Direct E-jet printing of three-dimensional fibrous scaffold for tendon tissue engineering.

Tissue engineering (TE) offers a promising strategy to restore diseased tendon tissue. However, a suitable scaffold for tendon TE has not been achieved with current fabrication techniques. Herein, we report the development of a novel electrohydrodynamic jet printing (E-jetting) for engineering 3D tendon scaffold with high porosity and orientated micrometer-size fibers. The E-jetted scaffold comprised tubular multilayered micrometer-size fibrous bundles, with interconnected spacing and geometric anisotropy along the longitudinal direction of the scaffold. Fiber diameter, stacking pattern, and interfiber distance have been observed to affect the structural stability of the scaffold, of which the enhanced mechanical strength can be obtained for scaffolds with thick fibers as the supporting layer. Human tenocytes showed a significant increase in cellular metabolism on the E-jetted scaffolds as compared to that on conventional electrospun scaffolds (2.7-, 2.8-, and 3.1-fold increase for 150, 300, and 600 µm interfiber distance, respectively; p < 0.05). Furthermore, the scaffolds provided structural support for human tenocytes to align with controlled orientation along the longitudinal direction of the scaffold, and promoted the expression of collagen type I. For the first time, E-jetting has been explored as a novel scaffolding approach for tendon TE, and offers a 3D fibrous scaffold to promote organized tissue reconstruction for potential tendon healing.