For decades, households have sprayed or wiped down surfaces to kill bacteria – but Colombian scientist Sandra Arias is investigating smart materials that use nothing more than their microscopic, spiky texture to kill bacteria.
Scientists had previously noticed that cicada and dragonfly wings featured surface that on the microscopic scale were able to naturally rupture bacterial cells.
Arias developed a spiky surface of her own using bacterial cellulose hydrogels, which are commonly employed in biomedical settings like wound dressing and artificial skin: spikes millionths of a meter long were shown to rupture gram-positive bacteria (the family that contains the deadly Staphylococcus aureus) , but not mammalian cells like those found in humans.
“My results demonstrated a simple, scalable, and sustainable strategy to confer bactericidal properties to hydrogels by only altering its texture and without the use of antimicrobials,” she said.
Arias says she sees these hydrogels as stepping stone to use similar structures invisible to the naked eye to develop materials that can kill bacteria in a similar way.
“My work on cellulose demonstrates a simple and economical way to confer bactericidal activity to material by altering its surface texture at the nanoscale,” she said, “I think a similar strategy can be applied to textiles, food packaging, and a variety of other materials of industrial and clinical significance that require bactericidal properties.”
From Coffee To Cells
Arias, who is now a Postdoctoral associate at Cornell University, doesn’t come from a long line of scientists, in fact, she was the first of her family to go to university.
“I grew up on a small coffee farm in Aguadas, Colombia, where my family still cultivates coffee,” she said, “As a child, I always portrayed myself as a scientist, wearing a white lab coat and working in a laboratory.
Arias says she is was fortunate that her parents were “relentless models of work ethic and excellence” and that she owes most of her professional advancement to mentors who were willing to support and invest in her at different stages of her career.
“Notably, as an undergraduate at the University of Antioquia, I had the opportunity to work on transnational research projects that contributed to my academic record and my desire to pursue a Phd,” she said.
During 2020, while working on a project that has the potential to save lives, Arias has faced personal tragedy.
“The Covid-19 pandemic has affected me profoundly at a personal level,” she said, “My parents, siblings, and I were reuniting for my Ph.D. graduation in May at the University of Illinois, after saving and anticipating this trip for several years.”
But not only was the trip called off, her father fell ill and passed away in June of 2020.
” I couldn’t travel to Colombia to see him for the last time,” she said, adding that the United States visa restriction changes for international students announced at different points of the years were an additional source of stress and uncertainty.
Arias is far from the only Colombian who is making strides in technology at the cellular level. Marlene Jimenez and Carlos Velez at the University of Antioquia in Medellin, Colombia, developed a technique to turn stem cells found in umbilical cord tissue into cholinergic neurons — a type of brain cell — in just days.
The husband an wife team then used these cells to observe Alzheimer’s precursor molecules in cells taken from newborns – a boon for research into the earliest stages of a disease that doesn’t start to show symptoms until people are in their forties.