Tag Archives: University of Toronto (UofT)

An algorithm for modern quilting

Caption: Each of the blocks in this quilt were designed using an algorithm-based tool developed by Stanford researchers. Credit: Mackenzie Leake

I love the colours. This research into quilting and artificial intelligence (AI) was presented at SIGGRAPH 2021 in August. (SIGGRAPH is, also known as, ACM SIGGRAPH or ‘Association for Computing Machinery’s Special Interest Group on Computer Graphics and Interactive Techniques’.)

A June 3, 2021 news item on ScienceDaily announced the presentation,

Stanford University computer science graduate student Mackenzie Leake has been quilting since age 10, but she never imagined the craft would be the focus of her doctoral dissertation. Included in that work is new prototype software that can facilitate pattern-making for a form of quilting called foundation paper piecing, which involves using a backing made of foundation paper to lay out and sew a quilted design.

Developing a foundation paper piece quilt pattern — which looks similar to a paint-by-numbers outline — is often non-intuitive. There are few formal guidelines for patterning and those that do exist are insufficient to assure a successful result.

“Quilting has this rich tradition and people make these very personal, cherished heirlooms but paper piece quilting often requires that people work from patterns that other people designed,” said Leake, who is a member of the lab of Maneesh Agrawala, the Forest Baskett Professor of Computer Science and director of the Brown Institute for Media Innovation at Stanford. “So, we wanted to produce a digital tool that lets people design the patterns that they want to design without having to think through all of the geometry, ordering and constraints.”

A paper describing this work is published and will be presented at the computer graphics conference SIGGRAPH 2021 in August.

A June 2, 2021 Stanford University news release (also on EurekAlert), which originated the news item, provides more detail,

Respecting the craft

In describing the allure of paper piece quilts, Leake cites the modern aesthetic and high level of control and precision. The seams of the quilt are sewn through the paper pattern and, as the seaming process proceeds, the individual pieces of fabric are flipped over to form the final design. All of this “sew and flip” action means the pattern must be produced in a careful order.

Poorly executed patterns can lead to loose pieces, holes, misplaced seams and designs that are simply impossible to complete. When quilters create their own paper piecing designs, figuring out the order of the seams can take considerable time – and still lead to unsatisfactory results.

“The biggest challenge that we’re tackling is letting people focus on the creative part and offload the mental energy of figuring out whether they can use this technique or not,” said Leake, who is lead author of the SIGGRAPH paper. “It’s important to me that we’re really aware and respectful of the way that people like to create and that we aren’t over-automating that process.”

This isn’t Leake’s first foray into computer-aided quilting. She previously designed a tool for improvisational quilting, which she presented [PatchProv: Supporting Improvistiional Design Practices for Modern Quilting by Mackenzie Leake, Frances Lai, Tovi Grossman, Daniel Wigdor, and Ben Lafreniere] at the human-computer interaction conference CHI in May [2021]. [Note: Links to the May 2021 conference and paper added by me.]

Quilting theory

Developing the algorithm at the heart of this latest quilting software required a substantial theoretical foundation. With few existing guidelines to go on, the researchers had to first gain a more formal understanding of what makes a quilt paper piece-able, and then represent that mathematically.

They eventually found what they needed in a particular graph structure, called a hypergraph. While so-called “simple” graphs can only connect data points by lines, a hypergraph can accommodate overlapping relationships between many data points. (A Venn diagram is a type of hypergraph.) The researchers found that a pattern will be paper piece-able if it can be depicted by a hypergraph whose edges can be removed one at a time in a specific order – which would correspond to how the seams are sewn in the pattern.

The prototype software allows users to sketch out a design and the underlying hypergraph-based algorithm determines what paper foundation patterns could make it possible – if any. Many designs result in multiple pattern options and users can adjust their sketch until they get a pattern they like. The researchers hope to make a version of their software publicly available this summer.

“I didn’t expect to be writing my computer science dissertation on quilting when I started,” said Leake. “But I found this really rich space of problems involving design and computation and traditional crafts, so there have been lots of different pieces we’ve been able to pull off and examine in that space.”

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Researchers from University of California, Berkeley and Cornell University are co-authors of this paper. Agrawala is also an affiliate of the Institute for Human-Centered Artificial Intelligence (HAI).

