Improvement of stability and cell adhesion properties of polyelectrolyte multilayer films by chemical cross-linking.
Poly(L-lysine)/hyaluronan (PLL/HA) films were chemically cross-linked with a water soluble carbodiimide (EDC) in combination with a N-hydroxysulfo-succinimide (NHS) to induce amide formation. Fourier transform infrared spectroscopy confirms the conversion of carboxylate and ammonium groups into amide bonds. Quartz crystal microbalance-dissipation reveals that the cross linking reaction is accompanied by a change in the viscoelastic properties of the films leading to more rigid films. After the cross-linking reaction, both positively and negatively ending films exhibit a negative zeta potential. It is shown by fluorescence recovery after photobleaching measured by confocal laser scanning microscopy that cross-linking dramatically reduces the diffusion of the PLL chains in the network. Cross linking also renders the films highly resistant to hyaluronidase, an enzyme that naturally degrades hyaluronan. Finally, the adhesion of chondrosarcoma cells on the films terminating either with PLL or HA is also investigated. Whereas the non cross-linked films are highly resistant to cell adhesion, the cells adhere and spread well on the cross-linked films.
Institut National de la Santé et de la Recherche Médicale, Unité 595, Faculté de Chirurgie Dentaire, Université Louis Pasteur, 11 rue Humann, 67085 Strasbourg Cedex, France.
Ludovic
L
Richert
Fouzia
F
Boulmedais
Philippe
P
Lavalle
Jérôme
J
Mutterer
Emmanuelle
E
Ferreux
Gero
G
Decher
Pierre
P
Schaaf
Jean-Claude
JC
Voegel
Catherine
C
Picart
D002448:Cell Adhesion; D045744:Cell Line, Tumor; D003432:Cross-Linking Reagents / Q000737:chemistry* / Q000378:metabolism; D004355:Drug Stability; D004548:Elasticity; D005022:Ethyldimethylaminopropyl Carbodiimide / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry* / Q000378:metabolism; D018613:Microscopy, Confocal; D011107:Polylysine / Q000737:chemistry* / Q000378:metabolism; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D014014:Tissue Adhesives / Q000737:chemistry*; D014783:Viscosity
D003432:Cross-Linking Reagents; D012996:Solutions; D014014:Tissue Adhesives; D011107:Polylysine; D006820:Hyaluronic Acid; D005022:Ethyldimethylaminopropyl Carbodiimide