Decellularized ECM derived collagen bioinks

Abstract: 3D bioprinting allows for the manufacturing of tissue-like structures that could be used for culturing and studying cells in a microenvironment representative of the cell’s natural environment. In recent years, hydrogel bioinks from different biomaterials have been in development and utilized in tissue engineering applications. The most common biomaterial is collagen, the main component of the ECM, due to its high biocompatibility. However, collagen bioinks have poor mechanical properties, limiting their use for bioprinting without addition of chemical crosslinks. Efforts have been made in attempts to overcome these issues. In this project collagen hydrogels of high concentration derived from decellularized ECM of rat tail tendons were developed and examined for future use as bioink. After decellularization, the dECM was translated into pre-gels of varying concentrations and exposure to pepsin, to see how this would affect the gelation kinetics and rheological properties. The biochemical profile of the pre-gel consisted of collagen type 1 and various glycosaminoglycans. The pre-gels displayed promising rheological properties for direct printing. Regardless of concentration and pepsin exposure, the pre-gel displayed shear thinning behavior and gelation below 10 min. Increasing the concentration of the hydrogels, increased the storage modulus from 1 kPa to 10 kPA. Increasing the concentration, also affected the gelation temperature to below 37 °C. However, cells could not be cultured within the hydrogels. Further research would need to be done in order to evaluate the cell compatibility of the pre-gels and suitable printing approaches