P-109 Nanoflakes of molybdenum disulfide functionalized with catechins modulate the sperm capacitation resulting in an improvement of the IVF outcomes in a swine in vitro model
Authors: Cimini C , Bernabò N , Ramal-Sanchez M , Taraschi A , Belda-Perez R , Valbonetti L , Capachietti G , Scroccarello A , Della Pelle F , Compagnone D , Barboni B 
Published: June 2022

Abstract

Study question
Are there any potential effects derived from the exposure of spermatozoa to MoS2/catechins nanoflakes during the process of capacitation?

Summary answer
The spermatozoa exposure to MoS2/catechin nanoflakes do not induce toxicity on spermatozoa and modulate sperm capacitation in a swine in vitro model.

What is known already
Molybdenum disulfide (MoS2)is a 2D graphene-like material widely used in a pletora of applications, such as energy storage, catalysts, sensors, lubricants and friction reducers. The unique features of this nanomaterial suggest interesting applications in the biomedical field. To date, there are no data regarding the potential effects of MoS2 nanoflakes on the reproductive field.

Study design, size, duration
To evaluate the potential effects derived from the interaction between the sperm cells and this material, spermatozoa were exposed to MoS2/Catechins nanoflakes at 10, 1, 0.1 ppm, using catechins as control, during capacitation. Different sperm capacitation events were studied, mainly related to their physic-chemical properties (membrane) and biochemical pathways (intracellular signaling), and then IVF experiments were performed with MoS2/catechins and catechins (0.1 ppm). Ten independent experiments were carried out between November 2020 and November 2021.

Participants/materials, setting, methods
The sonochemical exfoliation of bulk MoS2 in water-soluble MoS2 nanoflakes was obtained with a flavonoid, catechin (CT), that acts as stabilizing agent remaining anchored onto the surface of the MoS2 sheets. Sperm cells from different animals were included in this study. To evaluate the parameters exposed, different techniques were used: fluorescence microscopy, flow cytometry, western blot and in vitro fertilization assay.

Main results and the role of chance
No significant differences were found in terms of sperm membrane modifications (acrosome damage and membrane disorder) and sperm biochemical pathways (PKA activity, tyrosine phosphorylation patterns, intracellular calcium concentration and mitochondrial activity) between the groups of study compared to the control group. From the results arise that MoS2/CT nanoflakes do not induce any negative effect on the parameters evaluated related to sperm capacitation. Moreover, the addition of MoS2/CT nanoflakes and CT alone at a specific concentration (0.1 ppm) has demonstrated to increase the spermatozoa fertilizing ability in an IVF assay by increasing the number of fertilized oocytes with respect to the control group.

Limitations, reasons for caution
Despite the promising results in terms of IVF outcomes, further studies are needed to investigate the nature of the interaction between spermatozoa and the MoS2, as well as the potential effects on embryonic development.

Wider implications of the findings
Our findings open new interesting perspectives regarding the use of 2D graphene-like materials obtained using natural/bio compounds, to implement new strategies to manage sperm capacitation.

Trial registration number
not applicable