An abstract for the paper “A Mathematical Foundation for Foundation Paper Pieceable Quilts” by Mackenzie Leake, Gilbert Bernstein, Abe Davis and Maneesh Agrawala can be found here along with links to a PDF of the full paper and video on YouTube.

Afterthought: I noticed that all of the co-authors for the May 2021 paper are from the University of Toronto and most of them including Mackenzie Leake are associated with that university’s Chatham Labs.

Council of Canadian Academies (CCA): science policy internship and a new panel on Public Safety in the Digital Age

It’s been a busy week for the Council of Canadian Academies (CCA); I don’t usually get two notices in such close order.

2022 science policy internship

The application deadline is Oct. 18, 2021, you will work remotely, and the stipend for the 2020 internship was $18,500 for six months.

Here’s more from a September 13, 2021 CCA notice (received Sept. 13, 2021 via email),

CCA Accepting Applications for Internship Program

The program provides interns with an opportunity to gain experience working at the interface of science and public policy. Interns will participate in the development of assessments by conducting research in support of CCA’s expert panel process.

The internship program is a full-time commitment of six months and will be a remote opportunity due to the Covid-19 pandemic.

Applicants must be recent graduates with a graduate or professional degree, or post-doctoral fellows, with a strong interest in the use of evidence for policy. The application deadline is October 18, 2021. The start date is January 10, 2022. Applications and letters of reference should be addressed to Anita Melnyk at internship@cca-reports.ca.

More information about the CCA Internship Program and the application process can be found here. [Note: The link takes you to a page with information about a 2020 internship opportunity; presumably, the application requirements have not changed.]

Good luck!

Expert Panel on Public Safety in the Digital Age Announced

I have a few comments (see the ‘Concerns and hopes’ subhead) about this future report but first, here’s the announcement of the expert panel that was convened to look into the matter of public safety (received via email September 15, 2021),

CCA Appoints Expert Panel on Public Safety in the Digital Age

Access to the internet and digital technologies are essential for people, businesses, and governments to carry out everyday activities. But as more and more activities move online, people and organizations are increasingly vulnerable to serious threats and harms that are enabled by constantly evolving technology. At the request of Public Safety Canada, [emphasis mine] the Council of Canadian Academies (CCA) has formed an Expert Panel to examine leading practices that could help address risks to public safety while respecting human rights and privacy. Jennifer Stoddart, O.C., Strategic Advisor, Privacy and Cybersecurity Group, Fasken Martineau DuMoulin [law firm], will serve as Chair of the Expert Panel.

“The ever-evolving nature of crimes and threats that take place online present a huge challenge for governments and law enforcement,” said Ms. Stoddart. “Safeguarding public safety while protecting civil liberties requires a better understanding of the impacts of advances in digital technology and the challenges they create.”

As Chair, Ms. Stoddart will lead a multidisciplinary group with expertise in cybersecurity, social sciences, criminology, law enforcement, and law and governance. The Panel will answer the following question:

Considering the impact that advances in information and communications technologies have had on a global scale, what do current evidence and knowledge suggest regarding promising and leading practices that could be applied in Canada for investigating, preventing, and countering threats to public safety while respecting human rights and privacy?

“This is an important question, the answer to which will have both immediate and far-reaching implications for the safety and well-being of people living in Canada. Jennifer Stoddart and this expert panel are very well-positioned to answer it,” said Eric M. Meslin, PhD, FRSC, FCAHS, President and CEO of the CCA.

More information about the assessment can be found here.

The Expert Panel on Public Safety in the Digital Age:

