Customizable 3D-printed scaffolds for meniscal replacement: Mechanical insights into urethane-based poly(ethylene glycol) polymer

The menisci, essential fibrocartilaginous structures within the knee joint, play a critical role in load distribution, stability, and shock absorption. Meniscal injuries can result from acute trauma, degeneration, or arise as secondary consequences of other knee pathologies. Meniscus regeneration has emerged as a promising approach to address these challenges by developing biomimetic replacements that restore native function. The mechanical properties of scaffold materials are pivotal in the success of meniscus regeneration, given the complex and dynamic loading environment within the knee joint. This study presents a comprehensive mechanical characterization of a novel scaffold material—acrylate end-capped urethane-based poly(ethylene glycol) (AUP)—designed specifically for meniscus regeneration applications. AUP is a synthetic polymer that demonstrates remarkable potential due to its tuneable mechanical and structural properties. This work focuses on evaluating AUP’s mechanical performance and its implications for fabricating functional meniscal constructs. Key mechanical properties analyzed include the tensile Young’s modulus (3.19–3.49 MPa), compressive modulus (2–3.32 MPa), storage modulus (5.76–8.2 MPa), loss modulus (0.08–0.14 MPa), swelling degree (200–295 %), gel fraction (>88 %), and fatigue durability (target 200,000 cycles). Utilizing advanced 3D printing techniques, the AUP hydrogel scaffold structure is customized to replicate the mechanical behavior of distinct meniscal zones. This paper underscores the critical importance of mechanical characterization in developing AUP-based scaffolds for effective meniscus regeneration. The integration of mechanically optimized scaffolds offers a pathway toward restoring joint function, alleviating pain, and improving the overall quality of life for patients affected by meniscal damage.