Microstructural Effects of Melt Electrowritten-Reinforced Hydrogel Scaffolds for Engineering Thick Skin Substitutes

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Regenerative Medicine

Background:

• Engineering skin tissue substitutes with native-like properties remains a challenge.
• Melt electrowriting (MEW) fabricates ordered structures mimicking the extracellular matrix (ECM).

Purpose of the Study:

• To assess the impact of microstructure on mechanical strength and cellular behavior in MEW-fabricated scaffolds for skin tissue.
• To develop hybrid scaffolds combining polycaprolactone (PCL) and gelatin for enhanced skin regeneration.

Main Methods:

• Fabrication of PCL scaffolds with 0-90°, 60-120° mesh, and honeycomb microstructures using MEW.
• Infilling scaffolds with gelatin hydrogel and encapsulating human skin dermal fibroblasts (HSFs) and human umbilical vein endothelial cells (HUVECs).
• Mechanical tensile testing and cell viability/morphology assessments.

Main Results:

• Honeycomb microstructured hybrid scaffolds exhibited superior elongation at failure and suitable elastic modulus for skin applications.
• All scaffolds supported over 90% cell viability and preserved cell morphology.
• Scaffold geometry guided HSF alignment, and HUVEC CD31 expression (indicating vascularization) significantly increased, particularly in 0-90° mesh and honeycomb designs.

Conclusions:

• Microstructural design in hybrid scaffolds plays a critical role in guiding cell behavior and promoting vascularization for skin tissue engineering.
• The honeycomb MEW-gelatin hybrid scaffold shows significant potential for creating full-thickness skin tissue substitutes with desirable mechanical and physicochemical properties.