Differentiated Stem Cell-Seeded Gelatin/PLA/P(3HB-co-4HB) Meniscal Scaffold with Biocompatibility and Mechanical Strength.

Laceration is one of the most common meniscus injuries, which can cause knee joint dysfunction. The treatment of meniscus injuries remains one of the greatest challenges in orthopedics. In this study, a three-dimensional sponge-like Poly(lactic acid)/Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (PLA/P(3HB-co-4HB)) scaffold with oriented microtubules was fabricated using an improved gradient thermal phase separation technique. The scaffold surface was modified by adsorbing gelatin. The surface-modified scaffolds and the unmodified scaffolds were divided into two groups. All preparation parameters were adjusted to meet tissue engineering requirements. The prepared scaffolds were tested for porosity, compression modulus, hydrophilicity, and degradability. Following scaffold preparation, induced differentiated rabbit bone marrow mesenchymal stem cells (BMSCs) were seeded to evaluate scaffold cytocompatibility. Cell proliferation was observed in the two scaffold groups, and cell viability was analyzed using CCK-8 assay, scanning electron microscopy (SEM), and confocal microscopy. Histological staining was performed to comparatively study cell synthetic function. Subsequently, tissue reconstruction and regeneration were evaluated following subcutaneous implantation of gelatin/PLA/P(3HB-co-4HB) scaffolds loaded with induced differentiated BMSCs in the dorsal regions of athymic nude mice. Results demonstrated that the gelatin/PLA/P(3HB-co-4HB) scaffold exhibited good cell compatibility, providing a suitable microenvironment for cell proliferation and differentiation. Furthermore, the scaffold supported the growth of seeded induced differentiated rabbit MSCs in vivo, maintaining meniscus cell phenotyping and function. The cell-laden scaffold has the potential to generate meniscus fibrocartilage.