November 30, 2022
Gold nanoparticles have been the subject of scientific research for many years, particularly for their application in cancer treatment. Faculty and students in the departments of biology and chemistry joined together to take a novel approach to their own research when they created the multiuse nanoparticles out of natural sources such as lemongrass and green tea to test their effectiveness against cervical and melanoma cancer cells.
“Gold nanoparticles are traditionally synthesized using commercially available chemical compounds,” said Pavithra Vivekanand, associate professor of biology. “The advantage of using natural sources is that they are more environmentally friendly and hopefully less toxic to all cells. What we found in the course of our research is that the gold nanoparticles synthesized from green sources were more potent against the cancer cells than chemically synthesized nanoparticles.”
To create the gold nanoparticles, biology major Brooke Weaver ’22 boiled lemongrass to create an extract. The extract was then combined with gold chloride to form the “green” nanoparticle. Creating the extract wasn’t as easy as it sounds.
“It took my predecessor and me many trials using different store brands of lemongrass as well as trying different procedures to make sure the extract was as pure as possible,” Weaver said. “If the glassware wasn’t properly cleaned or the extract wasn’t filtered, often the nanoparticles will discolor.”
Swarna Basu, professor of chemistry, Weaver exposed cervical and melanoma cancer cells to the green-sourced nanoparticles and traditional nanoparticles for 48 hours, after which Weaver found that the green synthesized nanoparticles were “much more potent in killing the cancer cells,” she said.After mastering this process under the direction of
The next step was to determine “how” the cells were dying — because there is a good way and a bad way to die, Vivekanand explained. Their research determined that the cancer cells were dying by apoptosis, an orderly process of cell death and the one hoped for by Vivekanand. The reverse is known as necrosis, in which the dying cell’s contents spill out and cause inflammation.
“Many of the chemicals and additives used in the traditional synthesis of gold nanoparticles can be toxic to humans. This is why it is important to find ways to create these nanoparticles using natural components,” Vivekanand said. “That our research has found these natural compounds to be even more potent against cancer cells than traditional methods is very exciting and underscores the importance of pursuing basic research to get insights that may be used to develop novel cancer treatments.”
Weaver is looking forward to contributing her data to the existing scientific body of knowledge.
“Much of the available research surrounding these green nanoparticles focuses on characterizing their size, shape and light absorption. There are very few studies that examine the possible cytotoxic effects these nanoparticles present to various cancer cell lines,” Weaver said. “I’m very excited to publish my own findings to the scientific community that corroborates the existing studies.”
Using Honey To Suppress Inflammation
Elsewhere in the lab, biomedical sciences major John Duncan ’23 conducted similar research to determine if gold nanoparticles synthesized from honey were effective in changing how immune cells respond to inflammation.
“It has been determined that varieties of gold nanoparticles inhibit the proinflammatory response of macrophages, which fight bacteria, that can be triggered by bacterial lipopolysaccharide, which is a structural component of a bacterial cell,” Duncan said. “Since honey has known anti-inflammatory and antioxidant properties, we wanted to used honey-synthesized gold nanoparticles to test their effects on LPS-activated macrophages.”
In addition to testing commercially produced honey purchased at a local grocery store, Duncan also used honey gathered from Susquehanna’s own beehives at the Center for Environmental Education and Research — dark honey collected in the fall and light honey collected in the spring.
Preliminary results suggest that honey-synthesized gold nanoparticles inhibit a cell’s inflammatory response.
“Interestingly, the response appears to be specific to interleukin-6, a protein that helps to regulate immune response,” Duncan said. “Our preliminary findings are very encouraging. Given that high levels of proinflammatory proteins are associated with numerous chronic inflammatory diseases, finding a relatively novel way to suppress these proteins may have therapeutic implications.”
After graduating from Susquehanna in December, Weaver plans to attend dental school in the future. Duncan is in the process of applying to doctoral programs in the biomedical sciences and integrated life sciences.