Maryam Eslami
Harvard Medical School
USA
Title: Synthesis of scaffold for heart valve based on Molecular patterns and study of its effects (Mechanically، Biologically، Collagen 1 and Elastin Genes Expression) on Valvular Interstitial Cells
Biography
Biography: Maryam Eslami
Abstract
The incidence and prevalence of heart valve disease is increasing worldwide and the number of heart valve replacements is expected to increase significantly in the future. By mimicking the main tissue structures and properties of human heart value, tissue engineering offers new options for the replacements. Applying an appropriate scaffold in fabricating tissue engineered heart valves (TEHVs) is of importance since it affects the secretion of the main extracellular matrix (ECM) components, collagen 1 and elastin, which are crucial for providing the mechanical, elastic and tensile strength of TEHVs.Using biliogical, mechanical and Real Time PCR experiments, the relative collagen 1 and elastin genes expression levels obtained for three samples of each examined valvular interstitial cells (VICs)-seeded scaffolds including electrospun poly(glycerol sebacate) (PGS)-poly (ε-caprolactone) (PCL) microfibrous scaffolds, methacrylated gelatin (GelMA) and methacrylated hyaluronic acid (HAMA) based hydrogel-only and the composite (consists of PGS-PCL and hydrogel) scaffolds. Sheep mitral valvular interstitial cells were encapsulated in the hydrogel and evaluated in hydrogel-only, PGS–PCL scaffold-only, and composite scaffold conditions. Although the cellular viability and metabolic activity were similar among all scaffold types, the presence of the hydrogel improved the three-dimensional distribution of mitral valvular interstitial cells. As seen by similar values in both the Young’s modulus and the ultimate tensile strength between the PGS–PCL scaffolds and the composites, microfibrous scaffolds preserved their mechanical properties in the presence of the hydrogels. Our results showed that the level of relative expression of collagen and elastin genes was higher in the VICs- encapsulated composite scaffolds compared to PGS-PCL-only and hydrogel-only scaffolds and the difference was statistically significant (P < 0.05). The maximum difference of elastin and collagen 1 genes expression was between the composite scaffold and the hydrogel-only scaffold, with the most and the least quantity, respectively.The VICs-encapsulated composite scaffold was observed to be more inductive to ECM secretion over the PGS-PCL-only and hydrogel-only scaffolds. This composite scaffold can serve as a three-dimensional structure model for heart valve tissue engineering with the capability of providing the necessary mechanical-properties such as, elasticity and tensile strength and the ability to grow, repair and be remodelled as a tissue.