Magnetic Nanoclusters Kill Hard-To-Reach Tumors

Researchers at Oregon State University have developed an improved technique for using magnetic nanoclusters to kill hard-to-reach tumorsMagnetic nanoparticles – tiny pieces of matter as small as one-billionth of a meter – have shown anti-cancer promise for tumors easily accessible by syringe, allowing the particles to be injected directly into the cancerous growth. Once injected into the tumor, the nanoparticles are exposed to an alternating magnetic field, or AMF. This field causes the nanoparticles to reach temperatures in excess of 100 degrees Fahrenheit, which causes the cancer cells to die. But for some cancer types such as prostate cancer, or the ovarian cancer used in the Oregon State study, direct injection is difficult. In those types of cases, a “systemicdelivery method – intravenous injection, or injection into the abdominal cavity – would be easier and more effective.

The challenge for researchers has been finding the right kind of nanoparticles – ones that, when administered systemically in clinically appropriate doses, accumulate in the tumor well enough to allow the AMF to heat cancer cells to death.

Olena Taratula and Oleh Taratula of the OSU College of Pharmacy tackled the problem by developing nanoclusters, multiatom collections of nanoparticles, with enhanced heating efficiency. The nanoclusters are hexagon-shaped iron oxide nanoparticles doped with cobalt and manganese and loaded into biodegradable nanocarriers.

There had been many attempts to develop nanoparticles that could be administered systemically in safe doses and still allow for hot enough temperatures inside the tumor,” said Olena Taratula, associate professor of pharmaceutical sciences. “Our new nanoplatform is a milestone for treating difficult-to-access tumors with magnetic hyperthermia. This is a proof of concept, and the nanoclusters could potentially be optimized for even greater heating efficiency.”

Findings were published in ACS Nano.

Source: https://today.oregonstate.edu/

Perovskite Solar Cells One Giant Step Closer To The Market

Harnessing energy from the sun, which emits immensely powerful energy from the center of the solar system, is one of the key targets for achieving a sustainable energy supplyLight energy can be converted directly into electricity using electrical devices called solar cells. To date, most solar cells are made of silicon, a material that is very good at absorbing light. But silicon panels are expensive to produce.

Scientists have been working on an alternative, made from perovskite structures. True perovskite, a mineral found in the earth, is composed of calcium, titanium and oxygen in a specific molecular arrangement. Materials with that same crystal structure are called perovskite structuresPerovskite structures work well as the light-harvesting active layer of a solar cell because they absorb light efficiently but are much cheaper than silicon. They can also be integrated into devices using relatively simple equipment. For instance, they can be dissolved in solvent and spray coated directly onto the substrate.

Materials made from perovskite structures could potentially revolutionize solar cell devices, but they have a severe drawback: they are often very unstable, deteriorating on exposure to heat. This has hindered their commercial potential. The Energy Materials and Surface Sciences Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), led by Prof. Yabing Qi, has developed devices using a new perovskite material that is stable, efficient and relatively cheap to produce, paving the way for their use in the solar cells of tomorrow. This material has several key features:

  • First, it is completely inorganic – an important shift, because organic components are usually not thermostable and degrade under heat. Since solar cells can get very hot in the sun, heat stability is crucial. By replacing the organic parts with inorganic materials, the researchers made the perovskite solar cells much more stable..  “The solar cells are almost unchanged after exposure to light for 300 hours,” says Dr. Zonghao Liu, an author on the paper.
  • Second feature: Inorganic perovskite solar cells tend to have lower light absorption than organic-inorganic hybrids, however, but the OIST researchers doped their new cells with manganese in order to improve their performance. Manganese changes the crystal structure of the material, boosting its light harvesting capacity.  “Just like when you add salt to a dish to change its flavor, when we add manganese, it changes the properties of the solar cell,” says Liu.
  • Thirdly, in these solar cells, the electrodes that transport current between the solar cells and external wires are made of carbon, rather than of the usual gold. Such electrodes are significantly cheaper and easier to produce, in part because they can be printed directly onto the solar cells. Fabricating gold electrodes, on the other hand, requires high temperatures and specialist equipment such as a vacuum chamber.

The findings are published in Advanced Energy Materials. Postdoctoral scholars Dr. Jia Liang and Dr. Zonghao Liu made major contributions to this work.

Source: https://www.oist.jp/