Tissue-Engineered Cartilage for Nasal Reconstruction: Mechanical Stimulation Through Bidirectional Bending

Saba Rafieian; Stephen D. Waldman; Jeffrey A. Fialkov; Cari M. Whyne
Annals of Biomedical Engineering, Volume 54, pages 381–392, Published: 24 November 2025

https://doi.org/10.1007/s10439-025-03916-7

1 citation · 1 en 2025–2026

Les titres, résumés et légendes des publications sont présentés en anglais.

Abstract

Purpose

In nasal reconstruction, cartilage struts are used to create the structural foundation of the nose. These struts, carved from autologous or allogeneic grafts of costal cartilage, are often limited by availability, warping, or resorption. This study aimed to investigate the mechanical and biochemical outcomes of applying dynamic bidirectional bending to tissue-engineered constructs, hypothesizing that such stimulation would improve matrix synthesis and mechanical properties.

Methods

Chondrocyte-seeded agarose struts were subjected to two weeks of dynamic bidirectional four-point bending at peak-to-peak strain amplitudes of 0, 2.5, 5, and 7.5%, for 1200 cycles at 1 Hz starting after a two-week pre-culture. Constructs were analyzed for DNA, proteoglycan, and collagen content, and evaluated via histology, polarized light microscopy, and four-point bending tests. Outcomes were compared to unstimulated controls, unidirectionally stimulated constructs, and native septal cartilage.

Results

Bidirectional bending at a 2.5% strain amplitude increased collagen content by 74% and bending modulus by 72% relative to controls. Under 5% strain amplitudes, proteoglycan accumulation peaked with a 51% increase. Constructs stimulated unidirectionally showed reduced matrix deposition. Histological analysis demonstrated enhanced ECM deposition with region-specific proteoglycan and collagen distribution, partially resembling zonal patterns in native cartilage, although engineered constructs remained mechanically inferior to native septal cartilage.

Conclusion

Dynamic bidirectional bending enhances the biochemical and mechanical properties of tissue-engineered constructs. Lower strain amplitudes were most effective, supporting its consideration in developing mechanically robust grafts for nasal reconstruction. Further optimization of loading protocols and culture duration is needed to bridge the gap with native tissue performance.

Keywords:

Bending properties; Bidirectional bending; Extracellular matrix synthesis; Nasal reconstruction; Strain amplitude; Tissue-engineered cartilage.

Utilisation des équipements

Des structures allongées en agarose ensemencées de chondrocytes ont subi une stimulation dynamique bidirectionnelle en flexion à quatre points, puis une évaluation en flexion à quatre points pour la reconstruction nasale. Le résumé disponible distingue la stimulation de l’évaluation mécanique, sans identifier les appareils. Il ne permet donc pas d’établir si un Mach-1 Mechanical Tester assurait la stimulation, mesurait les propriétés en flexion ou remplissait un autre rôle.