Table 6 Summary of laser-assisted immobilization of sperm for intracytoplasmic sperm injection
From: Applications of laser technology in the manipulation of human spermatozoa
Study | Source of sperm | Strategy for immobilization of sperm | Target regions for immobilization | Intensity of laser | Duration of exposure | No. oocytes fertilized/Total MII oocytes) | No. good-quality embryos/Total MII oocytes | No. pregnancies | No. live births | Main findings | References |
|---|---|---|---|---|---|---|---|---|---|---|---|
Montag et al. (2000) | Fresh ejaculated sperm | Single or double laser shot | The middle region of the sperm tail | 0.25Â mJ, 0.5Â mJ, 1.0Â mJ, 2.0Â mJ, 2.5Â mJ, 3.0Â mJ | NA | NA | NA | NA | NA | Laser can be used for immobilization and membrane permeabilization of the sperm tail. | [102] |
Ebner et al. (2001) | Fresh ejaculated sperm | Double laser shot | The middle and end regions of the sperm tail | 1.5Â mJ, 1.0Â mJ | 15 ms, 10 ms | 174/262 (66.4%) | 58/262 (22.1%) | NA | NA | There were no significant differences in rates of fertilization, early cleavage, or blastocyst formation between laser-assisted immobilization and mechanical immobilization groups. | [100] |
Eroglu et al. 2002 | Fresh ejaculated sperm | NA | The middle region of the sperm tail | NA | NA | 13/78 (17%) | NA | NA | NA | Laser-assisted immobilization of sperm may be useful in ICSI procedures. | [101] |
Ebner et al. (2002) | Fresh ejaculated sperm | Double laser shot irradiations | The middle and end regions of the sperm tail | 1.5Â mJ, 1.0Â mJ | 15 ms, 10 ms | 3/4 (75%) | NA | 1 | 1 | Successful birth was achieved after transfer of embryos derived from laser-immobilized sperm. | [99] |
Debrock et al. (2003) | Fresh ejaculated sperm | Double laser shot | Aside of the middle of the sperm tail followed by a second shot directly to the middle of the sperm tail | NA | NA | 89/179 (49.7%) | NA | 3/10 (30%) | 2/10 (20%) | No difference was observed in fertilization rate, cleavage, or blastocyst formation when oocytes were injected with sperm immobilized with laser compared to sperm immobilized with mechanical method. | [98] |
Li et al. (2004) | Fresh sperm from testicular biopsies | Single laser shot | Behind the middle section of the sperm tail | NA | 1 ms | 68/95 (71.6%) | 51/95 (53.7%) | NA | NA | There were no significant differences in rates of fertilization, cleavage, and good-quality embryos between laser immobilization and mechanical immobilization groups. | [104] |
Xu et al. (2007) | Fresh ejaculated sperm | Single laser shot | Behind the middle section of the sperm tail | NA | 0.45 ms | NA | NA | NA | NA | Laser-assisted sperm immobilization did not cause direct damage to the sperm DNA. | [103] |
Chan et al. (2017) | Fresh ejaculated sperm | NA | Head and midpiece region; principal piece Region; end piece region | NA | NA | NA | NA | NA | NA | Laser-assisted immobilization did not result in any external membrane damages besides morphological changes at SEM level. | [97] |