Towards a Whole Sample Imaging Approach Using Diffusion Tensor Imaging to Examine the Foreign Body Response to...

Area of Science:

• Biomaterials Science
• Medical Imaging
• Tissue Engineering

Background:

• Analyzing fibrous capsules from the Foreign Body Response (FBR) is crucial for medical device biocompatibility.
• Traditional histological methods with random sampling may miss 3D spatial distributions in large animal studies.
• Non-destructive imaging is needed for high-resolution analysis of capsules around human-sized implants.

Purpose of the Study:

• To demonstrate diffusion tensor imaging (DTI) as a non-destructive method for high-resolution imaging of fibrous capsules.
• To analyze the microstructural organization of fibrous capsules surrounding two different macroencapsulation devices in a porcine model.
• To validate DTI findings against established histological and imaging techniques.

Main Methods:

• Diffusion Tensor Imaging (DTI) was used for non-destructive, high-resolution 3D imaging of fibrous capsules.
• Analysis was performed on capsules surrounding macroencapsulation devices implanted in a porcine model for 21 days.
• DTI results were validated using histological analysis, micro computed tomography (microCT), and scanning electron microscopy (SEM).

Main Results:

• DTI successfully visualized the 3D microstructural organization of fibrous capsules.
• DTI distinguished microstructural differences between capsules surrounding devices with varying materials and surface topographies.
• DTI-derived metrics provided insights into capsule organization, corroborated by microCT, SEM, and histology.

Conclusions:

• DTI is a powerful non-destructive tool for characterizing fibrous capsule microarchitecture.
• This method overcomes limitations of traditional techniques in large animal pre-clinical studies.
• Non-invasive characterization using DTI can accelerate the clinical translation of novel implantable devices.