title: Functionalization of polysulfide nanoparticles and their performance as circulating carriers.
abstract: We here present an evaluation of the carrier performance of nanoparticles that are biofunctional, i.e. derivatized to provide a controlled biological activity, and environmentally responsive, since they respond to the presence of oxidants. In particular, we focus on the possibilities (a) to make the nanoparticles detectable and (b) to control their uptake in phagocytic cells, which determines their lifetime in vivo. We first describe techniques for labeling selectively the nanoparticle surface or bulk with imaging moieties (fluorophores or gold). We then show how surface composition and size, which are both controlled through the use of PEG derivatives, influence uptake by macrophages in vitro and blood circulation in vivo: for example, in vitro uptake is negligible for small (40 nm) particles but not for larger (100 nm) ones and, correspondingly, in vivo blood circulation half-life time decreases from 6.0 to 2.9 h. However, upon decoration with RGD peptides also the small particles can be significantly internalized.
authors.affiliation: Laboratory for Regenerative Medicine and Pharmacobiology, AAB039, Integrative Biosciences Institute, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.
authors.forename: Annemie
authors.initials: A
authors.lastname: Rehor
authors.forename: Hugo
authors.initials: H
authors.lastname: Schmoekel
authors.forename: Nicola
authors.initials: N
authors.lastname: Tirelli
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Hubbell
mesh_terms: D000818:Animals; D004337:Drug Carriers; D008422:Materials Testing; D051379:Mice; D009000:Monocytes / Q000378:metabolism*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011126:Polypropylenes / Q000737:chemistry* / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013440:Sulfides / Q000737:chemistry* / Q000493:pharmacokinetics*
chemical_list: D004337:Drug Carriers; D011126:Polypropylenes; D013440:Sulfides; C032915:polysulfide