In Vivo Evaluation of Biointegration and Resorption of Polypropylene and Vicryl-Based Tissue-Engineered Meshes via MRI and ICG Fluorescence Imaging

Abstract

The development of tissue-engineered urethral grafts requires optimal biodegradable matrices to prevent stenosis and chronic inflammation. This study evaluated the in vivo biointegration and degradation of tissue-engineered constructs (TECs) based on polypropylene and Vicryl meshes, coated with a copolymer and seeded with murine myoblasts (C2C12) or fibroblasts (A9). TECs were implanted subcutaneously in Balb/c mice. Longitudinal non-invasive monitoring of matrix resorption, tissue ingrowth, and fibrosis was performed over 50–60 days using indocyanine green (ICG) fluorescence imaging and 1T MRI.
By day 14, Vicryl-based matrices exhibited significantly accelerated degradation, showing a 65% reduction in ICG fluorescence compared to a 25% decrease in polypropylene groups. While cellular components did not alter the overall resorption rate, MRI revealed crucial differences in biointegration. Polypropylene meshes induced pronounced fibrous encapsulation. In contrast, cell-seeded Vicryl constructs (particularly with A9 fibroblasts) demonstrated active cellular ingrowth, rapid replacement by granulation tissue, and a significant reduction in fibrous capsule thickness by day 28. Notably, ICG clearance kinetics correlated with the degree of tissue remodeling, reflecting macrophage-mediated dye clearance in active regeneration zones.
In conclusion, Vicryl-based resorbable matrices combined with fibroblasts offer superior regenerative potential for urethral grafts by minimizing fibrotic complications. Furthermore, combined ICG and MRI monitoring provides a robust, non-invasive platform for predicting implant behavior and optimizing TEC compositions for clinical translation.

Speaker

Astemir Likhov
Federal Research Centre of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
Russia

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