title: PEGylation of nanosubstrates (titania) with multifunctional reagents: at the crossroads between nanoparticles and nanocomposites.
abstract: Titania (anatase) nanoparticles were successfully PEGylated through the use of catechol (dopamine)-terminated PEG derivatives. The resulting materials were characterized by excellent stability at neutral pH and extremely low toxicity (phagocytic and nonphagocytic cell lines). In particular, we focused on the comparison between mono- and bis-catechol PEGs. Due to the double terminal anchorage on the titania surface, bis-catechol ligands can produce chains differing from classical monoanchored PEG in conformation (horseshoe-shaped vs brush) and thus the possibility of  interactions with biomolecules. At the same time, less than quantitative catechol binding may lead to the presence of dangling chains with unbound catechols which can polymerize and eventually produce PEG/titania nanocomposite colloids. Our results on double-functional PEG2000 show the latter to be the case. Pluronic F127 was also used as a bifunctional ligand, leading to nanocomposite aggregates with an even larger organic content.
authors: School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Manchester, United Kingdom.
authors: Tania
authors: T
authors: Kotsokechagia
authors: Noha M
authors: NM
authors: Zaki
authors: Karen
authors: K
authors: Syres
authors: Piero
authors: P
authors: de Leonardis
authors: Andrew
authors: A
authors: Thomas
authors: Francesco
authors: F
authors: Cellesi
authors: Nicola
authors: N
authors: Tirelli
mesh_terms: D000818:Animals; D002396:Catechols / Q000737:chemistry*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003102:Colloids; D005347:Fibroblasts / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D051379:Mice; D018625:Microscopy, Atomic Force; D008968:Molecular Conformation; D053761:Nanocomposites / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D010586:Phagocytes / Q000187:drug effects; D056951:Photoelectron Spectroscopy; D020442:Poloxamer / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D013818:Thermogravimetry; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D002396:Catechols; D003102:Colloids; D008024:Ligands; D020442:Poloxamer; C009495:titanium dioxide; D011092:Polyethylene Glycols; D014025:Titanium