Bionanoparticles of amphiphilic copolymers polyacrylate bearing cholesterol and ascorbate for drug delivery

In this study, a series of amphiphilic polymers with poly(ascorbyl acrylate) (PAAA) as hydrophilic blocks and polyacrylate bearing side-chain cholesteryl mesogens (PCholDEGA) as hydrophobic blocks were prepared using a combination of four-step reactions consisting of two consecutive reversible addition-fragmentation chain transfer (RAFT), desulfurization, and hydrogenolysis under normal pressure. The thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) as well as wide-angle X-ray diffraction (WAXD) studies showed that the copolymers with PCholDEGA as major block had relatively high stability and clear isotropization temperature (Ti). Small-angle X-ray diffraction (SAXD) investigation exhibited that the copolymers had bilayer smectic A structure. Their self-assembly behavior was monitored by turbidity change using UV–vis spectrometer, and the morphology and size of the nanoparticles via self-assembly were detected using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The entrapment efficiency and loading capacity of these amphiphilic copolymers were investigated using nile red and drug molecule Ibuprofen. These polymeric micelles with PAAA shell extending into the aqueous solution and strong hydrophobic PCholDEGA core have potential abilities to act as promising nanovehicles with high loading and targeting delivery.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (99 K)Download as PowerPoint slideHighlights► The core–shell-shaped micelles were formed by the self-assemble of PCholDEGA-block-(PAAA-rad-PBnAAA). ► A bilayer smectic A structure was detected for the polymers having long PCholDEGA-block. ► Strong hydrophobic interaction of PCholDEGA-block led to the high-loading efficiency of the amphiphilic polymers.