Development of printable nanoengineered composite hydrogels based on human amniotic membrane for wound healing application

Recently, decellularized amniotic membranes (dAM) have attracted significant interest as a valuable source for the development of shear-thinning hydrogels and bioinks. However, the inferior rheological behavior and weak mechanical durability restrict the printability of the hydrogels and their stability after threedimensional (3D) bioprinting. Therefore, a chemical or physical modification with biocompatible components is necessary to improve dAM-derived hydrogels' properties. The present study proposes a strategy to fabricate printable dAM-derived hydrogels (DAMHs) supplemented with sodium alginate and Laponite nanoplatelets. Rheological experiments determined the key role of Laponite nanoplatelets in tailoring the shear-thinning behavior of the DAMHs. The dynamic mechanical modulus of the hydrogel was significantly enhanced (up to 16 folds, for example, storage modulus increased from * 0.5 to 8.4 kPa by adding 1% Laponite), which facilitated 3D printing of free-standing constructs without compromising biological properties. Meanwhile, excess agglomeration of the nanoplatelets in an ion-containing medium leading to nozzle clogging was observed at high Laponite concentrations ( >= 2%). Microstructural evaluations also revealed nanoplatelet-induced changes in the pore structures of the hydrogel, i.e., a finer pore structure was obtained. In vitro biological assays affirmed the biocompatibility of the nanoengineered hydrogels, while wound healing experiments revealed the positive effect of Laponite on fibroblast cell migration, as evidenced by * 30% enhancement in the wound healing rate after 36 h. Generally, the results obtained in this study demonstrate that the developed nanoengineered hydrogel provides suitable structural integrity and biocompatibility, highlighting its potential for therapeutic applications, particularly tissue engineering. [GRAPHICS] .

Automated summary

Recently, decellularized amniotic membranes (dAM) have been modified with sodium alginate and Laponite nanoplatelets to improve their rheological behavior and mechanical durability for 3D bioprinting. The addition of Laponite significantly enhanced the shear-thinning behavior and dynamic mechanical modulus of the hydrogel, enabling the printing of free-standing constructs without compromising biological properties. However, excessive agglomeration of the nanoplatelets at high concentrations was observed, leading to nozzle clogging. Overall, the nanoengineered hydrogel showed suitable structural integrity and biocompatibility, highlighting its potential for tissue engineering applications.