Mannosylated poly(ethylene oxide)-b-poly(epsilon-caprolactone) diblock copolymers: synthesis, characterization, and interaction with a bacterial lectin.
A novel bioeliminable amphiphilic poly(ethylene oxide)-b-poly(epsilon-caprolactone) (PEO-b-PCL) diblock copolymer end-capped by a mannose residue was synthesized by sequential controlled polymerization of ethylene oxide and epsilon-caprolactone, followed by the coupling of a reactive mannose derivative to the PEO chain end. The anionic polymerization of ethylene oxide was first initiated by potassium 2-dimethylaminoethanolate. The ring-opening polymerization of epsilon-caprolactone was then initiated by the omega-hydroxy end-group of PEO previously converted into an Al alkoxide. Finally, the saccharidic end-group was attached by quaternization of the tertiary amine alpha-end-group of the PEO-b-PCL with a brominated mannose derivative. The copolymer was fully characterized in terms of chemical composition and purity by high-resolution NMR spectroscopy and size exclusion chromatography. Furthermore, measurements with a pendant drop tensiometer showed that both the mannosylated copolymer and the non-mannosylated counterpart significantly decreased the dichloromethane/water interfacial tension. Moreover, these amphiphilic copolymers formed monodisperse spherical micelles in water with an average diameter of approximately 11 nm as measured by dynamic light scattering and cryo-transmission electron microscopy. The availability of mannose as a specific recognition site at the surface of the micelles was proved by isothermal titration microcalorimetry (ITC), using the BclA lectin (from Burkholderia cenocepacia), which interacts selectively with alpha-D-mannopyranoside derivatives. The thermodynamic parameters of the lectin/mannose interaction were extracted from the ITC data. These colloidal systems have great potential for drug targeting and vaccine delivery systems.
Rieger
Jutta
J
Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP53, 38041 Grenoble cedex 9, France.
Stoffelbach
Francois
F
Cui
Di
D
Imberty
Anne
A
Lameignere
Emilie
E
Putaux
Jean-Luc
JL
Jérôme
Robert
R
Jérôme
Christine
C
Auzély-Velty
Rachel
R
D001672:Biocompatible Materials / Q000737:chemistry*; D019117:Burkholderia / Q000378:metabolism; D002151:Calorimetry; D002236:Carbohydrate Conformation; D037102:Lectins / Q000737:chemistry* / Q000378:metabolism; D008358:Mannose; D008422:Materials Testing; D008823:Micelles; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*
D001672:Biocompatible Materials; D037102:Lectins; D008823:Micelles; D011091:Polyesters; C405621:poly(epsilon-caprolactone-co-ethylene oxide); D011092:Polyethylene Glycols; D008358:Mannose