Genipin crosslinking promotes biomechanical reinforcement and pro-regenerative macrophage polarization in bioartificial tubular substitutes

• Published in: Biomedicine & pharmacotherapy Vol. 174; p. 116449
• Main Authors: Berasain, Jone, Ávila-Fernández, Paula, Cárdenas-Pérez, Rocío, Cànaves-Llabrés, Antoni Ignasi, Etayo-Escanilla, Miguel, Alaminos, Miguel, Carriel, Víctor, García-García, Óscar Darío, Chato-Astrain, Jesús, Campos, Fernando
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.05.2024; Elsevier
• Subjects: Animals; Anti-inflammatory response; Biocompatible Materials - chemistry; Biocompatible Materials - pharmacology; Biomechanical Phenomena; Biomechanical properties; Cell Survival - drug effects; Cross-Linking Reagents - chemistry; Cross-Linking Reagents - pharmacology; Fibrin - metabolism; Fibrin-agarose; Genipin; Hydrogels - chemistry; Hydrogels - pharmacology; Iridoids - pharmacology; Macrophage polarization; Macrophages - drug effects; Macrophages - metabolism; Mice; Peripheral nerve; RAW 264.7 Cells; Sepharose - chemistry; Sepharose - pharmacology; Tissue Engineering - methods; Tissue Scaffolds - chemistry; Anti-inflammatory response; Peripheral nerve; Biomechanical properties; Macrophage polarization; Fibrin-agarose; Genipin
• ISSN: 0753-3322; 1950-6007
• DOI: 10.1016/j.biopha.2024.116449

Traumatic nerve injuries are nowadays a significant clinical challenge and new substitutes with adequate biological and mechanical properties are in need. In this context, fibrin-agarose hydrogels (FA) have shown the possibility to generate tubular scaffolds with promising results for nerve repair. However, to be clinically viable, these scaffolds need to possess enhanced mechanical properties. In this line, genipin (GP) crosslinking has demonstrated to improve biomechanical properties with good biological properties compared to other crosslinkers. In this study, we evaluated the impact of different GP concentrations (0.05, 0.1 and 0.2% (m/v)) and reaction times (6, 12, 24, 72 h) on bioartificial nerve substitutes (BNS) consisting of nanostructured FA scaffolds. First, crosslinked BNS were studied histologically, ultrastructurally and biomechanically and then, its biocompatibility and immunomodulatory effects were ex vivo assessed with a macrophage cell line. Results showed that GP was able to improve the biomechanical resistance of BNS, which were dependent on both the GP treatment time and concentration without altering the structure. Moreover, biocompatibility analyses on macrophages confirmed high cell viability and a minimal reduction of their metabolic activity by WST-1. In addition, GP-crosslinked BNS effectively directed macrophage polarization from a pro-inflammatory (M1) towards a pro-regenerative (M2) phenotype, which was in line with the cytokines release profile. In conclusion, this study considers time and dose-dependent effects of GP in FA substitutes which exhibited increased biomechanical properties while reducing immunogenicity and promoting pro-regenerative macrophage shift. These tubular substitutes could be useful for nerve application or even other tissue engineering applications such as urethra. [Display omitted]