December 6, 2007

PHILADELPHIA - The next cancer-fighting therapeutic could be growing in your garden, according to research presented today, at the American Association for Cancer Research's Sixth Annual International Conference on Frontiers in Cancer Prevention Research, being held from December 5 to 8 in Philadelphia, Pennsylvania.

For example, a black raspberry-based gel might offer a means of stopping oral lesions from turning into a particularly dangerous and disfiguring form of cancer. And new studies show that cancer prevention might come in drinkable form: green tea extract, a powerful antioxidant, shows efficacy against colorectal cancer; and a new berry-rich beverage, made from a combination of known plant-based antioxidants, could prevent or slow the growth of prostate cancer.

Chemopreventative effects of a topically applied black raspberry gel on oral premalignant tumors. Abstract no. B35:

Oral squamous cell carcinoma is a deadly cancer that, even when treated successfully, often leaves patients permanently disfigured. Other than radical surgery, there are few known treatments. Researchers at Ohio State University, however, report a Phase I/II trial demonstrating that a gel made from black raspberries shows promise in preventing or slowing the malignant transformation of precancerous oral lesions.

"Black raspberries are full of anthocyanins, potent antioxidants that give the berries their rich, dark color, and our findings show these compounds have a role in silencing cancerous cells," said Susan Mallery, D.D.S., Ph.D., professor in the Department of Oral Maxillofacial Surgery and Pathology at Ohio State University's College of Dentistry. "This gel appears to be a valid means of delivering anthocyanins and other cancer-preventing compounds directly to precancerous cells, since it slowed or reduced lesion progression in about two-thirds of study participants."

According to American Cancer Society statistics, oral cancer is one of the deadliest of all cancers, with about 35,000 new cases each year in the United States and 7,500 deaths annually. These cancers generally begin as small, often unnoticed, lesions inside the mouth. "More than a third of untreated precancerous oral lesions will undergo malignant transformation into squamous cell cancer, but we do not have the capability to predict which lesions will progress," Mallery said.

The National Cancer Institute-funded trial included 30 participants, 20 of whom had identifiable precancerous lesions, and 10 normal controls. Each of the participants was instructed to gently dry the lesion sites (or a pre-selected control site for the normal participants) and rub the gel into the area four times a day, once after each meal and at bedtime.

After six weeks, about 35 percent of the trial participants' lesions showed an improvement in their microscopic diagnosis, while another 45 percent showed that their lesions had stabilized. About 20 percent showed an increase in their lesional microscopic diagnoses. Importantly, none of the participants experienced any side effects from the gel.

"The trial was designed to test the safety of the gel and detect any possible toxicity, but the next obvious step is a multicenter, double-blind, placebo-controlled Phase II study," Mallery said. "Such a study would enable us to determine that the black raspberries are the active factor and not just the gel base or the act of drying and rubbing the lesions."

The researchers also collected cell samples from the lesion sites of each participant before and after treatment in order to study the genetics and biology of the lesions. The majority of patients with precancerous lesions at the start of the trial showed elevated levels of COX-2 and iNOS, two proteins closely correlated with inflammation and malignant progression. Following treatment, Mallery says, levels of those proteins in the treated lesional epithelial cells decreased dramatically.

Mallery and her colleagues also examined samples for three tumor suppressor genes in order to determine what researchers call "loss of heterozygosity," whether or not a cancer cell has lost one of its two copies of the gene. Such loss greatly increases a cell's chances of losing the benefit of the tumor suppressor genes due to a second mutation or gene silencing event. Following the trial, the researchers noted that many lesions returned to normal, retaining both copies of each tumor suppressor gene. "We speculate that the chemopreventive compounds in black raspberries assist in modulating cell growth by promoting programmed cell death or terminal differentiation, two mechanisms that help "reeducate" precancerous cells," Mallery said.

"Oral cancer is a debilitating disease and there is a desperate need for early detection and management of precancerous lesions," Mallery said. "While screening can help detect the disease early - and survival rates are definitely improved the earlier the disease is caught - many of these precancerous lesions recur despite complete surgical removal. There are currently no effective chemopreventive treatments which could conceivably serve as either adjunctive or alternative approaches to surgery."

According to Mallery, the development of black raspberries as potential cancer-fighters is the result of decades of research into identification of naturally derived chemopreventive compounds by Ohio State researcher Gary D. Stoner, Ph.D., an emeritus professor at Ohio State University's College of Medicine and Public Health. Clinical studies stemming from his research are currently underway for oral, esophageal and colorectal cancer.

