3D bioprinted scaffolds based on functionalized gelatin for soft tissue engineering

3D bioprinting application in the medical field requires optimized and adapted bioinks/biomaterials, along with processing as scaffolds with morphology and structure that mimic human tissues. Various polymeric hydrogels have been tested in bioinks elaboration in order to support the cells biology. In this context, the paper presents the preparation of versatile bioadhesive hydrogels based on methacrylated gelatin, moderate crosslinked with poly (ethylene glycol) diacrylate, and 3D bioprinted as bioadhesive scaffolds for skin tissue engineering. Gelatin with various methacrylation degrees, confirmed by FTIR and H1NMR and analytical methods (TNBS, nynhydrin assay), mixed with poly (ethylene glycol) diacrylate and biocompatible photoinitiator led to stable gels, with rheological characteristics (yield stress and shear-thinning behavior) beneficial for bioprinting. Scaffolds with controllable shape and morphology have been obtained by bioprinting and polymers UV crosslinking. The 3D scaffolds absorb fluids and their biostability increases in presence of poly (ethylene glycol) diacrylate. Cell cultures of fibroblasts/ keratinocytes demonstrated the scaffolds cytocompatibility. The cells preserved the normal morphology, were adherent to substrate and formed uniform monolayers. The bioadhesion characteristics increased by adding poly (ethylene glycol) diacrylate as macromolecular crosslinker. The scaffolds absorb the blood plasma, promote the local accumulation of fibrinogen, and accelerate the adhesion of the blood components, with impact on angiogenesis, suitability characteristic for skin tissue engineering applications.