Emerging Nanoassembly of Polyrotaxanes Comprising Acetylated α-Cyclodextrins and High-Molecular-Weight Axle Polymer

Asato Tonegawa; Atsushi Tamura; Nobuhiko Yui

doi:10.1021/acsmacrolett.9b00280

Emerging Nanoassembly of Polyrotaxanes Comprising Acetylated α-Cyclodextrins and High-Molecular-Weight Axle Polymer

ACS Macro Lett. 2019 Jul 16;8(7):826-834. doi: 10.1021/acsmacrolett.9b00280. Epub 2019 Jun 19.

Authors

Asato Tonegawa¹, Atsushi Tamura¹, Nobuhiko Yui¹

Affiliation

¹ Department of Organic Biomaterials, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062, Japan.

PMID: 35619503
DOI: 10.1021/acsmacrolett.9b00280

Abstract

Acetylated α-cyclodextrin (α-CD)/poly(ethylene glycol) (PEG)-based polyrotaxanes (Ac-PRXs) with varying degrees of acetylation (DA) and molecular weight of axle PEG were synthesized and their solubility in aqueous solutions was investigated. Ac-PRXs with low DA (less than 35%) were dissolved in aqueous solutions without considering the molecular weight of axle PEG, whereas Ac-PRXs with high DA (more than 40%) and low molecular weight of axle PEG (less than 35000) were precipitated into the solutions. Interestingly, Ac-PRXs with high DA and high molecular weight of axle PEG (100000) exhibited a colloidal dispersion in aqueous solutions. It is considered that the threaded acetylated α-CDs formed hydrophobic microenvironments via hydrophobic interactions and the noncovered segments of axle PEGs provided colloidal stability. Furthermore, the potential application of Ac-PRX_100k as a drug carrier was examined and it was established that Ac-PRX_100k can encapsulate a hydrophobic drug. Accordingly, acetylation of PRXs is a viable approach to promote solubility in aqueous solutions and prepare self-assembled nanoparticles.