Synthesis and characterization of photocurable star-shaped and linear polymers based on polylactic acid (PLA) and polyethylene glycol (PEG)

Abstract

3D bioprinting has emerged as a novel biofabrication technology with diverse applications in the field of tissue engineering as it allows the construction of three-dimensional structures that can act as functional tissue and can replace damaged one. The choice of suitable biomaterials is essential to ensure the proper functioning of the bioprinted tissues. In this context, research is focused on developing novel polymers and copolymers, which are engineered for optimal mechanical properties and crosslinking efficiency under two-photon irradiation. These materials aim to surpass traditional bioinks by providing enhanced printability, cell viability, and functional tissue formation. The innovation also includes functionalization techniques that aim to improve crosslinking kinetics. This work focuses on the development of a photocrosslinkable star-shaped and linear polymers and copolymers based on polylactic acid (PLA) and polyethylene glycol (PEG), that can be applied as a biomaterial ink for 2-photon 3D bioprinting (2PP). The polymers have been functionalized using methacrylate groups which are photosensitive groups that lead to the photocrosslinking process under two-photon irradiation. The structures of the synthesized polymers and copolymers have been characterized using 1H NMR and FTIR techniques and the kinetics of crosslinkage has been monitored by photo rheology. The thermal characterization has been carried out by Differential Scanning Calorimetry (DSC). Morphology has been assessed by Field Emission-Scanning Electron Microscopy (FESM).