Browsing by Author "Bardhan, Rizia"

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    Delivery of nanoparticles to brain metastases of breast cancer using a cellular Trojan horse
    (Springer, 2012) Choi, Mi-Ran; Bardhan, Rizia; Stanton-Maxey, Katie J.; Badve, Sunil; Nakshatri, Harikrishna; Stantz, Keith M.; Cao, Ning; Halas, Naomi J.; Clare, Susan E.; Laboratory for Nanophotonics
    As systemic cancer therapies improve and are able to control metastatic disease outside the central nervous system, the brain is increasingly the first site of relapse. The blood-brain barrier (BBB) represents a major challenge to the delivery of therapeutics to the brain. Macrophages originating from circulating monocytes are able to infiltrate brain metastases while the BBB is intact. Here, we show that this ability can be exploited to deliver both diagnostic and therapeutic nanoparticles specifically to experimental brain metastases of breast cancer.
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    Nanostructures for plasmon enhanced fluorescence sensing: From photophysics to biomedicine
    (2010) Bardhan, Rizia
    Metallic nanostructures exhibit unique plasmonic properties when optically excited, which includes modification of the spontaneous emission and lifetime of fluorophores in their vicinity. Here we utilize silica (SiO2) core encapsulated in gold (Au) shell nanoshells for emission enhancement of weak near-infrared (NIR) emitting fluorophores, including Indocyanine green (ICG) and IR800. The fluorescence enhancement of ICG molecules as a function of distance from the surface of nanoshells was studied. A maximum enhancement of 50X at a distance of 7 nm from the nanoshells surface, and minimum enhancement of 7X at 42 nm from nanoshells surface was achieved. Additionally, fluorescence enhancement of IR800 molecules induced by nanoshells was compared with that of Au nanorods. The quantum yield of IR800 was enhanced from 7% to 86% in the case of nanoshells and 74 % for nanorods. The native lifetime of IR800 decreased from 564 ps to 121 ps when conjugated to nanorods and 68 ps for nanoshells. We then demonstrated a biomedical application of plasmon enhanced fluorescence sensing by utilizing nanoshell based complexes (nanocomplexes) for simultaneous fluorescence optical imaging as well as magnetic resonance imaging of cancer cells in vitro and in vivo. Nanocomplexes were fabricated by encapsulating nanoshells with a SiO2 epilayer doped with iron oxide nanoparticles and ICG molecules, which resulted in a high T2 relaxivity (390 mM-1sec-1) and 45X fluorescence enhancement of ICG. The nanocomplexes were covalently conjugated with antibodies to enable active targeting in vitro and in vivo. In addition they were utilized for photothermal therapy of cancer cells in vitro. Furthermore, other plasmonic nanostructures relevant for biomedical applications were also synthesized in the sub-100 nm regime including Au/SiO2/Au nanoshells and cuprous oxide core coated with Au shell nanoshells. Excellent agreement between their experimental and theoretical optical properties was achieved. Additionally, physical and chemical properties of mesostructures relevant for photonic devices including sub-micrometer zinc oxide structures and Mesostars composed of a mixture of iron oxides and Au were also studied.
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    Targeting pancreatic cancer with magneto-fluorescent theranostic gold nanoshells
    (Future Medicine, 2014) Chen, Wenxue; Ayala-Orozco, Ciceron; Biswal, Nrusingh C.; Perez-Torres, Carlos; Bartels, Marc; Bardhan, Rizia; Stinnet, Gary; Liu, Xian-De; Ji, Baoan; Deorukhkar, Amit; Brown, Lisa V.; Guha, Sushovan; Pautler, Robia G.; Krishnan, Sunil; Halas, Naomi J.; Joshi, Amit
    Aim: We report a magneto-fluorescent theranostic nanocomplex targeted to neutrophil gelatinase-associated lipocalin (NGAL) for imaging and therapy of pancreatic cancer. Materials & methods: Gold nanoshells resonant at 810 nm were encapsulated in silica epilayers doped with iron oxide and the near-infrared (NIR) dye indocyanine green, resulting in theranostic gold nanoshells (TGNS), which were subsequently conjugated with antibodies targeting NGAL in AsPC-1-derived xenografts in nude mice. Results: Anti-NGAL-conjugated TGNS specifically targeted pancreatic cancer cells in vitro and in vivo providing contrast for both NIR fluorescence and T2-weighted MRI with higher tumor contrast than can be obtained using long-circulating, but nontargeted, PEGylated nanoparticles. The nanocomplexes also enabled highly specific cancer cell death via NIR photothermal therapy in vitro. Conclusion: TGNS with embedded NIR and magnetic resonance contrasts can be specifically targeted to pancreatic cancer cells with expression of early disease marker NGAL, and enable molecularly targeted imaging and photothermal therapy.