Assessing the Potential of Gel–SA–MgHA Composite Biomaterial Ink for 3D Bioprinting Tracheal Stents

Diseases such as injury, stenosis, and tumors of the long trachea usually require the removal of the affected part of the trachea. There is an urgent need to implant tracheal stents as substitutes in clinical practice. In this paper, Mg²⁺ was first doped into hydroxyapatite (HA) matrix by hydrothermal synthesis and then mixed with gelatin sodium alginate (Gel–SA) double network crosslinked hydrogel to prepare gelatin sodium alginate magnesium doped hydroxyapatite (Gel–SA–MgHA) composite biomaterial ink. The trachea stent was prepared by 3D bioprinting technology and its physicochemical, mechanical, and biological properties were systematically evaluated. Due to the large number of hydrophilic groups on the surface of the HA matrix, the addition of MgHA improved the hydrophilicity of tracheal stents. The mechanical properties of the stent first increase and then decrease with the increase of MgHA content. When the MgHA content is 4 wt%, the tracheal stent has the optimal mechanical properties. In vitro cytology experiments have confirmed that the four stent materials have good cell compatibility and proliferation characteristics. Overall, Gel–SA–4MgHA has the best mechanical and cytological properties, and has certain potential in the clinical application of tracheal stents.