Dr. Friederike Dehli (Heidelberg, DE), Meret Kaliske (Heidelberg, DE), Isabel Potthof (Heidelberg, DE), Prof. Dr. Daniela Duarte Campos (Heidelberg, DE)
Abstract text (incl. figure legends and references)
Introduction: Corneal damage is among the leading causes of blindness1 and is currently treated by corneal transplantations. To address the associated donor shortage2, in vivo corneal tissue engineering seeks to replace the damaged tissue by fabricating an artificial cornea directly on the patient"s eye. For this purpose, we aim at developing visible light crosslinkable bioinks.
Objectives: A blue light crosslinkable system based on riboflavin and methacryloylated gelatin (Gel-MA) was studied with regards to cytotoxicity and crosslinking behavior. Furthermore, keratocytes encapsulated in the hydrogels were studied after one and three days in culture.
Materials and Methods: The influence of the co-initiator arginine on the gelation point of a 30 wt. % Gel-MA solution was examined via photorheology. The MTT assay was used to test the cytotoxicity of different riboflavin and arginine concentrations. Additionally, the encapsulation of keratocytes in 30 wt. % Gel-MA hydrogels was studied via a gel-casting process and the viability was determined via live/dead staining.
Results: Upon increasing the arginine concentration from 15 mM to 610 mM, the gelation point decreased from 4 min to 1 min 20 s. However, the metabolic activity of keratocytes continuously decreased with increasing arginine concentration. Different concentrations of riboflavin had no effect on the metabolic activity. Furthermore, keratocytes have a viability of about 90 % on Day 1 and 78 % on Day 3 after encapsulation.
Conclusion: The studied system is a good candidate for the generation of Gel-MA hydrogels via blue light. A compromise must be met on the concentration of the co-initiator to ensure a fast gelation and minimize cell toxicity. In further experiments, the printability of the system will be tested.
References:
J. M. J. Roodhooft. Bull. Soc. belge Ophtalmol. 2002, 283, 19. Gain, P.; Jullienne, R.; He, Z.; Aldossary, M.; Acquart, S.; Cognasse, F.; Thuret, G. JAMA Ophthalmol 2016, 134 (2), 167.