A pinboard by
Ami Jo

Graduate Researcher, Virginia Tech


Using polymer nanoparticles as a delivery mechanism can be more effective and efficient than when administering the drug alone using traditional methods. By fluorescently tagging them, we can track the particles to ensure they are reaching their intended target. However, more is not necessarily better, there is an optimum fluorescent molecule loading because these molecules can quench each other and result in less signal. The surface of the particles can also be functionalized by adding targeting ligands to target specific biological markers and increase the specificity of delivery. My work is a systematic study looking at how changing parameters such as fluorophore loading or polymer compositions affects the characteristics on the resulting nanoparticles. Because every application requires slightly different traits, understanding how to tailor and manipulate the particle characteristics is essential to increase nanoparticle versatility and utility in the drug delivery field.


Biodistribution and fate of core-labeled (125)I polymeric nanocarriers prepared by Flash NanoPrecipitation (FNP).

Abstract: Non-invasive medical imaging techniques such as positron emission tomography (PET) imaging are powerful platforms to track the fate of radiolabeled materials for diagnostic or drug delivery applications. Polymer-based nanocarriers tagged with non-standard PET radionuclides with relatively long half-lives (e.g. (64)Cu: t1/2 = 12.7 h, (76)Br: t1/2 = 16.2h, (89)Zr: t1/2 = 3.3 d, (124)I: t1/2 = 4.2 d) may greatly expand applications of nanomedicines in molecular imaging and therapy. However, radiolabeling strategies that ensure stable in vivo association of the radiolabel with the nanocarrier remain a significant challenge. In this study, we covalently attach radioiodine to the core of pre-fabricated nanocarriers. First, we encapsulated polyvinyl phenol within a poly(ethylene glycol) coating using Flash NanoPrecipitation (FNP) to produce stable 75 nm and 120 nm nanocarriers. Following FNP, we radiolabeled the encapsulated polyvinyl phenol with (125)I via electrophilic aromatic substitution in high radiochemical yields (> 90%). Biodistribution studies reveal low radioactivity in the thyroid, indicating minimal leaching of the radiolabel in vivo. Further, PEGylated [(125)I]PVPh nanocarriers exhibited relatively long circulation half-lives (t1/2 α = 2.9 h, t1/2 β = 34.9 h) and gradual reticuloendothelial clearance, with 31% of injected dose in blood retained at 24 h post-injection.

Pub.: 14 Apr '16, Pinned: 02 Aug '17