The gel looks deceptively like black raspberry jam, but it certainly does not taste like something you would want to spread on toast, Mallery says. The bioadhesive gel, which contains 10 percent freeze dried black raspberries, is devoid of many of the tasty sugars found in native berries.

The black raspberry gel was manufactured by the University of Kentucky's Good Manufacturing Production (GMP) facility. NanoMed Pharmaceuticals is partnering with OSU investigators Mallery, Stoner and Peter E. Larsen D.D.S. and Russell J. Mumper, Ph.D., of the University of North Carolina, in product development.

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The mission of the American Association for Cancer Research is to prevent and cure cancer. Founded in 1907, AACR is the world's oldest and largest professional organization dedicated to advancing cancer research. The membership includes nearly 26,000 basic, translational, and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and more than 70 other countries. AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants. The AACR Annual Meeting attracts more than 17,000 participants who share the latest discoveries and developments in the field. Special Conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment, and patient care. AACR publishes five major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention. Its most recent publication, CR, is a magazine for cancer survivors, patient advocates, their families, physicians, and scientists. It provides a forum for sharing essential, evidence-based information and perspectives on progress in cancer research, survivorship, and advocacy.

American Association for Cancer Research. Found at: http://www.aacr.org/home/about-us/news.aspx?d=937.

Mumper, an expert in vaccine and cancer drug delivery systems, will serve as the director of the School's new Center for Nanotechnology in Drug Delivery. The CNDD is part of a larger nanomedicine initiative at UNC that bridges disciplines in medicine, chemistry, and pharmacy. The center's central mission is to quickly and safely translate new nanotechnologies into human clinical trials to improve the quality of life. The CNDD will bring together scientists to create nano-scale pharmaceutical innovations, such as vaccines to prevent cancer, sensors to detect cancer and heart disease, and therapeutics to seek out and destroy tumors and their metastases.

"My research focus has been translating pharmaceutical inventions from our labs into clinical investigations to improve patient care," says Mumper, who comes to UNC from the University of Kentucky. "This requires a highly collaborative environment, and UNC is clearly one of the best places for this. My family and I are thrilled to be in Chapel Hill, to be part of something special, and to contribute to UNC's pursuit of excellence."

Mumper is the author of more than 165 peer-reviewed papers and abstracts, has more than thirty awarded or pending patent applications, and serves on the editorial board of three scientific journals. In addition, he is a cofounder of NanoMed Pharmaceuticals Inc. and Four Tigers LLC, both based on technologies developed in his labs.

"Russ Mumper is a significant addition to our division and School," says Leaf Huang, PhD, who chairs the Division of Molecular Pharmaceutics. "His leadership in building up the program in nanotechnology for drug delivery will be an important milestone."

Before coming to UNC, Mumper had been a faculty member in the Department of Pharmaceutical Sciences in UK's College of Pharmacy since 1999, serving as the department's vice chair from 2004 to 2007. While at UK, Mumper received more than $6 million in research grants and contracts as principal investigator and more than $8 million total.

From 1999 to 2006, he was the associate director of UK's Center for Pharmaceutical Science and Technology, a unique university-based, FDA-registered GMP pharmaceutical manufacturing facility. He led the CPST's efforts to complete full product development that led to the successful submission of seven Investigational New Drugs and the commencement of human clinical trials with both industrial and university partners.

"Dr. Mumper is an outstanding addition to our faculty," says Bob Blouin, dean of the School. "His expertise, dedication, and experience, both in industry and in academia, will help us tremendously in our ongoing effort to build a research enterprise that will translate into improvements in patient care."

Mumper received a PhD in pharmaceutical sciences and a BA in chemistry from UK. After completing a postdoctoral fellowship at the Center for Bioengineering at the University of Washington in 1992, he spent seven years in product development in the pharmaceutical and biotechnology industries, working for companies in North Carolina and Texas before returning to academia at his alma mater in 1999.

In 2006, he received the AAPS Lipid-Based Drug Delivery Award sponsored by Gattefossé Corporation and the American Association of Pharmaceutical Scientists. In 2007, he was recognized by the UK Alumni Association as one of six "Great Teachers" at UK, the oldest continuously given award for teaching at the university.

