Category Archives: medicine

Gold nanorod instabilities

A Dec. 8, 2014 news item on Nanowerk focuses on research from Australia,

Researchers at Swinburne University of Technology [Melbourne, Australia]  have discovered an instability in gold nanoparticles that is critical for their application in future technology.

Gold nanorods are important building blocks for future applications in solar cells, cancer therapy and optical circuitry.

However their stability is under question due to their peculiar reshaping behaviour below melting points.

A Dec. 8, 2014 Swinburne University of Technology press release, which originated the news item, discusses melting points and shape instabilities in the context of this research,

A solid normally does not change its shape unless it reaches its melting point, or surface melting points. It is also known that the melting point for nanoparticles is suppressed due to their size.

PhD student Adam Taylor (now a postdoctoral researcher at Swinburne) said it came as a surprise that reshaping is observed well below these melting points. Until now, no one could explain this peculiar behaviour.

“In our work, we have discovered both theoretically and experimentally that the reshaping mechanism for nanoparticles below melting point is surface atom diffusion, rather than melting,” Mr Taylor said.

Surface atom diffusion is a process involving the motion of molecules at solid material surfaces that can generally be thought of in terms of particles jumping between adjacent adsorption sites on a surface.

“Surface atom diffusion always existed in bulk solids, but this is the first evidence that its effect is enhanced at the nano-size, dominating over the traditional theory of melting,” Associate Professor James Chon, who is supervising Mr Taylor’s research, said.

Mr Taylor said the more finely nanoparticles are shaped, the less stable they become.

“This is important, for example, for solar panel manufacturers as the more needle-like these nanoparticles are shaped the less stable they become. If you put these particles into a solar panel to concentrate light they may not last long in the sun before they degrade,” Mr Taylor said.

“This discovery will be crucial for future applications of gold nanorods, as people will need to reconsider their stability when applying them to solar cells, cancer therapeutic agents and optical circuitry.”

The researchers have provided an illustration of their work,

Courtesy Swinburne University of Technology

Courtesy Swinburne University of Technology

Here’s a link to and citation for the research,

Below Melting Point Photothermal Reshaping of Single Gold Nanorods Driven by Surface Diffusion by Adam B. Taylor, Arif M. Siddiquee, and James W. M. Chon. ACS Nano, Article ASAP DOI: 10.1021/nn5055283 Publication Date (Web): November 18, 2014

Copyright © 2014 American Chemical Society

This paper is behind a paywall but should you be in Australia and eligible to attend, there’s another opportunity to learn more; Taylor will be presenting his work at the Australian Institute of Physics conference on December 10, 2014 in Canberra.

US Food and Drug Administration approval for next generation spinal interbody fusion implant

For the first time, the US Food and Drug Administration (FDA) has approved a nanotechnology-enabled interbody spinal fusion implant, according to a Nov. 12, 2014 news item on Azonano,

Titan Spine, a medical device surface technology company focused on developing innovative spinal interbody fusion implants, today announced that it has received 510(k) clearance from the U.S. Food and Drug Administration (FDA) to market its Endoskeleton® line of interbody fusion implants featuring its next-generation nanoLOCKTM surface technology.

This clearance marks Titan’s line of Endoskeleton® spinal implants as the first FDA-approved interbody fusion devices to feature nanotechnology.

A Nov. 22, 2014 news item on Today’s Medical Developments.com provides more detail about the implants,

Titan’s new nanoLOCK surface technology enhances the company’s line of Endoskeleton devices with an increased amount of nano-scaled textures to up-regulate a statistically significant greater amount of the osteogenic and angiogenic growth factors that are critical for bone growth and fusion when compared to PEEK and the company’s current surface.

Barbara Boyan, Ph.D., dean of the School of Engineering at Virginia Commonwealth University, and an investigator in various Titan Spine studies, said, “This new surface technology further enhances Titan’s current surface and is the result of extensive research in how to create a significantly greater amount of nano-scaled textures that we have shown to be important for the osteogenic response necessary for fusion. The nanoLOCK surface topography is far different than what is found on titanium-coated PEEK implants. In addition, the nanoLOCK surface is not created by applying a coating, but rather is formed by a reductive process of the titanium itself. This eliminates the potential for delamination, which is a concern for products with a PEEK-titanium interface. My team is proud to collaborate with Titan Spine to help develop such a differentiated technology that is truly designed to benefit both patients and surgeons.”

Titan’s nanoLOCK surface is a significant advancement of the company’s first-generation surface. The patented nanoLOCK manufacturing process creates additional textures at the critical nano level. However, there are no changes to the device indications for use, design, dimensions, or materials. Additionally, mechanical testing demonstrated that the strength of the company’s line of Endoskeletonimplants are unaffected by the new surface treatment.

Earlier this year Titan Spine announced the first surgery using one of its Endoskeleton implants. From a July 14, 2014 Titan Spine press release,

Titan Spine, a medical device surface technology company focused on developing innovative spinal interbody fusion implants, today announced that it has received clearance from the U.S. Food and Drug Administration (FDA) to commercially release its Endoskeleton® TL system, a spinal fusion system utilizing a lateral approach. The Endoskeleton® TL represents the first lateral fusion device to feature surface technology that is designed to participate in the fusion process by creating an osteogenic response to the implant’s topography.

The Endoskeleton® TL device utilizes Titan’s proprietary roughened titanium surface technology which has been shown to upregulate the production of osteogenic and angiogenic factors that are critical for bone growth and fusion. In addition, the design of the TL device incorporates large windows and large internal volumes to allow for significant bone graft packing, clear CT and MRI imaging, desired bone graft loading, and the ability to pack additional bone graft material within the device following implantation. Members of the TL design team include Kade Huntsman, M.D., Orthopedic Spine Surgeon with the Salt Lake Orthopaedic Clinic in Salt Lake City, Utah; Andy Kranenburg, M.D., Co-Medical Director of the Providence Medford Medical Center Spine Institute in Medford, OR; Axel Reinhardt, M.D., Head of the Department of Spinal Surgery at the Specialized Orthopaedic Hospital in Potsdam, Germany; and Paul Slosar, M.D., Chief Medical Officer for Titan Spine.

