The foreign body response: emerging cell types and considerations for targeted therapeutics

Area of Science:

• Biomaterials Science
• Immunology
• Tissue Engineering

Background:

• The foreign body response (FBR) is a significant challenge in biomaterials, causing chronic immune reactions and implant isolation.
• Current understanding of FBR mediators is incomplete, necessitating exploration of diverse cellular players.
• Modulating immune responses to biomaterials is key for enhancing tissue repair and integration.

Purpose of the Study:

• To review the emerging roles of T cells, stromal-immune cell interactions, and senescent cells in the FBR.
• To highlight the need for deeper investigation into these cell types for therapeutic target identification.
• To discuss factors influencing FBR in humans, such as models, aging, microbiota, and sex differences.

Main Methods:

• Literature review focusing on recent studies of cellular mechanisms in FBR.
• Analysis of the role of specific cell types (T cells, senescent cells) and cell-cell interactions.
• Discussion of translational considerations for human FBR.

Main Results:

• Emerging evidence points to T cells, stromal-immune interactions, and senescent cells as critical, yet underappreciated, contributors to the FBR.
• These cellular components significantly influence the host's reaction to synthetic biomaterials.
• Understanding these heterogeneous responses is crucial for designing next-generation immunomodulatory materials.

Conclusions:

• A comprehensive understanding of the heterogeneous host cell response in FBR is essential for improving biomaterial performance.
• Targeting novel cellular mediators can lead to enhanced implant integration and reduced fibrous encapsulation.
• Future research should focus on these cellular players and human-specific factors to advance biomaterial design.