Effect of heating process on the formation of nanoparticles of elastin model polypeptide, (GVGVP)251, by gamma-ray crosslinking

Nanoparticles were prepared by the thermosensitive aggregation of the elastin model polypeptide, (GVGVP)₂₅₁, and gamma-ray crosslinking. Three different heating processes, “slow heating,” “fast heating,” and “heat shock,” were used for the aggregation of the peptide, followed by gamma-ray crosslinking. Only the “heat shock” process successfully yielded stable nanoparticles with diameters of less than ca. 150 nm and a narrow size distribution. Circular dichroism (CD) spectrometry showed that this polypeptide formed a type-II β-turn structure when the temperature was increased to above the cloudy point in the case of the “heat shock” process; suggesting that this structure might contribute to stable nanoparticle formation by gamma-rays. CD spectrometry also suggested that this structure would be affected during the formation of stable crosslinked particles.