Preservation of exosomes at room temperature using lyophilization

Area of Science:

• Biotechnology
• Nanomedicine
• Cell Biology

Background:

• Exosomes hold significant therapeutic potential but require stable preservation methods for practical application.
• Current storage at -80°C limits exosome handling and transportation.
• Room temperature preservation is desirable for broader exosome utilization.

Purpose of the Study:

• To develop and evaluate a room temperature exosome preservation method using lyophilization.
• To compare lyophilized exosome properties with those stored at -80°C.
• To assess the impact of lyophilization on exosome integrity, pharmacokinetics, and functional activity.

Main Methods:

• Exosomes were lyophilized with and without trehalose (cryoprotectant).
• PAGE analysis was used to assess protein and RNA integrity.
• Pharmacokinetics of Gaussia luciferase (gLuc)-labeled exosomes were evaluated in mice.
• Activity of loaded gLuc and CpG DNA in lyophilized exosomes was measured.

Main Results:

• Lyophilization without trehalose caused exosome aggregation; trehalose prevented this.
• Proteins and RNA within exosomes were protected by lyophilization with trehalose.
• Lyophilization minimally affected exosome pharmacokinetics after intravenous injection.
• Lyophilized exosomes retained gLuc and CpG DNA activity for 4 weeks at 25°C.

Conclusions:

• Lyophilization in the presence of trehalose is an effective method for room temperature exosome storage.
• This technique preserves exosome integrity and function, expanding their therapeutic and delivery applications.
• Trehalose-assisted lyophilization offers a practical alternative to ultra-low temperature storage for exosomes.