Dual-Function Antibacterial Micelle via Self-Assembling Block Copolymers with Various Antibacterial Nanoparticles

Antibacterial biomaterials with kill-resist dual functions by combining multiple active components have been constructed, with a final aim at decreasing the incidence of biomaterial-centered infection. Self-assemblies of bactericidal ZnO or Ag-ZnO nanoparticles (NPs) with triblock copolymers, poly(ethylene glycol)-b-poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-poly(ethylene glycol) (PEG-PHBV-PEG), showed a hydrophobic PHBV layer on NPs with PEG segments exposed outside via hydrogen bonding, resulting in long PEG (M _w = 2000) aggregation and short PEG (M _w = 1000) aggregation, respectively. These nanocomposite aggregations released ZnO or Ag-ZnO rapidly within initial few hours, and about 42-45% of NPs were left in the nanocomposites in deionized water for 16 d to improve the long-term antibacterial activity further. At the concentration below 50 μg/mL, the nanocomposite aggregation was cell-compatible with ATDC5 and showed sterilization rates over 91% against Escherichia coli and 98% against Staphylococcus aureus. Long PEG aggregation showed greater cell proliferation capacity than short PEG aggregation, as well as better bacterial resistance and bactericidal activity against both E. coli and S. aureus. The flexible self-assembling antibacterial NPs with antifouling block copolymers via adjusting the component ratio or the segment length have shown premise in the construction of the dual-function antibacterial materials.