Source: University of North Carolina

"I am extremely pleased to have the opportunity to partner with a research and development executive of Harry's caliber," said Stephen Benoit, NanoMed's President and CEO. "His extensive experience in preclinical discovery research, product and business development within the biotechnology and pharmaceutical industries should prove to be a tremendous asset to NanoMed as we build our drug pipeline and forge strategic product development relationships," Benoit added. NanoMed's lead product is a nanoparticle formulation of an FDA-approved cancer drug used to treat adults diagnosed with acute myeloid leukemia. This lead product is expected to enter human clinical trials in 2008.

"NanoMed is an exciting company with an innovative nanotechnology platform for the rapid development of a diversified portfolio of therapeutic and diagnostic products," said Dr. Ledebur. "I am thrilled to be joining the NanoMed team and to be given the opportunity to bring NanoMed's products to market while helping to build a sustainable specialty pharmaceutical company," Ledebur added.

Previously, Dr. Ledebur was Vice President of Research & Development and Discovery Programs for Caprion Pharmaceuticals Inc., as well as Program Head of the Antigen Presenting Cell Program at US-based Valentis, Inc. (formerly GeneMedicine, Inc.). He began his career at Boehringer Ingelheim Pharmaceuticals Inc. Dr. Ledebur received his Ph.D. in Molecular & Cell Biology from Pennsylvania State University and his B.Sc. in Biochemistry from The Ohio State University.

About NanoMed
NanoMed Pharmaceuticals®, Inc. (www.nanomedpharm.com) is an early-stage specialty pharmaceutical company dedicated to developing improved therapeutic and diagnostic products to treat or detect cancer and other serious diseases. The company's lead product is a nanoparticle formulation of an FDA-approved cancer drug used to treat adults diagnosed with acute myeloid leukemia. This lead product is being developed using Nanotemplate Engineering™, the company's proprietary nanoparticle manufacturing technology used to formulate small molecules, peptides, proteins, plasmid DNA, and diagnostic agents. NanoMed is headquartered in Kalamazoo, Michigan.

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KALAMAZOO, MI, (May 22, 2007) - NanoMed Pharmaceuticals, Inc., an early-stage specialty pharmaceutical company dedicated to developing improved therapeutic and diagnostic products to treat or detect cancer and other serious diseases, announced today that it has elected to its Board of Directors, Gabriel Leung, President, Oncology, at OSI Pharmaceuticals, a leading biotechnology company and maker of Tarceva®.

"We are extremely pleased to have attracted an executive of Gabe's caliber to the Board," said Stephen Benoit, NanoMed's President and CEO, and Patrick G. Morand, NanoMed's Chairman and Managing Director, SWMF Life Science Fund, the company's lead investor. "There is no question that he will play a critical role in helping us to build our drug pipeline," Benoit added. NanoMed's lead product is a nanoparticle formulation of an FDA-approved cancer drug used to treat adults diagnosed with acute myeloid leukemia. This lead product is expected to enter human clinical trials in 2008.

Before joining OSI, Mr. Leung was Group Vice President, Global Prescription Business at Pharmacia, where he served on the CEO's Operating Committee and headed up the company's Oncology Franchise with business and medical affairs operations in over 80 countries. Mr. Leung also oversaw all the oncology research and development projects and portfolio strategies as the co-chair of Pharmacia's Oncology Development Committee. During his 4-year tenure at Pharmacia, which ended with the acquisition by Pfizer, Mr. Leung doubled the size of the oncology business to $1.3 billion in revenues, building it into one of the then largest oncology therapeutic companies in the world. He orchestrated two new product launches and helped build one of the strongest oncology pipelines in the industry through acquisition and in-licensing. Mr. Leung began his career in the pharmaceutical industry at Eastman Pharmaceuticals/Sterling Drug Inc., and then had a distinguished career at Bristol-Myers Squibb working on blockbuster products including Pravachol®, Taxol®, and Paraplatin®.

"NanoMed is an exciting emerging specialty pharmaceutical company with a promising nanoparticulate formulation technology that can be leveraged to develop a broad pipeline of pharmaceutical products for use in oncology and many other therapeutic areas," said Mr. Leung. "I am pleased to have the opportunity to help them grow as a member of the company's Board."

Mr. Leung is a pharmacist, trained at the University of Texas at Austin where he earned his pharmacy degree with High Honors. Following some years of practice in the hospital environment, Mr. Leung earned his M.S. degree at the University of Wisconsin-Madison with concentration in pharmaceutical marketing. Mr. Leung is a member of the National Cancer Institute Clinical Trial Advisory Committee and is the founding chairman of the Life Sciences Consortium, an initiative of the CEO Roundtable on Cancer. He is also an active member and a member of the Nominating Committee of C-Change (www.cchangetogether.org), a national initiative chaired by former President George Bush and Mrs. Barbara Bush with the goal of eliminating cancer as a major public health problem at the earliest possible time.