Dr. Huntsman performed the first surgeries utilizing the Endoskeleton® TL on July 9th, 2014 at St. Mark’s Hospital in Salt Lake City, Utah. …

“The Endoskeleton® TL device is the first application of surface technology to the lateral approach,” commented Dr. Slosar. “The ability to orchestrate cellular behavior and promote bone growth in response to an interbody device has not been in the lateral surgeon’s armamentarium until now. The TL is the byproduct of a unique collaboration between academic biomaterial scientists, spine surgeons, and industry experts to create a truly differentiated lateral interbody device that is designed to benefit both patients and surgeons. With the addition of the TL device, Titan Spine now offers its surface technology and complete line of titanium devices for virtually all interbody fusion spine surgery procedures in the cervical and lumbar spine.”

The full line of Endoskeleton® devices features Titan Spine’s proprietary implant surface technology, consisting of a unique combination of roughened topographies at the macro, micro, and cellular levels. [emphasis mine] This combination of surface topographies is designed to create an optimal host-bone response and actively participate in the fusion process by promoting new bone growth, encouraging natural production of bone morphogenetic proteins (BMP’s) and creating the potential for a faster and more robust fusion.

It would seem the implant used in the July 2014 surgery is not nanotechnology-enabled, which suggests nanoLOCK is a next-generation implant being marketed only a few months after the first generation was made available. Unfortunately, the Titan Spine website is still partially (‘surface technology’ tab) under construction so I was not able to find more details about the technology. In any event, that’s quite a development pace.

Remotely controlling bone regeneration with metallic nanoparticles

A Nov. 24, 2014 news item on ScienceDaily heralds some bone regeneration research which was published back in Sept. 2014,

Researchers in bone tissue regeneration believe they have made a significant breakthrough for sufferers of bone trauma, disease or defects such as osteoporosis.

Medical researchers from Keele University and Nottingham University have found that magnetic nanoparticles coated with targeting proteins can stimulate stem cells to regenerate bone. Researchers were also able to deliver the cells directly to the injured area, remotely controlling the nanoparticles to generate mechanical forces and maintain the regeneration process through staged releases of a protein growth stimulant.

A Nov. 17, 2014 Keele University (UK) press release, which originated the news item, describes the issues the researchers are addressing and their research approach,

The current method for repairing bone that can’t heal itself is through a graft taken from the patient. Unfortunately, this can be a painful, invasive procedure, and when the area that needs repair is too large or the patient has a skeletal disorder such as there can sometimes be a lack of healthy bone for grafting.

For this reason, spurring the growth of new bone through injected stem cells is an area of great interest to medical researchers. Much progress has been made, but a major hurdle remains – finding an appropriate means to stimulate the differentiation of the stem cells so they become the quality of bone tissue needed in a quantity large enough to treat patients effectively.

James Henstock, Ph.D. led the Biotechnology and Biological Sciences Research Council (BBSRC)-funded study, alongside Alicia El Haj, Ph.D., and colleagues at Keele University’s Institute for Science and Technology in Medicine, as well as Kevin Shakesheff, Ph.D., from the University of Nottingham’s School of Pharmacy.

James Henstock said: “Injectable therapies for regenerative medicine show great potential as a minimally invasive route for introducing therapeutic stem cells, drug delivery vehicles and biomaterials efficiently to wound sites.”

“In our investigation we coated magnetic nanoparticles with specific targeting proteins then controlled them remotely with an external magnetic field to simulate exercise. We wanted to learn how this might affect the injected stem cells and their ability to restore functional bone.”

The team of researchers conducted their test using two models: chicken foetal femurs and tissue-engineered collagen hydrogels. In both instances the results showed an increase in bone formation and density without causing any mechanical stress to the construct or surrounding tissue.

“This work demonstrates that providing the appropriate mechanical cues in conjunction with controlled release of growth factors to these injectable cell therapies can have a significant impact on improving bone growth. It also could potentially improve tissue engineering approaches for translational medicine” Dr. Henstock said.

Here’s a link to and a citation for the published paper,

Remotely Activated Mechanotransduction via Magnetic Nanoparticles Promotes Mineralization Synergistically With Bone Morphogenetic Protein 2: Applications for Injectable Cell Therapy by James R. Henstock, Michael Rotherham, Hassan Rashidi, Kevin M. Shakesheff, and Alicia J. El Haja. Stem Cells Trans Med September 2014 sctm.2014-0017  (First Published Online September 22, 2014 doi: 10.5966/sctm.2014-0017)

This paper is open access but you do need to sign up for a free registration for access to the website.

RNA interference: a Tekmira deal and a new technique births Solstice Biologics

I have two news items concerning ribonucleic acid interference (RNAi). The first item features Tekmira Pharmaceuticals Corporation (a Canadian company located in the Vancouver area) and a licencing deal with Dicerna Pharmaceuticals (Massachusetts, US), according to a Nov. 18, 2014 news item on Azonano,

Tekmira Pharmaceuticals Corporation a leading developer of RNA interference (RNAi) therapeutics, today announces a licensing and collaboration agreement with Dicerna Pharmaceuticals, Inc. Tekmira has licensed its proprietary lipid nanoparticle (LNP) delivery technology for exclusive use in Dicerna’s primary hyperoxaluria type 1 (PH1) development program.

Under the agreement, Dicerna will pay Tekmira $2.5 million upfront and payments of $22 million in aggregate development milestones, plus a mid-single-digit royalty on future PH1 sales. This new partnership also includes a supply agreement with Tekmira providing clinical drug supply and regulatory support in the rapid advancement of the product candidate.

The agreement announced today follows the successful testing and demonstration of positive results combining Tekmira’s LNP technology with DCR-PH1 in pre-clinical animal models.

I don’t entirely understand what they mean by “pre-clinical animal models” as I’ve not noticed the term “pre-clinical” applied to animal testing before this. It’s possible they mean they’ve run tests on animals (in vivo) and are now proceeding to human clinical trials or it could mean they’ve run in silico (computer modeling) or in vitro (test tube/test slide) tests and are now proceeding to animal tests. If anyone should have some insights, please do share them with me in the comments section.

A Nov. 17, 2014 Tekmira news release, which originated the news item, describes the deal in more detail,

Dicerna will use Tekmira’s third generation LNP technology for delivery of DCR-PH1, Dicerna’s Dicer substrate RNA (DsiRNA) molecule, for the treatment of PH1, a rare, inherited liver disorder that often results in kidney failure and for which there are no approved therapies.

