View : 688 Download: 0

Incorporation of d-alanine into poly(ethylene glycol) and l-poly(alanine-co-phenylalanine) block copolymers affects their nanoassemblies and enzymatic degradation

Title
Incorporation of d-alanine into poly(ethylene glycol) and l-poly(alanine-co-phenylalanine) block copolymers affects their nanoassemblies and enzymatic degradation
Authors
Joo M.K.Ko D.Y.Jeong S.J.Park M.H.Shinde U.P.Jeong B.
Ewha Authors
정병문Pramod B. Shinde
SCOPUS Author ID
정병문scopus; Pramod B. Shindescopus
Issue Date
2013
Journal Title
Soft Matter
ISSN
1744-683XJCR Link
Citation
Soft Matter vol. 9, no. 33, pp. 8014 - 8022
Indexed
SCI; SCIE; SCOPUS WOS scopus
Document Type
Article
Abstract
Poly(ethylene glycol)-poly(alanine-co-phenylalanine) (PEG-PAF) block copolymers with similar molecular weights were synthesized to investigate the effect of the partial incorporation of d-alanine into PEG-l-PAF. The ratio of l-alanine to d-alanine of the polymer varied over 100/0, 80/20, 60/40, 50/50, and 0/100. Circular dichroism and FTIR spectra indicated that the PEG-PAFs with the mixed composition of l-alanine and d-alanine exhibited dominantly random coil structures, whereas the PEG-PAF with the enantiomeric alanine (100/0 or 0/100) exhibited right-handed or left-handed α-helical structures as well as β-sheet structures, respectively. Dynamic light scattering of the polymer aqueous solution indicated that the size of nanoassemblies significantly decreased as a result of the partial incorporation of d-alanine into PEG-l-PAF. The most probable diameters were 20-40 nm and 80-105 nm for the PEG-PAFs with a mixed composition (l-alanine/d-alanine ratios of 80/20, 60/40, and 50/50) and an enantiomeric composition (l-alanine/d-alanine ratios of 0/100 and 100/0), respectively. As the temperature increased, the relative β-sheet content decreased for PEG-PAF with the enantiomeric alanine, while there was no significant change in random coil structures of PEG-PAFs with a mixed composition. 13C-NMR spectra suggest the dehydration and decrease in molecular motion of PEG during the sol-to-gel transition of PEG-PAF. Through the partial incorporation of d-alanine into PEG-l-PAF, thermogelling behaviour was also observed at much higher temperatures and concentrations due to the difference in the secondary structure and nanoassembly of the polymers. The enzymatic degradability of PEG-PAF also decreased as a result of the partial incorporation of d-alanine into PEG-l-PAF. The paper suggests that partial incorporation of d-alanine into an l-polypeptide block copolymer can be a useful method in designing a biodegradable material as well as controlling nanoassemblies of the polymer. This journal is © The Royal Society of Chemistry.
DOI
10.1039/c3sm51272j
Appears in Collections:
자연과학대학 > 화학·나노과학전공 > Journal papers
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

BROWSE