Tag Archives: Duchenne muscular dystrophy

Yes! Art, genetic modifications, gene editing, and xenotransplantation at the Vancouver Biennale (Canada)

Patricia Piccinini’s Curious Imaginings Courtesy: Vancouver Biennale [downloaded from http://dailyhive.com/vancouver/vancouver-biennale-unsual-public-art-2018/]

Up to this point, I’ve been a little jealous of the Art/Sci Salon’s (Toronto, Canada) January 2018 workshops for artists and discussions about CRISPR ((clustered regularly interspaced short palindromic repeats))/Cas9 and its social implications. (See my January 10, 2018 posting for more about the events.) Now, it seems Vancouver may be in line for its ‘own’ discussion about CRISPR and the implications of gene editing. The image you saw (above) represents one of the installations being hosted by the 2018 – 2020 edition of the Vancouver Biennale.

While this posting is mostly about the Biennale and Piccinini’s work, there is a ‘science’ subsection featuring the science of CRISPR and xenotransplantation. Getting back to the Biennale and Piccinini: A major public art event since 1988, the Vancouver Biennale has hosted over 91 outdoor sculptures and new media works by more than 78 participating artists from over 25 countries and from 4 continents.

Quickie description of the 2018 – 2020 Vancouver Biennale

The latest edition of the Vancouver Biennale was featured in a June 6, 2018 news item on the Daily Hive (Vancouver),

The Vancouver Biennale will be bringing new —and unusual— works of public art to the city beginning this June.

The theme for this season’s Vancouver Biennale exhibition is “re-IMAGE-n” and it kicks off on June 20 [2018] in Vanier Park with Saudi artist Ajlan Gharem’s Paradise Has Many Gates.

Gharem’s architectural chain-link sculpture resembles a traditional mosque, the piece is meant to challenge the notions of religious orthodoxy and encourages individuals to image a space free of Islamophobia.

Melbourne artist Patricia Piccinini’s Curious Imaginings is expected to be one of the most talked about installations of the exhibit. Her style of “oddly captivating, somewhat grotesque, human-animal hybrid creature” is meant to be shocking and thought-provoking.

Piccinini’s interactive [emphasis mine] experience will “challenge us to explore the social impacts of emerging biotechnology and our ethical limits in an age where genetic engineering and digital technologies are already pushing the boundaries of humanity.”

Piccinini’s work will be displayed in the 105-year-old Patricia Hotel in Vancouver’s Strathcona neighbourhood. The 90-day ticketed exhibition [emphasis mine] is scheduled to open this September [2018].

Given that this blog is focused on nanotechnology and other emerging technologies such as CRISPR, I’m focusing on Piccinini’s work and its art/science or sci-art status. This image from the GOMA Gallery where Piccinini’s ‘Curious Affection‘ installation is being shown from March 24 – Aug. 5, 2018 in Brisbane, Queensland, Australia may give you some sense of what one of her installations is like,

Courtesy: Queensland Art Gallery | Gallery of Modern Art (QAGOMA)

I spoke with Serena at the Vancouver Biennale office and asked about the ‘interactive’ aspect of Piccinini’s installation. She suggested the term ‘immersive’ as an alternative. In other words, you won’t be playing with the sculptures or pressing buttons and interacting with computer screens or robots. She also noted that the ticket prices have not been set yet and they are currently developing events focused on the issues raised by the installation. She knew that 2018 is the 200th anniversary of the publication of Mary Shelley’s Frankenstein but I’m not sure how the Biennale folks plan (or don’t plan)  to integrate any recognition of the novle’s impact on the discussions about ‘new’ technologies .They expect Piccinini will visit Vancouver. (Note 1: Piccinini’s work can  also be seen in a group exhibition titled: Frankenstein’s Birthday Party at the Hosfselt Gallery in San Francisco (California, US) from June 23 – August 11, 2018.  Note 2: I featured a number of international events commemorating the 200th anniversary of the publication of Mary Shelley’s novel, Frankenstein, in my Feb. 26, 2018 posting. Note 3: The term ‘Frankenfoods’ helped to shape the discussion of genetically modified organisms and food supply on this planet. It was a wildly successful campaign for activists affecting legislation in some areas of research. Scientists have not been as enthusiastic about the effects. My January 15, 2009 posting briefly traces a history of the term.)

