| Popis: |
Tissue loss and end-stage organ failure has been a significant health challenge for millions of Americans, with the total national health cost exceeding $400 billion per year. Tissue engineering aims to address this challenge. During the process of tissue engineering, scaffolds and matrices are needed as supporting structures for cells to grow. Meanwhile, the roughness and stiffness of the scaffold material can largely influence cell growth and differentiation. The macro- and meso- structures of the scaffold, along with the functional groups or growth factors present on the surface plays an important role in cell function. Poly(ester urea) (PEU) is regarded as a promising biodegradable scaffold material for tissue engineering. In this study, physical and mechanical properties including Young’s modulus, storage modulus, water uptake profile, and degradation rate for PEUs of different structures were tested. Two different amino acids, phenylalanine and leucine, and various diol lengths were used in the synthesis of these PEUs. In this study, the data show that changing the amino acid from leucine (LEU) to phenylalanine (PHE) can result in a 20 degree increase in Tg, and a 30% increase in storage modulus. Tuning the length of the diols reduces the stiffness of the polymer backbone affording multiple opportunities to tune the property of the polymer. A structure-property relationship profile for PEUs can therefore be established.The effect of macro structure of poly(L-lactic acid) (PLLA) and poly(e-caprolactone) (PCL) scaffold was also explored. Electrospinning was used to fabricate fibrous scaffold of non-woven mats. 4-dibenzocyclooctynol (DIBO) terminated PCL was electrospun into nanofibers. The existence of DIBO groups on the surface was characterized by attaching an azide functionalized florescent dye. DIBO-PLLA was electrospun into fiber mats and functionalized by YIGSR peptide via metal-free click reaction on the DIBO group. Both random and uniaxial aligned conformations were used to investigate the effect of structure change and surface functionalization of the peptide on neuron differentiation and growth. |