“This new agreement validates our leadership position in RNAi delivery with LNP technology, and it underscores the significant value we can bring to partners who leverage our technology. Our LNP technology is enabling the most advanced applications of RNAi therapeutics in the clinic, and it continues to do so. We are excited to be working with Dicerna to be able to advance a needed therapeutic for the treatment of PH1,” said Dr. Mark J. Murray, Tekmira’s President and CEO.

“As a core pillar of our business strategy, we continue to engage in partnerships where our technology improves the risk profile and accelerates the development programs of our collaborators and provides meaningful non-dilutive financing to TKMR,” added Dr. Murray.

“Dicerna is focused on realizing the full clinical potential of our proprietary pipeline of highly targeted RNAi therapies by applying proven technologies,” said Douglas Fambrough, Ph.D., Chief Executive Officer of Dicerna. “By drawing on Tekmira’s extensive and deep experience with lipid nanoparticle delivery to the liver, the agreement will streamline the development path for DCR-PH1. We look forward to initiating Phase 1 trials of DCR-PH1 in 2015, aiming to fill a high unmet medical need for patients with PH1.”

The news release also provides a high level description of the various technologies being researched and brought to market and a bit more information about the liver disorder being addressed by this research,

About RNAi

RNAi therapeutics have the potential to treat a number of human diseases by “silencing” disease-causing genes. The discoverers of RNAi, a gene silencing mechanism used by all cells, were awarded the 2006 Nobel Prize for Physiology or Medicine. RNAi trigger molecules often require delivery technology to be effective as therapeutics.

AboutTekmira’s LNP Technology

Tekmira believes its LNP technology represents the most widely adopted delivery technology for the systemic delivery of RNAi triggers. Tekmira’s LNP platform is being utilized in multiple clinical trials by Tekmira and its partners. Tekmira’s LNP technology (formerly referred to as stable nucleic acid-lipid particles, or SNALP) encapsulates RNAi triggers with high efficiency in uniform lipid nanoparticles that are effective in delivering these therapeutic compounds to disease sites. Tekmira’s LNP formulations are manufactured by a proprietary method which is robust, scalable and highly reproducible, and LNP-based products have been reviewed by multiple regulatory agencies for use in clinical trials. LNP formulations comprise several lipid components that can be adjusted to suit the specific application.

About Primary Hyperoxaluria Type 1 ( PH1)

PH1 is a rare, inherited liver disorder that often results in severe damage to the kidneys. The disease can be fatal unless the patient undergoes a liver-kidney transplant, a major surgical procedure that is often difficult to perform due to the lack of donors and the threat of organ rejection. In the event of a successful transplant, the patient must live the rest of his or her life on immunosuppressant drugs, which have substantial associated risks. Currently, there are no FDA approved treatments for PH1.

PH1 is characterized by a genetic deficiency of the liver enzyme alanine:glyoxalate-aminotransferase (AGT), which is encoded by the AGXT gene. AGT deficiency induces overproduction of oxalate by the liver, resulting in the formation of crystals of calcium oxalate in the kidneys. Oxalate crystal formation often leads to chronic and painful cases of kidney stones and subsequent fibrosis (scarring), which is known as nephrocalcinosis. Many patients progress to end-stage renal disease (ESRD) and require dialysis or transplant. Aside from having to endure frequent dialysis, PH1 patients with ESRD may experience a build-up of oxalate in the bone, skin, heart and retina, with concomitant debilitating complications. While the true prevalence of primary hyperoxaluria is unknown, it is estimated to be one to three cases per one million people.1 Fifty percent of patients with PH1 reach ESRD by their mid-30s.2

About DCR-PH1

Dicerna is developing DCR-PH1, which is in preclinical development, for the treatment of PH1. DCR-PH1 is engineered to address the pathology of PH1 by targeting and destroying the messenger RNA (mRNA) produced by HAO1, a gene implicated in the pathogenesis of PH1. HAO1 encodes glycolate oxidase, a protein involved in producing oxalate. By reducing oxalate production, this approach is designed to prevent the complications of PH1. In preclinical studies, DCR-PH1 has been shown to induce potent and long-term inhibition of HAO1 and to significantly reduce levels of urinary oxalate, while demonstrating long-term efficacy and tolerability in animal models of PH1.

About Dicerna’s Dicer Substrate Technology

Dicerna’s proprietary RNAi molecules are known as Dicer substrates, or DsiRNAs, so called because they are processed by the Dicer enzyme, which is the initiation point for RNAi in the human cell cytoplasm. Dicerna’s discovery approach is believed to maximize RNAi potency because the DsiRNAs are structured to be ideal for processing by Dicer. Dicer processing enables the preferential use of the correct RNA strand of the DsiRNA, which may increase the efficacy of the RNAi mechanism, as well as the potency of the DsiRNA molecules relative to other molecules used to induce RNAi.

You can find more information about Tekmira here and about Dicerna here. I mentioned Tekmira previously in a Sept. 28, 2014 post about Ebola and treatments.

Further south at the University of California at San Diego (UCSD), researcher and founder of Solstice Biologics, Dr Steven Dowdy has developed and patented a new technique for delivering RNAi drugs into cells according to a Nov. 18, 2014 news item on Azonano,

Small pieces of synthetic RNA trigger a RNA interference (RNAi) response that holds great therapeutic potential to treat a number of diseases, especially cancer and pandemic viruses. The problem is delivery — it is extremely difficult to get RNAi drugs inside the cells in which they are needed. To overcome this hurdle, researchers at University of California, San Diego School of Medicine have developed a way to chemically disguise RNAi drugs so that they are able to enter cells. Once inside, cellular machinery converts these disguised drug precursors — called siRNNs — into active RNAi drugs. …

A Nov. 17, 2014 UCSD news release (also on EurekAlert) by Heather Buschman, which originated the news item, describes the issues with delivering RNAi drugs to cells and the new technique,

“Many current approaches use nanoparticles to deliver RNAi drugs into cells,” said Steven F. Dowdy, PhD, professor in the Department of Cellular and Molecular Medicine and the study’s principal investigator. “While nanotechnology protects the RNAi drug, from a molecular perspective nanoparticles are huge, some 5,000 times larger than the RNAi drug itself. Think of delivering a package into your house by having an 18-wheeler truck drive it through your living room wall — that’s nanoparticles carrying standard RNAi drugs. Now think of a package being slipped through the mail slot — that’s siRNNs.”