  • Jennifer Stoddart (Chair), O.C., Strategic Advisor, Privacy and Cybersecurity Group, Fasken Martineau DuMoulin [law firm].
  • Benoît Dupont, Professor, School of Criminology, and Canada Research Chair in Cybersecurity and Research Chair for the Prevention of Cybercrime, Université de Montréal; Scientific Director, Smart Cybersecurity Network (SERENE-RISC). Note: This is one of Canada’s Networks of Centres of Excellence (NCE)
  • Richard Frank, Associate Professor, School of Criminology, Simon Fraser University; Director, International CyberCrime Research Centre International. Note: This is an SFU/ Society for the Policing of Cyberspace (POLCYB) partnership
  • Colin Gavaghan, Director, New Zealand Law Foundation Centre for Law and Policy in Emerging Technologies, Faculty of Law, University of Otago.
  • Laura Huey, Professor, Department of Sociology, Western University; Founder, Canadian Society of Evidence Based Policing [Can-SEPB].
  • Emily Laidlaw, Associate Professor and Canada Research Chair in Cybersecurity Law, Faculty of Law, University of Calgary.
  • Arash Habibi Lashkari, Associate Professor, Faculty of Computer Science, University of New Brunswick; Research Coordinator, Canadian Institute of Cybersecurity [CIC].
  • Christian Leuprecht, Class of 1965 Professor in Leadership, Department of Political Science and Economics, Royal Military College; Director, Institute of Intergovernmental Relations, School of Policy Studies, Queen’s University.
  • Florian Martin-Bariteau, Associate Professor of Law and University Research Chair in Technology and Society, University of Ottawa; Director, Centre for Law, Technology and Society.
  • Shannon Parker, Detective/Constable, Saskatoon Police Service.
  • Christopher Parsons, Senior Research Associate, Citizen Lab, Munk School of Global Affairs & Public Policy, University of Toronto.
  • Jad Saliba, Founder and Chief Technology Officer, Magnet Forensics Inc.
  • Heidi Tworek, Associate Professor, School of Public Policy and Global Affairs, and Department of History, University of British Columbia.

Oddly, there’s no mention that Jennifer Stoddart (Wikipedia entry) was Canada’s sixth privacy commissioner. Also, Fasken Martineau DuMoulin (her employer) changed its name to Fasken in 2017 (Wikipedia entry). The company currently has offices in Canada, UK, South Africa, and China (Firm webpage on company website).

Exactly how did the question get framed?

It’s always informative to look at the summary (from the reports Public Safety in the Digital Age webpage on the CCA website),

Information and communications technologies have profoundly changed almost every aspect of life and business in the last two decades. While the digital revolution has brought about many positive changes, it has also created opportunities for criminal organizations and malicious actors [emphasis mine] to target individuals, businesses, and systems. Ultimately, serious crime facilitated by technology and harmful online activities pose a threat to the safety and well-being of people in Canada and beyond.

Damaging or criminal online activities can be difficult to measure and often go unreported. Law enforcement agencies and other organizations working to address issues such as the sexual exploitation of children, human trafficking, and violent extremism [emphasis mine] must constantly adapt their tools and methods to try and prevent and respond to crimes committed online.

A better understanding of the impacts of these technological advances on public safety and the challenges they create could help to inform approaches to protecting public safety in Canada.

This assessment will examine promising practices that could help to address threats to public safety related to the use of digital technologies while respecting human rights and privacy.

The Sponsor:

Public Safety Canada

The Question:

Considering the impact that advances in information and communications technologies have had on a global scale, what do current evidence and knowledge suggest regarding promising and leading practices that could be applied in Canada for investigating, preventing, and countering threats to public safety while respecting human rights and privacy?

Three things stand out for me. First, public safety, what is it?, second, ‘malicious actors’, and third, the examples used for the issues being addressed (more about this in the Comments subsection, which follows).

What is public safety?

Before launching into any comments, here’s a description for Public Safety Canada (from their About webpage) where you’ll find a hodge podge,

Public Safety Canada was created in 2003 to ensure coordination across all federal departments and agencies responsible for national security and the safety of Canadians.

Our mandate is to keep Canadians safe from a range of risks such as natural disasters, crime and terrorism.

Our mission is to build a safe and resilient Canada.

The Public Safety Portfolio

A cohesive and integrated approach to Canada’s security requires cooperation across government. Together, these agencies have an annual budget of over $9 billion and more than 66,000 employees working in every part of the country.

Public Safety Partner Agencies

The Canada Border Services Agency (CBSA) manages the nation’s borders by enforcing Canadian laws governing trade and travel, as well as international agreements and conventions. CBSA facilitates legitimate cross-border traffic and supports economic development while stopping people and goods that pose a potential threat to Canada.

The Canadian Security Intelligence Service (CSIS) investigates and reports on activities that may pose a threat to the security of Canada. CSIS also provides security assessments, on request, to all federal departments and agencies.

The Correctional Service of Canada (CSC) helps protect society by encouraging offenders to become law-abiding citizens while exercising reasonable, safe, secure and humane control. CSC is responsible for managing offenders sentenced to two years or more in federal correctional institutions and under community supervision.

The Parole Board of Canada (PBC) is an independent body that grants, denies or revokes parole for inmates in federal prisons and provincial inmates in province without their own parole board. The PBC helps protect society by facilitating the timely reintegration of offenders into society as law-abiding citizens.

