Macrophage phagocytic activity toward adhering staphylococci on cationic and patterned hydrogel coatings versus common biomaterials.
Biomaterial-associated-infection causes failure of biomaterial implants. Many new biomaterials have been evaluated for their ability to inhibit bacterial colonization and stimulate tissue-cell-integration, but neglect the role of immune cells. This paper compares macrophage phagocytosis of adhering Staphylococcus aureus on cationic-coatings and patterned poly(ethylene)glycol-hydrogels versus common biomaterials and stainless steel in order to identify surface conditions that promote clearance of adhering bacteria. Staphylococci were allowed to adhere and grow on the materials in a parallel-plate-flow-chamber, after which murine macrophages were introduced. From the decrease in the number of adhering staphylococci, phagocytosis-rates were calculated, and total macrophage displacements during an experiment determined. Hydrophilic surfaces had the lowest phagocytosis-rates, while common biomaterials had intermediate phagocytosis-rates. Patterning of poly(ethylene)glycol-hydrogel coatings increased phagocytosis-rates to the level of common biomaterials, while on cationic-coatings phagocytosis-rates remained relatively low. Likely, phagocytosis-rates on cationic coatings are hampered relative to common biomaterials through strong electrostatic binding of negatively-charged macrophages and staphylococci. On polymeric biomaterials and glass, phagocytosis-rates increased with macrophage displacement, while both parameters increased with biomaterial surface hydrophobicity. Thus hydrophobicity is a necessary surface condition for effective phagocytosis. Concluding, next-generation biomaterials should account for surface effects on phagocytosis in order to enhance the ability of these materials to resist biomaterial-associated-infection.
University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700 AD Groningen, The Netherlands.
Joana F
JF
da Silva Domingues
University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700 AD Groningen, The Netherlands.
Steven
S
Roest
Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, NJ, USA.
Yi
Y
Wang
University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700 AD Groningen, The Netherlands. Electronic address: h.c.van.der.mei@umcg.nl.
Henny C
HC
van der Mei
Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, NJ, USA.
Matthew
M
Libera
University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700 AD Groningen, The Netherlands.
Theo G
TG
van Kooten
University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, P.O. Box 196, 9700 AD Groningen, The Netherlands.
Henk J
HJ
Busscher
D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects*; D002412:Cations; D002460:Cell Line; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D015169:Colony Count, Microbial; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology*; D051379:Mice; D010587:Phagocytosis / Q000187:drug effects*; D011108:Polymers / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects*
D002412:Cations; D020099:Coated Materials, Biocompatible; D011108:Polymers; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate
Biomaterial-associated infection; Cationic coatings; Phagocytosis; Poly(ethylene)glycol coatings; Water contact angles