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Understanding Nanoparticles for a more Sustainable World

November 27, 2014

Pranab Das

Biology post-doctoral fellow Dr. Pranab Das

Engineered nanoparticles and their toxicity are a driving force in Dr. Pranab Das's research. Dr. Das, a Queen's SARC awarded post-doctoral fellow at the Department of Biology, explains that the issue of potential harmfulness is currently the main concern associated with engineered nanoparticles (ENPs), whose diameter is smaller than 0.0001 millimeters: "Although ENPs have beneficial uses in agricultural and biomedical applications, environmental remediation, pharmaceuticals, cosmetics, food and beverages, automotive materials, goods for children, and more, they are then released into the environment in amounts that are toxicologically relevant."

Dr. Das's interest in Biological Sciences was initiated at an early age. Growing up in Bangladesh, he followed this interest by completing a BSc and MSc in Environmental Sciences at the Institute of Marine Sciences, University of Chittagong, Bangladesh. "Albert Einstein said, 'your imagination is your preview of life's coming attractions' and this rings true for me", explains Dr. Das. "It was always my goal to study environmental sciences in Canada." Before joining Queen's, Das completed his PhD at Trent University, studying nanoparticle effects on water fleas, algae and bacteria. Dr. Das's doctoral research can be applied to indicate the potential risk of toxic effects that may occur among these aquatic organisms near the bottom of the food chain, which can help in developing policies for sustainable ecosystem management.

Pranab Das

Dr. Pranab Das studies the effect of nanosilver particles on human gut bacteria

Dr. Das brings this expertise to Queen's, while applying it to a different context. In his post-doctoral research he studies the effect of nanosilver particles on human gut bacteria. Together with his faculty advisor Prof. Virginia Walker he is using a human gut consortia model, "RePOOPulate", developed by Dr. Emma Allen-Vercoe (University of Guelph) and Dr. Elaine Petrof (Kingston General Hospital). "RePOOPulate" is a synthetic stool substitute, which was designed to treat C. difficile infections. In this instance, rather than being used as therapy, RePOOPulate is used as a model community.

"We were surprised to see a significant perturbation of this community with ENPs even at the lowest concentration (25 ppm) that I used. I think that this is the first time anyone has looked at the effect of this potential toxin on the human gut bacteria", explains Dr. Das. "It is important as there is an increasing amount of ENP exposure in our lives through different routes such as inhalation, ingestion or direct contact. My research showed that the nanosilver added to the rePOOPulate reduced metabolic activity in the synthetic stool sample, perturbed fatty acids and significantly changed the population of bacteria. In other words, it showed how significantly nanoparticles impact our 'gut ecosystem'."

These findings have now been published (Queen’s Researcher’s Pranab Das and Virginia Walker, KGH's Julie AK McDonald and Elaine Petrof, and University of Guelph’s Emma Allen-Vercoe; available online in the Journal of Nanomedicine & Nanotechnology. Dr. Das was also able to present his results at the Annual Meeting of the Society of Environmental Toxicology and Chemistry (funded in part by a PDF Travel Award from the Office of Post-Doctoral Training) at Vancouver, BC. His research was also recently featured in ‘’ news and also in ‘Queen’s Gazette’ amongst others.

He is optimistic that the impact of his research will go beyond these publications: “We hope this research will also prompt a thorough investigation of nanosilver toxicity on our overall health.”

Since arriving in 2008, Dr. Das has become well-adjusted to life in Canada. Together with his wife and two young sons, he finds support in the Kingston community as well as in Bangladeshi communities in Canada. Queen’s has also been a productive environment for Dr. Das: “My goal as a researcher is to help achieve an environmentally sustainable world. With my work at Queen’s, I am contributing to this goal, while following my career plans.” After completing his post-doctoral fellowship, Dr. Pranab Das would like to work as an academic or as a full-time environmental scientist with a government or another well-known environmental organization.