The Royal Canadian Mounted Police (RCMP) enforces Canadian laws, prevents crime and maintains peace, order and security.

So, Public Safety includes a spy agency (CSIS), the prison system (Correctional Services and Parole Board), and the national police force (RCMP) and law enforcement at the borders with the Canada Border Services Agency (CBSA). None of the partner agencies are dedicated to natural disasters although it’s mentioned in the department’s mandate.

The focus is largely on criminal activity and espionage. On that note, a very senior civilian RCMP intelligence official, Cameron Ortis*, was charged with passing secrets to foreign entities (malicious actors?). (See the September 13, 2021 [updated Sept. 15, 2021] news article by Amanda Connolly, Mercedes Stephenson, Stewart Bell, Sam Cooper & Rachel Browne for CTV news and the Sept. 18, 2019 [updated January 6, 2020] article by Douglas Quan for the National Post for more details.)

There appears to be at least one other major security breach; that involving Canada’s only level four laboratory, the Winnipeg-based National Microbiology Lab (NML). (See a June 10, 2021 article by Karen Pauls for Canadian Broadcasting Corporation news online for more details.)

As far as I’m aware, Ortis is still being held with a trial date scheduled for September 2022 (see Catherine Tunney’s April 9, 2021 article for CBC news online) and, to date, there have been no charges laid in the Winnipeg lab case.

Concerns and hopes

Ordinarily I’d note links and relationships between the various expert panel members but in this case it would be a big surprise if they weren’t linked in some fashion as the focus seems to be heavily focused on cybersecurity (as per the panel member’s bios.), which I imagine is a smallish community in Canada.

As I’ve made clear in the paragraphs leading into the comments, Canada appears to have seriously fumbled the ball where national and international cybersecurity is concerned.

So getting back to “First, public safety, what is it?, second, ‘malicious actors’, and third, the examples used for the issues,” I’m a bit puzzled.

Public safety as best I can tell, is just about anything they’d like it to be. ‘Malicious actors’ is a term I’ve seen used to imply a foreign power is behind the actions being held up for scrutiny.

The examples used for the issues being addressed “sexual exploitation of children, human trafficking, and violent extremism” hint at a focus on crimes that cross borders and criminal organizations, as well as, like-minded individuals organizing violent and extremist acts but not specifically at any national or international security concerns.

On a more mundane note, I’m a little surprised that identity theft wasn’t mentioned as an example.

I’m hopeful there will be some examination of emerging technologies such as quantum communication (specifically, encryption issues) and artificial intelligence. I also hope the report will include a discussion about mistakes and over reliance on technology (for a refresher course on what happens when organizations, such as the Canadian federal government, make mistakes in the digital world; search ‘Phoenix payroll system’, a 2016 made-in-Canada and preventable debacle, which to this day is still being fixed).

In the end, I think the only topic that can be safely excluded from the report is climate change otherwise it’s a pretty open mandate as far as can be told from publicly available information.

I noticed the international panel member is from New Zealand (the international component is almost always from the US, UK, northern Europe, and/or the Commonwealth). Given that New Zealand (as well as being part of the commonwealth) is one of the ‘Five Eyes Intelligence Community’, which includes Canada, Australia, the UK, the US, and, NZ, I was expecting a cybersecurity expert. If Professor Colin Gavaghan does have that expertise, it’s not obvious on his University of Otaga profile page (Note: Links have been removed),

Research interests

Colin is the first director of the New Zealand Law Foundation sponsored Centre for Law and Policy in Emerging Technologies. The Centre examines the legal, ethical and policy issues around new technologies. To date, the Centre has carried out work on biotechnology, nanotechnology, information and communication technologies and artificial intelligence.

In addition to emerging technologies, Colin lectures and writes on medical and criminal law.

Together with colleagues in Computer Science and Philosophy, Colin is the leader of a three-year project exploring the legal, ethical and social implications of artificial intelligence for New Zealand.

Background

Colin regularly advises on matters of technology and regulation. He is first Chair of the NZ Police’s Advisory Panel on Emergent Technologies, and a member of the Digital Council for Aotearoa, which advises the Government on digital technologies. Since 2017, he has been a member (and more recently Deputy Chair) of the Advisory Committee on Assisted Reproductive Technology. He was an expert witness in the High Court case of Seales v Attorney General, and has advised members of parliament on draft legislation.

