Can a cumulus cell complex be used to select spermatozoa for assisted reproduction?

Abstract

Since the onset of intracytoplasmic sperm injection, researchers have intensified the search for the ideal spermatozoa to be used for injection. The aim of this study was to record the functional role of cumulus cell interaction with human spermatozoa as far as capacitation, acrosome reaction, morphology, zona binding and chromatin packaging quality are concerned. Using a previously described cumulus oophorus model, we recorded specific sperm functional aspects of sperm populations that transverse a cumulus cells mass. Control spermatozoa were kept under similar experimental conditions in the culture media only. Results indicated cumulus cells to be beneficial to spermatozoa as far as functional and capacitational events are concerned. The mean percentage of morphologically normal spermatozoa in the control sample was 6.9%, while the spermatozoa that traversed the cumulus oophorus (test) had a significantly higher percentage of normal forms (mean 9.5%; P < or = 0.01). We observed a decline in the percentage of CMA3-positive spermatozoa when we compared the control population (49.1%) to the test, i.e. 38.4%, (P = <0.05), thus implying that the spermatozoa with good chromatin condensation increased during cumulus penetration. Significantly more (P < or = 0.01) acrosome-reacted spermatozoa were found in the penetrated spermatozoa (mean 23%) than in the control spermatozoa (mean 11%). The test spermatozoa had a higher zona binding capacity with significantly more (P < or = 0.01) tightly bound spermatozoa on the hemizona (61 +/- 15) than the control spermatozoa (47 +/- 18). In the absence of sophisticated and expensive sperm selection products, the use of a cumulus model to select spermatozoa for intracellular sperm injection seems to be an alternative method.

Sperm selection before intracytoplasmic sperm injection

“…A capillary-cumulus model was established to study the role of the cumulus in the selection of sperm for fertilization and penetrating sperm had a higher morphology, capacitation, acrosome reaction, progressive motility, linearity, ZP binding ability (70), and protamination (71). This data was confirmed in a later study and it was suggested that the capillary-cumulus model could be used to select sperm for ICSI (72).…”

A novel sorting technology allows for highly efficient selection of sperm without chromatin damage

“…Although our work has focused on sperm DNA damage it is quite possible that other yet poorly understood biological properties of sperm may be as critical in selecting optimal sperm. Existing means of evaluating sperm in a non-consumptive manner include the utilization of cumulus cells and zonae pellucida of immature oocytes to improve selection of optimal sperm [Black et al 2010;Franken and Bastiaan 2009;Paes Almeida Ferreira de Braga et al 2009]. Other studies have considered the use of Raman microspectrometry; however, the technique has not been thoroughly evaluated in assessing if it improves IVF outcomes [Huser et al 2009].…”

Sperm preparation: state-of-the-art—physiological aspects and application of advanced sperm preparation methods

“…Among the cheaper methods is the utilization of cumulus cells in a Pasteur pipette 165 or zonae pellucidae of immature oocytes [162][163][164] as there are no differences in normal sperm morphology and DNA integrity of zona-bound sperm between mature and immature oocytes. 89 Franken and Bastiaan 165 showed that the percentages of cells with normal morphology, good quality chromatin condensation and tightly zona-bound spermatozoa were significantly higher in the cumulus-penetrated fraction of spermatozoa and speculate that this might be a possible means for the selection of functional spermatozoa for ART. However, for both approaches, the availability of cumuli and zonae pellucidae might be a problem, which would limit the applicability of the methods.…”