Small Extracellular Vesicles Engineered Using Click Chemistry to Express Chimeric Antigen Receptors Show Enhanced...

Area of Science:

• Regenerative Medicine
• Hepatology
• Nanomedicine

Background:

• Acetaminophen (APAP) overdose causes severe liver injury, potentially leading to acute liver failure (ALF).
• N-acetylcysteine (NAC) is the standard treatment but has limitations and adverse effects in ALF.
• Mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) show therapeutic promise for liver injury, but lack targeting specificity.

Purpose of the Study:

• To develop a targeted delivery system for MSC-derived EVs to enhance treatment efficacy in ALF.
• To engineer chimeric antigen receptor-modified sEVs (CAR-sEVs) for precise liver targeting via ASGR1.

Main Methods:

• Metabolic glycoengineering of MSCs with N-azidoacetyl-mannosamine (Ac4ManNAz) to produce azido-modified sEVs (N3-sEVs).
• Bioorthogonal click chemistry to conjugate N3-sEVs with a DBCO-tagged scFv targeting ASGR1, creating CAR-sEVs.
• Validation of CAR-sEV efficacy in APAP-induced ALF models.

Main Results:

• Engineered CAR-sEVs demonstrated enhanced specificity for hepatocytes by targeting ASGR1.
• CAR-sEV treatment significantly reduced serum liver enzymes and mitigated liver damage in ALF models.
• The therapy promoted hepatocyte proliferation and improved overall liver function.

Conclusions:

• MSC-derived CAR-sEVs represent an advanced cell-free therapy with enhanced targeting for ALF treatment.
• This targeted approach improves therapeutic efficacy in ameliorating APAP-induced liver injury.
• The study highlights the potential of bioorthogonal chemistry in developing precision nanomedicine for liver diseases.