Application of Electrospun Fibers in Modulating Foreign Body Response

Background Introduction

In the field of biomedicine, the use of implantable medical devices (such as subcutaneous implants) is becoming increasingly widespread. However, these devices often trigger an immune response in the host after implantation, known as the Foreign Body Response (FBR). FBR is a complex immune reaction that typically results in the encapsulation of the implant by fibrous tissue, thereby affecting its functionality. To improve the long-term performance of implantable medical devices, researchers have been exploring methods to modulate FBR. In recent years, electrospun fibers have been recognized as a potential solution due to their high porosity and biomimetic properties. Electrospun fibers can mimic the natural extracellular matrix (ECM), promote tissue regeneration, and reduce fibrotic reactions.

This article aims to explore the application of electrospun fibers in modulating FBR, providing a detailed analysis of how parameters such as fiber diameter, polymer selection, and fiber orientation influence FBR. It also proposes strategies for further optimizing electrospun fibers through surface modifications.

Source of the Paper

This article was authored by Taron M. Bradshaw and Mark H. Schoenfisch, both from the Department of Chemistry at the University of North Carolina at Chapel Hill. The paper was published in 2025 in the journal ACS Biomaterials Science & Engineering, titled Properties of Electrospun Fibers That Influence Foreign Body Response Modulation.

Main Content of the Paper

1. Fabrication of Electrospun Fibers and Their Impact on FBR

Electrospun fibers are formed by dissolving natural or synthetic polymers in a solvent and extruding the solution through a metallic capillary under an applied electric field. Electrospun fibers exhibit high porosity and a high surface area-to-volume ratio, enabling them to mimic the natural ECM and provide an environment for cell attachment, proliferation, and differentiation. Studies have shown that the porous surface of electrospun fibers can promote tissue regeneration and reduce fibrotic reactions, thereby improving the biocompatibility of implants.

Influence of Fiber Diameter

Fiber diameter is one of the critical factors influencing FBR. Research indicates that fiber diameter directly affects cell infiltration and nutrient diffusion. Smaller fiber diameters (e.g., 300 nm) can promote cell proliferation and angiogenesis, while larger fiber diameters (e.g., 2.61 μm) can promote the differentiation of macrophages into an anti-inflammatory phenotype. However, different studies have reached conflicting conclusions regarding the ideal fiber diameter, suggesting that the choice of fiber diameter should be tailored to specific applications.

Polymer Selection and Composition

Electrospun fibers can be made from synthetic polymers (e.g., polycaprolactone, PCL) or natural polymers (e.g., chitosan). Synthetic polymers generally offer better mechanical properties, while natural polymers exhibit superior biocompatibility. By combining two or more polymers, the advantages of each can be integrated. For example, combining polylactic-co-glycolic acid (PLGA) with PCL can improve the mechanical properties and biocompatibility of the fibers.

Influence of Fiber Orientation

Fiber orientation is another important factor influencing FBR. Studies suggest that fiber orientation should match the structure of the natural ECM. For instance, randomly oriented fibers can promote random cell growth, while aligned fibers can promote directional cell growth. Additionally, fiber scaffolds with grid or lattice structures can combine the benefits of random and aligned orientations, facilitating cell migration and growth.

2. Surface Modifications for FBR Modulation

In addition to the intrinsic properties of the fibers, surface modifications of electrospun fibers can further modulate FBR. By conjugating biomolecules (e.g., growth factors, ECM components) to electrospun fibers, the duration of FBR modulation can be extended. For example, combining macrophage vesicles with electrospun fibers can drive the inflammatory response in a specific direction, reducing collagen deposition. Furthermore, incorporating transforming growth factor-β3 (TGF-β3) into electrospun fibers can promote chondrogenic differentiation and improve tendon-bone construct repair.

3. Future Perspectives

Although electrospun fibers show great potential in modulating FBR, many issues require further investigation. For instance, the optimal combination of fiber diameter, polymer selection, and fiber orientation needs to be tailored to specific applications. Additionally, strategies for surface modifications of electrospun fibers need further exploration, particularly the incorporation of drug molecules or other therapeutic agents to improve local tissue inflammatory responses.

Significance and Value of the Paper

This article systematically summarizes the application of electrospun fibers in modulating FBR, providing a detailed analysis of how parameters such as fiber diameter, polymer selection, and fiber orientation influence FBR. It also proposes strategies for further optimizing electrospun fibers through surface modifications. These studies provide important theoretical foundations for the development of novel biomaterials, offering significant scientific value and application prospects.

Highlights

1. Regulation of Fiber Diameter: The article thoroughly discusses the influence of fiber diameter on FBR and proposes strategies for selecting fiber diameters based on specific applications.
2. Polymer Selection and Composition: By combining synthetic and natural polymers, the article demonstrates how to integrate their respective advantages to improve the mechanical properties and biocompatibility of fibers.
3. Influence of Fiber Orientation: The article proposes that fiber orientation should match the structure of the natural ECM, providing new insights for designing biomimetic scaffolds.
4. Surface Modification Strategies: The article explores strategies for further modulating FBR through surface modifications, offering new directions for the development of novel biomaterials.

Conclusion

By systematically analyzing the application of electrospun fibers in modulating FBR, this article highlights their immense potential in the biomedical field. Future research should focus on further optimizing fiber fabrication parameters and surface modification strategies to achieve more effective FBR modulation and broader applications.