Tendon injuries heal poorly because tendon tissue has limited intrinsic regenerative capacity, and engineers have long sought scaffolds that can both hold mechanical load and guide cells toward a tendon-like identity.
Researchers fabricated electrospun nanofibrous scaffolds from polyurethane (PU) and methacrylated alginate (ALMA), incorporating decellularized tendon extracellular matrix (dECM). Aligned nanofibers were assembled into two architectures: stacked, non-braided scaffolds and braided scaffolds. Both were designed to support human umbilical cord-derived mesenchymal stem cells (hUC-MSCs).
Mechanical testing showed clear trade-offs between the two designs. Braided scaffolds reached a higher ultimate tensile load of 33.31 newtons and an elongation at failure of 180.75 percent, while non-braided scaffolds achieved a higher ultimate tensile stress of 0.801 megapascals and allowed better cell infiltration into the fiber structure.
Cell compatibility was assessed with MTT assays, which confirmed that hUC-MSCs remained viable on all scaffold variants. Proliferation was slightly higher on scaffolds containing ALMA, suggesting the methacrylated alginate component supports cell growth on the fiber surfaces.
Degradation behavior differed sharply between architectures. Over 30 days in phosphate-buffered saline, braided scaffolds lost 17.58 percent of their weight compared with 42.11 percent for non-braided scaffolds. In collagenase type 1 solution, which mimics enzymatic breakdown, braided scaffolds lost 18.75 percent while non-braided scaffolds lost 68 percent, indicating that braiding substantially slows degradation.
To test the scaffolds in a living system, the team implanted them into 1-centimeter Achilles tendon defects in rabbits. Tendon regeneration was evaluated histologically 12 weeks after surgery, providing a direct comparison of how the two architectures performed in a repair setting.
The histological results favored the braided design when cells were included. The braided, cell-seeded group showed superior tendon regeneration, with well-aligned collagen fibers and dense extracellular matrix deposition, features associated with more organized, tendon-like tissue formation.
The authors conclude that scaffold macroarchitecture critically influences tendon regeneration. Braided PU/ALMA scaffolds incorporating dECM and hUC-MSCs provided enhanced mechanical support, controlled degradation, and superior tissue integration in this rabbit model, which the team presents as a promising strategy for tendon tissue engineering.
As with any preclinical animal study, the findings require further validation before any human application, but the work highlights how a simple change in fiber assembly, from stacked layers to a braided structure, can reshape both mechanics and biological outcomes in regenerative scaffolds.
Subject of Research: Braided versus non-braided electrospun PU/ALMA scaffolds with tendon dECM and umbilical cord stem cells for Achilles tendon repair in rabbits
Article Title: Braided electrospun PU/ALMA scaffolds incorporating decellularized tendon ECM and umbilical cord stem cells for tendon tissue engineering in a rabbit model
Article References: Rajabi, A., Golshan, M., Pourentezari, M., Koohpeyma, F., Hosseinpour-soleimani, F., Karimi, M. H., & Alizadeh, A. (2026). Braided electrospun PU/ALMA scaffolds incorporating decellularized tendon ECM and umbilical cord stem cells for tendon tissue engineering in a rabbit model. BioMedical Engineering OnLine. https://doi.org/10.1186/s12938-026-01620-8
Image Credits: AI Generated
DOI: 10.1186/s12938-026-01620-8
Keywords: tendon tissue engineering, electrospun scaffolds, polyurethane, methacrylated alginate, decellularized extracellular matrix, mesenchymal stem cells, umbilical cord, braided scaffolds, Achilles tendon, rabbit model, degradation, histology
News Source: Gregory Coleman. (October 28, 2026). Braided scaffolds seeded with stem cells heal tendon defects in rabbits. Scienmag.
