Quantifying DNA-mediated liposome fusion kinetics with a fluidic trap

Area of Science:

• Biomimetic nanotechnology
• Synthetic biology
• Nanofluidics

Background:

• Liposomes, synthetic lipid vesicles formed via membrane fusion, are crucial for biosensing, drug delivery, and studying biological membrane fusion.
• Current bulk methods for liposome fusion lack precise control and characterization.

Purpose of the Study:

• To demonstrate and characterize DNA-induced liposome fusion in a nanofluidic trap.
• To investigate the kinetics and parameters of liposome fusion in a confined environment.

Main Methods:

• Utilizing a nanofluidic trap for controlled liposome fusion in a 15 femtoliter volume.
• Employing DNA as an inducer for homogeneous mixing and controlled fusion.
• Characterizing liposome size and charge before and after fusion using the nanofluidic chip.

Main Results:

• Demonstrated DNA-induced liposome fusion within the nanofluidic trap.
• Established that the fusion reaction follows second-order kinetics.
• Quantified the fusion rate as (170 ± 30)/(M⁻¹s⁻¹) times the square number of DNA molecules per liposome.
• Achieved full characterization of liposome size and charge post-fusion.

Conclusions:

• Nanofluidic trapping enables precise, controlled liposome fusion with homogeneous mixing.
• The chip-based approach allows for reduced sample volume (down to 440 vesicles) and parallelization for systematic studies.
• This method advances synthetic biology, diagnostics, and drug delivery applications through controlled liposome self-assembly.