He is a frustrated writer of science fiction, but compensates with occasional appearances on panels at SF conventions.

I appreciate the sense of humour evident in that last line.

Almost breaking news

Wednesday, September 15, 2021 an announcement of a new alliance in the Indo-Pacific region, the Three Eyes (Australia, UK, and US or AUKUS) was made.

Interestingly all three are part of the Five Eyes intelligence alliance comprised of Australia, Canada, New Zealand, UK, and US. Hmmm … Canada and New Zealand both border the Pacific and last I heard, the UK is still in Europe.

A September 17, 2021 article, “Canada caught off guard by exclusion from security pact” by Robert Fife and Steven Chase for the Globe and Mail (I’m quoting from my paper copy),

The Canadian government was surprised this week by the announcement of a new security pact among the United States, Britain and Australia, one that excluded Canada [and New Zealand too] and is aimed at confronting China’s growing military and political influence in the Indo-Pacific region, according to senior government officials.

Three officials, representing Canada’s Foreign Affairs, Intelligence and Defence departments, told the Globe and Mail that Ottawa was not consulted about the pact, and had no idea the trilateral security announcement was coming until it was made on Wednesday [September 15, 2021] by U.S. President Joe Biden, British Prime Minister Boris Johnson and Australian Prime Minister Scott Morrison.

The new trilateral alliance, dubbed AUKUS, after the initials of the three countries, will allow for greater sharing of information in areas such as artificial intelligence and cyber and underwater defence capabilities.

Fife and Chase have also written a September 17, 2021 Globe and Mail article titled, “Chinese Major-General worked with fired Winnipeg Lab scientist,”

… joint research conducted between Major-General Chen Wei and former Canadian government lab scientist Xiangguo Qiu indicates that co-operation between the Chinese military and scientists at the National Microbiology Laboratory (NML) went much higher than was previously known. The People’s Liberation Army is the military of China’s ruling Communist Party.

Given that no one overseeing the Canadian lab, which is a level 4 and which should have meant high security, seems to have known that Wei was a member of the military and with the Cameron Ortis situation still looming, would you have included Canada in the new pact?

*ETA September 20, 2021: For anyone who’s curious about the Cameron Ortis case, there’s a Fifth Estate documentary (approximately 46 minutes): The Smartest Guy in the Room: Cameron Ortis and the RCMP Secrets Scandal.

Space and sound (music from the Milky Way)

A May 17, 2021 posting on the Canadian Broadcasting Corporation (CBC) Radio Ideas programme blog describes and hosts embedded videos and audio clips of space data sonfications and visualizations,

After years of attempts and failures to get a microphone to Mars, NASA’s [US National Aeronautics and Space Administration] latest rover, Perseverance, succeeded. It landed in February carrying two microphones.

For Jason Achilles Mezilis, a musician and record producer who has also worked for NASA, listening to the haunting Martian wind was an emotional experience.

“I’m in this bar half drunk, and I go over to the corner and I listen to it on my cellphone and … I broke down.”

The atmosphere of Mars is a little thinner than Earth’s, but it still has enough air to transmit sound.

Ben Burtt, an Oscar-winning sound designer, editor and director, made the sounds of cinematic space fantasy — from Star Wars to WALL-E to Star Trek. But he’s also deeply interested in the sound of actual space reality.

“All sound is a form of wind, really. It’s a puff of air molecules moving. And when I heard the sound, I thought: ‘Well, you know, I’ve heard this many times in my headphones on recording trips,'” Burtt said

SYSTEM Sounds, founded by University of Toronto astrophysicist and musician Matt Russo, translates data from space into music. 

Planets or moons sometimes fall into what’s called “orbital resonance,” where two or more bodies pull each other into a regular rhythm. One example is the three inner moons of Jupiter: Ganymede, Europa, and Io. 

“The rhythm is very similar to what a drummer might play. There’s a very simple regularity,” Russo said.

“And there’s something about our ears and our auditory system that finds that pleasing, finds repeating rhythms with simple ratios between them pleasing or natural sounding. It’s predictable. So it gives you something to kind of latch on to emotionally.”

Russo created this tool to illustrate the musical rhythm of the Galilean moons. 

During the pandemic, scientists at NASA, with the help of SYSTEM Sounds, tried to find new ways of connecting people with the beauty of space. The result was “sonic visualizations,” translating data captured by telescopes into sound instead of pictures.