The beauty of RNAi is that it selectively blocks production of target proteins in a cell, a finding that garnered a Nobel Prize in 2006. While this is a normal process that all cells use, researchers have taken advantage of RNAi to inhibit specific proteins that cause disease when overproduced or mutated, such as in cancer. First, researchers generate RNAi drugs with a sequence that corresponds to the gene blueprint for the disease protein and then delivers them into cells. Once inside the cell, the RNAi drug is loaded into an enzyme that specifically slices the messenger RNA encoding the target protein in half. This way, no protein is produced.

As cancer and viral genes mutate, RNAi drugs can be easily evolved to target them. This allows RNAi therapy to keep pace with the genetics of the disease — something that no other type of therapy can do. Unfortunately, due to their size and negatively charged chemical groups (phosphates) on their backbone, RNAi drugs are repelled by the cellular membrane and cannot be delivered into cells without a special delivery agent.

It took Dowdy and his team, including Bryan Meade, PhD, Khirud Gogoi, PhD, and Alexander S. Hamil, eight years to find a way to mask RNAi’s negative phosphates in such a way that gets them into cells, but is still capable of inducing an RNAi response once inside.

In the end, the team added a chemical tag called a phosphotriester group. The phosphotriester neutralizes and protects the RNA backbone — converting the ribonucleic acid (RNA) to ribonucleic neutral (RNN), and thus giving the name siRNN. The neutral (uncharged) nature of siRNNs allows them to pass into the cell much more efficiently. Once inside the cell, enzymes cleave off the neutral phosphotriester group to expose a charged RNAi drug that shuts down production of the target disease protein. siRNNs represent a transformational next-generation RNAi drug.

“siRNNs are precursor drugs, or prodrugs, with no activity. It’s like having a tool still in the box, it won’t work until you take it out,” Dowdy said. “Only when the packaging — the phosphotriester groups — is removed inside the cells do you have an active tool or RNAi drug.”

The findings held up in a mouse model, too. There, Dowdy’s team found that siRNNs were significantly more effective at blocking target protein production than typical RNAi drugs — demonstrating that once siRNNs get inside a cell they can do a better job.

“There remains a lot of work ahead to get this into the clinics. But, in theory, the therapeutic potential of siRNNs is endless,” Dowdy said. “Particularly for cancer, viral infections and genetic diseases.”

The siRNN technology forms the basis for Solstice Biologics, a biotech company in La Jolla, Calif. that is now taking the technique to the next level. Dowdy is a co-founder of Solstice Biologics and serves as a Board Director.

Here’s a link to and a citation for the research paper,

Efficient delivery of RNAi prodrugs containing reversible charge-neutralizing phosphotriester backbone modifications by Bryan R Meade, Khirud Gogoi, Alexander S Hamil, Caroline Palm-Apergi, Arjen van den Berg, Jonathan C Hagopian, Aaron D Springer, Akiko Eguchi, Apollo D Kacsinta, Connor F Dowdy, Asaf Presente, Peter Lönn, Manuel Kaulich, Naohisa Yoshioka, Edwige Gros, Xian-Shu Cui, & Steven F Dowdy. Nature Biotechnology (2014) doi:10.1038/nbt.3078 Published online 17 November 2014

This paper is behind a paywall.

I have not been able to locate a website for Solstice Biologics but did find a rather curious item about Dr. Dowdy and a shooting incident last year. From a Sept. 18, 2013 news article by Kat Robinson for thewire.sheknows.com,

A wealthy San Diego community is shaken after a man opens fire on his former neighborhood early Wednesday morning. Police say Hans Petersen, a 48-year-old man, is the prime suspect in the shooting of Steven Dowdy and Michael Fletcher.

There’s also a Nov. 8, 2013 article about the incident by Lucas Laursen for Nature magazine,

On September 18 [2013], former Traversa Therapeutics CEO Hans Petersen went on a shooting spree. One of two people wounded was molecular biologist Steven Dowdy, a professor at University of California San Diego (UCSD) School of Medicine, in La Jolla, and cofounder of Traversa, according to a San Diego police report.…

The rest of the article is behind a paywall.

Nano and stem cell differentiation at Rutgers University (US)

A Nov. 14, 2014 news item on Azonano features a nanoparticle-based platform for differentiating stem cells,

Rutgers University Chemistry Associate Professor Ki-Bum Lee has developed patent-pending technology that may overcome one of the critical barriers to harnessing the full therapeutic potential of stem cells.

A Nov. 1, 2104 Rutgers University news release, which originated the news item, describes the challenge in more detail,

One of the major challenges facing researchers interested in regenerating cells and growing new tissue to treat debilitating injuries and diseases such as Parkinson’s disease, heart disease, and spinal cord trauma, is creating an easy, effective, and non-toxic methodology to control differentiation into specific cell lineages. Lee and colleagues at Rutgers and Kyoto University in Japan have invented a platform they call NanoScript, an important breakthrough for researchers in the area of gene expression. Gene expression is the way information encoded in a gene is used to direct the assembly of a protein molecule, which is integral to the process of tissue development through stem cell therapeutics.

Stem cells hold great promise for a wide range of medical therapeutics as they have the ability to grow tissue throughout the body. In many tissues, stem cells have an almost limitless ability to divide and replenish other cells, serving as an internal repair system.

Transcription factor (TF) proteins are master regulators of gene expression. TF proteins play a pivotal role in regulating stem cell differentiation. Although some have tried to make synthetic molecules that perform the functions of natural transcription factors, NanoScript is the first nanomaterial TF protein that can interact with endogenous DNA. …

“Our motivation was to develop a highly robust, efficient nanoparticle-based platform that can regulate gene expression and eventually stem cell differentiation,” said Lee, who leads a Rutgers research group primarily focused on developing and integrating nanotechnology with chemical biology to modulate signaling pathways in cancer and stem cells. “Because NanoScript is a functional replica of TF proteins and a tunable gene-regulating platform, it has great potential to do exactly that. The field of stem cell biology now has another platform to regulate differentiation while the field of nanotechnology has demonstrated for the first time that we can regulate gene expression at the transcriptional level.”

