title: Self-assembled gold coating enhances X-ray imaging of alginate microcapsules.
abstract: Therapeutic biomolecules produced from cells encapsulated within alginate microcapsules (MCs) offer a potential treatment for a number of diseases. However the fate of such MCs once implanted into the body is difficult to establish. Labelling the MCs with medical imaging contrast agents may aid their detection and give researchers the ability to track them over time thus aiding the development of such cellular therapies. Here we report the preparation of MCs with a self-assembled gold nanoparticle (AuNPs) coating which results in distinctive contrast and enables them to be readily identified using a conventional small animal X-ray micro-CT scanner. Cationic Reversible Addition-Fragmentation chain Transfer (RAFT) homopolymer modified AuNPs (PAuNPs) were coated onto the surface of negatively charged alginate MCs resulting in hybrids which possessed low cytotoxicity and high mechanical stability in vitro. As a result of their high localized Au concentration, the hybrid MCs exhibited a distinctive bright circular ring even with a low X-ray dose and rapid scanning in post-mortem imaging experiments facilitating their positive identification and potentially enabling them to be used for in vivo tracking experiments over multiple time-points.
authors.affiliation: Beijing Key Lab of Bioprocess, Beijing University of Chemical Technology, Beijing, PR China. twtan@mail.buct.edu.cn.
authors.forename: Fengxiang
authors.initials: F
authors.lastname: Qie
authors.forename: Alberto
authors.initials: A
authors.lastname: Astolfo
authors.forename: Malsha
authors.initials: M
authors.lastname: Wickramaratna
authors.forename: Martin
authors.initials: M
authors.lastname: Behe
authors.forename: Margaret D M
authors.initials: MD
authors.lastname: Evans
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Hughes
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Hao
authors.forename: Tianwei
authors.initials: T
authors.lastname: Tan
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000818:Animals; D016477:Artifacts; D002460:Cell Line; D003287:Contrast Media / Q000737:chemistry; D003952:Diagnostic Imaging / Q000379:methods*; D020723:Glucuronic Acid / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D020100:Hydrogels / Q000737:chemistry; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000166:cytology; D016381:Islets of Langerhans Transplantation; D009682:Magnetic Resonance Spectroscopy; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D008970:Molecular Weight; D036103:Nanotechnology / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D051381:Rats; D013314:Stress, Mechanical; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013696:Temperature; D055114:X-Ray Microtomography; D014965:X-Rays
chemical_list: D000464:Alginates; D003287:Contrast Media; D006603:Hexuronic Acids; D020100:Hydrogels; D007328:Insulin; D011108:Polymers; D013438:Sulfhydryl Compounds; D006046:Gold; D020723:Glucuronic Acid