Biomaterial Surface-Mediated Macrophages Exert Immunomodulatory Roles by Exosomal CCL2-Induced Membrane Integrin β1...

Area of Science:

• Biomaterials Science
• Immunology
• Regenerative Medicine

Background:

• The interplay between biomaterials and the immune system is crucial for tissue engineering.
• Macrophage (MΦ)-derived exosomes play a role in this interaction, but their modulation by biomaterial surfaces is underexplored.

Purpose of the Study:

• To investigate how different titanium implant surface topographies affect MΦ-derived exosome immunomodulatory functions.
• To identify key molecular mechanisms involved in biomaterial-immune cell interactions mediated by exosomes.

Main Methods:

• Macrophage (MΦs) were cultured on untreated, nanostructured, and type I collagen (Col-I)-decorated nanostructured titanium surfaces.
• MΦ-derived exosomes were extracted and their immunomodulatory effects on recipient cells were analyzed.
• The role of C-C motif chemokine ligand 2 (CCL2) in exosome-mediated immune suppression was investigated.

Main Results:

• Exosomes from untreated surfaces were rich in inflammatory cytokine CCL2, suppressing recipient cell functions via C-C motif chemokine receptor 2 binding.
• Nanostructured and Col-I-decorated surfaces yielded exosomes with significantly lower CCL2 levels.
• This reduction in CCL2 moderated the inhibitory effects of exosomes on recipient cells.

Conclusions:

• CCL2 is a key mediator in the interaction between biomaterial-induced exosomes and the host immune system.
• Biomaterial surface design, particularly nanostructuring and Col-I decoration, can modulate exosome content and function.
• Targeting CCL2 in exosomes presents a potential strategy for developing advanced biomaterials to enhance tissue repair and regeneration.