Sequential polydepsipeptides containing tripeptide sequences and α-hydroxy acids as biodegradable carriers
✍ Scribed by Masaru Yoshida; Masaharu Asano; Minoru Kumakura; Ryoichi Katakai; Tooru Mashimo; Hisako Yuasa; Hidetoshi Yamanaka
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 506 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0014-3057
No coin nor oath required. For personal study only.
✦ Synopsis
Biodegradable polydepsipeptides having the sequences of L-alanyl-L-amino acyl-7-ethyl L-glutamyl-L-hydroxy acyl [AIa-AA--GIu(OEt)-HA] were synthesized to evaluate the hydrolysis of the specimens by the action of enzymes. The enzymatic degradatio n and its degradation pattern were strongly dependent on the difference in size of side chain residues of L-aminoacyl and L-hydroxyacyl units in the sequence and, as a result, it was found that the introduction of L-leucic acid (Hmp) as HA unit in an Ala-Ala-Clu(OEt)-HA sequence leads to a typical S-type degradation pattern, in contrast to a parabolic-type for the introduction of glycolic acid (Hea). From the difference in action of enzymes, it was concluded that the sequential polydepsipeptides are much more subject to hydrolysis by esterase-type enzymes rather than by protease-type enzymes. For comparison, the in vivo degradation was examined; it depended strongly on the site of implantation, and degrading to the greatest extent when implanted in the kidney. Microscopic observation showed that the degradation occurs heterogeneously at the surface of the specimen with formation of micropores.