Most images of space come from data translated into colours, such as Cassiopeia A, the remains of an exploded star. 

A given colour is usually assigned to the electromagnetic signature of each chemical in the dust cloud. But instead of assigning a colour, a musical note can be assigned, allowing us to hear Cassiopeia A instead of just seeing it.

There are several embedded videos and the Ideas radio interview embedded in the May 17, 2021 posting. Should you be interested, you can find System Sounds here.

You will find a number of previous postings (use the search term ‘data sonification’); the earliest concerning ‘space music’ is from February 7, 2014. You’ll also find Matt Russo, the TRAPPIST-1 planetary system, and music in a May 11, 2017 posting.

Blue quantum dots and your television screen

Scientists used equipment at the Canadian Light Source (CLS; synchrotron in Saskatoon, Saskatchewan, Canada) in the quest for better glowing dots on your television (maybe computers and telephones, too?) screen. From an August 20, 2020 news item on Nanowerk,

There are many things quantum dots could do, but the most obvious place they could change our lives is to make the colours on our TVs and screens more pristine. Research using the Canadian Light Source (CLS) at the University of Saskatchewan is helping to bring this technology closer to our living rooms.

An August 19, 2020 CLS news release (also received via email) by Victoria Martinez, which originated the news item, explains what quantum dots are and fills in with technical details about this research,

Quantum dots are nanocrystals that glow, a property that scientists have been working with to develop next-generation LEDs. When a quantum dot glows, it creates very pure light in a precise wavelength of red, blue or green. Conventional LEDs, found in our TV screens today, produce white light that is filtered to achieve desired colours, a process that leads to less bright and muddier colours.

Until now, blue-glowing quantum dots, which are crucial for creating a full range of colour, have proved particularly challenging for researchers to develop. However, University of Toronto (U of T) researcher Dr. Yitong Dong and collaborators have made a huge leap in blue quantum dot fluorescence, results they recently published in Nature Nanotechnology.

“The idea is that if you have a blue LED, you have everything. We can always down convert the light from blue to green and red,” says Dong. “Let’s say you have green, then you cannot use this lower-energy light to make blue.”

The team’s breakthrough has led to quantum dots that produce green light at an external quantum efficiency (EQE) of 22% and blue at 12.3%. The theoretical maximum efficiency is not far off at 25%, and this is the first blue perovskite LED reported as achieving an EQE higher than 10%.

The Science

Dong has been working in the field of quantum dots for two years in Dr. Edward Sargent’s research group at the U of T. This astonishing increase in efficiency took time, an unusual production approach, and overcoming several scientific hurdles to achieve.

CLS techniques, particularly GIWAXS [grazing incidence wide-angle X-ray scattering] on the HXMA beamline [hard X-ray micro-analysis (HXMA)], allowed the researchers to verify the structures achieved in their quantum dot films. This validated their results and helped clarify what the structural changes achieve in terms of LED performance.

“The CLS was very helpful. GIWAXS is a fascinating technique,” says Dong.

The first challenge was uniformity, important to ensuring a clear blue colour and to prevent the LED from moving towards producing green light.

“We used a special synthetic approach to achieve a very uniform assembly, so every single particle has the same size and shape. The overall film is nearly perfect and maintains the blue emission conditions all the way through,” says Dong.

Next, the team needed to tackle the charge injection needed to excite the dots into luminescence. Since the crystals are not very stable, they need stabilizing molecules to act as scaffolding and support them. These are typically long molecule chains, with up to 18 carbon-non-conductive molecules at the surface, making it hard to get the energy to produce light.

“We used a special surface structure to stabilize the quantum dot. Compared to the films made with long chain molecules capped quantum dots, our film has 100 times higher conductivity, sometimes even 1000 times higher.”

This remarkable performance is a key benchmark in bringing these nanocrystal LEDs to market. However, stability remains an issue and quantum dot LEDs suffer from short lifetimes. Dong is excited about the potential for the field and adds, “I like photons, these are interesting materials, and, well, these glowing crystals are just beautiful.”

