Bioprinting technologies, and in particular extrusion-based bioprinting, are considered promising technologies for the fabrication of complex 3D structures that mimics the physicochemical and architectural features of native tissues. Recently, multiscale porous GelMA scaffolds have been successfully used for the treatment of soft tissue injuries. These scaffolds were made from colloidal bioinks that were formed by a single-step foaming technique. These colloidal inks were easy to print and offered bioadhesion upon in situ crosslinking.  To enhance their biological effectiveness, we explored their functionalization with nanoliposomes that have emerged as one of the most promising drug delivery systems. It is widely accepted that nanoparticle inclusion in hydrogels may enhance and modify their biological, mechanical, and physical characteristics. 

In this study, we investigated the dose dependent effects of nanoliposome incorporation in the properties of the colloidal inks and the formed scaffolds. The inks were made of solutions of 10, 15, 20% (w/v) of GelMA with 0.5% photoinitiator, and 0.5% starch as surfactant and foam stabilizer. We evaluated the physico-chemical and mechanical properties related to printability. The results indicated that by adding nanoliposomes with different concentrations, the Young’s modulus increased accordingly. In addition, by enhancing the concentration of liposomes, the viscosity of bioinks increased up to 10 times higher, so that meant minimizing the difficulty of cell viability in concentrated GelMA bioinks used to improve printability