The 2018 – 2020 Vancouver Biennale and science

A June 7, 2018 Vancouver Biennale news release provides more detail about the current series of exhibitions,

The Biennale is also committed to presenting artwork at the cutting edge of discussion and in keeping with the STEAM (science, technology, engineering, arts, math[ematics]) approach to integrating the arts and sciences. In August [2018], Colombian/American visual artist Jessica Angel will present her monumental installation Dogethereum Bridge at Hinge Park in Olympic Village. Inspired by blockchain technology, the artwork’s design was created through the integration of scientific algorithms, new developments in technology, and the arts. This installation, which will serve as an immersive space and collaborative hub for artists and technologists, will host a series of activations with blockchain as the inspirational jumping-off point.

In what is expected to become one of North America’s most talked-about exhibitions of the year, Melbourne artist Patricia Piccinini’s Curious Imaginings will see the intersection of art, science, and ethics. For the first time in the Biennale’s fifteen years of creating transformative experiences, and in keeping with the 2018-2020 theme of “re-IMAGE-n,” the Biennale will explore art in unexpected places by exhibiting in unconventional interior spaces.  The hyperrealist “world of oddly captivating, somewhat grotesque, human-animal hybrid creatures” will be the artist’s first exhibit in a non-museum setting, transforming a wing of the 105-year-old Patricia Hotel. Situated in Vancouver’s oldest neighbourbood of Strathcona, Piccinini’s interactive experience will “challenge us to explore the social impacts of emerging bio-technology and our ethical limits in an age where genetic engineering and digital technologies are already pushing the boundaries of humanity.” In this intimate hotel setting located in a neighborhood continually undergoing its own change, Curious Imaginings will empower visitors to personally consider questions posed by the exhibition, including the promises and consequences of genetic research and human interference. …

There are other pieces being presented at the Biennale but my special interest is in the art/sci pieces and, at this point, CRISPR.

Piccinini in more depth

You can find out more about Patricia Piccinini in her biography on the Vancouver Biennale website but I found this Char Larsson April 7, 2018 article for the Independent (UK) more informative (Note: A link has been removed),

Patricia Piccinini’s sculptures are deeply disquieting. Walking through Curious Affection, her new solo exhibition at Brisbane’s Gallery of Modern Art, is akin to entering a science laboratory full of DNA experiments. Made from silicone, fibreglass and even human hair, her sculptures are breathtakingly lifelike, however, we can’t be sure what life they are like. The artist creates an exuberant parallel universe where transgenic experiments flourish and human evolution has given way to genetic engineering and DNA splicing.

Curious Affection is a timely and welcome recognition of Piccinini’s enormous contribution to reaching back to the mid-1990s. Working across a variety of mediums including photography, video and drawing, she is perhaps best known for her hyperreal creations.

As a genre, hyperrealism depends on the skill of the artist to create the illusion of reality. To be truly successful, it must convince the spectator of its realness. Piccinini acknowledges this demand, but with a delightful twist. The excruciating attention to detail deliberately solicits our desire to look, only to generate unease, as her sculptures are imbued with a fascinating otherness. Part human, part animal, the works are uncannily familiar, but also alarmingly “other”.

Inspired by advances in genetically modified pigs to generate replacement organs for humans [also known as xenotransplantation], we are reminded that Piccinini has always been at the forefront of debates concerning the possibilities of science, technology and DNA cloning. She does so, however, with a warm affection and sense of humour, eschewing the hysterical anxiety frequently accompanying these scientific developments.

Beyond the astonishing level of detail achieved by working with silicon and fibreglass, there is an ethics at work here. Piccinini is asking us not to avert our gaze from the other, and in doing so, to develop empathy and understanding through the encounter.

I encourage anyone who’s interested to read Larsson’s entire piece (April 7, 2018 article).

According to her Wikipedia entry, Piccinini works in a variety of media including video, sound, sculpture, and more. She also has her own website.

