Magnetic and Plasmonic Contrast Agents in Optical Coherence Tomography

Oldenburg, Amy L.; Blackmon, Richard L.; Sierchio, Justin M.

doi:10.1109/jstqe.2016.2553084

Cited by 8 publications

(3 citation statements)

References 124 publications

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“…In the future, this DT-OCT model will be extended to diffusion of anisotropic particles, including rotational and translational motions. Anisotropic particles are advantageous for studying tissue properties, since many have shape-dependent optical properties that can be used to tune probes for tissue contrasting and with other OCT methods, including spectroscopic and photothermal OCT (Oldenburg, Blackmon & Sierchio 2016). Additionally, the information obtained from knowing both translational and rotational particle motion has potential for elucidating particle transport within more highly confined structures, as opposed to the weakly-constrained regime discussed here.…”

Section: Resultsmentioning

confidence: 99%

Diffusion tensor optical coherence tomography

Marks¹,

Blackmon²,

Oldenburg³

2018

Phys. Med. Biol.

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Abstract. In situ measurements of diffusive particle transport provide insight into tissue architecture, drug delivery, and cellular function. Analogous to diffusiontensor magnetic resonance imaging (DT-MRI), where the anisotropic diffusion of water molecules is mapped on the millimeter scale to elucidate the fibrous structure of tissue, here we propose diffusion-tensor optical coherence tomography (DT-OCT) for measuring directional diffusivity and flow of optically scattering particles within tissue. Because DT-OCT is sensitive to the sub-resolution motion of Brownian particles as they are constrained by tissue macromolecules, it has the potential to quantify nanoporous anisotropic tissue structure at micrometer resolution as relevant to extracellular matrices, neurons, and capillaries. Here we derive the principles of DT-OCT, relating the detected optical signal from a minimum of 6 probe beams with the 6 unique diffusion tensor and 3 flow vector components. The optimal geometry of the probe beams is determined given a finite numerical aperture, and a high-speed hardware implementation is proposed. Finally, Monte Carlo simulations are employed to assess the ability of the proposed DT-OCT system to quantify anisotropic diffusion of nanoparticles in a collagen matrix, an extracellular constituent that is known to become highly aligned during tumor development.

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Section: Resultsmentioning

confidence: 99%

Diffusion tensor optical coherence tomography

Marks¹,

Blackmon²,

Oldenburg³

2018

Phys. Med. Biol.

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“…This can be avoided through the use of magnetic contrast agents that further noticeably increases the resolution of the ultrasound images [ 79 ]. OCT combined with magnetic or plasmonic nanoparticles was demonstrated to improve the cross-section absorption about five orders of magnitude larger than conventional indocyanine green in the near-infrared spectral region [ 80 ]. The MRI technique is convenient for monitoring the progress of ocular diseases such as diabetic retinopathy, age macular degeneration, ocular tumor angiogenesis, etc.…”

Section: Current Uses Of Mnps As Pharmaceutical Formulations: Ocular Cancer Diagnosis and Treatmentmentioning

confidence: 99%

Advantages and Disadvantages of Using Magnetic Nanoparticles for the Treatment of Complicated Ocular Disorders

Schneider‐Futschik

Reyes-Ortega

2021

Pharmaceutics

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Nanomaterials provide enormous opportunities to overcome the limitations of conventional ocular delivery systems, such as low therapeutic efficacy, side effects due to the systemic exposure, or invasive surgery. Apart from the more common ocular disorders, there are some genetic diseases, such as cystic fibrosis, that develop ocular disorders as secondary effects as long as the disease progresses. These patients are more difficult to be pharmacologically treated using conventional drug routes (topically, systemic), since specific pharmacological formulations can be incompatible, display increased toxicity, or their therapeutic efficacy decreases with the administration of different kind of chemical molecules. Magnetic nanoparticles can be used as potent drug carriers and magnetic hyperthermia agents due to their response to an external magnetic field. Drugs can be concentrated in the target point, limiting the damage to other tissues. The other advantage of these magnetic nanoparticles is that they can act as magnetic resonance imaging agents, allowing the detection of the exact location of the disease. However, there are some drawbacks related to their use in drug delivery, such as the limitation to maintain efficacy in the target organ once the magnetic field is removed from outside. Another disadvantage is the difficulty in maintaining the therapeutic action in three dimensions inside the human body. This review summarizes all the application possibilities related to magnetic nanoparticles in ocular diseases.

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“…OCT can be tailored to detect labelled particles with high sensitivity. Labelling can be performed magnetically and by plasmonic resonance, leading to selective absorption and scattering (Oldenburg et al, 2016). Moreover, contrast can be generated by optical anisotropy and diffusion (Kalkman et al, 2010).…”

Section: Potential For Flow and Aerosol Measurementsmentioning

confidence: 99%