(194ah) Optimized Process to Produce Gelatin Methacryloyl (GelMA)

Víctor Hugo Sánchez Rodríguez^1,2*, Sara Cristina Pedroza González¹*, Jesús Valencia Gallegos¹, Mario Moisés Álvarez¹, Grissel Trujillo de Santiago^1,2

¹ Centro de Biotecnología-FEMSA, Tecnológico de Monterrey, Escuela de Ingeniería y Ciencias

² Departamento de Mecatrónica y Eléctrica, Tecnólogico de Monterrey, Escuela de Ingeniería y Ciencias

*VHSR and SCPG contributed equally to this work.

Gelatin methacryloyl (GelMA) is a semisynthetic biomaterial that conserves the advantages of native collagen such as the presence of cell-binding domains with protease-cleavage sites. GelMA-based hydrogels are currently used as biomaterials to develop cell-laden systems for several biomedical applications. This biomaterial provides the necessary physiological microenvironment and biocompatibility for tissue engineering studies. However, currently used methods to produce GelMA do not consider a strict control of the key parameters of the reaction process (i.e., mixing, location and rate of addition of methacrylic anhydrate, and pH) which leads to batch to batch inconsistencies and low yields.

In this work, we present a semi-automated method for the synthesis and purification of a GelMA-based hydrogel with the aim of standardizing the process to enhance yield and quality of the final product. Our protocol includes the use of a custom-made jacketed reactor with temperature, agitation, and pH control. The addition of methacrylic anhydrate, the key reagent of the synthesis, is controlled by a syringe pump. A continuous dialysis stage follows reaction, effectively shortening the time needed for methacrylic acid removal. Automated equipment and pH control reduce synthesis and purification time and enhance reactivity leading to higher degree of substitution. Using this synthesis and purification strategies, we conducted multiple sets of GelMA production and correlated reaction conditions to final yields and qualities of the product. Moreover, we present information on the rates of methacryloyl functionalization during the reaction stage, and the rate of methacrylic acid removal during the purification stage. While conventional protocols require a 2 weeks preparation time and result in inconsistent quality of the final product, the methodologies presented here yield consistent quality GelMA in 7-8 days.