Tiny islands set sperm spinning


Protein islands trap individual sperm cells for motility analysis

A platform for simultaneously screening thousands of sperm cells could lead to more efficient identification of high performing sperm for fertility treatments.

Assisted reproductive technologies have revolutionised the fertility world, however, sperm must be carefully picked on the basis of specific characteristics, including motility, to increase the chance of a successful pregnancy. However, more than half of the sperm selected for intra-cytoplasmic sperm injection (ICSI) using current procedures are damaged.

Discussions with fertility experts who kept finding the same issues with sperm quality inspired Loes Segerink and her team at the University of Twente, in the Netherlands, to search for a solution.

They used micro-contact printing to produce adhesive islands, ranging from 5 to 50µm in size, that can trap sperm and provide a platform for motility analysis. The islands, made of the protein fibronectin, are patterned onto polystyrene surfaces using polydimethylsiloxane stamps, and kept apart by sperm repellent pluronic acid F-127. Optimal adhesion of single cells was found for islands with a 10µm diameter.

After adhesion sperm demonstrated a spinning behaviour. Recognition software measured the rotational movements of individual captured sperm to identify premium specimens – the fastest spinners equalling the most motile.

The most motile sperm can be identified by their protein island coordinates and then recovered for ICSI

Segerink hopes the work will result in a ‘better understanding of male fertility’ as sperm can be recovered for further morphology and DNA integrity analysis. This also means that the best quality sperm could be chosen and retrieved for fertilisation procedures.

Shuichi Takayama, a biomedical engineer at the University of Michigan, US, says this is a clever way to trap and keep track of a single sperm while at the same time allowing sufficient freedom to allow evaluation of motility. However, he also questions the scalability of the technique as the study ‘deals with relatively small numbers of sperm’.

References

This paper is free to access until 1st April 2014. Download it here:

J P Frimat et al, Lab Chip, 2014, DOI: 10.1039/c4lc00050a


Related Content

Raman hope for childless couples

20 January 2009 News Archive

news image

Non-invasive IVF test checks sperm for healthy DNA

The birth of the pill

27 August 2010 Premium contentFeature

news image

Fifty years after its birth, John Mann reports on the conception and evolution of the contraceptive pill

Most Read

Bubble wrap could send lab costs packing

23 July 2014 Research

news image

Potential bubbles up across wide range of uses as storage and test vessels, especially for poor countries

Coffee cup confusion

20 July 2014 Research

news image

Scientists call for better labelling after research highlights inconsistencies in the chemical composition of a cup of coffee

Most Commented

Bubble wrap could send lab costs packing

23 July 2014 Research

news image

Potential bubbles up across wide range of uses as storage and test vessels, especially for poor countries

Relativity behind mercury's liquidity

21 June 2013 Research

news image

First evidence that relativistic effects are indeed responsible for mercury's low melting point