In Vivo Evaluation of Biointegration and Resorption of Polypropylene and Vicryl-Based Tissue-Engineered Meshes via MRI and ICG Fluorescence Imaging
Astemir R. Likhov1, Natalia V. Rassomakhina1, Veronika N. Volodina1, Mikhail Krasnov1, Ulyana A. Apukhtina1, Tatiana I. Yaremenko1, Ilya V. Turchin2, Victoria V. Zherdeva1; 1Federal Research Centre of Biotechnology of the Russian Academy of Sciences, Moscow, Russia; 2Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russia
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 dual-labeled copolymer and seeded with murine myoblasts (C2C12) or fibroblasts (A9), alongside polymer-only and cell-only control groups. TECs were implanted subcutaneously in BALB/c mice. Longitudinal non-invasive monitoring of matrix resorption, tissue ingrowth, and fibrosis was performed over 28 days using indocyanine green (ICG) fluorescence imaging and 1T MRI.
ICG fluorescence imaging revealed distinct degradation profiles: Vicryl-based matrices exhibited rapid clearance, with >90% signal reduction by Day 10 and near-complete resorption by Day 20–28. In contrast, polypropylene matrices showed prolonged retention, with detectable signal persisting at Day 28. Control groups demonstrated intermediate clearance for polymer-only constructs and cell-type-specific ICG kinetics for cell-only groups (e.g., transient ICG retention by A9 fibroblasts at Day 20). While mesh composition dictated bulk resorption rates, 1T 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 significantly reduced fibrous capsule thickness by Day 28. Notably, ICG clearance kinetics in Vicryl groups outpaced physical mass loss, 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, achieving complete resorption and minimizing fibrotic complications within 28 days. Furthermore, combined ICG and MRI monitoring provides a robust, non-invasive platform for tracking real-time matrix degradation and tissue remodeling, enabling the optimization of 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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