Phagocytosis of Escherichia coli biofilm cells with different aspect ratios: a role of substratum material stiffness

Yanrui Zhao, Fangchao Song, Hao Wang, Junlin Zhou, Dacheng Ren

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Bacterial biofilms play an important role in chronic infections due to high-level tolerance to antibiotics. Thus, it is important to eradicate bacterial cells that are attached to implanted medical devices of different materials. Phagocytosis is a key process of the innate immunity to eliminate invading pathogens. Previous research demonstrated that the efficiency of phagocytosis is affected by the aspect ratio of polymer beads. Recently, we reported that the stiffness of polydimethylsiloxane (PDMS) influences Escherichia coli biofilm formation and the biofilm cells on stiff (5:1) PDMS are 46.2% shorter than those on soft (40:1) PDMS. Based on these findings, we hypothesized that E. coli cells attached on stiff PDMS can be more effectively removed via phagocytosis. This hypothesis was tested in the present study using viability assays, flow cytometry, and cell tracking. The results revealed that shorter E. coli cells detached from stiff PDMS were easier to be phagocytized than the longer cells from soft PDMS surfaces. Furthermore, macrophage cells were found to be more motile on stiff PDMS surfaces and more effective at phagocytosis of E. coli cells attached on these surfaces. These results may help the design of better biomaterials to reduce fouling and associated infections.

Original languageEnglish (US)
Pages (from-to)6473-6481
Number of pages9
JournalApplied Microbiology and Biotechnology
Issue number16
StatePublished - Aug 1 2017


  • Bacteria
  • Biofilm
  • Phagocytosis
  • Polydimethylsiloxane
  • Stiffness

ASJC Scopus subject areas

  • Biotechnology
  • Applied Microbiology and Biotechnology


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