Gene editing and xenotransplantation

Sarah Zhang’s June 8, 2018 article for The Atlantic provides a peek at the extraordinary degree of interest and competition in the field of gene editing and CRISPR ((clustered regularly interspaced short palindromic repeats))/Cas9 research (Note: A link has been removed),

China Is Genetically Engineering Monkeys With Brain Disorders

Guoping Feng applied to college the first year that Chinese universities reopened after the Cultural Revolution. It was 1977, and more than a decade’s worth of students—5.7 million—sat for the entrance exams. Feng was the only one in his high school to get in. He was assigned—by chance, essentially—to medical school. Like most of his contemporaries with scientific ambitions, he soon set his sights on graduate studies in the United States. “China was really like 30 to 50 years behind,” he says. “There was no way to do cutting-edge research.” So in 1989, he left for Buffalo, New York, where for the first time he saw snow piled several feet high. He completed his Ph.D. in genetics at the State University of New York at Buffalo.

Feng is short and slim, with a monk-like placidity and a quick smile, and he now holds an endowed chair in neuroscience at MIT, where he focuses on the genetics of brain disorders. His 45-person lab is part of the McGovern Institute for Brain Research, which was established in 2000 with the promise of a $350 million donation, the largest ever received by the university. In short, his lab does not lack for much.

Yet Feng now travels to China several times a year, because there, he can pursue research he has not yet been able to carry out in the United States. [emphasis mine] …

Feng had organized a symposium at SIAT [Shenzhen Institutes of Advanced Technology], and he was not the only scientist who traveled all the way from the United States to attend: He invited several colleagues as symposium speakers, including a fellow MIT neuroscientist interested in tree shrews, a tiny mammal related to primates and native to southern China, and Chinese-born neuroscientists who study addiction at the University of Pittsburgh and SUNY Upstate Medical University. Like Feng, they had left China in the ’80s and ’90s, part of a wave of young scientists in search of better opportunities abroad. Also like Feng, they were back in China to pursue a type of cutting-edge research too expensive and too impractical—and maybe too ethically sensitive—in the United States.

Here’s what precipitated Feng’s work in China, (from Zhang’s article; Note: Links have been removed)

At MIT, Feng’s lab worked on genetically engineering a monkey species called marmosets, which are very small and genuinely bizarre-looking. They are cheaper to keep due to their size, but they are a relatively new lab animal, and they can be difficult to train on lab tasks. For this reason, Feng also wanted to study Shank3 on macaques in China. Scientists have been cataloging the social behavior of macaques for decades, making it an obvious model for studies of disorders like autism that have a strong social component. Macaques are also more closely related to humans than marmosets, making their brains a better stand-in for those of humans.

The process of genetically engineering a macaque is not trivial, even with the advanced tools of CRISPR. Researchers begin by dosing female monkeys with the same hormones used in human in vitro fertilization. They then collect and fertilize the eggs, and inject the resulting embryos with CRISPR proteins using a long, thin glass needle. Monkey embryos are far more sensitive than mice embryos, and can be affected by small changes in the pH of the injection or the concentration of CRISPR proteins. Only some of the embryos will have the desired mutation, and only some will survive once implanted in surrogate mothers. It takes dozens of eggs to get to just one live monkey, so making even a few knockout monkeys required the support of a large breeding colony.

The first Shank3 macaque was born in 2015. Four more soon followed, bringing the total to five.

To visit his research animals, Feng now has to fly 8,000 miles across 12 time zones. It would be a lot more convenient to carry out his macaque research in the United States, of course, but so far, he has not been able to.

He originally inquired about making Shank3 macaques at the New England Primate Research Center, one of eight national primate research centers then funded by the National Institutes of Health in partnership with a local institution (Harvard Medical School, in this case). The center was conveniently located in Southborough, Massachusetts, just 20 miles west of the MIT campus. But in 2013, Harvard decided to shutter the center.

The decision came as a shock to the research community, and it was widely interpreted as a sign of waning interest in primate research in the United States. While the national primate centers have been important hubs of research on HIV, Zika, Ebola, and other diseases, they have also come under intense public scrutiny. Animal-rights groups like the Humane Society of the United States have sent investigators to work undercover in the labs, and the media has reported on monkey deaths in grisly detail. Harvard officially made its decision to close for “financial” reasons. But the announcement also came after the high-profile deaths of four monkeys from improper handling between 2010 and 2012. The deaths sparked a backlash; demonstrators showed up at the gates. The university gave itself two years to wind down their primate work, officially closing the center in 2015.

