Quantum dots deliver vitamin D to tumors for possible inflammatory breast cancer treatment


QDOTS imagesCAKXSY1K 8February 1, 2013

The shortened daylight of a Maine winter may make for long, dark nights – but it has shone a light on a novel experimental approach to fighting inflammatory breast cancer (IBC), an especially deadly form of breast cancer.

Read more at: http://phys.org/news/2013-02-quantum-dots-vitamin-d-tumors.html#jCp

Breast Cancer Treatments  – Chat w/Our Oncology Info Experts And Learn Your Treatment Options. – cancercenter.com The new approach enlists the active form of Vitamin D3, called calcitriol, which is delivered therapeutically by quantum dots. Quantum dots are an engineered light-emitting nanoscale delivery vehicle. This new preliminary work shows the dots can be used to rapidly move high concentrations of calcitriol to targeted tumor sites where cancer cells accumulate, and also through the lymph system where the cancer spreads.

With this approach, the calcitriol can fight on multiple fronts and the targeted location can be visualized with an imaging system tracking the quantum dots. The research will be presented at the 57th Annual Meeting of the Biophysical Society (BPS), held Feb. 2-6, 2013, in Philadelphia, Pa. University of Delaware cancer researcher Anja Nohe was living in Maine when she first received funding from the Maine Cancer Foundation to determine the effect of calcitriol on breast cancer cells. Reading cancer literature helped her make connections between cancer, vitamin D, and the daylight regime of higher latitudes. “By talking with talented colleagues about these ideas, the foundation was set for the current project,” she says. After moving to the University of Delaware, she began working with Kenneth Van Golen, “an expert in the biology of IBC,” to evaluate calcitriol. Compared to other forms of breast cancer, IBC is especially difficult to treat. It has a five-year survival rate of 40% versus 87% for all other breast cancers.

A big part of what makes IBC treatment difficult is its multi-site growth pattern. Current aggressive treatments such as combinations of chemotherapy, surgery and radiation, have failed to significantly improve IBC survival rates. This early experimental work on mice is encouraging because data show calcitriol can inhibit invasion and migration of SUM149 cells, an IBC cell line. “New IBC therapies are urgently needed, which is why the goal of my work is to find a successful treatment for inflammatory breast cancer, especially one with fewer side effects,” Nohe says.

More information: Presentation #2953-Pos, “Using calcitriol conjugated quantum dots to target inflammatory breast cancer tumors and metastasis in vivo,” will take place at 10:30 a.m. on Wednesday, Feb. 6, 2013, in the Pennsylvania Convention Center, Hall C. ABSTRACT: tinyurl.com/acw94xg Provided by American Institute of Physics

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Read more at: http://phys.org/news/2013-02-quantum-dots-vitamin-d-tumors.html#jCp

Scientists demonstrate high-efficiency quantum dot solar cells


 

Research shows newly developed solar powered cells may soon outperform conventional photovoltaic technology. Scientists from the National Renewable Energy Laboratory (NREL) have demonstrated the first solar cell with external quantum efficiency (EQE) exceeding 100 percent for photons with energies in the solar range. (The EQE is the percentage of photons that get converted into electrons within the device.) The researchers will present their findings at the AVS 59th International Symposium and Exhibition, held Oct. 28 — Nov. 2, in Tampa, Fla.

While traditional semiconductors only produce one electron from each photon, nanometer-sized crystalline materials such as quantum dots avoid this restriction and are being developed as promising photovoltaic materials. An increase in the efficiency comes from quantum dots harvesting energy that would otherwise be lost as heat in conventional semiconductors. The amount of heat loss is reduced and the resulting energy is funneled into creating more electrical current.

By harnessing the power of a process called multiple exciton generation (MEG), the researchers were able to show that on average, each blue photon absorbed can generate up to 30 percent more current than conventional technology allows. MEG works by efficiently splitting and using a greater portion of the energy in the higher-energy photons. The researchers demonstrated an EQE value of 114 percent for 3.5 eV photons, proving the feasibility of this concept in a working device.

Joseph Luther, a senior scientist at NREL, believes MEG technology is the right direction. “Since current solar cell technology is still too expensive to completely compete with non-renewable energy sources, this technology employing MEG demonstrates that the way in which scientists and engineers think about converting solar photons to electricity is constantly changing,” Luther said. “There may be a chance to dramatically increase the efficiency of a module, which could result in solar panels that are much cheaper than non-renewable energy sources.”