Teams from Swansea University and India found mixing tea leaf extract with cadmium sulphate (CdSO4) and sodium sulphide (Na2S) formed nanoparticles that went on to penetrate the nanopores of cancer cells.
According to lead project researcher Dr Sudhagar Pitchaimuthu, these nanoparticles, or quantum dots “confirm previous evidence that tea leaf extract can be a non-toxic alternative to making quantum dots using chemicals”.
“The real surprise, however, was that the dots actively inhibited the growth of the lung cancer cells. We hadn’t expected this.
“The cadmium sulfide quantum dots (CdS QDs) derived from tea leaf extract showed exceptional fluorescence emission in cancer cell bioimaging compared to conventional CdS nanoparticles.
“Quantum dots are therefore a very promising avenue to explore for developing new cancer treatments.”
The type of tea Camellia sinensis and its array of polyphenols, amino acids, caffeine, vitamins, minerals, and antioxidants appear not only to act as a toxic-free particle stabilising agent but also an antibacterial, haemolytic and anticancer agent.
This kind of nanoparticle holds much promise, particularly in cancer treatment nanotechnology, for example in tumour imaging, drug delivery and diagnosis and addressing cancer.
Its main advantage is its highly precise nature coupled with reduced side effects stemming from distribution of cytotoxic drugs.
Along with researchers from KSR Institute of Technology and Bharathiar University in India, the team began looking at the antibacterial activity of the CdS QDs comparing it with different types of bacteria growth.
Along with CdS QDs’ ability to inhibit this bacterial growth, the team also looked to demonstrate cytotoxicity toward A549 cancer cells when compared to a control (no QD treatment).
This cytotoxicity effect on A549 cancer cells was compared to the drug, cisplatin. Additionally, these CdS QDs produced high-contrast fluorescence images of A549 cancer cells indicating a strong interaction with the cancer cell.
To further understand the role of CdS QDs in bioimaging and cytotoxicity effect in A549 cells, fluorescence emission and flow cytometry analyses were performed.
A flow cytometry analysis confirmed that the CdS QDs was inhibiting the A549 cell growth.
“Building on this exciting discovery, the next step is to scale up our operation, hopefully with the help of other collaborators,” said Dr Pitchaimuthu.
“We want to investigate the role of tea leaf extract in cancer cell imaging, and the interface between quantum dots and the cancer cell.
“We would like to set up a “quantum dot factory” which will allow us to explore more fully the ways in which they can be used.”
Source: Applied Nano Materials
Published online ahead of print: doi/full/10.1021/acsanm.8b00147
“Green-Synthesis-Derived CdS Quantum Dots Using Tea Leaf Extract: Antimicrobial, Bioimaging, and Therapeutic Applications in Lung Cancer Cells.”
Authors: Sudhagar Pitchaimuthu et al