Self-assembly and pH-responsive properties of poly(L-glutamic acid-r-L-leucine) and poly(L-glutamic acid-r-L-leucine)-b-polysarcosine

Abstract

Polypeptides and polypeptoids were widely used as biomedical materials because of their good biocompatibility. In this work we reported a series of pH-responsive copolypeptides and polypeptide-polypeptoid block copolymers, i.e. random copolymers of L-glutamic acid (Glu) with L-leucine (Leu) [poly(Glu-r-Leu)s], as well as their block copolymers with polysarcosine (polySar). Well-defined poly(Glu-r-Leu)s with predictable compositions and molecular weights were synthesized by ring opening polymerization of corresponding N-carboxyanhydride monomers. We investigated the relationship between hydrophilicity-hydrophobicity transition and copolymer composition. With increasing Leu fraction, both the pH value of cloud point and the micellar size increased. Poly(Glu-r-Leu) with 60% Leu exhibited a cloud point at the pH of 5.0 to 6.0 the same as that in endosome and lysosome. Poly(Glu-r-Leu)-b-polySars assembled in phosphate buffer and performed pH-responsive morphology change from orbicular micelles at high pH to worm-like micelles at low pH. They were potential pH-responsive carriers for drug and gene delivery to enhance cargo release in cellules.

Study on the Effect of Zizyphus Jujuba lZhanshanmizaor Dormancy Release by Cover

“…8). The change trend is consistent with the research consequence of Tian [11], but inconsistent with Li [12]. During natural dormancy, soluble protein content decreased, probably because jujube tree had entered deep dormancy and the low temperature hindered the synthesis of protein or accelerated the hydrolysis of protein.…”

Advance in Hybrid Peptides Synthesis

“…Polymerization methods provide new insights in the synthesis of peptide/peptoid hybrids with high molecular weight and different structures such as block, random and alternating polymer structures. Many studies were reported about the sequential synthesis of peptide/peptoid hybrid polymer with block structure by ring-opening polymerization of 𝛼-NCAs (Figure 11), [54,[98][99][100][101] which had already been reviewed by Barz and Ling. [55,102] Polysarcosine with stealth-like properties was always used as peptoid block and combined with polypeptide block with functionality and stimuli-responsiveness.…”

Template‐Directed Fabrication of Anatase TiO2 Hollow Nanoparticles and Their Application in Photocatalytic Degradation of Methyl Orange

“…[11][12][13][14] However, fabrication of polymeric nanoparticles is usually a tedious and time-consuming process, which is often uneconomic and difficult to scale up. [15][16][17][18] Direct fabrication of nano-objects via polymerizationinduced self-assembly (PISA), which have been developed in recent years, [19][20][21][22][23][24][25][26] may be one of the best methods to solve this problem. PISA strategy allows fabricating of polymeric nanoparticles at much high concentrations, and has become a powerful strategy for fabrication of polymeric nanoparticles.…”