pH‐Responsive Micelle‐Forming Amphiphilic Triblock Copolymers

Abstract

A novel pH‐responsive micellar nanoparticle based on poly(ethylene glycol)–polydimethylsiloxane–poly(ethylene glycol) triblock copolymer with benzoic imine linkage is reported. A new synthetic approach to produce the pH‐cleavable polymer that can self‐assemble into stable micellar nanoparticle is presented. Such nanoparticles are stable at physiological pH, but degrade at slightly acidic pH, making this system potentially suitable to exploit pH gradients in biological compartments. The precursors, intermediates, final polymers, and micellar nanoparticles are characterized in detail by various spectroscopic techniques, gel permeation chromatography, and particle size measurements.

Modern Trends in Polymerization-Induced Self-Assembly

“…The contraction of the corona was caused by the statistical association of insoluble B-units in the amphiphilic corona [56,57]. At higher micelle concentrations, inter-corona association of insoluble B-units leads to the formation of micellar gels [58][59][60][61].…”

“…An amazing feature of ABC-block copolymers is their ability to form myriad morphologies ranging from "simple" spheres, cylinders, and lamellae up to complex multi-segregated nanoparticles of intriguing shapes [6][7][8]38,48,61,69,78,79]. The complex morphologies have been given unusual names that reflect the creative thinking of the researchers who first discovered them.…”

Application of Nanoparticles in Tumour Targeted Drug Delivery and Vaccine

“…It contains a large number of interstitial cells and immune cells and is an environment in which tumour cells depend on for survival (Schulz et al, 2019). Smart nanodrug delivery platforms utilize the internal phenomena of the TEM [e.g., low pH (Bener et al, 2020), overexpressed enzymes (Liu et al, 2017), and hyperthermia] or external stimuli (e.g., light, heat, and magnetic fields) to control the release of drugs (Shrestha et al, 2021). pHresponsive nano-formulations use pH changes to cause conformational or solubility changes, charge reversal, and chemical bond cleavage.…”

“…pHresponsive nano-formulations use pH changes to cause conformational or solubility changes, charge reversal, and chemical bond cleavage. The control and release of drugs from the tumour environment are achieved through the acidic environment of the tumour mesenchyme combined with acid-sensitive chemical bonding, thereby facilitating the endocytosis and targeting of nano-agents (Bener et al, 2020;Lin et al, 2020). By comparing poly(ethylene glycol)poly(benzyl-l-aspartate) (PPA) and poly-imino-poly(benzyl-laspartate) (PIPA) block copolymers, Pu et al (Pu et al, 2019) found that PIPAH had a better drug release rate and antitumour effect than that of pH-insensitive PPAH because the imine bond of PIPAH utilizes the acidic condition of the TME to more effectively release the active drug.…”

Polymeric Nanoplatforms for the Delivery of Antibacterial Agents

“…[15][16][17] This strategy shows great potential in the treatment of various diseases, including cancer, bacterial infection, inflammation infection, etc. [15,[18][19][20][21][22][23][24] Macromolecular methods and nanotechnology are becoming more and more promising in the construction of DDS for enhanced antibiotic delivery, which encourages the development of polymeric nanoplatforms for the delivery of antibacterial agents. [25] Unfortunately, the effectiveness of antibiotic use is relatively poor, which might be ascribed to the lack of targeting ability.…”