Preparation of PEGylated Iodine-Loaded Nanoparticles via Polymer-Directed Self-Assembly

The preparation of size-tunable PEGylated, iodine-loaded nanoparticles is investigated for biomedical applications. Di-iodination of polyvinyl phenol and encapsulation of the iodinated polymer via directed self-assembly with an amphiphilic polyethylene glycol-based diblock copolymer are reported. Nanoparticles with iodine loadings up to 45 wt% are achieved using a rapid, scalable process. The size of the nanoparticles can be readily tuned between 35 and 130 nm by increasing the ionic strength of the antisolvent used during nanoparticle self-assembly. The resulting PEGylated iodine-loaded nanoparticles have potential applications in nanomedicine for 1) quantitative biodistribution analysis via inductively coupled plasma mass spectrometry (ICP-MS) or 2) X-ray contrast in biomedical imaging. For quantitative biodistribution studies using ICP-MS, a limit of detection of 2 µg mL⁻¹ in mouse serum is achieved. For biomedical imaging, the X-ray attenuation rates are comparable to currently commercially available iodine-based contrast agents. Therefore, encapsulation of the iodinated polymer enables formulation of trackable, size tunable nanoparticles as a versatile platform for developing nanomedicines.