Biodegradable photo-crosslinked polymer substrates with concentric microgrooves for regulating MC3T3-E1 cell...

Area of Science:

• Biomaterials Science
• Cell Biology
• Tissue Engineering

Background:

• Cell-biomaterial interactions are governed by both material properties and surface topography.
• Biodegradable polymers offer tunable mechanical properties for biomedical applications.
• Osteoprogenitor cell behavior is crucial for bone regeneration and requires specific microenvironmental cues.

Purpose of the Study:

• To investigate how mechanical properties and microgroove topography of poly(ϵ-caprolactone) triacrylate (PCLTA) substrates influence mouse pre-osteoblastic MC3T3-E1 cell behavior.
• To systematically analyze the effects of varying microgroove dimensions (width and depth) on cell attachment, proliferation, alignment, and osteogenic differentiation.
• To correlate substrate stiffness and microgroove characteristics with cellular responses, including mineralization and gene expression.

Main Methods:

• Synthesis of two poly(ϵ-caprolactone) triacrylates (PCLTAs) with different molecular weights (∼7000 and ∼10000 g mol(-1)) to create polymer networks with distinct mechanical properties.
• Fabrication of microgrooved substrates using replica molding with controlled groove widths (7.5–91.2 μm) and depths (0.2–10 μm).
• Culturing mouse pre-osteoblastic MC3T3-E1 cells on substrates with varying stiffness and microgroove dimensions, followed by analysis of cell attachment, proliferation, morphology, mineralization, and gene expression (osteocalcin).

Main Results:

• Stiffer PCLTA substrates significantly enhanced MC3T3-E1 cell attachment and proliferation compared to softer substrates.
• Microgroove topography, independent of substrate stiffness, regulated MC3T3-E1 cell alignment, nuclear shape, and cytoskeleton organization.
• Narrower microgrooves (7.5 μm width, 10 μm depth) most effectively aligned cells and promoted higher mineral deposition and osteocalcin gene expression, indicating enhanced osteogenic differentiation.

Conclusions:

• Substrate stiffness plays a primary role in supporting initial cell attachment and proliferation, while microgroove topography dictates cell morphology and osteogenic potential.
• Optimized microgroove dimensions, particularly narrow and deep features, can guide cell behavior towards enhanced osteogenic differentiation on biodegradable polymers.
• This study provides insights into designing biomaterial surfaces with tailored mechanical and topographical cues for effective bone tissue engineering applications.