Non-specific adsorption of complement proteins affects complement activation pathways of gold nanomaterials

Area of Science:

• Immunology
• Nanomedicine
• Biomaterials

Background:

• The complement system is crucial for innate immunity and defense against foreign materials.
• Gold nanomaterials (AuNMs) are extensively used in nanomedicine, but their immunological effects require further investigation.

Purpose of the Study:

• To investigate the immunological response of different gold nanomaterial (AuNM) shapes on the complement system.
• To understand the role of complement activation in the cellular uptake of AuNMs.

Main Methods:

• Utilized spherical gold nanoparticles, gold nanostars, and gold nanorods.
• Assessed complement system activation and the formation of the SC5b-9 complex.
• Examined interactions between complement recognition molecules and AuNMs in vitro.
• Investigated the cellular uptake of AuNMs by U937 cells.

Main Results:

• All tested AuNMs activated all three complement pathways, leading to SC5b-9 complex formation.
• Complement recognition molecules interacted with AuNMs, with correlations observed in classical and alternative pathways.
• Complement activation mediated the cellular uptake of AuNMs by U937 cells expressing complement receptors.

Conclusions:

• Gold nanomaterials elicit a significant complement system response.
• Complement activation influences the interaction and uptake of AuNMs by cells.
• These findings highlight potential immunological challenges for the clinical translation of AuNMs.