(95q) Self-Assembled Polycaprolactone Matrices

Gelatin is a natural polymer with favorable biological properties, but lacks the mechanical properties necessary for optimal tissue engineering usage. Polycaprolactone (PCL) is a synthetic, biodegradable polymer with favorable mechanical properties but inadequate biological properties. The objective of this study was to analyze the biomechanical properties of blending gelatin and PCL in different volumes and compositions. Both polymers were dissolved in 94% acetic acid. Scaffolds were spontaneously generated by extruding the solution into water, ethanol, or NaHCO₃ solution. Ethanol and UV radiation were used to sterilize each scaffold and vacuum dried. Differential scanning calorimetry analysis indicated presence of gelatin in UV sterilized samples but not in ethanol sterilized. Ponceau staining further confirmed the presence of gelatin in the formed scaffold. Tensile properties of 2-D scaffolds were analyzed in dry conditions at room temperature. Scaffolds formed from 5mL solution had greater stiffness than scaffolds formed from 10mL. Also, gelatin blends had a greater stiffness than pure PCL scaffolds of equal volumes. Scanning electron microscopy analysis indicated different surface structures on the scaffolds and relative pore sizes. A four-week study on scaffold degradation at 37°C in 5% CO₂/95% air, in phosphate buffer solution (pH=7.4), indicated no major changes in weight. Media acidity increased more in the final week, possibly indicating an increase in degradation. In vitro cell cultures were conducted using mouse embryonic fibroblasts. After the five days, the scaffolds were sacrificed and tested for viability using MTT-Formazan assay. Results showed pure PCL scaffolds supporting more cell viability than gelatin blended scaffolds. In summary, scaffolds of pure PCL showed a significant improvement in cellular activity and a lesser stiffness relative to gelatin blended scaffolds.