Bend, flow, build: the broad world of nanotech and 3D printing

21 November 2016

As a rheologist, Dr Anson Ma has spent years studying the microstructure and flow behaviour of matter, and he finds the most pleasure in seeing his work culminate in something that benefits people.

From cancer therapy to personalised medicine, enhanced oil recovery to flexible smartphones, each groundbreaking new technology has either been fully realised or is currently in the pipeline. Technological advancements in nanotechnology and 3D printing, in particular, have had arguably the most profound impact on human lives in the recent years.

“I like seeing how technology and scientific knowledge make an impact on peoples’ lives. And I get the most satisfaction from practical applications of our fundamental research,” he said.

Ma is a principal investigator at the Complex Fluids Laboratory of the University of Connecticut and is involved in several nanotechnology and 3D printing projects with a wide range of applications.

Targeted drug delivery

In a bid to manufacture newer, more improved drugs, the pharmaceutical industry long ago embraced the medicinal use of nanoparticles for treating genetic and terminal illnesses. However, current medication for cancer treatment is very potent and can damage healthy tissues and cause discomfort for the patient.

Still under development, scientists have come up with the use of nanoparticles to deliver drugs to cancer cells. By taking advantage of the “enhanced permeability and retention” effect, according to which once released into the bloodstream, nanoparticles tend to accumulate primarily in tumour because of leaky vascular structures typically found near the tumour sites, this method delivers potentially harmful drugs right to the tumour, reducing the damage done to healthy tissue.

Ma’s project sponsored by the National Science Foundation in the U.S. is on understanding the flow behaviour of drug-carrying particles released into blood streams.

“If we use nanoparticles as a drug carrier, where do they go once they enter the bloodstream and how do they behave before they get a chance to approach the cancer sites? This is the underlying question we aim to answer through our research,” said Ma. “Of particular interest is whether there’s a certain particle size and shape that would be best for delivering cancer drugs more specifically to the tumour sites.” Their findings were recently published in Biophysical Journal.

He added: “Next we’d like to study how the complex geometry, such as constriction and bifurcation, of blood vessels will affect where the particles go once they enter the bloodstream. The key lies in understanding how particles of different sizes and shapes interact with blood components as well as the blood vessel wall.”

Biomedical applications of 3D printing

Ma has also been collaborating with his colleague from the Pharmaceutical Sciences Department in using 3D printing to make drug tablets. 3D printing offers excellent manufacturing flexibility and enables the greater market responsiveness that many pharmaceutical companies are seeking. There are also a number of intrinsic advantages of 3D printing drugs.

“I see my father take his medication every day. If we look at the composition of the drugs he’s taking, most of them aren’t active ingredients but excipients, which just make up the volume,” explained Ma.

“If we can print drugs, we could potentially have personalised medicine on demand,” added Ma. “We could go to a pharmacist and print a single tablet containing all the drugs we need. This way, we don’t need to take so many tablets at once, and the drug dosage can also be adjusted as needed.”

Additionally, 3D printing allows for spatial control of the drug composition within the tablet, which will further open up the possibility of controlling the drug release profile for optimal drug efficacy.

“Further, biomaterials can be used in 3D printing to create human and animal culture models. These models can be used for studying disease progression and drug screening. This will reduce the use of real human or animal subjects and accelerate drug and product development cycle,” added Ma. He is collaborating with medical experts at the UConn Health Centre to create disease models to understand cancer progression, for example.

Similarly, cosmetic and personal care giants like L’Oreal wish to test their products on 3D printed skin, amid concerns from wildlife and nature activists against the use of animals in the cosmetic industry.

Nanoparticles for enhanced oil recovery

One of the biggest global challenges in the 21st century is the increasing demand of energy consumption even while natural resources remain limited. It is vital to enhance oil recovery by improving the yield of oil wells.

Traditionally, water flooding is used to stimulate production in an oil field. But crude oil is much more viscous than water. So water is not going to be very effective in displacing the oil from the ground.

Imagine washing dirty plates in the kitchen. Water alone won’t be able to displace oil completely. We add detergents, which are surfactants to help displace oil from the plates. It is exactly the same idea, except instead of using detergent we use nanoparticles.

“Nanoparticles may be used as a more stable surfactant to aid enhanced oil recovery,” said Ma “But particles need to be of appropriate size, shape, and wettability to mobilise the oil effectively. Costs, abundance, and environmental friendliness are also important factors to consider.”

With the support of the National Science Foundation, Ma, and his team has been studying how the size and shape of particles influence their ability in acting as a surfactant. The findings may also impact the development of more stable agricultural, pharmaceutical, and personal care products that are emulsion-based.

