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Posts Tagged ‘nanoparticles’

Novel Cancer-Targeting “Cornell Dot” Nanoparticle Approved for First-In-Human Clinical Trial

Posted by Paul Cacciatore on February 1, 2011

“Cornell Dots” — brightly glowing nanoparticles — may soon be used to light up cancer cells to aid in diagnosing and treating cancer. The U.S. Food and Drug Administration (FDA) has approved the first clinical trial in humans of the new technology. It is the first time the FDA has approved using an inorganic material in the same fashion as a drug in humans.

“Cornell Dots” (or “C dots”) — brightly glowing nanoparticles — may soon be used to light up cancer cells to aid in diagnosing and treating cancer. The U.S. Food and Drug Administration (FDA) has approved the first clinical trial in humans of the new technology. It is the first time the FDA has approved using an inorganic material in the same fashion as a drug in humans.

Michelle Bradbury, M.D., Ph.D., Clinician-Scientist, Neuroradiology Service, Memorial Sloan-Kettering Cancer Center; Assistant Professor, Radiology, Weill Cornell Medical College; Lead Study Investigator

Researchers at Memorial Sloan-Kettering Cancer Center’s Nanotechnology Center, along with collaborators at Cornell University and Hybrid Silica Technologies, have received approval for their first Investigational New Drug Application (IND) from the FDA for an ultrasmall silica inorganic nanoparticle platform for targeted molecular imaging of cancer, which may be useful for cancer treatment in the future. Center researchers are about to launch their first-in-human clinical trial in melanoma patients using this first-of-its-kind inorganic nanoparticle to be approved as a drug. “This is a very exciting and important first step for this new particle technology that we hope will ultimately lead to significant improvements in patient outcomes and prognoses for a number of different cancers,” said Michelle Bradbury, M.D., Ph.D., a clinician-scientist on Memorial Sloan-Kettering’s Neuroradiology Service and an assistant professor of radiology at Weill Cornell Medical College, who is the lead investigator of the study, along with Snehal Patel, M.D., a surgeon on Memorial Sloan-Kettering’s Head and Neck Service, who is a co-principal investigator.

“This is a very exciting and important first step for this new particle technology that we hope will ultimately lead to significant improvements in patient outcomes and prognoses for a number of different cancers.”

– Michelle Bradbury, M.D., Ph.D., lead investigator of the study and clinician-scientist on Memorial Sloan-Kettering’s Neuroradiology Service and an assistant professor of radiology at Weill Cornell Medical College

C dots were initially developed as optical probes at Cornell University, Ithaca, by Ulrich Wiesner, Ph.D., a professor of materials science and engineering who, along with Hybrid Silica Technologies, the supplier of C dots, has spent the past eight years precisely engineering these particles. C dots are silica spheres less than 8 nanometers in diameter that enclose several dye molecules. (A nanometer is one-billionth of a meter, about the length of three atoms in a row.) The silica shell, essentially glass, is chemically inert and small enough to pass through the body and out in the urine. For clinical applications, the dots are coated with polyethylene glycol so the body will not recognize them as foreign substances.

C dots were subsequently modified at Memorial Sloan-Kettering for use in PET (positron emission tomography) imaging. C dots are tiny silica spheres that contain dye that glows three times more brightly than simple free dyes when excited by light of a specific wavelength. C dots can “light up” cancer cells, and act as tumor tracers for tracking the movement of cells and assisting in the optical diagnosis of tumors near the skin surface. The attachment of a radioactive label produces a new generation of multimodal (PET-optical) particle probes that additionally enable deeper detection, imaging, and monitoring of drug delivery using three-dimensional PET techniques.

Ulrich Wiesner, Ph.D. (left), a Cornell University Professor of Materials Science & Engineering, works with graduate students Jennifer Drewes & Kai Ma to characterize the size & brightness of C dots in their Bard Hall lab. (Photo: Jason Koski/University Photography)

C dots can be tailored to any particle size. Previous imaging experiments in mice conducted by the Memorial Sloan-Kettering team showed that particles of a very small size (in the 5 to 7 nanometer range) could be retained in the bloodstream and efficiently cleared through the kidneys after applying a neutral surface coat. More recently, the research team molecularly customized C dots to create a new particle platform, or probe, that can target surface receptors or other molecules expressed on tumor surfaces and that can be cleared through the kidneys.

Using PET scans, C dots can be imaged to evaluate various biological properties of the tumors, including tumor accumulation, spread of metastatic disease to lymph nodes and distant organs, and treatment response to therapy. The information gained from imaging tumors targeted with this multimodal platform may also assist physicians in defining tumor borders for surgery, and improving real-time visualization of small vascular beds, anatomic channels, and neural structures during surgery.

