Dendritic poly(benzyl ether)‐b‐poly(N‐vinylcaprolactam) block copolymers: Self‐organization in aqueous media, thermoresponsiveness and biocompatibility

Abstract

Four generations of new amphiphilic thermoresponsive linear‐dendritic block copolymers (LDBCs) with a linear poly(N‐vinylcaprolactam) (PNVCL) block and a dendritic poly(benzyl ether) block are synthesized by atom transfer radical polymerization (ATRP) of N‐vinylcaprolactam (NVCL) using dendritic poly(benzyl ether) chlorides as initiators. The copolymers have been characterized by 1H NMR, FTIR, and GPC showing controlled molecular weight and narrow molecular weight distribution (PDI ≤ 1.25). Their self‐organization in aqueous media and thermoresponsive property are highly dependent on the generation of dendritic poly(benzyl ether) block. It is observed for the LDBCs that the self‐assembled morphology changes from irregularly spherical micelles, vesicles, rod‐like large compound vesicles (LCVs), to the coexistence of spherical micelles and rod‐like LCVs, as the generation of the dendritic poly(benzyl ether) increases. The results of a cytotoxicity study using an MTT assay method with L929 cells show that the LDBCs are biocompatible. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 300–308

Thermal and enzymatic dual‐stimuli responsive linear‐dendritic block copolymers based on poly(N‐vinylcaprolactam)

“…However, the molecular weights from gel permeation chromatography (GPC) have a significant difference between the M n,NMR values and M n, theo values. This result may be attributed to the difference in hydrodynamic volume of the copolymers and the linear PS standards used for calibration 27,38 …”

“…Although the lower critical solution temperature (LCST) of PNVCL is close to LCST of poly( N ‐isopropylacrylamide) (PNIPAM), the most representative thermoresponsive polymer, there are significant differences in the thermodynamic and molecular mechanisms underlying the phase transition 25,26 . In comparison with PNIPAM, PNVCL has some obvious advantages, such as lower interaction with biomolecules and no tendency to crystallize 27 . The 2, 2′‐dimethylolpropionic acid (bis‐MPA) molecule, comprising two hydroxyl groups and one carboxylic group, has successfully been developed for the construction of dendritic materials, such as monodisperse dendrons and dendrimers or polydisperse hyperbranched polymers and linear‐dendritic hybrids.…”

Amphiphilic polylactide‐poly(ethylene oxide)‐poly(propylene oxide) block copolymers: Self‐assembly behavior and cell affinity

“…(B)—in D 2 O; the other 1 H NMR spectra in D 2 O can be found in Supporting Information, SM1–2]. The aggregates therefore comprise a hydrophobic PLA core and a hydrophilic polyether shell, as the mobility of the internal PLA segments is restricted by the formation of the core–shell structure in the aqueous medium . From 2D DOSY NMR, the diffusion coefficient at 25 °C in D 2 O of 5.8 × 10 −11 m 2 s −1 was calculated for PEO signal in PLA 6 –PEO 8 –PLA 6 copolymer (Supporting Information, Fig.…”

Drug Delivery Systems from Self-Assembly of Dendron-Polymer Conjugates †

“…While a majority of studies reported to date have utilized PEG-based polymers as the hydrophilic segment, a few studies have also focused on utilization of other hydrophilic polymers. Recently, Bi and coworkers reported thermoresponsive micellar aggregates prepared from diblock constructs composed of poly(benzyl ether) dendrons and linear poly( N -vinylcaprolactam) [ 77 ]. Dendritic poly(benzyl ether) blocks containing a benzyl chloride group at their focal point were used as initiators for atom transfer radical polymerization of N -vinylcaprolactam.…”