TY - JOUR

T1 - Femtosecond laser-induced fusion of nonadherent cells and two-cell porcine embryos

AU - Kuetemeyer, Kai

AU - Lucas-Hahn, Andrea

AU - Petersen, Bjoern

AU - Niemann, Heiner

AU - Heisterkamp, Alexander

N1 - Funding information: We thank Maren Ziegler, Erika Lemme, and Petra Hassel for their outstanding support in the lab. This work was supported by funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) within the Cluster of Excellence “REBIRTH” (from Regenerative Biology to Reconstructive Therapy).

PY - 2011/8/1

Y1 - 2011/8/1

N2 - Cell fusion is a fundamental biological process that can be artificially induced by different methods. Although femtosecond (fs) lasers have been successfully employed for cell fusion over the past few years, the underlying mechanisms are still unknown. In our experimental study, we investigated the correlation between fs laser-induced cell fusion and membrane perforation, and the influence of laser parameters on the fusion efficiency of nonadherent HL-60 cells. We found that shorter exposure times resulted in higher fusion efficiencies with a maximum of 21% at 10 ms and 100 mJ/cm 2 (190 mW). Successful cell fusion was indicated by the formation of a long-lasting vapor bubble in the irradiated area with an average diameter much larger than in cell perforation experiments. With this knowledge, we demonstrated, for the first time, the fusion of very large parthenogenetic two-cell porcine embryos with high efficiencies of 55 at 20 ms and 360 mJ/cm 2 (670 mW). Long-term viability of fused embryos was proven by successful development up to the blastocyst stage in 70% of cases with no significant difference to controls. In contrast to previous studies, our results indicate that fs laser-induced cell fusion occurs when the membrane pore size exceeds a critical value, preventing immediate membrane resealing.

AB - Cell fusion is a fundamental biological process that can be artificially induced by different methods. Although femtosecond (fs) lasers have been successfully employed for cell fusion over the past few years, the underlying mechanisms are still unknown. In our experimental study, we investigated the correlation between fs laser-induced cell fusion and membrane perforation, and the influence of laser parameters on the fusion efficiency of nonadherent HL-60 cells. We found that shorter exposure times resulted in higher fusion efficiencies with a maximum of 21% at 10 ms and 100 mJ/cm 2 (190 mW). Successful cell fusion was indicated by the formation of a long-lasting vapor bubble in the irradiated area with an average diameter much larger than in cell perforation experiments. With this knowledge, we demonstrated, for the first time, the fusion of very large parthenogenetic two-cell porcine embryos with high efficiencies of 55 at 20 ms and 360 mJ/cm 2 (670 mW). Long-term viability of fused embryos was proven by successful development up to the blastocyst stage in 70% of cases with no significant difference to controls. In contrast to previous studies, our results indicate that fs laser-induced cell fusion occurs when the membrane pore size exceeds a critical value, preventing immediate membrane resealing.

KW - cell fusion

KW - cell surgery

KW - femtosecond laser

KW - membrane perforation

KW - parthenogenetic embryo

KW - somatic cell nuclear transfer

KW - vapor bubble

UR - http://www.scopus.com/inward/record.url?scp=79961058461&partnerID=8YFLogxK

U2 - 10.1117/1.3609818

DO - 10.1117/1.3609818

M3 - Article

C2 - 21895341

AN - SCOPUS:79961058461

VL - 16

JO - Journal of biomedical optics

JF - Journal of biomedical optics

SN - 1083-3668

IS - 8

M1 - 088001

ER -