Posts Tagged ‘fertilization’

A Magnetically controlled Mechanical Propeller for Immotile Sperm

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

Researchers from the Institute for Integrative Nanosciences, IFW Dresden, Germany and Material Systems for Nanoelectronics, Chemnitz University of Technology, Germany have developed something known as the spermbot, a remotely controlled sperm movement controlling robot that could help create babies of the future. It is a magnetically powered robotic “suit” that can strap itself to individual sperm and help guide it faster towards the egg. According to the inventors all the initial tests with the spermbot have delivered promising results.

The purpose of the spermbot is to solve one of the widely talked about causes of infertility in men which is poor motility of sperm. Low sperm motility, or otherwise healthy sperm that just can’t swim, can be a big factor in infertility. While the development of the spermbot is in its early stages, this is already being talked about as a promising alternative to existing popular techniques that are expensive and come with a high failure rate. These include methods like in-vitro fertilization and artificial insemination. Only 30 percent of the traditional “spray-and-pray” approach ends up with success, which warranted the need for an alternative procedure like the spermbot. According to the report, initial experiments show a marked increase in the probability of the spermbot-assisted sperm to reach its intended destination. The process of fertilization can be completed inside the body or in the lab, inside a petri-dish.

The spermbot is a coat of microscopic metal polymers shaped into a helix. It can attach itself to the tail of the spermatozoid, and then, using a hybrid micromotor, it can help propel the sperm faster towards the egg. The direction the sperm needs to take is controlled using a rotating magnetic field. In fact, even the motion of the sperm can be remote-controlled by simply adjusting this magnetic field. Once the spermbot propels the sperm towards the egg and the sperm manages to implant itself into the egg, the bionic part of the spermbot detaches itself from the tail.

While the initial experiments look promising, there is still some way to go before the spermbot technique is regularly used. To start off, scientists have very few sample size to correctly evaluate the results, and unless more comprehensive tests are carried out, it would not be possible to start using them on human subjects. Another major stumbling block is that there is currently no way to film the spermbot in action while it is moving inside the body. This also means that doctors would not be able to correctly direct it towards the egg. Another concern is the response of the body’s own immune system to the spermbot. The use of the spermbot could trigger a reaction from the body’s immune system, the results of which cannot be predicted without comprehensive clinical trials. The idea of the spermbot looks promising right now, but it is still too early to call it a replacement to the tried and tested methods like in-vitro fertilization and artificial insemination. In fact, it would take a few years for the procedure to be made available to patients if clinical trials are successfully completed.







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Reporter and Curator: Dr. Sudipta Saha, Ph.D.


With the progress in IVF, the contribution of the Fallopian tube towards successful reproduction has been comparatively overlooked. It is clear from the success of IVF, which of course bypasses tubal transport that exposure to the tubal milieu is not an absolute requisite for fertilization or implantation to occur. Thus, the Fallopian tube is often now thought of as little more than a mere conduit. However, in fertilization in vivo, the Fallopian tube plays an essential role in gamete transport, fertilization and the early development of the embryo. It is becoming increasingly evident that the mechanism of tubal transport is much more complex than first thought and can be affected by a wide range of factors and conditions that may impair fertility. The Fallopian tube plays an essential role in tubal transport of both gametes and embryos and in early embryogenesis. The tube undergoes cyclical changes in morphology and ciliary activity in response to ovarian hormones. Whilst the varying contributions to tubal transport of ciliary activity, muscle contractions and secretory activity remain undetermined, there is emerging evidence that muscle contractions may play a role in mixing of secretions rather than in propulsion of gametes and embryos. Ciliary activity is more vigorous in the secretory phase of the menstrual cycle. Many pathological conditions associated with infertility and ectopic pregnancy have been shown either to destroy cilia or to reduce ciliary motion or both. Gonococcal infection produces both destruction of the ciliated cells and reduced ciliary activity, whereas chlamydia also destroys the tubal mucosa. Although the micro-organism itself does not appear to alter ciliary beat, the inflammation and oedema associated with chlamydial salpingitis has been shown to reduce CBF (ciliary beat frequency). Peritoneal fluid from women with mild-and-moderate endometriosis reduces CBF significantly in vitro. An ‘ovum capture inhibitor’ has been described in the peritoneal fluid of women with endometriosis, which covers the fimbrial cilia resulting in a complete but reversible loss of ovum capture ability. The ‘immotile cilia syndrome’ is known to be associated with subfertility. Deciliation is found in Fallopian tubes of women with a past history of ectopic gestation. These women are at increased risk of future tubal pregnancies. This evidence suggests an important role for the tubal cilia in the mechanism of gamete and embryo transport. Further research needs to be undertaken to investigate the functioning of the cilia in vivo. Only one study has measured physiological CBF in vivo, and this needs to be extended to the effect of pathological states on CBF. Direct examination of the effect of conditions such as endometriosis or pelvic inflammatory disease on ovum transport may be possible in animal models using laparoscopy to investigate ovum pick-up and falloposcopy to study ovum transit along the tube. It is only as we begin to understand more about the complex interactions of the effectors of tubal transport that we approach the possibility of being able to improve tubal transport in women afflicted with tubal infertility.


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