“They screwed themselves,” Michael Halassa, the MIT neuroscientist who spoke at Feng’s symposium, told me in Shenzhen. Wei-Dong Yao, another one of the speakers, chimed in, noting that just two years later CRISPR has created a new wave of interest in primate research. Yao was one of the researchers at Harvard’s primate center before it closed; he now runs a lab at SUNY Upstate Medical University that uses genetically engineered mouse and human stem cells, and he had come to Shenzhen to talk about restarting his addiction research on primates.

Here’s comes the competition (from Zhang’s article; Note: Links have been removed),

While the U.S. government’s biomedical research budget has been largely flat, both national and local governments in China are eager to raise their international scientific profiles, and they are shoveling money into research. A long-rumored, government-sponsored China Brain Project is supposed to give neuroscience research, and primate models in particular, a big funding boost. Chinese scientists may command larger salaries, too: Thanks to funding from the Shenzhen local government, a new principal investigator returning from overseas can get 3 million yuan—almost half a million U.S. dollars—over his or her first five years. China is even finding success in attracting foreign researchers from top U.S. institutions like Yale.

In the past few years, China has seen a miniature explosion of genetic engineering in monkeys. In Kunming, Shanghai, and Guangzhou, scientists have created monkeys engineered to show signs of Parkinson’s, Duchenne muscular dystrophy, autism, and more. And Feng’s group is not even the only one in China to have created Shank3 monkeys. Another group—a collaboration primarily between researchers at Emory University and scientists in China—has done the same.

Chinese scientists’ enthusiasm for CRISPR also extends to studies of humans, which are moving much more quickly, and in some cases under less oversight, than in the West. The first studies to edit human embryos and first clinical trials for cancer therapies using CRISPR have all happened in China. [emphases mine]

Some ethical issues are also covered (from Zhang’s article),

Parents with severely epileptic children had asked him if it would be possible to study the condition in a monkey. Feng told them what he thought would be technically possible. “But I also said, ‘I’m not sure I want to generate a model like this,’” he recalled. Maybe if there were a drug to control the monkeys’ seizures, he said: “I cannot see them seizure all the time.”

But is it ethical, he continued, to let these babies die without doing anything? Is it ethical to generate thousands or millions of mutant mice for studies of brain disorders, even when you know they will not elucidate much about human conditions?

Primates should only be used if other models do not work, says Feng, and only if a clear path forward is identified. The first step in his work, he says, is to use the Shank3 monkeys to identify the changes the mutations cause in the brain. Then, researchers might use that information to find targets for drugs, which could be tested in the same monkeys. He’s talking with the Oregon National Primate Research Center about carrying out similar work in the United States. ….[Note: I have a three-part series about CRISPR and germline editing* in the US, precipitated by research coming out of Oregon, Part 1, which links to the other parts, is here.]

Zhang’s June 8, 2018 article is excellent and I highly recommend reading it.

I touched on the topic of xenotransplanttaion in a commentary on a book about the science  of the television series, Orphan Black in a January 31,2018 posting (Note: A chimera is what you use to incubate a ‘human’ organ for transplantation or, more accurately, xenotransplantation),

On the subject of chimeras, the Canadian Broadcasting Corporation (CBC) featured a January 26, 2017 article about the pig-human chimeras on its website along with a video,

The end

I am very excited to see Piccinini’s work come to Vancouver. There have been a number of wonderful art and art/science installations and discussions here but this is the first one (I believe) to tackle the emerging gene editing technologies and the issues they raise. (It also fits in rather nicely with the 200th anniversary of the publication of Mary Shelley’s Frankenstein which continues to raise issues and stimulate discussion.)

In addition to the ethical issues raised in Zhang’s article, there are some other philosophical questions:

  • what does it mean to be human
  • if we are going to edit genes to create hybrid human/animals, what are they and how do they fit into our current animal/human schema
  • are you still human if you’ve had an organ transplant where the organ was incubated in a pig

There are also going to be legal issues. In addition to any questions about legal status, there are also fights about intellectual property such as the one involving Harvard & MIT’s [Massachusetts Institute of Technology] Broad Institute vs the University of California at Berkeley (March 15, 2017 posting)..

While I’m thrilled about the Piccinini installation, it should be noted the issues raised by other artworks hosted in this version of the Biennale are important. Happily, they have been broached here in Vancouver before and I suspect this will result in more nuanced  ‘conversations’ than are possible when a ‘new’ issue is introduced.