About NanoMed
NanoMed Pharmaceuticals®, Inc. (www.nanomedpharm.com) is an early-stage specialty pharmaceutical company dedicated to developing improved therapeutic and diagnostic products to treat or detect cancer and other serious diseases. The company's lead product is a nanoparticle formulation of an FDA-approved cancer drug used to treat adults diagnosed with acute myeloid leukemia. This lead product is being developed using Nanotemplate Engineering™, the company's proprietary nanoparticle manufacturing technology used to formulate small molecules, peptides, proteins, plasmid DNA, and diagnostic agents. NanoMed is headquartered in Kalamazoo, Michigan.

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Source: University of Kentucky College of Pharmacy News 

Source: University of Kentucky College of Pharmacy News 

Kalamazoo, Mich. (Thursday, July 6, 2006) -- NanoMed Pharmaceuticals Inc., a developer of a nanoparticle manufacturing technology for treating patients undergoing chemotherapy, said that it has closed on a Series A preferred round of venture financing.

The sole investor in the round was the Southwest Michigan First (SWMF) Life Science Venture Fund, which invests in life science companies in the Kalamazoo, Mich. area.

With the funding, NanoMed will move its headquarters from Lexington, Ky. to the Michigan Technical Education Center in Kalamazoo, Mich. The company's laboratories will be located in the Advanced Science & Technology Commercialization Center at the University of Kentucky.

Founded in May 2000, this is the first institutional investment for NanoMed, which has been funded by seed funding and founders' investments until this point. While NanoMed President and CEO Stephen Benoit told VentureWire in August 2002 that the company was raising a Series A round, the company did not complete that funding. Benoit now cites a climate unwelcome to VC funding post-9/11 in 2002 and 2003.

NanoMed has developed a technology that allows for the drug to be trapped in solid nanoparticles. The chemical properties of the drug are then masked, aiming to prevent the patient from becoming resistant to the chemotherapy.

Benoit said NanoMed is looking to initiate clinical trials for its first candidate, Idarubicin NP, for treating patients undergoing chemotherapy for acute myelogenous leukemia, in about 18 months. The company's second candidate, Paclitaxel NP, for the treatment of metastatic breast cancer, is in preclinical development, Benoit said.

Benoit estimates the funding from the Series A round will last for more than a year. After that, the company plans to the company will look to start raising a Series B round in the next nine to 15 months, he said.

With the round, SWMF Managing Director Patrick G. Morand and Southwest Michigan Innovation Center Chief Executive Douglas R. Morton will join NanoMed's board.

Founded last summer, NanoMed is the first investment for SWMF, which currently has a total of $50 million in private equity. Of the investment in NanoMed, Morand said that half of the money will be invested at the closing, with the other half to be paid in about six to eight months dependent on milestones.

"We're interested in a broad array of life science companies, whether it is agriculture, human health or animal health," Morand said of SWMF, whose fund will spend a minimum of $500,000 and a maximum of $5 million on early stage companies. "I suspect by the time we're fully invested we will have 10 to 15 companies."

NanoMed currently has one full-time employee, with about five contract researchers through the University of Kentucky.

KALAMAZOO, MI., (July 5, 2006) - NanoMed Pharmaceuticals, Inc., an advanced drug delivery company developing nanoparticle-based therapeutic and diagnostic products to treat or detect disease, announced today that it has closed on its first round of venture financing. The investment was led by the SWMF Life Science Venture Fund, a $50 million private equity fund investing exclusively in promising life science companies having a presence in the Kalamazoo Region.

"Clearly, this is a very important milestone for NanoMed," said Stephen Benoit, President and CEO. "We are honored to be the first company in the SWMF Life Science Fund's portfolio," said Benoit, "and we are extremely pleased to have secured the necessary funding that will enable us to continue our development of nanoparticle-based drugs that we hope will lead to improved outcomes for patients undergoing chemotherapy for AML and breast cancer."

"This is an exciting time, not only for Southwest Michigan First, but for the Kalamazoo Region," said Ron Kitchens, Southwest Michigan First Chief Executive Officer and General Partner of the SWMF Life Science Venture Fund. "We have been growing steadily as a life science cluster and this announcement is further evidence of our work towards realizing that success," Kitchens added.