Here’s an image illustrating NanoScript and gold nanoparticles,

Courtesy Rutgers University

Courtesy Rutgers University

The news release goes on to describe the platform’s use of gold nanoparticles,

NanoScript was constructed by tethering functional peptides and small molecules called synthetic transcription factors, which mimic the individual TF domains, onto gold nanoparticles.

“NanoScript localizes within the nucleus and initiates transcription of a reporter plasmid by up to 30-fold,” said Sahishnu Patel, Rutgers Chemistry graduate student and co-author of the ACS Nano publication. “NanoScript can effectively transcribe targeted genes on endogenous DNA in a nonviral manner.”

Lee said the next step for his research is to study what happens to the gold nanoparticles after NanoScript is utilized, to ensure no toxic effects arise, and to ensure the effectiveness of NanoScript over long periods of time.

“Due to the unique tunable properties of NanoScript, we are highly confident this platform not only will serve as a desirable alternative to conventional gene-regulating methods,” Lee said, “but also has direct employment for applications involving gene manipulation such as stem cell differentiation, cancer therapy, and cellular reprogramming. Our research will continue to evaluate the long-term implications for the technology.”

Lee, originally from South Korea, joined the Rutgers faculty in 2008 and has earned many honors including the NIH Director’s New Innovator Award. Lee received his Ph.D. in Chemistry from Northwestern University where he studied with Professor Chad. A. Mirkin, a pioneer in the coupling of nanotechnology and biomolecules. Lee completed his postdoctoral training at The Scripps Research Institute with Professor Peter G. Schultz. Lee has served as a Visiting Scholar at both Princeton University and UCLA Medical School.

The primary interest of Lee’s group is to develop and integrate nanotechnologies and chemical functional genomics to modulate signaling pathways in mammalian cells towards specific cell lineages or behaviors. He has published more than 50 articles and filed for 17 corresponding patents.

Here’s a link to and a citation for the paper,

NanoScript: A Nanoparticle-Based Artificial Transcription Factor for Effective Gene Regulation by Sahishnu Patel, Dongju Jung, Perry T. Yin, Peter Carlton, Makoto Yamamoto, Toshikazu Bando, Hiroshi Sugiyama, and Ki-Bum Lee. ACS Nano, 2014, 8 (9), pp 8959–8967 DOI: 10.1021/nn501589f Publication Date (Web): August 18, 2014
Copyright © 2014 American Chemical Society

This paper is behind a paywall.

Killing mosquitos and other pests with genetics-based technology

Having supplied more than one tasty meal for mosquitos (or, as some prefer, mosquitoes), I am not their friend but couldn’t help but wonder about unintended consequences (as per Max Weber) on reading about a new patent awarded to Kansas State University (from a Nov. 12, 2014 news item on Nanowerk),

Kansas State University researchers have developed a patented method of keeping mosquitoes and other insect pests at bay.

U.S. Patent 8,841,272, “Double-Stranded RNA-Based Nanoparticles for Insect Gene Silencing,” was recently awarded to the Kansas State University Research Foundation, a nonprofit corporation responsible for managing technology transfer activities at the university. The patent covers microscopic, genetics-based technology that can help safely kill mosquitos and other insect pests.

A Nov. 12, 2014 Kansas State University news release, which originated the news item, provides more detail about the research,

Kun Yan Zhu, professor of entomology; Xin Zhang, research associate in the Division of Biology; and Jianzhen Zhang, visiting scientist from Shanxi University in China, developed the technology: nanoparticles comprised of a nontoxic, biodegradable polymer matrix and insect derived double-stranded ribonucleic acid, or dsRNA. Double-stranded RNA is a synthesized molecule that can trigger a biological process known as RNA interference, or RNAi, to destroy the genetic code of an insect in a specific DNA sequence.

The technology is expected to have great potential for safe and effective control of insect pests, Zhu said.

“For example, we can buy cockroach bait that contains a toxic substance to kill cockroaches. However, the bait could potentially harm whatever else ingests it,” Zhu said. “If we can incorporate dsRNA specifically targeting a cockroach gene in the bait rather than a toxic substance, the bait would not harm other organisms, such as pets, because the dsRNA is designed to specifically disable the function of the cockroach gene.”

Researchers developed the technology while looking at how to disable gene functions in mosquito larvae. After testing a series of unsuccessful genetic techniques, the team turned to a nanoparticle-based approach.

Once ingested, the nanoparticles act as a Trojan horse, releasing the loosely bound dsRNA into the insect gut. The dsRNA then triggers a genetic chain reaction that destroys specific messenger RNA, or mRNA, in the developing insects. Messenger RNA carries important genetic information.

In the studies on mosquito larvae, researchers designed dsRNA to target the mRNA encoding the enzymes that help mosquitoes produce chitin, the main component in the hard exoskeleton of insects, crustaceans and arachnids.

Researchers found that the developing mosquitoes produced less chitin. As a result, the mosquitoes were more prone to insecticides as they no longer had a sufficient amount of chitin for a normal functioning protective shell. If the production of chitin can be further reduced, the insects can be killed without using any toxic insecticides.

While mosquitos were the primary insect for which the nanoparticle-based method was developed, the technology can be applied to other insect pests, Zhu said.

“Our dsRNA molecules were designed based on specific gene sequences of the mosquito,” Zhu said. “You can design species-specific dsRNA for the same or different genes for other insect pests. When you make baits containing gene-specific nanoparticles, you may be able to kill the insects through the RNAi pathway. We see this having really broad applications for insect pest management.”

The patent is currently available to license through the Kansas State University Institute for Commercialization, which licenses the university’s intellectual property. The Institute for Commercialization can be contacted at 785-532-3900 and [email protected]

Eight U.S. patents have been awarded to the Kansas State University Research Foundation in 2014 for inventions by Kansas State University researchers.

Here’s an image of the ‘Trojan horse’ nanoparticles,

The nanoparticles, pictured as gold colored, are less than 100 nanometers in diameter. photo credit: bogdog Dan via photopincc

The nanoparticles, pictured as gold colored, are less than 100 nanometers in diameter. photo credit: bogdog Dan via photopincc

My guess is that the photographer has added some colour such as the gold and the pink to enhance the image as otherwise this would be a symphony of grey tones.

So, if this material will lead to weakened chitin such that pesticides and insecticides are more effective, does this mean that something else in the food chain will suffer because it no longer has mosquitos and other pests to munch on?