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

Bipolar-shell resurfacing for blue LEDs based on strongly confined perovskite quantum dots by Yitong Dong, Ya-Kun Wang, Fanglong Yuan, Andrew Johnston, Yuan Liu, Dongxin Ma, Min-Jae Choi, Bin Chen, Mahshid Chekini, Se-Woong Baek, Laxmi Kishore Sagar, James Fan, Yi Hou, Mingjian Wu, Seungjin Lee, Bin Sun, Sjoerd Hoogland, Rafael Quintero-Bermudez, Hinako Ebe, Petar Todorovic, Filip Dinic, Peicheng Li, Hao Ting Kung, Makhsud I. Saidaminov, Eugenia Kumacheva, Erdmann Spiecker, Liang-Sheng Liao, Oleksandr Voznyy, Zheng-Hong Lu, Edward H. Sargent. Nature Nanotechnology volume 15, pages668–674(2020) DOI: https://doi.org/10.1038/s41565-020-0714-5 Published: 06 July 2020 Issue Date: August 2020

This paper is behind a paywall.

If you search “Edward Sargent,” he’s the last author listed in the citation, here on this blog, you will find a number of postings that feature work from his laboratory at the University of Toronto.

How many nanoparticle-based drugs does it take to kill a cancer tumour? More than 1%

According to an April 27, 2016 news item on Nanowerk researchers at the University of Toronto (Canada) along with their collaborators in the US (Harvard Medical School) and Japan (University of Tokyo) have determined that less than 1% of nanoparticle-based drugs reach their intended destination (Note: A link has been removed),

Targeting cancer cells for destruction while leaving healthy cells alone — that has been the promise of the emerging field of cancer nanomedicine. But a new meta-analysis from U of T’s [University of Toronto] Institute of Biomaterials & Biomedical Engineering (IBBME) indicates that progress so far has been limited and new strategies are needed if the promise is to become reality.

“The amount of research into using engineered nanoparticles to deliver cancer drugs directly to tumours has been growing steadily over the last decade, but there are very few formulations used in patients. The question is why?” says Professor Warren Chan (IBBME, ChemE, MSE), senior author on the review paper published in Nature Reviews Materials (“Analysis of nanoparticle delivery to tumours”). “We felt it was time to look at the field more closely.”

An April 25, 2016 U of T news release, which originated the news item, details the research,

Chan and his co-authors analysed 117 published papers that recorded the delivery efficiency of various nanoparticles to tumours — that is, the percentage of injected nanoparticles that actually reach their intended target. To their surprise, they found that the median value was about 0.7 per cent of injected nanoparticles reaching their targets, and that this number has not changed for the last ten years. “If the nanoparticles do not get delivered to the tumour, they cannot work as designed for many nanomedicines,” says Chan.

Even more surprising was that altering nanoparticles themselves made little difference in the net delivery efficiency. “Researchers have tried different materials and nanoparticle sizes, different surface coatings, different shapes, but all these variations lead to no difference, or only small differences,” says Stefan Wilhelm, a post-doctoral researcher in Chan’s lab and lead author of the paper. “These results suggest that we have to think more about the biology and the mechanisms that are involved in the delivery process rather than just changing characteristics of nanoparticles themselves.”

Wilhelm points out that nanoparticles do have some advantages. Unlike chemotherapy drugs which go everywhere in the body, drugs delivered by nanoparticles accumulate more in some organs and less in others. This can be beneficial: for example, one current treatment uses nanoparticles called liposomes to encapsulate the cancer drug doxorubicin.

This encapsulation reduces the accumulation of doxorubicin in the heart, thereby reducing cardiotoxicity compared with administering the drug on its own.

Unfortunately, the majority of injected nanoparticles, including liposomes, end up in the liver, spleen and kidneys, which is logical since the job of these organs is to clear foreign substances and poisons from the blood. This suggests that in order to prevent nanoparticles from being filtered out of the blood before they reach the target tumour, researchers may have to control the interactions of those organs with nanoparticles.

It may be that there is an optimal particle surface chemistry, size, or shape required to access each type of organ or tissue.  One strategy the authors are pursuing involves engineering nanoparticles that can dynamically respond to conditions in the body by altering their surfaces or other properties, much like proteins do in nature. This may help them to avoid being filtered out by organs such as the liver, but at the same time to have the optimal properties needed to enter tumors.

More generally, the authors argue that, in order to increase nanoparticle delivery efficiency, a systematic and coordinated long-term strategy is necessary. To build a strong foundation for the field of cancer nanomedicine, researchers will need to understand a lot more about the interactions between nanoparticles and the body’s various organs than they do today. To this end, Chan’s lab has developed techniques  to visualize these interactions across whole organs using 3D optical microscopy, a study published in ACS Nano this week.

