Synthesis, Self-Assembly, and In Vitro Doxorubicin Release Behavior of Dendron-like/Linear/Dendron-like Poly(ε-caprolactone)-b-Poly(ethylene glycol)-b-Poly(ε-caprolactone) Triblock Copolymers

Abstract

Dendron-like/linear/dendron-like poly(epsilon-caprolactone)-b-poly(ethylene glycol)-b-poly(epsilon-caprolactone) triblock copolymers with controlled molecular weights (M(n) = 9550-30 460) and low polydispersities were synthesized by a click conjugation between dendron-like poly(epsilon-caprolactone) and bifunctional azide-terminated poly(ethylene glycol) (copolymer yield = 56-89%). Their molecular structures and physicochemical and self-assembly properties were thoroughly characterized by means of FT-IR, (1)H NMR, multiangle laser light scattering coupled with gel permeation chromatography, differential scanning calorimetry, wide-angle X-ray diffraction, dynamic light scattering, and transmission electron microscopy. Using a nanoprecipitation method, these triblock copolymers self-assembled into spherical flower-like micelles with an average diameter of less than 50 nm in aqueous solution, and both the copolymer composition and the dendritic topology of the hydrophobic core had no apparent influence on the morphology of nanoparticles. The critical aggregation concentrations of these copolymers ranged from 0.034 to 0.048 mg/mL. However, the anticancer doxorubicin-loaded nanoparticles showed worm-like micelles similar to blank nanoparticles fabricated by a dialysis method, and the loaded doxorubicin drug hardly affected the final morphology of nanoparticles. Moreover, the doxorubicin-loaded nanoparticles fabricated from the dumbbell copolymer showed a higher drug loading efficiency of 18% and a longer drug-release time of 45 days than the linear counterpart. Consequently, this provides a versatile strategy not only for the synthesis of biodegradable and biocompatible dendron-like/linear/dendron-like triblock copolymers with dumbbell topology by using click chemistry but also for fabricating worm-like doxorubicin-loaded nanoparticles for anticancer drug release.

Microwave irradiated click reactions on silicon surfaces via derivertization of covalently grafted poly(PEGMA) brushes

“…This band is assigned to the asymmetric stretching mode of cumulated double bond of AN 3 [49]. It is approximately consistent with azide-terminated monolayers on planar Au [22,23] and Si [3,27] surfaces, and also on nanoparticles [50][51][52][53], as well as with azide-carried polymers [54,55]. These azide groups behave normally as organic groups, different from the direct bonding of AN 3 to silicon metal (SiAN 3 ), which was reported at 2168 cm À1 (v a (AN@N + @N À )), due to the proximity effect of silicon metals [8].…”

Click Chemistry for Drug Delivery Nanosystems

“…Several interesting examples on the use of CuAAC for preparation of PEG-dendritic block copolymer-based micelles and other nanostructures have been reported by Dong's group (40)(41)(42). For instance, they prepared spherical flowerlike micelles of~50 nm by self-assembly in aqueous solution of dendron-like PCL-b-PEG-b-dendron-like PCL triblock copolymers prepared by CuAAC (CuBr, PMDETA, DMF) (Fig.…”

Biocompatible and biodegradable MOPEO‐b‐PCL diblock copolymer micelles as nanocontainers for drugs

“…Synthesis of the MOPEO-b-PCL copolymers was carried out by an anionic ring-opening block copolymerization with stannous octoat as an initiator, according to the chemical equation (1). To 10 g of MOPEG in an inert atmosphere a necessary quantity of ecaprolactone (depending on a wanted length of PCL block) and stannous octoat were added, and the reaction of a block copolymerization was carried out at 135 8C for 24 h. The molar ratio [Sn(Oct) 2 ]/[MOPEG] = 1 was used in all the cases.…”

“…One of the prospective manners to create such therapeutic systems is self-assembly of amphiphilic block copolymers containing immiscible biocompatible and biodegradable polymer components, for example polyethers and polyesters [1,2]. The copolymers with such nature can form micelles with different morphology in selective solvents.…”