YPIE Scientist: Maryam Aamir

Research: The concentration-dependent effects of non-nutritive sweeteners on the phase transition temperature and enthalpy of DOPC-based lipid membranes using Differential Scanning Calorimetry

Mentor: Dr. SungHee Lee

Awards: WESEF 2025 - 4th place in Biochemistry; SOMERS 2024 - 1st place in Animal Sciences; Regeneron STS Participant; Participant - Envirothon 2025 & 2026

Research Location: Iona University

Abstract:

Artificial sweeteners are a widely used alternative to sucrose due to increased incidences of obesity, diabetes, and metabolic syndrome, as well as heightened consumer awareness. Yet, their safety remains controversial. The World Health Organization advised against their use, while the US Food and Drug Administration continues widespread utilization, citing limited evidence of harmful effects due to a lack of detailed cellular-level studies. In this study, several artificial sweeteners were tested on Dipalmitoylphosphatidylcholine (DOPC)-based lipid membrane models. The effects of varying concentrations (0.4mM-20mM) of sorbitol and mannitol on phase transition temperature (Tm) and enthalpy were measured using Differential Scanning Calorimetry (DSC). Enthalpy and phase transition temperature were determined using the Thermal Analysis (TA) Universal software by ascertaining the main phase and apex temperatures, phase transition, and the area under the heat capacity curve. The sucrose control exhibited stable peaks, with enthalpy decreasing slightly from 0.6058 J/g to 0.5185 J/g across concentrations, indicating minimal disruption of membrane fluidity. The Sorbitol followed a similar trend; however, a sharp decrease in enthalpy was observed at the 20 mM concentration  (0.6445 J/g), and skewed peaks were observed, indicating membrane disruption at high concentrations. Mannitol also exhibited trends similar to those of sucrose control, with minor disruptions observed at higher concentrations. Overall, these findings suggest that sorbitol and mannitol do not substantially disrupt lipid membrane structure and permeability at most concentrations, indicating that these artificial sweeteners are not as harmful at the molecular membrane level as previously speculated, supporting their safety at typical intake levels.

Presentation Slides

About this Scientist:

Maryam Aamir is a senior at Yonkers High School, currently pursuing her IB Certificate. She will attend the Sophie Davis School of Biomedical Education in the fall, where she will pursue a seven-year BS/MD degree in the Biomedical Sciences. Maryam aspires to become a pediatrician, pursuing her dream of helping children and saving lives worldwide.