title: Fabrication of Gd/Eu-codoped SmPO4 nanorods for dual-modal magnetic resonance and bio-optical imaging.
abstract: Ln-based complexes can be used as T1-enhanced contrast agents of magnetic resonance (MR) imaging in clinical field. Herein, we present a facile and feasible biomineralization process to fabricate Gd/Eu-codoped SmPO4 nanorods (NRs) with silk fibroin (SF) peptides (codoped SF-NRs) as T1-enhanced contrast agents, which possess paramagnetic property, photoluminescence (PL), better cyto-/tissue-compatibility and longer half-life in blood due to SF coating on their surface. Their bio-distributions in TB-N mice via tail-vein injection indicated that, although SF-NRs could be safely cleared away through renal and fecal excretion, SF-NRs easily permeated and aggregated in tumors. The results of in vitro MR imaging demonstrate that the longitudinal relaxivity r1 value of codoped SF-NRs (0.31 Sm-Gd mM(-1) s(-1)) is not only significantly higher than those of Gd-doped and Eu-doped SmPO4 SF-NRs, but also higher than those of codoped pure NRs. The tests of in vivo T1 weighted MR imaging via intro-tumor injection and tail-vein injection confirm that, compared to the pure NRs, the codoped SF-NRs exhibited higher positive signal-enhancement ability. Furthermore, the better luminescence imaging of living cells under the fluorescence microscope (94% stronger than that of the NRs without SF). A formation mechanism of codoped SF-NRs is proposed, to explain the synergistic effect of Gd/Eu codoping and SF coating on their enhanced bio-compatibility, half-life in blood, T1-weighted MR imaging and PL imaging.
authors.affiliation: College of Materials Science and Engineering, Sichuan University, Chengdu 610065, People's Republic of China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Wu
authors.affiliation: College of Materials Science and Engineering, Sichuan University, Chengdu 610065, People's Republic of China. Electronic address: zbhuang@scu.edu.cn.
authors.forename: Zhongbing
authors.initials: Z
authors.lastname: Huang
authors.affiliation: College of Materials Science and Engineering, Sichuan University, Chengdu 610065, People's Republic of China.
authors.forename: Guangfu
authors.initials: G
authors.lastname: Yin
authors.affiliation: Molecular Imaging Center, Department of Radiology, West China Hospital of Sichuan University, No. 2, 4th Keyuan Road, Chengdu 610093, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Molecular Imaging Center, Department of Radiology, West China Hospital of Sichuan University, No. 2, 4th Keyuan Road, Chengdu 610093, China. Electronic address: gaofabao@yahoo.com.
authors.forename: Fabao
authors.initials: F
authors.lastname: Gao
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D003287:Contrast Media / Q000737:chemistry*; D005063:Europium / Q000737:chemistry* / Q000494:pharmacology; D005349:Fibroins / Q000737:chemistry; D005682:Gadolinium / Q000737:chemistry* / Q000494:pharmacology; D056945:Hep G2 Cells; D006801:Humans; D049449:Luminescence; D008279:Magnetic Resonance Imaging; D051379:Mice; D008819:Mice, Nude; D043942:Nanotubes / Q000737:chemistry*; D009374:Neoplasms, Experimental / Q000175:diagnosis; D061848:Optical Imaging; D010316:Particle Size; D010455:Peptides / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry* / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012493:Samarium / Q000737:chemistry* / Q000494:pharmacology; D047011:Silk / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003287:Contrast Media; D010455:Peptides; D010710:Phosphates; D017382:Reactive Oxygen Species; D047011:Silk; D012493:Samarium; D005063:Europium; D005349:Fibroins; D005682:Gadolinium
keywords: Gd/Eu-codoped; Luminescence imaging; Magnetic resonance imaging; Silk fibroin