Bravo 2018 – 2020 Vancouver Biennale!

* Germline editing is when your gene editing will affect subsequent generations as opposed to editing out a mutated gene for the lifetime of a single individual.

Art/sci and CRISPR links

This art/science posting may prove of some interest:

The connectedness of living things: an art/sci project in Saskatchewan: evolutionary biology (February 16, 2018)

A selection of my CRISPR posts:

CRISPR and editing the germline in the US (part 1 of 3): In the beginning (August 15, 2017)

NOTE: An introductory CRISPR video describing how CRISPR/Cas9 works was embedded in part1.

Why don’t you CRISPR yourself? (January 25, 2018)

Editing the genome with CRISPR ((clustered regularly interspaced short palindromic repeats)-carrying nanoparticles (January 26, 2018)

Immune to CRISPR? (April 10, 2018)

CRISPR-CAS9 and gold

As so often happens in the sciences, now that the initial euphoria has expended itself problems (and solutions) with CRISPR ((clustered regularly interspaced short palindromic repeats))-CAAS9 are being disclosed to those of us who are not experts. From an Oct. 3, 2017 article by Bob Yirka for phys.org,

A team of researchers from the University of California and the University of Tokyo has found a way to use the CRISPR gene editing technique that does not rely on a virus for delivery. In their paper published in the journal Nature Biomedical Engineering, the group describes the new technique, how well it works and improvements that need to be made to make it a viable gene editing tool.

CRISPR-Cas9 has been in the news a lot lately because it allows researchers to directly edit genes—either disabling unwanted parts or replacing them altogether. But despite many success stories, the technique still suffers from a major deficit that prevents it from being used as a true medical tool—it sometimes makes mistakes. Those mistakes can cause small or big problems for a host depending on what goes wrong. Prior research has suggested that the majority of mistakes are due to delivery problems, which means that a replacement for the virus part of the technique is required. In this new effort, the researchers report that they have discovered just a such a replacement, and it worked so well that it was able to repair a gene mutation in a Duchenne muscular dystrophy mouse model. The team has named the new technique CRISPR-Gold, because a gold nanoparticle was used to deliver the gene editing molecules instead of a virus.

An Oct. 2, 2017 article by Abby Olena for The Scientist lays out the CRISPR-CAS9 problems the scientists are trying to solve (Note: Links have been removed),

While promising, applications of CRISPR-Cas9 gene editing have so far been limited by the challenges of delivery—namely, how to get all the CRISPR parts to every cell that needs them. In a study published today (October 2) in Nature Biomedical Engineering, researchers have successfully repaired a mutation in the gene for dystrophin in a mouse model of Duchenne muscular dystrophy by injecting a vehicle they call CRISPR-Gold, which contains the Cas9 protein, guide RNA, and donor DNA, all wrapped around a tiny gold ball.

The authors have made “great progress in the gene editing area,” says Tufts University biomedical engineer Qiaobing Xu, who did not participate in the work but penned an accompanying commentary. Because their approach is nonviral, Xu explains, it will minimize the potential off-target effects that result from constant Cas9 activity, which occurs when users deliver the Cas9 template with a viral vector.

Duchenne muscular dystrophy is a degenerative disease of the muscles caused by a lack of the protein dystrophin. In about a third of patients, the gene for dystrophin has small deletions or single base mutations that render it nonfunctional, which makes this gene an excellent candidate for gene editing. Researchers have previously used viral delivery of CRISPR-Cas9 components to delete the mutated exon and achieve clinical improvements in mouse models of the disease.

“In this paper, we were actually able to correct [the gene for] dystrophin back to the wild-type sequence” via homology-directed repair (HDR), coauthor Niren Murthy, a drug delivery researcher at the University of California, Berkeley, tells The Scientist. “The other way of treating this is to do something called exon skipping, which is where you delete some of the exons and you can get dystrophin to be produced, but it’s not [as functional as] the wild-type protein.”

The research team created CRISPR-Gold by covering a central gold nanoparticle with DNA that they modified so it would stick to the particle. This gold-conjugated DNA bound the donor DNA needed for HDR, which the Cas9 protein and guide RNA bound to in turn. They coated the entire complex with a polymer that seems to trigger endocytosis and then facilitate escape of the Cas9 protein, guide RNA, and template DNA from endosomes within cells.

