Dual-Function Antibacterial Micelle <i>via</i> Self-Assembling Block Copolymers with Various Antibacterial Nanoparticles

Abstract

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)-<i>b</i>-poly(3-hydroxybutyrate-<i>co</i>-3-hydroxyvalerate)-poly(ethylene glycol) (PEG-PHBV-PEG), showed a hydrophobic PHBV layer on NPs with PEG segments exposed outside <i>via</i> hydrogen bonding, resulting in long PEG (<i>M</i> _w = 2000) aggregation and short PEG (<i>M</i> _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 <i>Escherichia coli</i> and 98% against <i>Staphylococcus aureus</i>. Long PEG aggregation showed greater cell proliferation capacity than short PEG aggregation, as well as better bacterial resistance and bactericidal activity against both <i>E. coli</i> and <i>S. aureus</i>. The flexible self-assembling antibacterial NPs with antifouling block copolymers <i>via</i> adjusting the component ratio or the segment length have shown premise in the construction of the dual-function antibacterial materials.