Sperm Motility Improvement on Nano-Diamond Coated Glass Substrates

Background: The employment of Nanotechnology as a valu-able tool could be beneficial to patients and also offer new alter-natives for assisted reproductive technology (ART). Focusing on the male infertility, particularly on sperm, Nanoparticles are mostly used for sperm purification, labeling, sorting, and imag-ing. However, toxicity of these particles are questionable along with their insignificant improvement of ART outcomes. This in turn sets aside their unique properties offered at Nanoscale and underestimates their potentials. In this essence, using nanopar-ticles as surface modifiers or coatings seems promising and less addressed. Surface modification by nanoparticles leads to the alteration of surface characteristics (e.g. roughness, elasticity, and surface charge). These alterations affect sperm behavior es-pecially its motility since sperms exhibit wall following behav-ior and surface accumulation. Moreover, surface modification is an attempt towards mimicking the complex in vivo environment of the female tract (highly folded and ciliated) with continu-ally changing surface topology. Here, we modified microscopic glass substrates with Nano-Diamond (ND) particles and inves-tigated the effect of surface modification on sperm motility.Materials and Methods: ND particles with average size of 28.5 nm were coated non-homogenously on microscopic glass substrates through a heat-and-quench process. The procedure was started by preparation of Nanofluid containing ND parti-cles, followed by heating the glass substrate and finally quench-ing the substrate in the Nanofluid. The washed and dried glass substrates were incubated for 10 minutes. Afterwards 3 μl of the processed human sperm sample was applied on the substrates (witness and modified). The imaging was done by a microscope digital camera and ImageJ software was used for image pro-cessing.Results: The results show that the sperm motion is significantly improved on modified substrates compared to that of the wit-ness mainly due to the lowering of the surface roughness.Conclusion: The results suggest that the usage of these im-proved surfaces can be good means for diagnosis of deficien-cies and can further be used for sperm selection in microfluidic devices. The selection in this manner would occur due to the distinction between motility of the sperms i.e. helping the better ones to reach the collection chamber in lesser time.

Keywords:

Nanotechnology , Assisted Reproductive Techniques , Nano-Diamond , Sperm Selection , Microfluidics