Spermatozoa for IVF and ICSI: how to choose the best?
Tiny islands – shelters for sperm
ChemPort.Ru based on Chemistry World: Tiny islands set sperm spinningA platform for simultaneous screening of thousands of sperm cells may prove to be an effective tool for identifying the most suitable material for artificial insemination.
Assisted reproductive technologies have become a revolution in perinatal therapy [in 2010, the Nobel Prize in Medicine and Physiology was awarded to Robert Edwards for the development of in vitro fertilization (IVF) technology]. However, to increase the chance of successful conception with the help of IVF and ICSI (intracytoplasmic sperm injection) procedures, careful selection of the seed is necessary, which is carried out on the basis of a number of characteristics, one of which, for example, is sperm motility. Unfortunately, the existing methods lead to damage to about half of the spermatozoa selected for the ICSI procedure.
Protein islets capture individual spermatozoa to determine their motility
(here and below are University of Twente drawings)
Communication with fertility experts and discussion of the shortcomings of existing methods of sperm quality analysis motivated researchers from the Loes Segerink group from the University of Twente (the Netherlands) to find a suitable solution to the problem.
Using the micro-contact printing method, the researchers obtained adhesive islands, the sizes of which varied from 5 to 50 micrometers, capable of capturing spermatozoa and serving as a platform for determining mobility. The islands made of fibronectin protein were fixed on a polystyrene substrate using polydimethylsiloxane, they were separated using the sperm repellent pluronic acid F-127. It was found that optimal adhesion of individual seed cells was observed for islands with a diameter of 10 microns.
After adhesion, the researchers studied the ability of spermatozoa anchored on protein islands to rotate using special analysis methods, respectively, the spermatozoa that showed the most active rotational movement and are the most mobile.
The spermatozoa with the greatest mobility can be determined by the coordinates of the islet,
to which they have stuck, after which the seed material can be selected for the ICSI procedure.
Segerink hopes that the results of her work can also be useful for a better understanding of male fertility, since with the help of a new method, sperm cells can be selected for further analysis of their morphology and the state of genetic material. All this means that with the help of protein islands, the most promising material can be selected for artificial insemination.
Shuichi Takayama, a biomedical technology specialist from the University of Michigan, notes that the method developed by Dutch scientists is a successful solution to the problem of tracking an individual sperm, while giving it sufficient freedom to determine its mobility. However, Takayama has a question about the possibility of scaling the new technology – in the article Frimat et al. Make it Spin: Individual Trapping of Sperm for Analysis and Recovery Using Micro-Contact Printing, published in the journal Lab on a Chip, describes experiments with a relatively small number of sperm.
Portal "Eternal youth" http://vechnayamolodost.ru24.02.2014