Complement activation cascade triggered by PEG-PL engineered nanomedicines and carbon nanotubes: the challenges ahead

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Immunology

Background:

• Poly(ethylene glycol)-phospholipid (PEG-PL) conjugates are widely used in nanomedicine for drug delivery.
• Idiosyncratic pseudoallergic reactions, including cardiopulmonary symptoms, have been reported with some PEG-PL nanomedicines.
• Complement activation is increasingly suspected as a factor in these hypersensitivity reactions.

Purpose of the Study:

• To investigate the molecular mechanisms underlying complement activation by PEG-PL nanomedicines.
• To explore the role of complement in hypersensitivity reactions to PEGylated nanomedicines.
• To examine complement activation by carbon nanotubes as a comparison.

Main Methods:

• Analysis of PEG-PL nanomedicine interactions with the complement system.
• Evaluation of complement activation pathways.
• Assessment of hypersensitivity responses in relevant models.
• Comparative study with carbon nanotubes.

Main Results:

• PEG-PL nanomedicines can activate the complement system, contrary to expectations.
• Complement activation appears to be a contributing factor, not the sole cause, of hypersensitivity.
• Specific molecular features of PEG-PL conjugates influence complement engagement.

Conclusions:

• The assumption that PEGylation universally suppresses complement activation is challenged.
• Understanding complement-mediated hypersensitivity is crucial for the safe design of PEG-PL nanomedicines.
• Further research is needed to elucidate the precise mechanisms and mitigate risks.