with a well-distributed nanosilver exhibited a matrix-degradation-based silver ions release in response to glutathione (GSH), resulting in a stronger antibacterial effect with nondegradable Ag-mesoporous silica nanoparticles (MSNs), Ag NPs, and silver nitrate on Escherichia coli and Staphylococcus aureus. Moreover, Ag-MONs show better biocompatibility than the Ag NPs and silver nitrate at the same silver dose. Our findings have provided a facile and economical route to fabricate nanosilver-decorated biodegradable mesoporous organosilica nanoparticles. These nanoparticles showed promising applications in the fields of biomedicine and catalysis.