One last note, usually my ‘mosquito’ pieces concern malaria and the most recent of those was a Sept. 4, 2014 posting about a possible malaria vaccine being developed at the University of Connecticut.

University of Toronto, ebola epidemic, and artificial intelligence applied to chemistry

It’s hard to tell much from the Nov. 5, 2014 University of Toronto news release by Michael Kennedy (also on EurekAlert but dated Nov. 10, 2014) about in silico drug testing focused on finding a treatment for ebola,

The University of Toronto, Chematria and IBM are combining forces in a quest to find new treatments for the Ebola virus.

Using a virtual research technology invented by Chematria, a startup housed at U of T’s Impact Centre, the team will use software that learns and thinks like a human chemist to search for new medicines. Running on Canada’s most powerful supercomputer, the effort will simulate and analyze the effectiveness of millions of hypothetical drugs in just a matter of weeks.

“What we are attempting would have been considered science fiction, until now,” says Abraham Heifets (PhD), a U of T graduate and the chief executive officer of Chematria. “We are going to explore the possible effectiveness of millions of drugs, something that used to take decades of physical research and tens of millions of dollars, in mere days with our technology.”

The news release makes it all sound quite exciting,

Chematria’s technology is a virtual drug discovery platform based on the science of deep learning neural networks and has previously been used for research on malaria, multiple sclerosis, C. difficile, and leukemia. [emphases mine]

Much like the software used to design airplanes and computer chips in simulation, this new system can predict the possible effectiveness of new medicines, without costly and time-consuming physical synthesis and testing. [emphasis mine] The system is driven by a virtual brain that teaches itself by “studying” millions of datapoints about how drugs have worked in the past. With this vast knowledge, the software can apply the patterns it has learned to predict the effectiveness of hypothetical drugs, and suggest surprising uses for existing drugs, transforming the way medicines are discovered.

My understanding is that Chematria’s is not the only “virtual drug discovery platform based on the science of deep learning neural networks” as is acknowledged in the next paragraph. In fact, there’s widespread interest in the medical research community as evidenced by such projects as Seurat-1’s NOTOX* and others. Regarding the research on “malaria, multiple sclerosis, C. difficile, and leukemia,” more details would be welcome, e.g., what happened?

A Nov. 4, 2014 article for Mashable by Anita Li does offer a new detail about the technology,

Now, a team of Canadian researchers are hunting for new Ebola treatments, using “groundbreaking” artificial-intelligence technology that they claim can predict the effectiveness of new medicines 150 times faster than current methods.

With the quotes around the word, groundbreaking, Li suggests a little skepticism about the claim.

Here’s more from Li where she seems to have found some company literature,

Chematria describes its technology as a virtual drug-discovery platform that helps pharmaceutical companies “determine which molecules can become medicines.” Here’s how it works, according to the company:

The system is driven by a virtual brain, modeled on the human visual cortex, that teaches itself by “studying” millions of datapoints about how drugs have worked in the past. With this vast knowledge, Chematria’s brain can apply the patterns it perceives, to predict the effectiveness of hypothetical drugs, and suggest surprising uses for existing drugs, transforming the way medicines are discovered.

I was not able to find a Chematria website or anything much more than this brief description on the University of Toronto website (from the Impact Centre’s Current Companies webpage),

Chematria makes software that helps pharmaceutical companies determine which molecules can become medicines. With Chematria’s proprietary approach to molecular docking simulations, pharmaceutical researchers can confidently predict potent molecules for novel biological targets, thereby enabling faster drug development for a fraction of the price of wet-lab experiments.

Chematria’s Ebola project is focused on drugs already available but could be put to a new use (from Li’s article),

In response to the outbreak, Chematria recently launched an Ebola project, using its algorithm to evaluate molecules that have already gone through clinical trials, and have proven to be safe. “That means we can expedite the process of getting the treatment to the people who need it,” Heifets said. “In a pandemic situation, you’re under serious time pressure.”

He cited Aspirin as an example of proven medicine that has more than one purpose: People take it for headaches, but it’s also helpful for heart disease. Similarly, a drug that’s already out there may also hold the cure for Ebola.

I recommend reading Li’s article in its entirety.

The University of Toronto news release provides more detail about the partners involved in this ebola project,

… The unprecedented speed and scale of this investigation is enabled by the unique strengths of the three partners: Chematria is offering the core artificial intelligence technology that performs the drug research, U of T is contributing biological insights about Ebola that the system will use to search for new treatments and IBM is providing access to Canada’s fastest supercomputer, Blue Gene/Q.

“Our team is focusing on the mechanism Ebola uses to latch on to the cells it infects,” said Dr. Jeffrey Lee of the University of Toronto. “If we can interrupt that process with a new drug, it could prevent the virus from replicating, and potentially work against other viruses like Marburg and HIV that use the same mechanism.”

The initiative may also demonstrate an alternative approach to high-speed medical research. While giving drugs to patients will always require thorough clinical testing, zeroing in on the best drug candidates can take years using today’s most common methods. Critics say this slow and prohibitively expensive process is one of the key reasons that finding treatments for rare and emerging diseases is difficult.

“If we can find promising drug candidates for Ebola using computers alone,” said Heifets, “it will be a milestone for how we develop cures.”

I hope this effort along with all the others being made around the world prove helpful with Ebola. it’s good to see research into drugs (chemical formulations) that are familiar to the medical community and can be used for a different purpose than originally intended. Drugs that are ‘repurposed’ should be cheaper than new ones and we already have data about side effects.

As for the “milestone for how we develop cures,” this team’s work along with all the international research on this front and on how we assess toxicity should certainly make that milestone possible.

* Full disclosure: I came across Seurat-1’s NOTOX project when I attended (at Seurat-1’s expense) the 9th World Congress on Alternatives to Animal Testing held in Aug. 2014 in Prague.

Researching a curcumin delivery system—a nutraceutical story

A Nov. 6, 2014 news item on ScienceDaily features research on delivering curcumin’s (a constituent of turmeric) health benefits more efficiently (there is a twist; for the impatient, you may want to scroll down to where I provide an excerpt from the university’s news release) from Ohio State University (US),

The health benefits of over-the-counter curcumin supplements might not get past your gut, but new research shows that a modified formulation of the spice releases its anti-inflammatory goodness throughout the body.

Curcumin is a naturally occurring compound found in the spice turmeric that has been used for centuries as an Ayurvedic medicine treatment for such ailments as allergies, diabetes and ulcers.

