title: Poly(ethylene glycol) and hydroxy functionalized alkane phosphate self-assembled monolayers reduce bacterial adhesion and support osteoblast proliferation.
abstract: OBJECTIVE
  Presently there is interest today in designing improved titanium surfaces capable of high bioactivity in order to promote strong anchorage of the bone surrounding implants while at the same time discouraging bioadhesion. Poly(ethylene glycol)-modified (PEG) alkane phosphate and OH-terminated alkane phosphates have been demonstrated to be spontaneously adsorbed onto titanium oxide surfaces and produce surfaces with different protein resistance in relation to the PEG surface density. This study aims to evaluate caries-associated Streptococcus mutans (S. mutans) adhesion and osteoblast proliferation while varying the PEG surface density of titanium surfaces.
  
  
  METHODS
  Bacterial adhesion was quantified by fluorescence microscopy and SAOS-2 human osteoblast proliferation was evaluated up to 7 days of culture in vitro. Metabolic activity of osteoblasts was measured by MTT test and the secretion of extracellular matrix proteins (osteopontin, osteocalcin and type I collagen) in culture medium was determined by immunoenzymatic assays.
  
  
  RESULTS
  As the PEG surface density increased, the bacterial adhesion considerably decreased when compared to uncoated titanium surfaces. The monomolecular coatings proved to be capable of supporting osteoblast proliferation with the greatest levels of metabolic activity at the highest PEG surface concentrations.
  
  
  CONCLUSIONS
  These results are extremely promising for potential clinical application in implant uses where both reduction of bacteria adhesion and stimulation of bone formation are highly desirable.
authors.affiliation: Biomaterials Laboratory, Bioengineering Department, Politecnico di Milano, Milan, Italy. sabrina.bozzini@polimi.it
authors.forename: Sabrina
authors.initials: S
authors.lastname: Bozzini
authors.forename: Paola
authors.initials: P
authors.lastname: Petrini
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Tanzi
authors.forename: Carla Renata
authors.initials: CR
authors.lastname: Arciola
authors.forename: Samuele
authors.initials: S
authors.lastname: Tosatti
authors.forename: Livia
authors.initials: L
authors.lastname: Visai
mesh_terms: D000473:Alkanes / Q000737:chemistry / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects*; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D020099:Coated Materials, Biocompatible; D024042:Collagen Type I / Q000378:metabolism; D017266:Dental Prosthesis; D006801:Humans; D007124:Immunoenzyme Techniques; D008856:Microscopy, Fluorescence; D016348:Osseointegration / Q000187:drug effects; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D015675:Osteocalcin / Q000378:metabolism; D053495:Osteopontin / Q000378:metabolism; D010710:Phosphates / Q000737:chemistry / Q000494:pharmacology*; D011092:Polyethylene Glycols / Q000737:chemistry / Q000494:pharmacology*; D011474:Prosthesis Design; D013295:Streptococcus mutans / Q000187:drug effects* / Q000254:growth & development; D013997:Time Factors; D014025:Titanium
chemical_list: D000473:Alkanes; D000890:Anti-Infective Agents; D020099:Coated Materials, Biocompatible; D024042:Collagen Type I; D010710:Phosphates; D015675:Osteocalcin; D053495:Osteopontin; D011092:Polyethylene Glycols; D014025:Titanium