Microfabrication of GelMA Hydrogels: A Review

In recent decades, the "GelMA" hydrogels as one of the biocompatible and biodegradable biomaterials are introduced in various applications of biomedical engineering. GelMA results from direct reaction of gelatin and methacrylic anhydride which has specific biological and physical properties making it suitable for the design and engineering of scaffolds, creating micro or nanoscale polymer nanocomposites, cell signaling, designing drug delivery systems, biosensors, and gene transfer or other biomedical engineering applications. GelMA forms cross-linked hydrogel by exposure to ultra-violet radiation. Various techniques could be applied in designing and manufacturing of GelMA in micro size, such as photopatterning, micromolding, self-assembly phenomenon, microfluidic, bioprinting, fibers and fabrics weaving. Three-dimensional structures and scaffolds based on GelMA hydrogel could be designed to mimic the structure of the natural tissue, used in tissue engineering and regeneration medicine. However, in this case, there are some challenges such as different length scales, making copies of capillary hollow microcapillaries, angiogenic production in micro size scale and limitations in oxygen-carrying through centimeter dimension, need to be investigated further. Using the combined methods of fabrication and exact investigations on the effect of process parameters and introduction of new additives could be the part of the solution. GelMA capabilities for use in various manufacturing methods, besides, its physical flexibility, mechanical and biological properties are promising for future biomedical applications and producing self-assembled organs with different types of cells.