The Formation of Biodegradable Polymeric Micelles from Newly Synthesized Poly(aspartic acid)‐block‐Polylactide AB‐Type Diblock Copolymers

Abstract

Summary: A poly(aspartic acid)‐block‐polylactide (PAsp‐block‐PLA) diblock copolymer was synthesized through the polymerization of β‐benzyl‐L‐aspartate‐N‐carboxyanhydride [Asp(OBzl)‐NCA] with amino‐terminating polylactide (NH2‐PLA) as a macroinitiator. The chain length of the PAsp segment could be easily controlled by changing the monomer/initiator ratio. Dynamic light scattering measurements of PAsp‐block‐PLA aqueous solutions revealed the formation of polymeric micelles. Changes in the micelles as a function of pH were investigated.The structure and formation of micelles of the poly(aspartic acid)‐block‐polylactide (PAsp‐block‐PLA) diblock copolymers synthesized here.imageThe structure and formation of micelles of the poly(aspartic acid)‐block‐polylactide (PAsp‐block‐PLA) diblock copolymers synthesized here.

Polypeptides and 100 Years of Chemistry of α‐Amino Acid N‐Carboxyanhydrides

“…[107] Most diblock copolymers consisting of a peptide block and another type of polymer chain may be subdivided into four classes (I-IV): I) amphiphilic copolymers containing a poly(ethylene oxide) (PEO) monomethyl ether block, [130][131][132][133][134][135][136][137][138][139][140][141][142] a-Amino Acid N-Carboxyanhydrides Angewandte Chemie II) amphiphilic copolymers based on a poly(oxazoline) as the hydrophilic block, [143,144] III) diblock copolymers based on macroinitiators that were prepared by polymerization of vinyl monomers, [111,[145][146][147][148][149][150] and IV) copolymers combining a peptide block with a biodegradable polyester block. [151][152][153][154][155][156][157] All diblock copolymers of classes I-III were prepared in such a way that a polymer with one primary amino end group was synthesized and served as macroinitiator for the ROP of NCAs. A typical example for a PEO-based diblock copolymer is presented in formula 47.…”

Negatively Charged Magnetite Nanoparticle Clusters as Efficient MRI Probes for Dendritic Cell Labeling and In Vivo Tracking

“…Then, benzyl groups on the side chains of this copolymer were removed to obtain amphiphilic diblock copolymer PAsp-PCL. [ 12 ] Number-average molecular weight of each block was estimated by the relative intensities in 1 H NMR, and the end product was accordingly denoted as PAsp 50 -PCL 65 . Critical micelle concentration (CMC) of PAsp-PCL micelle was 0.821 mg L −1 , which was determined by the pyrene fl uorescence methodology ( Figure S5, Supporting Information).…”

Polypeptide und 100 Jahre Chemie der α‐Aminosäure‐N‐carboxyanhydride

“…[107] Die meisten Diblockcopolymere, die einen nichtpeptidischen Block enthalten, lassen sich in folgende vier Gruppen unterteilen: I) amphiphile Copolymere mit einem Poly(ethylenoxid)(PEO)-Monomethylether-Block; [130][131][132][133][134][135][136][137][138][139][140][141][142] II) Diblockcopolymere mit einem hydrophilen PolyoxazolinBlock; [143,144] III) Diblockcopolymere, die Ketten aus Vinylmonomeren als hydrophobe Blöcke enthalten; [111,[145][146][147][148][149][150] IV) Kombinationen von Polypeptidblöcken mit biologisch abbaubaren Polyesterblöcken. [151][152][153][154][155][156][157] Alle Diblockcopolymere der Klassen I-III wurden so hergestellt, dass zuerst eine Polymerkette mit einer Aminogruppe synthetisiert und dann als Makroinitiator für die ROP eines NCA verwendet wurde. Ein typisches Beispiel für ein PEO-basiertes Diblockcopolymer ist die Verbindung 47.…”

“…[111] Die Synthesen von Diblockcopolymeren aus l-Lactid (Polymer 56; Schema 29) folgten derselben Strategie. [151][152][153] Ein Boc-geschützter Aminoalkohol diente als Coinitiator in Kombination mit einem metallhaltigen Initiator wie Et 2 Zn für die ROP von l-Lactid. Die Abspaltung der Boc-Gruppe ergab NH 2 -terminierte Polylactide, die als Makroinitiatoren für die NCAs von l-Ala, l-Phe, l-Leu, g-Bzl-l-Glu und gBzl-l-Asp dienten.…”