The purpose of this trial is to evaluate the distribution, tissue, uptake, and safety of the particles in humans by PET imaging. This study will provide data that will serve as a baseline to guide the design of future surgical and oncologic applications in the clinic. “The use of PET imaging is an ideal imaging technology for sensitively monitoring very small doses of this new particle probe in first-in-human trials,” added Steven Larson, M.D., Chief of Memorial Sloan-Kettering’s Nuclear Medicine Service.

Memorial Sloan-Kettering nanochemist Oula Penate Medina, Ph.D., notes that “this is an important trial in that it will help to answer a number of key questions regarding future potential applications of this multimodal system. Once the door has been opened, new and emerging fields, such as targeted drug delivery, can be investigated. We expect that these particles can be adapted for multiple clinical uses, including the early diagnosis and treatment of various cancers, as well as for sensing changes in the microenvironment.”

“This clinical trial is the culmination of a longstanding collaborative effort with our colleagues at Cornell and Hybrid Silica Technologies, as well as a testament to our own institutional colleagues here at the Center,” Dr. Bradbury said. “With the support of many, in particular the Office of Clinical Research, we’ve pushed to translate the C dots from a laboratory idea to our first FDA IND-approved inorganic nanomedicine drug product to be tested in the clinic,” Dr. Bradbury said.

The work was funded in part by the Clinical and Translational Science Center, Weill Cornell Medical College, the Cornell Nanobiology Center, and the National Institutes of Health (NIH) Small-Animal Imaging Research Program (SAIRP). In addition to Drs. Bradbury, Penante-Medina, Larson, Patel, and Wiesner, the following Memorial Sloan-Kettering investigators contributed to and/or supported this work: Pat Zanzonico, Ph.D.; Heiko Schöder, M.D.; Elisa De Stanchina, Ph.D.; Hedvig Hricak, M.D., Ph.D., Chair of the Department of Radiology; as well as Hooisweng Ow, Ph.D., of Hybrid Silica Technologies, Inc.; Memorial Sloan-Kettering’s Office of Clinical Research; and the Cyclotron Core.

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Posted in Cancer Research, Clinical Trials, Discoveries, Nanotechnology, Targeted Therapies | Tagged: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a Comment »

Trojan Horse* For Ovarian Cancer–Nanoparticles Turn Immune System Soldiers Against Tumor Cells

Posted by Paul Cacciatore on August 1, 2009

In a feat of trickery, Dartmouth Medical School immunologists have devised a Trojan horse to help overcome ovarian cancer, unleashing a surprise killer in the surroundings of a hard-to-treat tumor. Using nanoparticles–ultra small bits– the team has reprogrammed a protective cell that ovarian cancers have corrupted to feed their growth, turning the cells back from tumor friend to foe. Their research, published online July 13 for the August Journal of Clinical Investigation, offers a promising approach to orchestrate an attack against a cancer whose survival rates have barely budged over the last three decades …

Hanover, N.H.—In a feat of trickery, Dartmouth Medical School immunologists have devised a Trojan horse to help overcome ovarian cancer, unleashing a surprise killer in the surroundings of a hard-to-treat tumor.

Using nanoparticles–ultra small bits– the team has reprogrammed a protective cell that ovarian cancers have corrupted to feed their growth, turning the cells back from tumor friend to foe. Their research, published online July 13 for the August Journal of Clinical Investigation, offers a promising approach to orchestrate an attack against a cancer whose survival rates have barely budged over the last three decades.

Dr. Jose Conejo-Garcia (right) with graduate student Juan Cubillos-Ruiz  (Photo Source:  Dartmouth Medical School News Release,

Dr. Jose Conejo-Garcia (right) with graduate student Juan Cubillos-Ruiz (Photo Source: Dartmouth Medical School News Release, 13 Jul. 09)

“We have modulated elements of the tumor microenvironment that are not cancer cells, reversing their role as accomplices in tumor growth to attackers that boost responses against the tumor,” said Dr. Jose Conejo-Garcia, assistant professor of microbiology and immunology and of medicine, who led the research. “The cooperating cells hit by the particles return to fighters that immediately kill tumor cells.”

The study, in mice with established ovarian tumors, involves a polymer now in clinical trials for other tumors. The polymer interacts with a receptor that senses danger to activate cells that trigger an inflammatory immune response.

The Dartmouth work focuses on dendritic cells–an immune cell particularly abundant in the ovarian cancer environment. It does take direct aim at tumor cells, so it could be an amenable adjunct to other current therapies.