In order to do HDR, “you have to provide the cell [with] the Cas9 enzyme, guide RNA by which you target Cas9 to a particular part of the genome, and a big chunk of DNA, which will be used as a template to edit the mutant sequence to wild-type,” explains coauthor Irina Conboy, who studies tissue repair at the University of California, Berkeley. “They all have to be present at the same time and at the same place, so in our system you have a nanoparticle which simultaneously delivers all of those three key components in their active state.”

Olena’s article carries on to describe how the team created CRISPR-Gold and more.

Additional technical details are available in an Oct. 3, 2017 University of California at Berkeley news release by Brett Israel (also on EurekAlert), which originated the news item (Note: A link has been removed) ,

Scientists at the University of California, Berkeley, have engineered a new way to deliver CRISPR-Cas9 gene-editing technology inside cells and have demonstrated in mice that the technology can repair the mutation that causes Duchenne muscular dystrophy, a severe muscle-wasting disease. A new study shows that a single injection of CRISPR-Gold, as the new delivery system is called, into mice with Duchenne muscular dystrophy led to an 18-times-higher correction rate and a two-fold increase in a strength and agility test compared to control groups.

Diagram of CRISPR-Gold

CRISPR–Gold is composed of 15 nanometer gold nanoparticles that are conjugated to thiol-modified oligonucleotides (DNA-Thiol), which are hybridized with single-stranded donor DNA and subsequently complexed with Cas9 and encapsulated by a polymer that disrupts the endosome of the cell.

Since 2012, when study co-author Jennifer Doudna, a professor of molecular and cell biology and of chemistry at UC Berkeley, and colleague Emmanuelle Charpentier, of the Max Planck Institute for Infection Biology, repurposed the Cas9 protein to create a cheap, precise and easy-to-use gene editor, researchers have hoped that therapies based on CRISPR-Cas9 would one day revolutionize the treatment of genetic diseases. Yet developing treatments for genetic diseases remains a big challenge in medicine. This is because most genetic diseases can be cured only if the disease-causing gene mutation is corrected back to the normal sequence, and this is impossible to do with conventional therapeutics.

CRISPR/Cas9, however, can correct gene mutations by cutting the mutated DNA and triggering homology-directed DNA repair. However, strategies for safely delivering the necessary components (Cas9, guide RNA that directs Cas9 to a specific gene, and donor DNA) into cells need to be developed before the potential of CRISPR-Cas9-based therapeutics can be realized. A common technique to deliver CRISPR-Cas9 into cells employs viruses, but that technique has a number of complications. CRISPR-Gold does not need viruses.

In the new study, research lead by the laboratories of Berkeley bioengineering professors Niren Murthy and Irina Conboy demonstrated that their novel approach, called CRISPR-Gold because gold nanoparticles are a key component, can deliver Cas9 – the protein that binds and cuts DNA – along with guide RNA and donor DNA into the cells of a living organism to fix a gene mutation.

“CRISPR-Gold is the first example of a delivery vehicle that can deliver all of the CRISPR components needed to correct gene mutations, without the use of viruses,” Murthy said.

The study was published October 2 [2017] in the journal Nature Biomedical Engineering.

CRISPR-Gold repairs DNA mutations through a process called homology-directed repair. Scientists have struggled to develop homology-directed repair-based therapeutics because they require activity at the same place and time as Cas9 protein, an RNA guide that recognizes the mutation and donor DNA to correct the mutation.

To overcome these challenges, the Berkeley scientists invented a delivery vessel that binds all of these components together, and then releases them when the vessel is inside a wide variety of cell types, triggering homology directed repair. CRISPR-Gold’s gold nanoparticles coat the donor DNA and also bind Cas9. When injected into mice, their cells recognize a marker in CRISPR-Gold and then import the delivery vessel. Then, through a series of cellular mechanisms, CRISPR-Gold is released into the cells’ cytoplasm and breaks apart, rapidly releasing Cas9 and donor DNA.

Schematic of CRISPR-Gold's method of action

CRISPR-Gold’s method of action (Click to enlarge).

A single injection of CRISPR-Gold into muscle tissue of mice that model Duchenne muscular dystrophy restored 5.4 percent of the dystrophin gene, which causes the disease, to the wild- type, or normal, sequence. This correction rate was approximately 18 times higher than in mice treated with Cas9 and donor DNA by themselves, which experienced only a 0.3 percent correction rate.

