An adhesive and injectable nanocomposite hydrogel of thiolated gelatin/gelatin methacrylate/Laponite® as a potential surgical sealant

Hemostatic adhesive hydrogels as sealants for surgical operations are one of the focus of the researches in the field of injectable materials. Herein, we evaluated the potential application of a mechanically robust nanocomposite hydrogel with significant adhesion strength and shorter blood clotting time. This hydrogel was composed of thiolated gelatin (Gel-SH) and gelatin methacrylate (GelMA) as the main matrix to support cell viability and proliferation, while polydopamine functionalized Laponite® (PD-LAP) were introduced to the structure to improve the mechanical properties, adhesion strength, and blood clotting. This hydrogel formed via Michael reaction between Gel-SH and GelMA, and covalent interaction between PD-LAP and hydrogel. Results revealed that presence of PD-LAP significantly controlled the swelling ratio, biodegradability, and mechanical properties of nanocomposite hydrogels. Tensile and compressive strength of nanocomposite hydrogels were measured in the range of 22–84 kPa and 54–153 kPa, respectively. Furthermore, nanocomposite hydrogels revealed excellent recovery ability, strong tissue adhesiveness and significantly less blood clotting time than Gel-SH/GelMA hydrogel (2.25 min). In the culture with L929 fibroblasts cells, viability more than 97% and high proliferation after 5 days of culture was estimated. The simplicity, low-cost, tunable mechanical properties, short blood clotting time, and cytocompatibility of the hydrogels composed of Gel-SH, GelMA, and PD-LAP highlight its potential as hemostat sealants.