NanoMed will locate its corporate headquarters at M-TEC in The Groves Business Park in Kalamazoo. The company's labs will be located initially at the Advanced Science & Technology Commercialization Center on the campus of the University of Kentucky.

About NanoMed
NanoMed Pharmaceuticals®, Inc. (www.nanomedpharm.com) is an advanced drug delivery company developing nanoparticle-based therapeutic and diagnostic products to treat or detect disease. The Company's initial focus is cancer therapeutics and diagnostics. NanoMed's core technology, Nanotemplate Engineering™, was invented by Russell J. Mumper, PhD and Michael Jay, PhD of the University of Kentucky College of Pharmacy. Nanotemplate Engineering is a nanoparticle manufacturing process used to formulate small molecules, peptides, proteins, plasmid DNA, and diagnostic agents. The company is headquartered in Kalamazoo, Michigan.

About SWMF Life Science Venture Fund

The Southwest Michigan First Life Science Venture Fund consists of $50 million in private equity exclusively for promising live science companies that have a presence in the Kalamazoo Region. For more information, go to www.swmfirst.com.

Writing in the Journal of Controlled Release, a team led by Russell Mumper, Ph.D., describes its work using untargeted nanoparticles made of cetyl alcohol and polysorbate, which the investigators have named E78 nanoparticles, as a delivery vehicle for the potent anticancer drug paclitaxel. Biodistribution studies with the formulation and with free paclitaxel revealed few significant differences in which the active drug ends up in the body.

Next, the investigators injected the nanoparticle-entrapped paclitaxel, empty nanoparticles, free paclitaxel, or saline directly into paclitaxel-resistant human colon tumors growing in mice. Nineteen days after injection, tumors in the animals treated with nanoparticle-entrapped paclitaxel were 47 percent smaller than those treated with free paclitaxel and 70 percent smaller than those in animals treated with plain nanoparticles or saline.

One surprising finding from this study was the fact that free paclitaxel had any effect at all on tumors known to be resistant to the drug. Further investigation showed that this effect was likely a result of paclitaxel's ability to inhibit angiogenesis. The researchers concluded that nanoparticulate-entrapped paclitaxel was able to suppress tumor growth by killing tumor cells directly and through inhibition of angiogenesis.

This work is detailed in a paper titled, "In-vivo efficacy of novel paclitaxel nanoparticles in paclitaxel-resistant human colorectal tumors." Based in part on these results, the NCI is now funding further work with a tumor-targeted version of this nanoparticle to determine if it can be used to overcome drug resistance in breast cancer patients.

Source: National Cancer Institute

Writing in the Journal of Controlled Release, a team led by Russell Mumper, Ph.D., describes its work using untargeted nanoparticles made of cetyl alcohol and polysorbate, which the investigators have named E78 nanoparticles, as a delivery vehicle for the potent anticancer drug paclitaxel. Biodistribution studies with the formulation and with free paclitaxel revealed few significant differences in which the active drug ends up in the body.

Next, the investigators injected the nanoparticle-entrapped paclitaxel, empty nanoparticles, free paclitaxel, or saline directly into paclitaxel-resistant human colon tumors growing in mice. Nineteen days after injection, tumors in the animals treated with nanoparticle-entrapped paclitaxel were 47 percent smaller than those treated with free paclitaxel and 70 percent smaller than those in animals treated with plain nanoparticles or saline.

One surprising finding from this study was the fact that free paclitaxel had any effect at all on tumors known to be resistant to the drug. Further investigation showed that this effect was likely a result of paclitaxel's ability to inhibit angiogenesis. The researchers concluded that nanoparticulate-entrapped paclitaxel was able to suppress tumor growth by killing tumor cells directly and through inhibition of angiogenesis.

This work is detailed in a paper titled, "In-vivo efficacy of novel paclitaxel nanoparticles in paclitaxel-resistant human colorectal tumors." Based in part on these results, the NCI is now funding further work with a tumor-targeted version of this nanoparticle to determine if it can be used to overcome drug resistance in breast cancer patients. An abstract of this paper is available through PubMed.

