title: Biofunctional polymer nanoparticles for intra-articular targeting and retention in cartilage.
abstract: The extracellular matrix of dense, avascular tissues presents a barrier to entry for polymer-based therapeutics, such as drugs encapsulated within polymeric particles. Here, we present an approach by which polymer nanoparticles, sufficiently small to enter the matrix of the targeted tissue, here articular cartilage, are further modified with a biomolecular ligand for matrix binding. This combination of ultrasmall size and biomolecular binding converts the matrix from a barrier into a reservoir, resisting rapid release of the nanoparticles and clearance from the tissue site. Phage display of a peptide library was used to discover appropriate targeting ligands by biopanning on denuded cartilage. The ligand WYRGRL was selected in 94 of 96 clones sequenced after five rounds of biopanning and was demonstrated to bind to collagen II alpha1. Peptide-functionalized nanoparticles targeted articular cartilage up to 72-fold more than nanoparticles displaying a scrambled peptide sequence following intra-articular injection in the mouse.
authors.affiliation: Institute of Bioengineering and Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Dominique A
authors.initials: DA
authors.lastname: Rothenfluh
authors.forename: Harry
authors.initials: H
authors.lastname: Bermudez
authors.forename: Conlin P
authors.initials: CP
authors.lastname: O'Neil
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Hubbell
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use; D001672:Biocompatible Materials / Q000737:chemistry*; D002356:Cartilage / Q000737:chemistry*; D002417:Cattle; D024043:Collagen Type II / Q000737:chemistry / Q000378:metabolism; D016503:Drug Delivery Systems; D007270:Injections, Intra-Articular; D007592:Joint Diseases / Q000188:drug therapy*; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011485:Protein Binding
chemical_list: D000893:Anti-Inflammatory Agents; D001672:Biocompatible Materials; D024043:Collagen Type II; D019151:Peptide Library; D010455:Peptides; D011108:Polymers