3D printing of uv-curable polyacrylamide hydrogel loaded with lignin

Abstract

This study aims to develop UV-curable polyacrylamide (PAM) hydrogels loaded with lignin and assess the feasibility of 3D printing using the Digital Light Processing (DLP) 3D printing technique. Lignin nanoparticles were incorporated into the acrylamide resin at varying concentrations ranging from 0 to 2.5 wt%, and subsequently fabricated via DLP 3D printing. The results indicated that PAM-lignin hydrogels were successfully 3D printed into intricate and customizable structures. The incorporation of lignin significantly impacts the properties of the hydrogels, particularly printability, porosity, gel fraction, and mechanical characteristics. Higher lignin content hinders the efficacy of light exposure during the 3D printing process, leading to difficulties in layer formation. Correspondingly, rheological measurements align with the gel fraction results, indicating a direct correlation between reduced gel fractions and diminished gel strength. Moreover, the 3D-printed PAM hydrogels with 1.0, 1.5 and 2.0 wt% exhibit potent antibacterial activity against both Gram-positive (S.aureus) and Gram-negative (E.coli) bacteria. Additionally, increased lignin loaded enhance antioxidant properties, Remarkbly, a 3D-printed PAM hydrogel with 1.5 wt% lignin exhibits the most promising antibacterial properties, rendering it a valuable candidate for applications necessitating antioxidant and antibacterial attributes.