Development of a Hybrid Nanoink for 3D Bioprinting of Heterogeneous Tumor Models

Abstract

Despite the rapid progress in applying three-dimensional (3D) printing in the field of tissue engineering, fabrication of heterogeneous and complex 3D tumor models remains a challenge. In this study, we report a hybrid nanoink (AGC) composed of alginate, gelatin methacryloyl (GelMA), and cellulose nanocrystal (CNC), designed for multinozzle microextrusion 3D printing of tumor models. Our results show that the ink consisting of 2 wt % alginate, 4 wt % GelMA, and 6 wt % cellulose nanocrystals (AGC246) possesses a superior shear-thinning property and little hysteresis in viscosity recovery. The fabrication of a colorectal cancer (CRC) model is demonstrated by printing a 3D topological substrate with AGC246 and then seeding/printing endothelial (EA-hy 926) and colorectal carcinoma (HCT 116) cells on top. Direct seeding of cells by dropping a cell suspension onto the 3D substrate with distinctive topological features (villi and trenches) deemed inadequate in either creating a monolayer of endothelial cells or precise positioning of cancer cell clusters, even with surface treatment to promote cell adhesion. In contrast, 3D biopinting of a CRC model using cell-laden AGC153, coupled with dual ultraviolet (UV) and ionic cross-linking, is shown to be successful. Hence, this study brings advancements in 3D bioprinting technology through innovative material and methodology designs, which could enable the fabrication of complex in vitro models for both fundamental studies of disease processes and applications in drug screening.

Progress in Gelatin as Biomaterial for Tissue Engineering

“…As this natural polymer provides a suitable environment for cell growth, inks composed of such material have been employed to design several tissue-like systems or models (tumor, skin, muscle) [112][113][114]. A noteworthy example developed a heterogeneous tumor system based on a composite ink consisting of gelatin, alginate and cellulose.…”

“…The construction demonstrated that the gelatin-based ink was suitable for printing various cell types within different shapes of the 3D system in vitro. Specifically, alginate and gelatin were responsible for biocompatibility and adhesion, respectively, while cellulose provided mechanical strength [114].…”

3D bioprinting tumor models mimic the tumor microenvironment for drug screening

“…Gelatin has also been used to produce GelMA, which is a popular bioink that enhances the mechanical capabilities of gelatin through photo-crosslinking. 50 Tang et al 51 reported a multinozzle micro-extrusion 3D bioprinting process using alginate, GelMA, and cellulose nanocrystals (CNCs) for colorectal cancer treatment models. Moreover, glioblastoma models have frequently been produced using protein-based bioinks containing gelatin, fibrinogen, and thrombin.…”

Biomimetic Microenvironmental Stiffness Boosts Stemness of Pancreatic Ductal Adenocarcinoma via Augmented Autophagy

“…Hydrogels with Different Stiffness. GelMA, as an acrylamide-modified gelatin (local hydrolysate of collagen) with excellent biological characteristics, has been widely used to resemble the microenvironment of multiple solid tumors, 32,34,35 and also acts as a mechanical interaction mimic platform as reported 36 although it may not be sufficient to accurately describe collagen biochemistry. From a processing perspective, GelMA hydrogels with tunable mechanical properties can be easily constructed by adjusting the UV exposure time and concentrations.…”