Evaluation of biopolymers blend hydrogel as a “biopaper” for cell and organ printing application: an in vitro study

Recent advances in tissue engineering strategies have led to the development of the concept of tissue or organ printing- a biomedical application of rapid prototyping technology that offers an interesting alternative to traditional solid scaffold-based tissue engineering. Biopaper is a bioprocessible biomimetic hydrogels that specially designed for the bioprinting process. In the present work, four different weight percentage ratios (100:0, 75:25, 50:50, 25:75) of agarosegelatin blend hydrogels have been studied for the construction of biopaper for bioprinting application. Prepared hydrogels were characterized in terms of gel point temperature, mechanical stability, morphological observation, glucose diffusion and in vitro degradation. Tissue fusion study was performed on Chinas Hamster Ovary cell aggregates embedded into the hydrogel. Based on obtained results, sol-gel transition point for samples with quite the same proportion of two components was in the physiological condition range (35-37°C). By adding gelatin content of hydrogels young’s modulus decreased about 4.5 times; furthermore, less denser network with larger pores were resulted that provided glucose diffusion into hydrogels. Amount of degradation linearly decreased by enhancing agarose part of samples. Evaluation of tissue fusion process on sample of 50:50 demonstrated relative permissivity of blend hydrogel with time scale of τcc = 60 h. Considering the result of this study, agarose-gelatin blend hydrogel with the same proportion of two components is capable to utilizing as a biopaper for bioprinting technology.