Source: National Cancer Institute

LEXINGTON, KY AND KALAMAZOO, MI (December 13, 2005) - NanoMed Pharmaceuticals, Inc. today announced that, under an Inter-institutional Agreement with The Ohio State University, the University of Kentucky Research Foundation has granted the company an option for an exclusive license to a novel Bioadhesive Berry Gel for the chemoprevention and treatment of oral epithelial dysplasia - the precancerous lesions that can develop into oral squamous cell carcinoma (SCC). Despite focused efforts to improve therapy, five-year survival rates for patients with advanced stage SCC remain discouragingly low. Of the estimated 30,000 newly diagnosed cases of oral cancer in the U.S. each year, only half of those diagnosed will be alive in 5 years. Worldwide the diagnoses of head and neck cancer are much greater, with over 350,000 to 400,000 new cases being found each year.

Faculty researchers at The Ohio State University and the University of Kentucky and UK's Center for Pharmaceutical Science and Technology have been collaborating for more than 18 months on the development of freeze-dried black raspberry gels for oral and topical cancer chemoprevention. Freeze-dried black raspberries have been shown to inhibit the growth of several forms of cancer in preclinical studies, and clinical trial results from an open, Phase I, multiple-dose pilot study in healthy volunteers showed that black raspberry extracts are well tolerated in humans. Based on these results to date, the Bioadhesive Berry Gel will be tested in humans.

Russell J. Mumper, Ph.D., vice chair and associate professor in the University of Kentucky, College of Pharmacy, Department of Pharmaceutical Sciences, who is also associate director of UK's Center for Pharmaceutical Science & Technology and a co-founder of NanoMed Pharmaceuticals, will oversee the production of the Bioadhesive Berry Gel. "The promising results in preclinical studies encouraged us to develop the bioadhesive gel," Mumper said. "This gel allows the delivery of more potent black raspberry extracts and is easily administered to the patient.

Mumper, in collaboration with researchers at The Ohio State University and the James Cancer Hospital and Solove Research Institute, will evaluate the Bioadhesive Berry Gel in 20 patients with oral lesions in a Phase I/Ia study to begin this month. The objective of the study is to investigate the chemotherapeutic efficacy of intraoral application of the Bioadhesive Berry Gel to induce regression, prevent recurrence, and inhibit progression in persons with oral epithelial dysplasia.

"As far as we know, there is no one anywhere else in the world using a bioadhesive gel like we are," said Dr. Susan Mallery, a dentist and oral pathologist in The Ohio State University College of Dentistry and a member of The OSU Comprehensive Cancer Center who has been collaborating with Dr. Mumper.
NanoMed expects that preliminary Phase I/Ia study data will be available by mid-year 2006.
About NanoMed Pharmaceuticals, Inc.

NanoMed Pharmaceuticals, Inc. is an advanced drug delivery systems company developing therapeutic and diagnostic products to treat or detect disease. The Company's initial focus is cancer therapeutics and diagnostics. NanoMed's core technology is Nanotemplate Engineering™, a flexible, rapid and scaleable nanoparticle manufacturing technology for the delivery of small molecules, peptides, proteins, plasmid DNA, and diagnostic agents.
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(October 3, 2005) Though many kinds of nanoparticles, loaded with a variety of drugs and imaging agents, are making their way toward the clinic, questions about nanoparticle toxicity remain to be answered. Given that the majority of nanoparticles are intended to travel to tumors through the bloodstream, the effects of nanoparticles on blood cells are of particular concern to those developing nanoparticle-based therapeutic and imaging agents. Now, a series of experiments by researchers at the University of Kentucky have found no ill effects when blood cells are exposed to one common type of nanoparticle.

Writing in the journal Pharmaceutical Research, a group headed by Russell Mumper, Ph.D., tested the compatibility of nanoparticles coated with polyethylene glycol, a polymer used to protect many types of nanoparticles from elimination by cells of the immune system. The investigators developed a testing methodology that enabled them to determine how nanoparticles affected a variety of in vitro and in vivo parameters, including blood clotting time, red blood cell damage, and platelet aggregation, or clumping.

Using a polyethylene glycol-coated nanoscale liposome as a generic nanoparticle, the investigators found that a concentration of nanoparticles one would expect to achieve in the blood stream produced no untoward biological effects on blood cells. Higher levels of the test nanoparticles did slow blood clotting, however. The researchers also noted that nanoparticle effects on blood cells are likely to depend on the particle size and surface properties, making the assays developed by these investigators useful for further studies of other nanoparticles.

This work is detailed in a paper titled, "Blood compatibility of cetyl alcohol/polysorbate-based nanoparticles." This paper was published online in advance of print publication. An abstract is available through PubMed.

Source: National Cancer Institute