Flexible electronics

“There’s a big push from the U.S. government in manufacturing innovation. They are interested in technologies that can be used for both military and civilian purposes. And that’s where flexible electronics come in,” said Ma, who currently serves on the Technical Council of America’s flexible hybrid electronic manufacturing innovation institute with over US$171 million investments from the federal government, state agencies, and private industry. “Currently, two major application platforms, namely human and structural health monitoring, are of interest.”

Human health and performance monitoring includes technologies like smart clothing, associated with sporting giants like Adidas and Under Armour. Similarly, Generic Electric has been working on a smart bandage that can collect sweat for human health monitoring.

“We can also imagine making different types of flexible sensors and embed them in automotive and aerospace structures” added Ma. “For example, we can include flexible sensors in the wings of a plane, so they can collect different information and sense if the structure is healthy.”

Opportunities

The world of nanotechnology is broad and the opportunities infinite. Apple has recently been awarded a patent it filed for future bendable, foldable iPhones using advanced carbon nanotube structures. This suggests of more similar consumer products further down the line.

“If you think of what could happen with nanotechnology in 10 years time or further, there is a possibility of metamaterials,” said Ma. Also a faculty member in both the Polymer and the Chemical Engineering Programs at the University of Connecticut, Ma best describes metamaterial by comparing it with the invisibility cloak in Harry Potter, a material with unusual property causing a negative refractive index.

A Russian physicist Victor Veselago in 1967 was the first to theoretically describe negative-index material and proved that they could transmit light. But the question remains whether or not they can manipulate light with a wide range of wavelengths. If the material can manipulate visible light, there is a potential of optical metamaterials, with properties that allows one to hide things in plain sight. The same technology may also enable computers running on light instead of electrons, leading to computers that are much faster and more efficient.

It doesn’t stop there. Researchers in the field have already envisioned and demonstrated mechanical metamaterials capable of mitigating vibrations while harvesting energy from them.

“For 3D printing, being able to create a fully functioning organ using a patient’s own cells would save thousands of people on organ transplantation lists and it is a possibility with the technological leaps we’re taking today,” said Ma.

He added: “These ideas definitely sound crazy but 20 years ago a mobile phone as a powerful computing device that fits in your pocket wasn’t imaginable. But working in this field isn’t easy either, it takes a lot of energy and patience.”

With widespread applications of nanoparticles such as sunscreens and antimicrobial garments, we definitely also need to address the safety and environmental impact of nanoparticles, which remain an active area of research.

Challenges

Despite the immense potential of nanotechnology and 3D printing, securing consistent research funding remains a challenge. The U.S., the leading country both in terms of advancement and investment in advanced technology just elected its new president.

“If our world leaders do not appreciate the value of research and only thinks of short-term results without investing for the longer-term future, then many great and potentially game-changing technology will not materialise and the betterment of science and technology will be slowed down tremendously,” said Ma.

It is important to realise that it may take decades before a technology is commercialised, said Ma. And this is exactly why it’s vital to have consistent, sustainable and reliable funding sources.

Another challenge is the human factor. Many talented students would rather go for a stable job than pursuing research after graduation. It is essential to foster the next generation and engage them in science and technology.

“As a member of the faculty I get to interact with many bright students and I have been trying very hard to recruit them so that we have people to lead the next wave,” said Ma “Continuity is the key to technological advancement. So it’s crucial we attract good people to participate in research.”

And finally, scientists have a responsibility to make people understand the significance of science and technology.

Says Ma: “We should be able to engage the general public and the government, make them realise the value of what we do in the simplest way and explain why it is absolutely necessary to invest in education, technology, research, and the future.”

Dr Anson Ma obtained both his B.Eng. in Chemical and Environmental Engineering and M.Phil. in Chemical Engineering from the Hong Kong University of Science and Technology in 2003 and 2005 respectively. He pursued his PhD in Chemical Engineering from the University of Cambridge with Croucher scholarship and U.K. government’s Overseas Research Students Awards Scheme (ORSAS) Scholarship. In 2009 he was named J Evans Attwell-Welch Postdoctoral Fellow at Rice University. He later joined the University of Connecticut in 2011 as a faculty member and since then has received a number of faculty awards, including the Distinguished Young Rheologist Award by TA Instruments in 2012, National Science Foundation CAREER award in 2013, 2015 Arthur B. Metzner Early Career Award by the Society of Rheology, and 3M non-tenured Faculty Award in 2016. Ma received a Croucher Scholarship in 2005.

To view Ma’s personal Croucher profile, please click here.