Despite
advancements in our knowledge of neutrophil responses to planktonic
bacteria during acute inflammation, much remains to be elucidated on how
neutrophils deal with bacterial biofilms in implant infections. Further
complexity transpires from the emerging findings on the role that
biomaterials play in conditioning bacterial adhesion, the variety of
biofilm matrices, and the insidious measures that biofilm bacteria
devise against neutrophils. Thus, grasping the entirety of
neutrophil-biofilm interactions occurring in periprosthetic tissues is a
difficult goal. The bactericidal weapons of neutrophils consist of the
following: ready-to-use antibacterial proteins and enzymes stored in
granules; NADPH oxidase-derived reactive oxygen species (ROS); and
net-like structures of DNA, histones, and granule proteins, which
neutrophils extrude to extracellularly trap pathogens (the so-called
NETs: an allusive acronym for "neutrophil extracellular traps").
Neutrophils are bactericidal (and therefore defensive) cells endowed
with a rich offensive armamentarium through which, if frustrated in
their attempts to engulf and phagocytose biofilms, they can trigger the
destruction of periprosthetic bone. This study speculates on how
neutrophils interact with biofilms in the dramatic scenario of implant
infections, also considering the implications of this interaction in
view of the design of new therapeutic strategies and functionalized
biomaterials, to help neutrophils in their arduous task of managing
biofilms.