Rabia Nazir
1Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
Title: Interlaced Scaffolds for Tissue Engineered Heart Valves (TEHVs)
Biography
Biography: Rabia Nazir
Abstract
Statement of the Problem: An ideal scaffold for the regeneration of valvular tissue should replicate the natural heart valve extracellular matrix (ECM) in terms of microstructure and properties 1, 2. Tissue engineers have achieved limited success so far in designing an ideal scaffold; scaffolds lack in mechanical compatibility, appropriate degradation rate, and microstructural similarity 3.
Methodology: This piece of research is the first attempt to develop interlaced scaffolds from collagen type I and hyaluronic acid (HA), polymers found in the natural valve, via a modified carbodiimide based crosslinking technique.
Findings: Scanning electron micrographs (SEM) and images of Alcian blue – Periodic acid Schiff (PAS) stained samples suggested that our crosslinking technique yielded an ECM mimicking microstructure with interlaced bands of collagen and HA in the hybrid scaffolds. Hybrid scaffolds also offered a wide range of pore size (66 – 126 µm) which fulfilled the criteria for valvular tissue regeneration. Swelling studies revealed that crosslinking densities of parent networks increased with increasing the concentration of the crosslinking agents whereas crosslinking densities of hybrid scaffolds averaged from those of parent collagen and HA networks. Fourier transform infrared spectroscopy (FTIR) showed that this technique could crosslink collagen type I and HA without denaturation. Cardiosphere derived cells (CDCs) attached and proliferated on all scaffolds in cell culture experiments as confirmed by AlamarBlue® assay and SEM images. The increase in crosslinking density, however, affected the cell affinity because of the engagement of the cell-attachment sites in the crosslinking process. CDCs seeded scaffolds also showed 50 % increase in bending modulus after 28 days of culture.
Conclusion & Significance: Findings from this study indicated that collagen/HA interlaced scaffolds have the potential to fill in the niche for designing an ideal TEHV 4. Furthermore, the properties of the interlaced scaffolds, fabricated by our crosslinking technique, can be tailored by controlling the crosslinking density which can also widen the scope of these scaffolds for other tissue engineering applications such as bone, cartilage etc.