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dc.contributor.advisor Colvin, Vicki L.
dc.creatorCho, Minjung
dc.date.accessioned 2013-09-16T14:57:38Z
dc.date.accessioned 2013-09-16T14:57:58Z
dc.date.available 2013-09-16T14:57:38Z
dc.date.available 2013-09-16T14:57:58Z
dc.date.created 2013-05
dc.date.issued 2013-09-16
dc.date.submitted May 2013
dc.identifier.urihttps://hdl.handle.net/1911/71938
dc.description.abstract In these days, nanomaterials are applied in a variety of biomedical applications including magnetic resonance imaging (MRI), cell imaging, drug delivery, and cell separation. Most MRI contrast agents affect the longitudinal relaxation time (T1) and transverse relaxation time (T2) of water protons in the tissue and result in increased positive or negative contrast. Here, we report the optimization of r1 (1/T1) or r2 (1/T2) relaxivity dynamics with diameter controlled gadolinium oxide nanocrystals (2~22 nm) and iron based magnetic nanocrystals (4 ~33 nm). The r1 and r2 MR relaxivity values of hydrated nanocrystals were optimized and examined depending on their core diameter, surface coating, and compositions; the high r1 value of gadolinium oxide was 40-60 S-1mM-1, which is 10-15 fold higher than that of commercial Gd (III) chelates (4.3~4.6 S-1mM-1). Moreover, in vitro toxicological studies revealed that polymer coated nanocrystals suspensions had no significant effect on human dermal fibroblast (HDF) cells even at high concentration. Towards multimodal imaging or multifunctional ability, we developed the iron oxide/QDs complexes, which consist of cores of iron oxide that act as nucleation sites for fluorescent QDs. The choice of variable QDs helped to visualize and remove large iron oxide materials in a magnetic separation. Additionally, diluted materials concentrated on the magnet could be fluorescently detected even at very low concentration. The designed MRI or multifunctional nanomaterials will give great and powerful uses in biomedical applications.
dc.format.mimetype application/pdf
dc.language.iso eng
dc.subjectMagnetic resonance imaging (MRI) contrast agents
Multifunctional magnetic fluorescent complexes
dc.title Biomedical Nanocrystal Agents: Design, Synthesis, and Applications
dc.contributor.committeeMember McDevitt, John T.
dc.contributor.committeeMember Wong, Michael S.
dc.date.updated 2013-09-16T14:57:58Z
dc.identifier.slug 123456789/ETD-2013-05-490
dc.type.genre Thesis
dc.type.material Text
thesis.degree.department Chemistry
thesis.degree.discipline Natural Sciences
thesis.degree.grantor Rice University
thesis.degree.level Doctoral
thesis.degree.name Doctor of Philosophy
dc.identifier.citation Cho, Minjung. "Biomedical Nanocrystal Agents: Design, Synthesis, and Applications." (2013) Diss., Rice University. https://hdl.handle.net/1911/71938.


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