Abstract
We have produced uncoated IONP by a co-precipitation method in a range of sizes and subsequently coated the nanoparticles using poly(glycerol adipate) using the interfacial deposition method. To produce the necessary thin coatings a relatively small addition of polymer (approx. 0.1–0.2 mg polymer per 38 mg IONP) was necessary. A number of different PGA polymer variants with different physicochemical properties were used and the results suggested that the polymer properties also affected the coating process. Optimum coatings only a few nm thick (1–3 nm) were obtained with a linear poly(ethylene glycol)-PGA copolymer modified with 40% pendant oleic acid moieties. The resulting sterically stabilised IONP were stable against aggregation at and above physiological salt concentrations. Preliminary experiments demonstrated that the nanoparticles had relaxivity values comparable to commercially available IONP of a similar size and could be taken up readily by cells. This coating method therefore shows promise for a variety of medical application