Collagen-carrageenan-chitosan sponge reinforced with 3D-printed polycaprolactone mesh for skin tissue engineering

Abstract

Biopolymers have gained prominence due to their potential in tissue engineering, which includes hydrophilicity, lower toxicity, reduced immune rejection, biocompatibility and biodegradability. However, biopolymers typically exhibit low mechanical strength, which decreases their application potential in tissue engineering. Composites of natural and synthetic polymers offer a robust solution to overcome this challenge, as the stiffness and durability of composites are enhanced by the presence of synthetic polymers. This study investigates two composite sandwich model scaffolds for skin tissue engineering, focusing on their structural and regenerative properties. The composite scaffolds were fabricated by combining freeze-drying and 3D-printing techniques. The outer layers of the scaffolds were fabricated using collagen-carrageenan (CO/CA-PCL) or collagen-carrageenan-chitosan (CO/CA/CH-PCL) through freeze drying, whereas the core layer was formed by 3D-printed polycaprolactone (PCL) mesh. Crosslinking was achieved in the vapor phase of glutaraldehyde and scaffold groups preserved their structure through 28 days after an initial weight loss on day 1. The CO/CA/CH-PCL scaffold showed a lower degradation rate with a cumulative weight loss of 28.6 +/- 5.5% compared to the CO/CA-PCL scaffold which indicates improved stability of the three-polymer sponge. Both scaffolds achieved water retention above 800% after 14 days of incubation which is critical for wound healing. Tensile strength of both scaffolds was successfully supported by 3D-printed PCL mesh. In vitro study has shown that the chitosan-bearing CO/CA/CH-PCL scaffold is promising for use in skin tissue engineering by supporting L929 attachment and high L929 cell viability. (c) 2025 Society of Chemical Industry.