Importantly, the study authors note, CRISPR-Gold faithfully restored the normal sequence of dystrophin, which is a significant improvement over previously published approaches that only removed the faulty part of the gene, making it shorter and converting one disease into another, milder disease.

CRISPR-Gold was also able to reduce tissue fibrosis – the hallmark of diseases where muscles do not function properly – and enhanced strength and agility in mice with Duchenne muscular dystrophy. CRISPR-Gold-treated mice showed a two-fold increase in hanging time in a common test for mouse strength and agility, compared to mice injected with a control.

“These experiments suggest that it will be possible to develop non-viral CRISPR therapeutics that can safely correct gene mutations, via the process of homology-directed repair, by simply developing nanoparticles that can simultaneously encapsulate all of the CRISPR components,” Murthy said.

CRISPR-Cas9

CRISPR in action: A model of the Cas9 protein cutting a double-stranded piece of DNA

The study found that CRISPR-Gold’s approach to Cas9 protein delivery is safer than viral delivery of CRISPR, which, in addition to toxicity, amplifies the side effects of Cas9 through continuous expression of this DNA-cutting enzyme. When the research team tested CRISPR-Gold’s gene-editing capability in mice, they found that CRISPR-Gold efficiently corrected the DNA mutation that causes Duchenne muscular dystrophy, with minimal collateral DNA damage.

The researchers quantified CRISPR-Gold’s off-target DNA damage and found damage levels similar to the that of a typical DNA sequencing error in a typical cell that was not exposed to CRISPR (0.005 – 0.2 percent). To test for possible immunogenicity, the blood stream cytokine profiles of mice were analyzed at 24 hours and two weeks after the CRISPR-Gold injection. CRISPR-Gold did not cause an acute up-regulation of inflammatory cytokines in plasma, after multiple injections, or weight loss, suggesting that CRISPR-Gold can be used multiple times safely, and that it has a high therapeutic window for gene editing in muscle tissue.

“CRISPR-Gold and, more broadly, CRISPR-nanoparticles open a new way for safer, accurately controlled delivery of gene-editing tools,” Conboy said. “Ultimately, these techniques could be developed into a new medicine for Duchenne muscular dystrophy and a number of other genetic diseases.”

A clinical trial will be needed to discern whether CRISPR-Gold is an effective treatment for genetic diseases in humans. Study co-authors Kunwoo Lee and Hyo Min Park have formed a start-up company, GenEdit (Murthy has an ownership stake in GenEdit), which is focused on translating the CRISPR-Gold technology into humans. The labs of Murthy and Conboy are also working on the next generation of particles that can deliver CRISPR into tissues from the blood stream and would preferentially target adult stem cells, which are considered the best targets for gene correction because stem and progenitor cells are capable of gene editing, self-renewal and differentiation.

“Genetic diseases cause devastating levels of mortality and morbidity, and new strategies for treating them are greatly needed,” Murthy said. “CRISPR-Gold was able to correct disease-causing gene mutations in vivo, via the non-viral delivery of Cas9 protein, guide RNA and donor DNA, and therefore has the potential to develop into a therapeutic for treating genetic diseases.”

The study was funded by the National Institutes of Health, the W.M. Keck Foundation, the Moore Foundation, the Li Ka Shing Foundation, Calico, Packer, Roger’s and SENS, and the Center of Innovation (COI) Program of the Japan Science and Technology Agency.

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

Nanoparticle delivery of Cas9 ribonucleoprotein and donor DNA in vivo induces homology-directed DNA repair by Kunwoo Lee, Michael Conboy, Hyo Min Park, Fuguo Jiang, Hyun Jin Kim, Mark A. Dewitt, Vanessa A. Mackley, Kevin Chang, Anirudh Rao, Colin Skinner, Tamanna Shobha, Melod Mehdipour, Hui Liu, Wen-chin Huang, Freeman Lan, Nicolas L. Bray, Song Li, Jacob E. Corn, Kazunori Kataoka, Jennifer A. Doudna, Irina Conboy, & Niren Murthy. Nature Biomedical Engineering (2017) doi:10.1038/s41551-017-0137-2 Published online: 02 October 2017

This paper is behind a paywall.