Anecdotal and scientific evidence suggests curcumin promotes health because it lowers inflammation, but it is not absorbed well by the body. Most curcumin in food or supplements stays in the gastrointestinal tract, and any portion that’s absorbed is metabolized quickly.

A Nov. 6, 2014 Ohio State University news release by Emily Caldwell (also on EurekAlert), which originated the news item, explains the interest in curcumin in more detail and describes the research in more detail,

Many research groups are testing the compound’s effects on disorders ranging from colon cancer to osteoarthritis. Others, like these Ohio State University scientists, are investigating whether enabling widespread availability of curcumin’s biological effects to the entire body could make it useful both therapeutically and as a daily supplement to combat disease.

“There’s a reason why this compound has been used for hundreds of years in Eastern medicine. And this study suggests that we have identified a better and more effective way to deliver curcumin and know what diseases to use it for so that we can take advantage of its anti-inflammatory power,” said Nicholas Young, a postdoctoral researcher in rheumatology and immunology at Ohio State and lead author of the study.

Curcumin powder was mixed with castor oil and polyethylene glycol in a process called nano-emulsion (think vinaigrette salad dressing), creating fluid teeming with microvesicles that contain curcumin. This process allows the compound to dissolve and be more easily absorbed by the gut to enter the bloodstream and tissues.

Feeding mice this curcumin-based drug shut down an acute inflammatory reaction by blocking activation of a key protein that triggers the immune response. The researchers were also the first to show that curcumin stops recruitment of specific immune cells that, when overactive, are linked to such problems as heart disease and obesity.

Young and his colleagues, including co-senior authors Lai-Chu Wu and Wael Jarjour of the Division of Rheumatology and Immunology at Ohio State’s Wexner Medical Center, now want to know if curcumin in this form can counter the chronic inflammation that is linked to sickness and age-related frailty. They have started with animal studies testing nano-emulsified curcumin’s ability to prevent or control inflammation in a lupus model.

“We envision that this nutraceutical could be used one day both as a daily supplement to help prevent certain diseases and as a therapeutic drug to help combat the bad inflammation observed in many diseases,” Young said. “The distinction will then be in the amount given – perhaps a low dose for daily prevention and higher doses for disease suppression.”

The term nutraceutical refers to foods or nutrients that provide medical or health benefits.

This news release notes the latest research is built on previous work,

The curcumin delivery system was created in Ohio State’s College of Pharmacy, and these researchers previously showed that concentrations of the emulsified curcumin in blood were more than 10 times higher than of curcumin powder suspended in water.

A more precise description of the current research is then provided (from the news release),

… From there, the researchers launched experiments in mice and cell cultures, generating artificial inflammation and comparing the effects of the nano-emulsified curcumin with the effects of curcumin powder in water or no treatment at all. [emphasis mine]

The researchers injected mice with lipopolysaccharide, a bacteria cell wall extract that stimulates an immune reaction in animals. Curcumin can target many molecules, but the research team zeroed in on NF-kB, a protein that is known to play an important role in the immune response.

In a specialized imaging machine, mice receiving plain curcumin lit up with bioluminescent signals indicating that NF-kB was actively triggering an immune response, while mice receiving nano-emulsified curcumin showed minimal signs – a 22-fold reduction – that the protein had been activated at all.

Knowing that curcumin delivered in this way could shut down NF-kB activation throughout the animals’ bodies, researchers looked for further details about the compound’s effects on inflammation. They found that nano-emulsified curcumin halted the recruitment of immune cells called macrophages that “eat” invading pathogens but also contribute to inflammation by secreting pro-inflammatory chemicals. And in cells isolated from human blood samples, macrophages were stopped in their tracks.

“This macrophage-specific effect of curcumin had not been described before,” Young said. “Because of that finding, we propose nano-emulsified curcumin has the best potential against macrophage-associated inflammation.”

Inflammation triggered by overactive macrophages has been linked to cardiovascular disease, disorders that accompany obesity, Crohn’s disease, rheumatoid arthritis, inflammatory bowel disease, diabetes and lupus-related nephritis.

Here’s a link to and a citation for the paper,

Oral Administration of Nano-Emulsion Curcumin in Mice Suppresses Inflammatory-Induced NFκB Signaling and Macrophage Migration by Nicholas A. Young, Michael S. Bruss, Mark Gardner, William L. Willis, Xiaokui Mo, Giancarlo R. Valiente, Yu Cao, Zhongfa Liu, Wael N. Jarjour, and Lai-Chu Wu. PLOS ONE Published: November 04, 2014 DOI: 10.1371/journal.pone.0111559

This paper is open accesss.

I have an Oct. 1, 2014 posting which features research on curcumin for healing wounds and on tumerone for stimulating the formation of stem cells in the brain.

Treating bacterial infections without antibiotics in Switzerland

One of the major problems in medicine is the growing tolerance to antibiotics consequently there are research teams around the world attempting to find alternatives. A team in Switzerland has proposed a new means of eliminating bacteria without inducing tolerance according to a Nov. 2, 2014 news item on ScienceDaily,

Ever since the development of penicillin almost 90 years ago, antibiotics have remained the gold standard in the treatment of bacterial infections. However, the WHO has repeatedly warned of a growing emergence of bacteria that develop antibiotic resistance. Once antibiotics do no longer protect from bacterial infection, a mere pneumonia might be fatal.

A team of international scientists has tested a novel substance, which has been developed by Eduard Babiychuk and Annette Draeger from the Institute of Anatomy, University of Bern in Switzerland. This compound constitutes a novel approach for the treatment of bacterial infections: the scientists engineered artificial nanoparticles made of lipids, “liposomes” that closely resemble the membrane of host cells. These liposomes act as decoys for bacterial toxins and so are able to sequester and neutralize them. Without toxins, the bacteria are rendered defenseless and can be eliminated by the cells of the host’s own immune system. The study will be published in Nature Biotechnology Nov 2nd [2014].

