<p>I. Gallium-hemoglobin Coated Silver
Nanoparticles for Antimicrobial Photodynamic Therapy Against Bacterial
Pathogens One of
the mechanisms for bacterial pathogens’ hemin acquisition is through
cell-surface hemin receptors (CSHRs), which are responsible for rapid hemin
recognition. GaPpIX, as a hemin analog, can be rapidly taken up by
CSHR-expressing bacteria, such as <i>Staphylococcus
aureus</i> (<i>S.aureus)</i>. Previous works
shown that GaPpIX has aPDI activity at micromolar level of concentration
following 10 seconds of 405-nm light exposure using LED array. The
photosensitizing ability of GaPpIX can be further enhanced by incorporating
with hemoglobin (GaHb) and 10 nm silver nanoparticles (AgNP). The results
suggested a higher aPDI activity of GaHb-AgNP than any of its components
against MRSA strains and neglectable cytotoxicity against keratinocytes.
GaHb-AgNPs were also found having aPDI activity against intracellular MRSA and <i>Mycobacterium abscessus </i>but not
effective against <i>S. aureus</i> biofilm.
GaHb-AgNPs have no significant toxicity toward macrophages with concentrations
lower than 22.64 μg/mL.</p>
<p> </p>
<p>II. Synthesis and Properties of Magnetic Gold Nanoparticles</p>
<p> Superparamagnetic
gold nanoparticles support hybrid magnetic and plasmonic properties that
can be exploited for a variety of applications. In this paper we present new
insights on the synthesis of magnetic gold nanoparticles (MGNPs) with an
emphasis on efficiency, scalability, and waste reduction, supported by a
comprehensive analysis of their physical and materials properties. Aqueous
suspensions of colloidal Fe<sub>3</sub>O<sub>4</sub> are conditioned with 5-kDa
polyethylene glycol and L-histidine
to mediate the nucleation and growth of gold by a mild reducing agent.
Isotropic MGNPs on the order of 100 nm can be synthesized using scalable
reaction conditions with Au:Fe mole ratios as low as 1:2 and cleansed with
generally regarded as safe (GRAS) chemicals for the removal of residual iron
oxide. High-resolution energy-dispersive x-ray imaging of individual MGNCs
revealed these to be ultrafine composites of gold and SPIO rather than core–shell structures. The
attenuated total reflectance infrared (ATR-IR) spectroscopy and Raman
spectroscopy indicated that the cleansing step does change the optical
properties of the synthesized MGNPs. Magnetometry of MGNCs in bulk powder form
confirmed their superparamagnetic nature, with bulk moments between 6 to 7
emu/g.</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/8398148 |
| Date | 14 August 2019 |
| Creators | Lu Lin (6875918) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/I_ANTIMICROBIAL_PHOTODYNAMIC_INACTIVATION_TARGETING_MULTIDRUG_RESISTANCE_WITH_GALLIUM-HEMOGLOBIN-COATED_SILVER_NANOPARTICLES_II_SYNTHESIS_AND_PROPERTIES_OF_MAGNETIC_GOLD_NANOPARTICLES/8398148 |
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