High therapeutic efficacy of 5-Fluorouracil-loaded exosomes against colon cancer cells.

The successful chemotherapeutic regime required for the clinical management of different cancers largely depends on the efficient drug delivery within the cancer cells. Exosomes have emerged as an enticing candidate for exploring their role as delivery vehicles. Exosomes are reported to be intrinsically nanosized vesicles competent for efficient delivery across the cellular membrane. In the present study, we assessed the feasibility of an autologous exosome-based drug delivery platform for delivering 5-Fluorouracil (5-FU) against human colon cancer HCT116 cells. Autologous exosomes have shown probable tropism toward the tumor microenvironment, which makes them the most competitive vehicle for drug delivery. It was observed that the autologous exosomes loaded with 5-FU showed an enhanced rate of drug release under acidic conditions. The result of the cell viability assay showed that treatment of 5-FU-loaded exosomes (equivalent to 5 µg 5-FU) resulted in enhanced cytotoxic effect in HCT116 cells as compared to an equivalent amount of free 5-FU (5 µg), which elucidated the efficient delivery of the 5-FU by exosomes inside the cancer cells. Subsequently, 5-FU-loaded exosomes led to increased nuclear condensation and fragmentation along with increased ROS production. In addition, 5-FU-loaded exosomes caused enhanced dissipation of mitochondrial membrane potential and caspase-3 activation, resulting in increased apoptosis induction. Our study also revealed that 5-FU-loaded exosomes upsurged the arrest in the cell cycle at the G0/G1 stage in HCT-116 cells and it was found to be associated with decreased CDK4 and Cyclin D1 expression concomitantly with the upregulation of CDK inhibitor, p21Cip1 expression. Thus, the findings from the present study highlight the advantages of autologous exosomes as a natural drug carrier which could efficiently deliver chemotherapeutic drugs to cancer cells.

Gender Differences in Smoking Attitude among Saudi Medical Students.

BACKGROUND: Smoking is a growing public health problem throughout the world. However, the attitude of males and females toward smoking may differ. Therefore, this study examines gender differences in smoking behavior and attitude among Saudi medical students. METHODS: From January 2020 to August 2020, a snowball cross-sectional online survey was conducted in five major regions of Saudi Arabia. Medical students (18 years or older) were invited to respond to the questionnaire. RESULTS: Out of the 421 respondents, 255 (60.6%) were female, 243 (57.7%) were between 18 and-24-year-old, and 164 (39%) were from the Eastern Province. The overall prevalence of smoking was 25.4% and was higher among males than females [(44% and 13.3%, respectively), P < 0.001]. However, there was no significant difference in the mean score of the overall attitude towards smoking between males and females [(3.02±0.44 and 3.00±0.34), respectively, P=0.64]. However, more female students believed e-cigarettes were harmful to health than male students [(4.19±1.04 and 4.45±0.9), respectively, P=0.002]. CONCLUSION: The study showed that male students smoke more than female students, and there were no significant differences in the overall attitudes score towards smoking. Therefore, campaigns are needed to decrease smoking rate, especially among male students.