In addition to this, the team has set up an open online database, called the Cancer Nanomedicine Repository that will enable the collection and analysis of data on nanoparticle delivery efficiency from any study, no matter where it is published. The team has already uploaded the data gathered for the latest paper, but when the database goes live in June, researchers from all over the world will be able to add their data and conduct real-time analysis for their particular area of interest.

“It is a big challenge to collect and find ways to summarize data from a decade of research but this article will be immensely useful to researchers in the field,” says Professor Julie Audet (IBBME), a collaborator on the study.

Wilhelm says there is a long way to go in order to improve the clinical translation of cancer nanomedicines, but he’s optimistic about the results. “From the first publication on liposomes in 1965 to when they were first approved for use in treating cancer, it took 30 years,” he says. “In 2016, we already have a lot of data, so there’s a chance that the translation of new cancer nanomedicines for clinical use could go much faster this time. Our meta-analysis provides a ‘reality’ check of the current state of cancer nanomedicine and identifies the specific areas of research that need to be investigated to ensure that there will be a rapid clinical translation of nanomedicine developments.”

I made time to read this paper,

Analysis of nanoparticle delivery to tumours by Stefan Wilhelm, Anthony J. Tavares, Qin Dai, Seiichi Ohta, Julie Audet, Harold F. Dvorak, & Warren C. W. Chan. Nature Reviews Materials 1, Article number: 16014 (2016  doi:10.1038/natrevmats.2016.14 Published online: 26 April 2016

It appears to be open access.

The paper is pretty accessible but it does require that you have some tolerance for your own ignorance (assuming you’re not an expert in this area) and time. If you have both, you will find a good description of the various pathways scientists believe nanoparticles take to enter a tumour. In short, they’re not quite sure how nanoparticles gain entry. As well, there are discussions of other problems associated with the field such as producing enough nanoparticles for general usage.

More than an analysis, there’s also a proposed plan for future action (from Analysis of nanoparticle delivery to tumours ),

UofT_30yrCancerMedicine

Current research in using nanoparticles in vivo has focused on innovative design and demonstration of utility of these nanosystems for imaging and treating cancer. The poor clinical translation has encouraged the researchers in the field to investigate the effect of nanoparticle design (for example, size, shape and surface chemistry) on its function and behaviour in the body in the past 10 years. From a cancer-targeting perspective, we do not believe that nanoparticles will be successfully translated to human use if the current ‘research paradigm’ of nanoparticle targeting continues because the delivery efficiency is too low. We propose a long-term strategy to increase the delivery efficiency and enable nanoparticles to be translated to patient care in a cost-effective manner from the research stage. A foundation for the field will be built by obtaining a detailed view of nanoparticle–organ interaction during nanoparticle transport to the tumour, using computational strategies to organize and simulate the results and the development of new tools to assess nanoparticle delivery. In addition, we propose that these results should be collected in a central database to allow progress in the field to be monitored and correlations to be established. A 30-year strategy was proposed and seemed to be a reasonable time frame because the first liposome system was reported in 1965 (Ref. 122) and the first liposome formulation (Doxil) was approved by the US Food and Drug Administration (FDA) in 1995 (Refs 91,92). This 30-year time frame may be shortened as a research foundation has already been established but only if the community can parse the immense amount of currently published data. NP, nanoparticle.

Another paper was mentioned in the news release,

Three-Dimensional Optical Mapping of Nanoparticle Distribution in Intact Tissues by Shrey Sindhwani, Abdullah Muhammad Syed, Stefan Wilhelm, Dylan R Glancy, Yih Yang Chen, Michael Dobosz, and Warren C.W. Chan.ACS Nano, Just Accepted Manuscript Publication Date (Web): April 21, 2016 DOI: 10.1021/acsnano.6b01879

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Finally, Melanie Ward in an April 26, 2016 article for Science News Hub has another approach to describing the research. Oddly, she states this,

However, the study warns about the lack of efficiency despite major economic investments (more than one billion dollars in the US in the past decade).

She’s right; the US has spent more than $1B in the last decade. In fact, they’ve allocated over $1B every year to the National Nanotechnology Initiative (NNI) for almost two decades for a total of more than $20B. You might want to apply some caution when reading. BTW, I think that’s a wise approach for everything you read including the blog postings here.