Microemulsion-Assisted Templating of Metal-Stabilized Poly(ethylene glycol) Nanoparticles

Abstract

Poly(ethylene glycol) (PEG) is well known to endow nanoparticles (NPs) with low-fouling and stealth-like properties that can reduce immune system clearance in vivo, making PEG-based NPs (particularly sub-100 nm) of interest for diverse biomedical applications. However, the preparation of sub-100 nm PEG NPs with controllable size and morphology is challenging.Herein, we report a strategy based on noncovalent coordination between PEG-polyphenolic ligands (PEG-gallol) and transition metal ions using a water-in-oil microemulsion phase to synthesize sub-100 nm PEG NPs with tunable size and morphology. The metal-phenolic coordination drives the self-assembly of the PEG-gallol/metal NPs: complexation between Mn II and PEG-gallol within the microemulsions yields a series of metal-stabilized PEG NPs, including 30-50 nm solid and hollow NPs, depending on the Mn II :gallol feed ratio. Variations in size and morphology are attributed to changes in hydrophobicity of the PEG-gallol/Mn II complexes at varying Mn II :gallol ratios based on contact angle measurements. Small-angle X-ray scattering analysis, which is used to monitor particle size and intermolecular interactions during NP evolution, reveals that ionic interactions are the dominant driving force in the formation of the PEG-gallol/Mn II NPs. pH and cytotoxicity studies, and the low-fouling properties of the PEG-gallol/Mn II NPs confirm their high biocompatibility and functionality, suggesting that PEG polyphenol-metal NPs are promising systems for biomedical applications.

Divergent Synthesis of Biocompatible Nearly Monodisperse Multi‐Functional Poly(ethylene glycol) Periodic Copolymers

“…are in general considered as suitable size for a range of biomedical applications such as intravenous drug delivery, imaging, etc. [ 50 ] Synthesis of such stable micelles and nanoparticles is always interesting topic. In our case, the amphiphilic PEG is expected to form stable micelles in water.…”

Plant-inspired Pluronic–gallol micelles with low critical micelle concentration, high colloidal stability, and protein affinity

“…The gallol groups, which are found in antioxidative polyphenols of plant extracts, can exhibit non-covalent interactions with various synthetic polymers ( e.g. , PEG, poly( N -isopropylacrylamide)) 17–19 and natural polymers ( e.g. , polysaccharides and proteins).…”

“…For micellization, octyl gallate, composed of one gallol group and a hydrophobic octyl group, was spontaneously associated with Pluronic F127 polymers. The gallol groups, which are found in antioxidative polyphenols of plant extracts, can exhibit non-covalent interactions with various synthetic polymers (e.g., PEG, poly(N-isopropylacrylamide)) [17][18][19] and natural polymers (e.g., polysaccharides and proteins). 20,21 We demonstrated that such intermolecular interactions of the gallol groups with the PEO segments of Pluronic® provide comparatively higher stability to the micelles than the polymer alone.…”

Microencapsulation of Ionic Liquid by Interfacial Self-Assembly of Metal-Phenolic Network for Efficient Gastric Absorption of Oral Drug Delivery

“…28,29 For example, Caruso et al synthesized MPN nanoparticles by the self-assembly of Mn(II) and PEGgallol at the interface of water in oil microemulsion. 29 Lee and Choi's group reported the self-assembly of Fe III −tannic acid at the fluidic interface by the transformation of Fe II to Fe III induced by O 2 . 30 Therefore, constructing MPN film coating at the IL/water interface may allow the encapsulation of IL in an aqueous medium and endow drug-loaded IL with microenvironment-responsive release.…”