pH‐Responsive Flower‐Type Micelles Formed by a Biotinylated Poly(2‐vinylpyridine)‐block‐poly(ethylene oxide)‐block‐poly(ε‐caprolactone) Triblock Copolymer

Abstract

In the present work, a method is proposed to assemble pH‐responsive, flower‐like micelles that can expose a targeting unit at their periphery upon a decrease in pH. The micelles are composed of a novel biotinylated triblock copolymer of poly(εε‐caprolactone)‐block‐poly(ethylene oxide)‐block‐poly(2‐vinylpyridine) (PCL‐b‐PEO‐b‐P2VP) and the non‐biotinylated analogue. The block copolymers are synthesized by sequential anionic and ring‐opening polymerization. The pH‐dependent micellization behaviour in aqueous solution of the triblock copolymers developed is studied using dynamic light scattering, zeta potential, transmission electron microscopy (TEM), and fluorimetric measurements. The shielding of the biotin at neutral pH and their availability at the micelle surface upon protonation is established by TEM and surface plasmon resonance with avidin and streptavidin‐coated gold surfaces. The preliminary stealthy behavior of these pH‐responsive micelles is examined using the complement activation (CH50) test.

Positively-Charged, Porous, Polysaccharide Nanoparticles Loaded with Anionic Molecules Behave as ‘Stealth’ Cationic Nanocarriers

“…Our study showed an inhibition of complement activation by BSA or DG loading inside NP + , which might be compared to inhibition obtained after long chain of poly(ethylene glycol) (PEG) addition to strong activator nanoparticles, as shown by Van Butsele et al, Aqil et al and Layer et al (48)(49)(50)(51). Indeed, PEG create a steric barrier around particles able to protect against protein adsorption due to a decrease of surface hydrophobicity and a neutralization of surface potential.…”

Steric Protected and Illumination‐Activated Tumor Targeting Accessory for Endowing Drug‐Delivery Systems with Tumor Selectivity

“…It is known that not all ligands on micelles are required for effective cell targeting. [ 29 ] The excessive addition of functional accessory did not further improve phototriggered uptake of fundamental micelles but led to un-specifi c intracellular accumulation. So 10p seems to be a better formula than 20p.…”

Dynamic Assembly of Block-Copolymers

“…In relation to the pH, a new structure is described, referred to as a semi-flower-like structure. It is reported that the P2VP couldn't really reach the inner PCL core and hydrophobic clusters of P2VP are formed beneath the curved PEO chains rather than being mixed with PCL in the micelle core [50].…”