| dc.description.abstract |
<p>Liposomes are excellent chemotherapy drug delivery agents, on the cutting edge
of cancer treatment technology. Since liposomes are already used to deploy cancer
drugs in patients, imaging capacity would make them dual-purpose "theranostic" vesicles.
Intermolecular double quantum coherence (iDQC) MRI is uniquely suited to this application,
as its contrast does not require any additional chemicals. Adding contrast agents
to liposomes can be time-consuming, add to toxicity, interfere with membrane function,
or adversely affect drug loading. Furthermore, iDQC contrast measures diffusion and
thus directly depends on membrane permeability and related properties. In this set
of experiments, it has been shown that iDQC signal from intra-liposomal water can
be distinguished from that of bulk water, and that the T2 dynamics of intra-liposomal
water are predictable and dependent on the percent of water encapsulated. These techniques
to distinguish between water molecules based on their current physical circumstances
lead to many novel possibilities in MRI, as nearly all the signal in conventional
MRI is from water protons. Based on the signal to noise ratio in the aforementioned
iDQC experiments, we predict that iDQC contrast from liposomes will be visible in
vivo, and propose to prove this in a murine model. By examining intra-liposomal water,
iDQC can be used to improve chemotherapy delivery via real time monitoring of liposome
location and drug release.</p>
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