Universal Microfluidic Platform for Multifunctional Surface Modification of Small Extracellular Vesicles.

Area of Science:

• Biotechnology
• Nanotechnology
• Materials Science

Background:

• Small extracellular vesicles (sEVs) are promising drug delivery vehicles due to their biocompatibility.
• Clinical translation of sEVs is hindered by donor cell source variability and poor targeting efficiency.
• Current engineering methods for sEVs are often inefficient and donor-dependent.

Purpose of the Study:

• To develop a universal surface engineering strategy for small extracellular vesicles (sEVs).
• To create a microfluidic device (ExoSE) for efficient lipid anchoring and ligand conjugation onto sEVs.
• To enhance the targeting capabilities and therapeutic potential of sEVs.

Main Methods:

• Developed the sEV Surface-Engineering (ExoSE) microfluidic device with nanofluidic and microfluidic modules.
• Utilized mechanoporation via nanochannels for efficient functionalized lipid insertion into sEV membranes.
• Employed optimized chemical reactions in a mixing module for rapid covalent attachment of targeting ligands.

Main Results:

• Achieved high lipid incorporation efficiencies (>97%) for sEVs from different sources.
• Demonstrated a 3- to 6-fold increase in ligand binding per sEV using NanoFCM analysis.
• Engineered sEVs showed enhanced in vitro transmembrane transport, glioma spheroid infiltration, and specific targeting of breast cancer cells (77.8% specificity).
• In vivo studies confirmed improved brain accumulation of engineered sEVs with no significant toxicity.

Conclusions:

• The ExoSE device provides a universal, scalable, and efficient platform for engineering sEVs.
• This strategy overcomes donor cell dependency and enhances targeting specificity for precision therapeutics.
• Engineered sEVs hold significant potential for advanced clinical applications in targeted drug delivery.