A self-reconfiguring metamorphic nanoinjector for injection into mouse zygotes

Area of Science:

• Biotechnology
• Microelectromechanical Systems (MEMS)
• Developmental Biology

Background:

• Efficient DNA delivery into zygotes is crucial for genetic manipulation in developmental biology.
• Existing methods may cause cell membrane damage, impacting embryo viability.
• Microscale devices offer potential for precise and minimally invasive cellular procedures.

Purpose of the Study:

• To present a novel surface-micromachined microelectromechanical system (MEMS) nanoinjector for DNA delivery into mouse zygotes.
• To design a nanoinjector capable of penetrating zygotes without tearing cell membranes and maintaining electrical connectivity.
• To evaluate the nanoinjector's performance using embryo viability as a key metric.

Main Methods:

• A surface-micromachined MEMS nanoinjector featuring a two-phase, self-reconfiguring metamorphic mechanism was developed.
• The mechanism includes a change-point six-bar mechanism for elevation and a compliant folded-beam suspension for in-plane translation.
• DNA delivery was achieved using an electrically charged, DNA-coated lance inserted into mouse zygotes (≈90 μm diameter).

Main Results:

• The nanoinjector successfully penetrated mouse zygotes, maintaining electrical connectivity.
• Embryo viability studies involving nearly 3000 nanoinjections showed 71.9% of treated zygotes progressed to the two-cell stage.
• This viability rate is comparable to the 79.6% observed in untreated embryos, indicating minimal membrane damage.

Conclusions:

• The developed MEMS nanoinjector effectively delivers DNA into mouse zygotes with high embryo viability.
• The self-reconfiguring metamorphic mechanism ensures precise penetration and preserves cell membrane integrity.
• This technology holds promise for advancing genetic manipulation techniques in reproductive biology and stem cell research.