Enhanced Fluorescence Imaging of Implants Based on Polyester Copolymers in Combination With MRI

Area of Science:

• Biomedical Engineering
• Materials Science
• Medical Imaging

Background:

• Biodegradable materials are crucial for biomedical applications, but in vivo monitoring methods are limited.
• Developing effective in vivo detection techniques for biodegradable implants is essential for assessing their degradation and integration.

Purpose of the Study:

• To develop and evaluate a multimodal imaging approach for in vivo monitoring of biodegradable polyester copolymer implants.
• To assess the efficacy of tissue optical clearing (TOC) in enhancing fluorescence imaging of implants.

Main Methods:

• Biodegradable polyester copolymers were labeled with indocyanine green (ICG).
• In vitro degradation was modeled, followed by subcutaneous implantation in BALB/c mice.
• Imaging was performed using ICG fluorescence, TOC with glycerol, and magnetic resonance imaging (MRI).

Main Results:

• Tissue optical clearing (TOC) with 70% glycerol significantly improved sample visualization.
• The TOC efficiency parameter (Q) showed variability, influenced by post-implantation healing.
• Peri-implantation inflammation and fibrosis, identified by MRI, affected TOC effectiveness (Q ranging from -30% to 70%).

Conclusions:

• ICG-labeled biodegradable implants combined with TOC and MRI offer a promising multimodal approach for in vivo monitoring.
• TOC enhances imaging but its efficacy is modulated by the host tissue's biological response.
• Understanding the interplay between implant degradation, host response, and imaging techniques is key for successful biomedical applications.