| Budget Amount *help |
¥3,920,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥420,000)
Fiscal Year 2007: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2006: ¥2,100,000 (Direct Cost: ¥2,100,000)
|
|---|
| Research Abstract |
Elastin is an essential component in animal tissues as well as collagen. Elastin molecules are formed by covalent bounds of a cross-linked network and their network can stretch and recoil like rubber band. This elasticity conform a flexibility to such as skin, blood vessels, and lungs, need to this elasticity in order to function [6]. Elastin molecules are composed largely of hydrophobic amino acid residues, such as glycine (G) ,alanine (A) ,proline (P) and valine (V) and their amino acids repeat as (GVGVP)n exist in the animals. On raising the temperature, they folded and assembled above a specific temperature called cloud point (CP) and it formed helical structure of type II beta-turn. Using these hydrophobic amino acid residues, unique thermoresponsive polypeptides: poly [(GVGVP)_<251>]was synthesized by Urry, et al. using Escherichia coli recombinant DNA technology and these polypeptides exhibit a remarkable biocompatibility. Utilizing these thermosensitive polypeptides, Nanoparticles were prepared utilizing the thermosensitive aggregation of the elastin model polypeptides; poly[(GVGVP)_<251>]and gamma-ray crosslinking. Three different heating methods, "Slow heating", "Fast heating", and "Heat shock", were applied for the aggregation of the peptide and examined to yield stable nanoparticles by gamma-ray crosslinking. As a result, only "heat shock" procedure yielded stable nanoparticles with diameters of less than ca. 150 nm and a narrow size distribution. CD spectrometry showed that this polypeptide formed type II beta-turn structure on raising temperature above cloud point(CP)with the "heat shock" procedure and, kept the structure within the crosslinked nanoparticles, suggesting that this structure would be crucial to yield stable crosslinked particles.
|
