Intracellular Photothermal Delivery for Suspension Cells Using Sharp Nanoscale Tips in Microwells

Area of Science:

• Biomedical Engineering
• Cell Biology
• Nanotechnology

Background:

• Intracellular delivery into suspension cells is crucial for biomedical research, including cancer immunotherapy.
• Existing delivery platforms face challenges in achieving high efficiency and viability for suspension cells.

Purpose of the Study:

• To develop a high-efficiency photothermal delivery approach for intracellular delivery into suspension cells.
• To demonstrate the platform's capability for delivering various biomolecules while maintaining cell viability.

Main Methods:

• Utilized self-aligned microfabrication to create microwell arrays with nanoscale metallic sharp tips.
• Employed laser-induced cavitation bubbles for controllable membrane disruption and cargo delivery.
• Tested delivery efficiency using Calcein green, FITC-dextran, β-lactamase, and a green fluorescence protein expression plasmid in Ramos suspension B cells.

Main Results:

• Achieved >84% efficiency for 0.6 kDa Calcein green and >45% for 2000 kDa FITC-dextran.
• Maintained cell viability >96% with a throughput exceeding 100,000 cells per minute.
• Demonstrated successful delivery and retained activity of β-lactamase and high transfection efficiency (>58%) for GFP plasmid with >89% viability.

Conclusions:

• The photothermal delivery platform offers a highly efficient and viable method for intracellular delivery into suspension cells.
• This technology has significant potential for applications in cancer immunotherapy and other cell-based research.
• The platform's scalability and efficiency address key limitations of current intracellular delivery systems.