“The cooperating cells hit by the particles return to fighters that immediately kill tumor cells.” —Dr. Jose Conejo-Garcia

“That’s the beautiful part of story–people usually inject these nanoparticles to target tumor cells. But we found that these dendritic cells that are commonly present in ovarian cancer were preferentially and avidly engulfing the nanoparticles. We couldn’t find any tumor cells taking up the nanoparticles, only the dendritic cells residing in the tumor,” explained Juan R. Cubillos-Ruiz, graduate student and first author.

Dendritic cells are phagocytes–the soldiers of the immune system that gobble up bacteria and other pathogens, but ovarian cancer has co-opted them for its own use, he continued. “So we were trying to restore the attributes of these dendritic cells–the good guys; they become Trojan horses.”

Cancer is more than tumor cells; many other circulating cells including the dendritic phagocytes converge to occupy nearby space. The dendritic cells around ovarian cancer scoop up the nanocomplexes, composed of a polymer and small interfering RNA (siRNA) molecules to silence their immunosuppressive activity.

Nanoparticle incorporation transforms them from an immunosuppressive to an immunostimulatory cell type at tumor locations, provoking anti-tumor responses and also directly killing tumor cells. The effect is particularly striking with an siRNA designed to silence the gene responsible for making an immune protein called PD-L.

The new findings also raise a warning flag about the use of gene silencing complexes in cancer treatment. Inflammation is a helpful immune response, but the researchers urge caution when using compounds that can enhance inflammation in a patient already weakened by cancer.

Ovarian cancer, which claims an estimated 15,000 US lives a year, is an accessible disease for nanoparticle delivery, according to the investigators. Instead of systemic administration, complexes can be put directly into the peritoneal cavity where the phagocytes take them up.

Samples of human ovarian cancer cells show similar responses to nanoparticle stimulation, the researchers observed, suggesting feasibility in the clinical setting. It could be part of a “multimodal approach,” against ovarian cancer, said Conejo-Garcia also a member of the Dartmouth’s Norris Cotton Cancer Center. “The prevailing treatment is surgical debulking, followed by chemotherapy. Our findings could complement those because they target not the tumor cells themselves, but different cells present around the tumor.”

Co-authors are Xavier Engle, Uciane K. Scarlett, Diana Martinez, Amorette Barber, Raul Elgueta, Li Wang, Yolanda Nesbeth and Charles Sentman of Dartmouth; Yvon Durant of University of New Hampshire, Andrew T Gewirtz of Emory, and Ross Kedl of University of Colorado.

The work was supported by grants from the National Institutes of Health, including the National Cancer Institute and National Center for Research Resources, a Liz Tilberis Award from the Ovarian Cancer Research Fund, and the Norris Cotton Cancer Center Nanotechnology Group Award.

Read an interview of Jose Conejo – Garcia with the Ovarian Cancer Research Fund.

Source: Trojan Horse for Ovarian Cancer–Nanoparticles Turn Immune System Soldiers against Tumor Cells, News Release, Dartmouth Medical School, July 13, 2009 (summarizing Cubillos-Ruiz JR, Engle X, Scarlett UK, et. al. Polyethylenimine-based siRNA nanocomplexes reprogram tumor-associated dendritic cells via TLR5 to elicit therapeutic antitumor immunity. J Clin Invest. 2009 Aug 3;119(8):2231-2244. doi: 10.1172/JCI37716. Epub 2009 Jul 13).

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* The Trojan Horse was a tale from the Trojan War, as told in Virgil’s Latin epic poem The Aeneid. The events in this story from the Bronze Age took place after Homer’s Iliad, and before Homer’s Odyssey. It was the strategy that allowed the Greeks finally to enter the city of Troy and end the conflict. In the best-known version, after a fruitless 10-year siege of Troy, the Greeks built a huge horse figure and hid a select force of men within it. The Greeks left the Horse at the city gates of Troy and pretended to sail away.  Thereafter, the Trojans pulled the Horse into their city as a victory trophy. That night the Greek force crept out of the Horse and opened the gates for the returning Greek army, which had sailed back to Troy under cover of night. The Greek army entered and destroyed the city, decisively ending the war. A “Trojan Horse” has come to mean any trick that causes a target to invite a foe into a securely protected bastion or place.

Posted in Medical Study Results, Monoclonal Antibody, Nanotechnology, Novel Therapies, Preclinical Testing | Tagged: , , , , , , , , , , , , , , , , , , , , , , , , | Leave a Comment »

 
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