title: Cross-linkable liposomes stabilize a magnetic resonance contrast-enhancing polymeric fastener.
abstract: Liposomes are commonly used to deliver drugs and contrast agents to their target site in a controlled manner. One of the greatest obstacles in the performance of such delivery vehicles is their stability in the presence of serum. Here, we demonstrate a method to stabilize a class of liposomes that load gadolinium, a magnetic resonance (MR) contrast agent, as a model cargo on their surfaces. We hypothesized that the sequential adsorption of a gadolinium-binding chitosan fastener on the liposome surface followed by covalent cross-linking of the lipid bilayer would provide enhanced stability and improved MR signal in the presence of human serum. To investigate this hypothesis, liposomes composed of diyne-containing lipids were assembled and functionalized via chitosan conjugated with a hydrophobic anchor and diethylenetriaminepentaacetic acid (DTPA). This postadsorption cross-linking strategy served to stabilize the thermodynamically favorable association between liposome and polymeric fastener. Furthermore, the chitosan-coated, cross-linked liposomes proved more effective as delivery vehicles of gadolinium than uncross-linked liposomes due to the reduced liposome degradation and chitosan desorption. Overall, this study demonstrates a useful method to stabilize a broad class of particles used for systemic delivery of various molecular payloads.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois, 61801 United States.
authors.forename: Cartney E
authors.initials: CE
authors.lastname: Smith
authors.forename: Hyunjoon
authors.initials: H
authors.lastname: Kong
mesh_terms: D000327:Adsorption; D048271:Chitosan / Q000737:chemistry*; D003287:Contrast Media / Q000737:chemistry*; D053280:Diynes / Q000737:chemistry*; D005682:Gadolinium / Q000737:chemistry*; D006801:Humans; D008027:Light; D008081:Liposomes / Q000138:chemical synthesis* / Q000528:radiation effects; D009682:Magnetic Resonance Spectroscopy; D004369:Pentetic Acid / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry*; D044967:Serum / Q000737:chemistry; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D003287:Contrast Media; D053280:Diynes; D008081:Liposomes; D010713:Phosphatidylcholines; C053923:1,2-bis(10,12-tricosadiynoyl)phosphatidylcholine; D004369:Pentetic Acid; D048271:Chitosan; D005682:Gadolinium