Dataset Information

Development of iron-doped silicon nanoparticles as bimodal imaging agents.

ABSTRACT: We demonstrate the synthesis of water-soluble allylamine-terminated Fe-doped Si (Si(xFe)) nanoparticles as bimodal agents for optical and magnetic imaging. The preparation involves the synthesis of a single-source iron-containing precursor, Na(4)Si(4) with x% Fe (x = 1, 5, 10), and its subsequent reaction with NH(4)Br to produce hydrogen-terminated Si(xFe) nanoparticles. The hydrogen-capped nanoparticles are further terminated with allylamine via thermal hydrosilylation. Transmission electron microscopy indicates that the average particle diameter is ?3.0 ± 1.0 nm. The Si(5Fe) nanoparticles show strong photoluminescence quantum yield in water (?10%) with significant T(2) contrast (r(2)/r(1) value of 4.31). Electron paramagnetic resonance and Mössbauer spectroscopies indicate that iron in the nanoparticles is in the +3 oxidation state. Analysis of cytotoxicity using the resazurin assay on HepG2 liver cells indicates that the particles have minimal toxicity.

SUBMITTER: Singh MP

PROVIDER: S-EPMC3383901 | biostudies-literature | 2012 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Development of iron-doped silicon nanoparticles as bimodal imaging agents.

Singh Mani P MP Atkins Tonya M TM Muthuswamy Elayaraja E Kamali Saeed S Tu Chuqiao C Louie Angelique Y AY Kauzlarich Susan M SM

ACS nano 20120529 6

We demonstrate the synthesis of water-soluble allylamine-terminated Fe-doped Si (Si(xFe)) nanoparticles as bimodal agents for optical and magnetic imaging. The preparation involves the synthesis of a single-source iron-containing precursor, Na(4)Si(4) with x% Fe (x = 1, 5, 10), and its subsequent reaction with NH(4)Br to produce hydrogen-terminated Si(xFe) nanoparticles. The hydrogen-capped nanoparticles are further terminated with allylamine via thermal hydrosilylation. Transmission electron mi ...[more]

PMID: 22616623

Similar Datasets

Project description:In vivo tracking of dendritic cell (DC) migration to the lymphatic system is essential for evaluating the outcome of DC-based immunotherapies. Novel multimodal imaging strategies with high analytical performance are urgently needed to supply complementary information about the migration and colonization of DCs. In this study, we designed a bimodal imaging agent, namely Au@Prussian blue-Gd@ovalbumin nanoparticles (APG@OVA NPs), for activating DCs and real-time tracking of DC migration process by magnetic resonance imaging (MRI). Moreover, the distribution of the colonized DCs in the lymphatic system was profiled at the single-cell levels based on surface-enhanced Raman scattering (SERS) technique. Methods: In this strategy, PBs as cyanide (CN)-bridged coordination blocks were assembled onto the gold nanoparticles core to provide SERS signal in the Raman-silent region (1800 and 2800 cm-1), which could avoid background signal interference. The doping Gd3+ located in the lattice of PB enables the MRI ability with high relaxivity of the probe. Ovalbumin, an egg allergen, was used as an antigen to activate DCs due to its immunological properties. The prepared APG@OVA NP agents were used to activate DCs with high efficacy and to track their migration and distribution in vivo through SERS/MR bimodal imaging. Results: The APG@OVA NP agents could not only enable DC activating and labeling, but also achieve real-time monitoring of DC migration in vivo and accurate profiling of DC distribution in the lymphatic system. MR imaging indicated the time-dependent migration of the APG@OVA NP-labeled DCs from the footpad to the sentinel lymph node. The background-free Raman mapping of the lymph node tissue slice demonstrated that the activated DCs have successfully colonized to the sentinel lymph node. Conclusion: Concerning the high activating efficacy, dual complementary imaging readouts, and low biological toxicity, the APG@OVA NPs act as high-performance tracking agents for DC-based immunotherapies.

Project description:This work highlights an automated method for enzyme immobilization via 4-triethoxysilylbutyraldehyde (TESB) and 11-triethoxysilylundecanal (TESU) derived silicone-based coupling agents. From the various coupling strategies we scrutinized, TESB and 4-triethoxysilylbutanoic acid (TESBA), the carboxylic acid derivative, were determined to be the most effective. The resulting immobilized enzyme particles (IEPs) displayed robustness and rapid digestion, while also implementing a more streamlined IEP washing procedure. The physical size of IEPs did not correlate to digestion efficiency, providing insights for potential cost-saving’s in enzyme utilization. Immobilization efficiency was determined to be 50.8 ± 7.7% as validated by Bradford's assay. Furthermore, we adapted the IEP procedure into an automated format with a Bravo liquid handler. This allowed for multiple enzymes, and/or coupling agents to be fabricated at once on a 96-well microplate, in a fraction of the time. The automated trypsin TESB and TESBA IEPs rivaled the classical in-gel digestion method for the analysis of Jurkat cell lysate, achieving similar protein group identifications. Moreover, pepsin IEPs favored cleavage at leucine (>50%) over phenylalanine, tyrosine, tryptophan, and methionine residues. Further, when miscleavages occurred, they tended to be at tyrosine residues, or when two aromatic residues were adjacent. The IEP method was then adapted for an in-situ immobilized enzyme microreactor (IMER) fabrication. We determined that TESBA could serve two roles by functionalizing the silica capillary's inner wall, and simultaneously acting as an enzyme coupler. The IMER digestion of bovine serum albumin (BSA), mirroring IEP digestion conditions, yielded a 33-40% primary sequence coverage per LC-MS/MS analysis in as little as 15 minutes. Overall, our findings underscore the potential of both IEP and IMER methods, paving the way for automated analysis and a reduction in enzyme waste through reuse, thereby contributing to a more cost-effective and timely study of the proteome.

Dataset Information

Development of iron-doped silicon nanoparticles as bimodal imaging agents.

Publications

Development of iron-doped silicon nanoparticles as bimodal imaging agents.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets