Nanomedicine Archives

Gold Nanoparticles Made to Heat Up from Near-Infrared Light for Tumor Killing

heat nanoparticles Gold Nanoparticles Made to Heat Up from Near Infrared Light for Tumor Killing

Gold has been a popular material to make nanoparticles because of its biocompatibility, but to get it to do some neat tricks isn’t enough to simply produce spherical gold nanoparticles. One limitation in using gold for killing tumors has been that cheap spherical gold nanoparticles are not plasmonic to near-infrared light, meaning they don’t heat up when such light illuminates them. Making gold nanoparticles plasmonic requires forming shapes out of the element that have been expensive to produce. Researchers at ETH Zurich (Eidgenössische Technische Hochschule Zürich) have developed a new technique for cheap manufacturing of different shapes of plasmonic gold-based nanoparticles that may open new possibilities for cancer treatment.

Instead of creating new shapes purely out of gold, a difficult process, the team instead arranged readily available spherical gold nanoparticles coated with silicon dioxide into plasmonic shapes. The silicon dioxide works like a spacer, keeping the gold spheres at predefined distances from each other, guaranteeing a correct geometry that produces the plasmonic effect. The team tested the nanoparticles by embedding them inside human breast cancer tumors and killing them with a four minute pulse from a low energy near-infrared laser.

Some details from the study abstract in Advanced Functional Materials:

Hybrid plasmonic-superparamagnetic nanoaggregates (50–100 nm in diameter) consisting of SiO2-coated Fe2O3 and Au (≈30 nm) nanoparticles were fabricated using scalable flame aerosol technology. By finely tuning the Au interparticle distance using the SiO2 film thickness (or content), the plasmonic coupling of Au nanoparticles can be finely controlled bringing their optical absorption to the near-IR that is most important for human tissue transmittance. The SiO2 shell facilitates also dispersion and prevents the reshaping or coalescence of Au particles during laser irradiation, thereby allowing their use in multiple treatments. These nanoaggregates have magnetic resonance imaging (MRI) capability as shown by measuring their r2 relaxivity while their effectiveness as photothermal agents is demonstrated by killing human breast cancer cells with a short, four minute near-IR laser irradiation (785 nm) at low flux (4.9 W cm-2).

Study in Advanced Functional MaterialsPhotothermal Killing of Cancer Cells by the Controlled Plasmonic Coupling of Silica-Coated Au/Fe2O3 Nanoaggregates

Press release: Hot nanoparticles for cancer treatments

Seeing the Invisible: Interview with Nanotronics CEO

Seeing the Invisible: Interview with Nanotronics CEO

Nanotechnology continues to hold significant promise for medicine, though not only in the form of nanorobots that swim through the blood stream. We recently had the opportunity to speak with Matthew Putman, the CEO of Nanotronics, which is developing cutting-edge diagnostic systems for medicine among other fields.

Shiv Gaglani, Medgadget: What exactly does Nanotronics do?

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Metal Layered Shrink Wrap Makes Fluorescent Markers Glow Brighter

Metal Layered Shrink Wrap Makes Fluorescent Markers Glow Brighter

Many current methods of detecting pathogens and biomarkers involve fluorescent particles that bind to their targets that then can be spotted using photodetectors while being in excited state. While this technique is continuing to revolutionize diagnostics and laboratory work, it’s often limited by the faintness of the fluorescence when small numbers of particles are being detected. One way to improve the sensitivity of fluorescent markers is to make them produce a stronger signal. Researchers at University of California, Irvine are reporting in journal Optical Materials Express the development of a new technique that significantly improves the brightness of fluorescing nanoparticles.

The technique involves applying layers of gold and nickel onto shrink wrap, the kind you have in your kitchen. When heated, the material wrinkles and compresses, creating a flower-like structure. Samples of goat anti-mouse immunoglobulin antibodies were tagged with fluorescent markers and placed on top of the new material. When tested in a laboratory setting, the resulting fluorescence in the near-infrared range was three orders of magnitude greater than without the metal enhanced fluorescence.

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Cancer Biomarker Detection Using Antibody-Coated Magnetic Nanoparticles

Cancer Biomarker Detection Using Antibody-Coated Magnetic Nanoparticles

Detecting disease markers in blood can be quite challenging, particularly when looking for rare proteins signaling the existence of a tumor. This is because blood is rich in all kind of molecules and compounds that create the false positive “noise” that makes it hard to see what is being searched for. Now a team of researchers at Fraunhofer Institute for Manufacturing Engineering and Automation in Germany have developed a new method that does away with the typical process of purifying the blood sample to remove the noise, but that instead focuses directly on its target.

After a blood sample is taken, a mixture of tiny magnetic nanoparticles coated with antibodies attracted by the target are added. These stick to the protein marker being searched for and a magnet outside the test tube can simply pull these particles out of whole blood. To make them visible, though, another set of antibodies with fluorescent nanoparticles is added that also stick to the same protein. The resulting glow is still weak, so the team resonates the particles using a fluctuating external magnetic field, making the fluorescing particles undulate and glow in sync, resulting in visible detection of the protein target.

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Advanced Nanoparticle System Kills Cancer Cells From Within

Advanced Nanoparticle System Kills Cancer Cells From Within

The latest cancer targeting nanoparticles being developed in labs around the world are getting ever more complex and are utilizing multiple mechanisms to find and strike their targets. Researchers at North Carolina State University and the University of North Carolina at Chapel Hill just published an article in Nature Communications describing a nanoparticle that delivers its killer payload only when inside cells by homing in on ATP (adenosine triphosphate).

ATP is the famous energy molecule that powers the activity inside of cells, and the new nanoparticle carries DNA strands bound to doxorubicin, an anti-cancer drug, than unfold when high levels of ATP are present. The nanoparticles themselves have a layer of hyaluronic acid (HA) that attracts some types of cancer cells, allowing the nanoparticles to enter and open up, releasing the folded DNA strands.

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New Nanoparticles Target Tumors, Release Killer Protein, Activate Immune System to Kill Cancer

New Nanoparticles Target Tumors, Release Killer Protein, Activate Immune System to Kill Cancer

Researchers from the Zaragoza UNAM (National Autonomous University of Mexico) have announced the development of a new nanoparticle that selectively targets cervical cancer cells, while sparing healthy tissue from damage. The nanoparticles ferry interleukin-2 (IL -2), a protein that’s normally produced by the T-cells of the immune system to differentiate between foreign material and the body itself, and to direct the actions of white blood cells. It has also been used in various therapies to kill cancer cells.

The nanoparticles are attracted by cancer cells and attach to them, releasing high concentrations of IL-2 into the tumor. Moreover, the same mechanism activates the immune system to jump into action and attack the tumor with its own bag of tricks. Because a person with cancer often has a diminished production of IL-2, the targeted delivery of large quantities of the cytokine helps overcome the tumor’s proactive defenses against the immune system. The team tested the therapeutic nanoparticles on animal models with promising success for humans.

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Evaluating Effectiveness of Cancer Killing Thermal Nanoparticles

Evaluating Effectiveness of Cancer Killing Thermal Nanoparticles

A promising approach currently being studied in labs around the world for killing cancer cells involves delivering nanoparticles to tumors that can be made to heat up in the presence of an electromagnetic field. It takes only about a ten degree rise in a tumor cell’s temperature for it to die, while healthy cells tend to be more resilient to heat.

Iron-oxide nanoparticles are probably the best for this job, but there’s a variety of ways of packaging them, so researchers at University of Cincinnati wanted to see which heat up best under the same conditions. The problem is not delivering too much RF energy which would destroy healthy tissue, so having efficient nanoparticles is very important. The team tested uncoated iron-oxide nanoparticles, iron-oxide nanoparticles coated with polyacrylic acid (PAA), a polystyrene nanosphere with iron-oxide nanoparticles uniformly embedded in its matrix, and

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Laser Light Opens Nanoparticles to Release Chemo Drugs Right to Tumors

Laser Light Opens Nanoparticles to Release Chemo Drugs Right to Tumors

Chemotherapy is an effective therapy for cancer, except for the side effect of killing the rest of the body with the toxin. Being able to deliver chemo drugs directly to the tumor while sparing the body’s healthy tissues may allow higher doses of the drug to attack cancer without killing the patient. Researchers at UCLA and University of Montpellier in France have developed light-activated particles that release their payloads when a special laser shines illuminates them.

The technique is based on mesoporous silica nanoparticles (MSN) the pores of which are filled with a chemo drug and plugged by “pseudo-rotaxane constituted by an azobenzene stalk and a β-cyclodextrin moiety.” When a two-photon laser illuminates the nanoparticles, the pores unclog and the medication is released. Because the laser frequency is set in the infrared range, the light penetrates sufficiently into the body to reach targets within  about 1.5 inches (4 cm), allowing for a variety of tumors, such as of the skin and breast, to receive treatment.

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Immunosuppressant-Loaded Nanoparticles Treat Symptoms of Duchenne Muscular Dystrophy in Mice

Immunosuppressant-Loaded Nanoparticles Treat Symptoms of Duchenne Muscular Dystrophy in Mice

Duchenne muscular dystrophy is a congenital disease that affects boys almost exclusively (“Jerry’s kids“) and leads to severe muscle dysfunction and death. Current therapies, primarily corticosteroids, are very limited in effectiveness – and introduce their own side effects that can make things worse. Now researchers at Washington University School of Medicine in St. Louis are reporting on a new technique that involves introducing nanoparticles – stuffed with rapamycin – to alleviate some of the symptoms of the disease.

Rapamycin is an immunosuppressant usually used to prevent organ rejection post transplantation, but has also been shown to aid with autophagy, or getting rid of cellular waste. The team loaded specially designed nanoparticles with rapamycin and delivered the solution into mouse models of Duchenne muscular dystrophy.  Mice receiving the new treatment had a significant increase in their muscular strength along with a boost in cardiac function (as measured by volume of blood pumped). These improvements were seen in both young and old mice with the disease, pointing toward a new therapy option for anyone with Duchenne.

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