Abstract

Tissue regeneration (TR) is currently one of the most challenging biotechnology unsolved problems. Tissue engineering (TE) is a multidisciplinary science that aims at solving the problems of TR. TE could solve pathologies and improve the quality of life of billions of people around the world suffering from tissue damage. New advances in stem cell (SC) research for the regeneration of tissue injuries has opened a new promising research field. However, research carried out nowadays with twodimensional (2D) cell cultures does not provide the expected results, as 2D cultures do not mimic the 3D structure of living tissue. Some of the commonly used polymers for cartilage regeneration are Poly-lactic acid (PLA) and its derivate as Poly-L-lactic acid (PLLA), Poly (glycolic acids) (PGAs) and derivate as Poly (lactic-co-glycolic acids) (PLGAs) and Polycaprolactone (PCL). All these materials can be printed using fused deposition modelling (FDM), a process in which a heated nozzle melts a thermoplastic filament and deposit it on a surface, drawing the outline and the internal filling of every layer. All these procedures use melting temperatures that decrease viability and cell survival. Research groups around the world are focusing their efforts on finding low-temperature printing thermoplastics or restricted geometries that avoid the contact of the thermoplastic and cells at a higher temperature than the physiologically viable. This has mainly 2 problems; new biomaterials need a long procedure of clearance before they can be used in clinical use, and restrictions in geometries will limit the clinical application of 3D printing in TE.