Spatial Presentation of Tissue-Specific Extracellular Matrix Components along Electrospun Scaffolds for Tissue...

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Regenerative Medicine
• Stem Cell Biology

Background:

• The bone-ligament interface (enthesis) is a complex, multiphasic region requiring specific cell phenotypes for proper function.
• Engineering this interface demands biomaterial substrates that can direct the differentiation of multiple cell types in a spatially defined manner.
• Current strategies lack the precise combination of biophysical and biochemical cues to replicate the native enthesis environment.

Purpose of the Study:

• To investigate the use of microfiber scaffolds functionalized with tissue-specific extracellular matrix (ECM) components to engineer the bone-ligament interface.
• To determine if spatially controlled presentation of ligament-ECM (L-ECM) and cartilage-ECM (C-ECM) can direct mesenchymal stem cell (MSC) differentiation towards enthesis-specific phenotypes.
• To evaluate the potential of apatite coating on C-ECM functionalized scaffolds to promote endochondral ossification.

Main Methods:

• Fabrication of electrospun microfiber scaffolds functionalized with L-ECM and C-ECM.
• Spatial control of L-ECM and C-ECM presentation along individual microfiber constructs.
• Functionalization of C-ECM regions with an apatite layer using simulated body fluid.
• Assessment of MSC differentiation via gene expression analysis (e.g., TNMD, SOX9, Collagen types I, III, X, Osteopontin) and cell morphology.

Main Results:

• L-ECM functionalization promoted ligament-specific gene expression (TNMD) and collagen production in MSCs.
• C-ECM functionalization induced chondrogenesis (round morphology, SOX9 expression) without exogenous growth factors.
• Multiphasic scaffolds with spatially arranged L-ECM and C-ECM, plus apatite coating, successfully directed MSC differentiation, showing TNMD expression in L-ECM regions and endochondral ossification markers (Collagen X, Osteopontin) in C-ECM/apatite regions.

Conclusions:

• Tissue-specific ECM components are effective cues for directing MSC differentiation in engineered biomaterial scaffolds.
• Spatially controlled functionalization of multiphasic scaffolds can replicate the complex cellular microenvironment of the bone-ligament enthesis.
• This approach holds promise for engineering complex biological interfaces and advancing regenerative medicine strategies for tendon and ligament repair.