A Nov. 3, 2014 news item on startupticker.ch provides more detail about the research and the startup which will be taking the research from the lab to the marketplace,

Artificial bait for bacterial toxins

In clinical medicine, liposomes are used to deliver specific medication into the body of patients. Here, the Bernese scientists have created liposomes which attract bacterial toxins and so protect host cells from a dangerous toxin attack. “We have made an irresistible bait for bacterial toxins. The toxins are fatally attracted to the liposomes, and once they are attached, they can be eliminated easily without danger for the host cells”, says Eduard Babiychuk who directed the study. “Since the bacteria are not targeted directly, the liposomes do not promote the development of bacterial resistance”, adds Annette Draeger. Mice which were treated with the liposomes after experimental, fatal septicemia survived without additional antibiotic therapy.

Treatment developed by the Swiss start-up LASCCO

The Technology transfer organisation of the Universities of Bern, Basel and Zurich “Unitectra” has filed a patent for this compound. The liposomal treatment is being developed as a new medicine named “CAL02″ by LASCCO SA, a Geneva-based biomedical company specialized in innovative technologies for diagnostics and therapeutics. The first clinical study, conducted on patients suffering from severe streptococcal pneumonia is scheduled for 2015.

“These in vivo studies strongly support our decision to conduct a first-in-human study next year in severely-ill patients with pneumococcal pneumonia” commented Samareh Azeredo da Silveira Lajaunias, Managing Director at LASCCO. “This new drug meets crucial medical needs, since virulence factors such as toxins are responsible for serious infection-related complications. These complications concern 23% of individuals affected by community-acquired pneumonia, extend hospitalisation in intensive care units, and tremendously increase the cost of care.”

A Nov. 2, 2014 LASCCO press release covers much of the same detail as the news items but is included here for completeness (i.e., my completeness issues).

Here’s a link to and a citation for the study,

Engineered liposomes sequester bacterial exotoxins and protect from severe invasive infections in mice by Brian D Henry, Daniel R Neill, Katrin Anne Becker, Suzanna Gore, Laura Bricio-Moreno, Regan Ziobro, Michael J Edwards, Kathrin Mühlemann, Jörg Steinmann, Burkhard Kleuser, Lukasz Japtok, Miriam Luginbühl, Heidi Wolfmeier, André Scherag, Erich Gulbins, Aras Kadioglu, Annette Draeger, & Eduard B Babiychuk. Nature Biotechnology (2014) doi:10.1038/nbt.3037 Published online 02 November 2014

This paper is behind a paywall.

Nanodiamond alternative to organic fluorophores to view inside living human cells

No sooner is a Nobel prize (2014) awarded for nanoscopy which makes use of fluorescence to observe processes in living cells than there is an announcement about a new technique that avoids fluorescence and its attendant shortcomings. From an Oct. 27, 2014 news item on Nanowerk (Note: A link has been removed),

Nanodiamonds are providing scientists with new possibilities for accurate measurements of processes inside living cells with potential to improve drug delivery and cancer therapeutics.

Published in Nature Nanotechnology (“Coherent anti-Stokes Raman scattering microscopy of single nanodiamonds”), researchers from Cardiff University have unveiled a new method for viewing nanodiamonds inside human living cells for purposes of biomedical research.

An Oct. 27, 2014 Cardiff University (Wales) news release, which originated the news item, explains why the use of nanodiamonds is superior to the use of organic flurophores,

Nanodiamonds are very small particles (a thousand times smaller than human hair) and because of their low toxicity they can be used as a carrier to transport drugs inside cells. They also show huge promise as an alternative to the organic fluorophores usually used by scientists to visualise processes inside cells and tissues.

A major limitation of organic fluorophores is that they have the tendency to degrade and bleach over time under light illumination. This makes it difficult to use them for accurate measurements of cellular processes. Moreover, the bleaching and chemical degradation can often be toxic and significantly perturb or even kill cells.

There is a growing consensus among scientists that nanodiamonds are one of the best inorganic material alternatives for use in biomedical research, because of their compatibility with human cells, and due to their stable structural and chemical properties.

Previous attempts by other research teams to visualise nanodiamonds under powerful light microscopes have run into the obstacle that the diamond material per se is transparent to visible light. Locating the nanodiamonds under a microscope had relied on tiny defects in the crystal lattice, which fluoresce under light illumination.

Production of the defects proved both costly and difficult to realise in a controlled way. Furthermore, the fluorescence light emitted by these defects, and in turn the image gleaned from the microscopic exploration of these flawed nanodiamonds, is sometimes also unstable.

In their latest paper, researchers from Cardiff University’s Schools of Biosciences and Physics showed that non-fluorescing nanodiamonds (diamonds without defects) can be imaged optically and far more stably via the interaction between the illuminating light and the vibrating chemical bonds in the diamond lattice structure which results in scattered light at a different colour.

The paper describes how two laser beams beating at a specific frequency are used to drive chemical bonds to vibrate in sync. One of these beams is then used to probe this vibration and generate a light, called coherent anti-Stokes Raman scattering (CARS).

By focusing these laser beams onto the nanodiamond, a high-resolution CARS image is generated. Using an in-house built microscope, the research team was able to measure the intensity of the CARS light on a series of single nanodiamonds of different sizes.

The nanodiamond size was accurately measured by means of electron microscopy and other quantitative optical contrast methods developed within the researcher’s lab. In this way, they were able to quantify the relationship between the CARS light intensity and the nanoparticle size.

Consequently, the calibrated CARS signal enabled the team to analyse the size and number of nanodiamonds that had been delivered into living cells, with a level of accuracy hitherto not achieved by other methods.

Professor Paola Borri from the School of Biosciences, who led the study, said: “This new imaging modality opens the exciting prospect of following complex cellular trafficking pathways quantitatively with important applications in drug delivery. The next step for us will be to push the technique to detect nanodiamonds of even smaller sizes than what we have shown so far and to demonstrate a specific application in drug delivery.”

Here’s a link to and a citation for the paper,

Coherent anti-Stokes Raman scattering microscopy of single nanodiamonds by Iestyn Pope, Lukas Payne, George Zoriniants, Evan Thomas, Oliver Williams, Peter Watson, Wolfgang Langbein, & Paola Borri. Nature Nanotechnology (2014) doi:10.1038/nnano.2014.210 Published online 12 October 2014

The paper is behind a paywall but there is a free preview with ReadCube Access.

For anyone who’d like to read more about fluorescence and its use in nanoscopy there’s my Oct. 8, 2014 posting about the 2014 Nobel Prize in Chemistry and in my Oct. 27, 2014 posting about a specific use for determining how bipolar disorder may affect the brain.