Preparation of thiolated poly（lactic acid）microspheres by amine ester reaction to simulate three-dimensional inkjet printing (3DP) biocompatible scaffolds

3D inkjet printing (3DP) technology offers the advantages of fast processing speed and high precision, but achieving a strong combination of "powder" and "ink" in polymer materials remains a great challenge. In this work, thiolated poly(lactic acid) (PLA) microspheres are fabricated through the amine-ester reaction between cysteine and PLA in a "green" water environment. 3DP is then simulated using thiolated PLA microspheres as the "powder", and acryloylmorpholine containing double bonds as the "ink". By virtue of the fast "thiol-ene click" reaction, the PLA scaffolds with a covalent bonding interface are fabricated within 20 s. Both the thiolated microspheres and scaffolds exhibit good biocompatibility, and the tensile strength of the scaffolds can reach 13.2 MPa, with the Young's modulus of 722 MPa, meeting the performance requirements of bone tissue scaffolds. Therefore, a new strategy to solve the interfacial bonding problem in 3DP technology are provided, facilitating the 3DP molding of PLA powder and promoting its application in the field of life and health.