ABSTRACT
INTRODUCTION: Hafnium alloys are employed in medical applications due to their biocompatibility and high corrosion resistance. These alloys have demonstrated osteogenic and antimicrobial activities in surgical implants and have been utilized in the treatment of sarcoma. Additionally, a sensor based on hafnium nanoparticles has been reported for the detection of coronavirus disease 2019. Despite the increasing usage of hafnium, a literature review reveals no studies examining its effects on sperm in both human and animal species. METHODS: Semen samples were analyzed according to the 2010 World Health Organization (WHO) criteria, and 20 normospermic specimens were included in the study. Three groups were formed: control, hafnium chloride 2 mg/mL, and 4 mg/mL. Motility and viability were assessed in all groups at the 20th and 40th minutes. RESULTS: The decrease in viable sperm count was found to be significant in the 2 mg/ml HfCl4 group (difference: 12.73 ± 0.8, p<0.001) and the 4 mg/ml HfCl4 group (difference: 41.72 ± 1.34, p<0.001) compared to the control group. A time-dependent decrease in sperm viability was significant across all groups (difference: 8.93 ± 0.59, p<0.001). The decrease in viable sperm count in the 4 mg/ml HfCl4 group was significant when compared to the 2 mg/ml HfCl4 group (difference: 29 ± 1.27, p<0.001). The decrease in total motile sperm count was observed in both the 2 mg/ml HfCl4 group (difference: 12.80 ± 1.30, p<0.001) and the 4 mg/ml HfCl4 group (difference: 35.63 ± 1.12, p<0.001) compared to the control group. Additionally, the decrease in total motile sperm count in the 4 mg/ml HfCl4 group was significant compared to the 2 mg/ml HfCl4 group (difference: 22.80 ± 1.60, p<0.001). A time-dependent decrease in total motile sperm count was also significant (difference: 6.03 ± 0.49, p<0.001). CONCLUSION: The study determined that hafnium chloride negatively affects sperm motility and viability in vitro. These effects may be due to the presence of an acidic environment. It has been demonstrated that instruments containing this element may pose a potential risk.
ABSTRACT
Mesenchymal stem cells (MSCs) are multipotent cells that have the ability to self-renew and regulate paracrine signalling and immune system processes. MSCs have extensive clinical applications in regeneration, functional reconstruction and cellular therapies. However, studies are needed to discover ways to improve the properties of MSCs, such as differentiation, and prevent senescence in culture, which are both very important for cell therapies. Royal jelly (RJ) is a nutritional substance produced by worker bees that contains a substantial amounts of proteins that are beneficial for cell growth and proliferation. RJ is widely used in traditional medicine today, and due to the specific components in its content, it has been reported to have antioxidant, antiproliferative, antimicrobial, neuroprotective, anti-inflammatory, immunomodulatory and anti-ageing properties. In our study, human Wharton's jelly mesenchymal stem cells (WJ-MSCs) derived from umbilical cord matrix were grown in culture medium supplemented with RJ. The control group comprised minimum essential medium (MEM) and 10% foetal bovine serum (FBS); RJ groups were formed using MEM, 10% FBS and 0.075 mg/ml or 0.150 mg/ml RJ. In our study, we evaluated the effect of RJ on WJ-MSC growth by MTT assay, proliferating cell nuclear antigen ELISA, ß-galactosidase activity assay, MitoTracker Green staining and differentiation tests in adipogenic, osteogenic and chondrogenic cell lines. It was observed that the number of mitochondria increased, senescence decreased and osteogenic differentiation increased after differentiation induction after the addition of RJ to MSC culture. In general, the results of this study indicate that WJ-MSCs enhance mitochondrial numbers and important cellular activities, such as antisenescence and osteogenic differentiation, and with increasing evidence from further studies, RJ supplementation may be found beneficial for the use of MSCs in bone engineering regenerative medicine or cell therapy.
