Discipline: Biological Sciences
Subcategory: Cell and Molecular Biology
Room: Exhibit Hall A
Adriana Ponton-Almodovar - Pontifical Catholic University of Puerto Rico
Co-Author(s): Luis Alamo-Nole, Pontifical Catholic University of Puerto Rico, Ponce, PR
Nanomaterials with optical properties such as Quantum Dots (QDs) have possible uses in diagnostics, photodynamic therapy or drug delivery. Living organisms can be in contact and absorb this nanomaterial which can participate in oxidation/reduction reactions inducing oxidative cell stress. Lipids, located on the plasmatic membrane, can suffer peroxidation that induces cellular apoptosis and death of living systems. A critical point to understand is how QDs enter cells and how they interact with the biological chemistry of cells. Small crystals should produce more reactive oxygen species (ROS) due to more surface area by mass. Liver human cells from hepatocellular carcinoma (HEP-G2) were cultivated in Eagle?s Minimum Essential Medium (EMEM) at 37?C and 5% CO2. HEP-G2 cells were exposed to CdSTe QDs (96-well plate) with concentrations of 0.1, 1.0, and 10.0 mg/L and incubated for 24-48 hours. Fluorescence of the QDs in the EMEM was monitored during the exposition time to corroborate integration of the QDs. Incorporation of QDs inside HEP-G2 was observed by fluorescence microscopy (changes in cell shape was also monitored). The number of viable cells was determined by the quantification of ATP production as an indicator of metabolically active cells. The oxidative stress was evaluated through the production of ROS, such as H2O2. It was observed that the viability was affected by the oxidative stress produced due to the crystal size accumulation of the QDs. ROS (H2O2) production increased when higher concentrations of QDs were added to the cells, and large crystal sizes (CdSTe 150 and 180 ?C) produced more ROS. Overall, the viability and oxidative stress response of HEP-G2 were dependent on the concentration and crystal size of the QDs. As future work, the oxidative stress of the HEP-G2 cells will be evaluated after exposition to these CdSTe QDs with light irradiation.
Funder Acknowledgement(s): Research reported in this publication was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103475.
Faculty Advisor: Dr. Luis Alamo-Nole, firstname.lastname@example.org
Role: As a Junior Research Assistant, my tasks include the cultivation of the human liver cells from hepatocellular carcinoma within a sterile environment, and perform specific assays to evaluate the viability and oxidative stress production after exposure to CdSTe QDs at different crystal sizes.