Influences of protein films on antibacterial or bacteria-repellent surface coatings in a model system using silicon wafers.
Immobilization of defined chemical functionalities to biomaterial surfaces is employed to optimize them not only for tissue compatibility but also for prevention of bacterial infection. Grafting surfaces with chains of poly(ethylene glycol) (PEG) results in bacterial repellence whereas modification with cationic groups conveys them with bactericidal properties. Since biomaterials in situ will become exposed to a protein-rich environment, it is necessary to investigate the influence of prior protein adsorption on the antibacterial activity of this type of chemical surface modification. In the present study, we immobilized short-chain PEG and two pyridinium group-containing methacrylate monomers, 12-methacryloyloxydodecylpyridinium bromide (MDPB) and 6-methacryloyloxyhexylpyridinium chloride (MHPC), to silicon wafer model surfaces to investigate the influence of prior protein adsorption on the bactericidal activity of the surface coating towards subsequently attached bacteria. Adsorbed amounts of human serum albumin and salivary proteins were found to be two times higher on cationic compared to PEG-modified surfaces. An analogous tendency was found for attachment of Streptococcus gordonii and Streptococcus mutans to the same surfaces without prior protein exposure. However, most bacteria attached to cationic surfaces were found to be dead. Prior exposure of cationic surfaces to protein solutions drastically altered bacterial attachment dependent on the type of protein solution and bacterial species employed. Significantly, the original bactericidal activity of pyridinium-coated surfaces was found greatly reduced upon adsorption of a protein film. As a conclusion we propose that future approaches should combine the protein- and bacteria-repellent properties of PEG-coatings with the bactericidal function of charged cationic groups.
Müller
Rainer
R
Department of Operative Dentistry and Periodontology, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany. rainer.mueller@chemie.uni-regensburg.de
Eidt
Andreas
A
Hiller
Karl-Anton
KA
Katzur
Verena
V
Subat
Michael
M
Schweikl
Helmut
H
Imazato
Satoshi
S
Ruhl
Stefan
S
Schmalz
Gottfried
G
D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000378:metabolism; D001422:Bacterial Adhesion; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D050296:Microbial Viability; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000378:metabolism; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D011726:Pyridinium Compounds / Q000737:chemistry* / Q000378:metabolism; D012463:Saliva / Q000737:chemistry / Q000378:metabolism; D012709:Serum Albumin / Q000737:chemistry / Q000378:metabolism; D012825:Silicon / Q000737:chemistry; D013291:Streptococcus / Q000166:cytology*; D054773:Streptococcus gordonii / Q000166:cytology; D013295:Streptococcus mutans / Q000166:cytology
D000900:Anti-Bacterial Agents; D020099:Coated Materials, Biocompatible; D011506:Proteins; D011726:Pyridinium Compounds; D012709:Serum Albumin; D011092:Polyethylene Glycols; D012825:Silicon