Controlling Nanoemulsion Surface Chemistry with Poly(2-Oxazoline) Amphiphiles

Abstract

Emulsions are dynamic materials that have been extensively employed within pharmaceutical, food and cosmetics industries. However, their use beyond conventional applications has been hindered by difficulties in surface functionalization, and an inability to selectively control physicochemical properties. Here, we employ custom poly(2-oxazoline) block copolymers to overcome these limitations. We demonstrate that poly(2-oxazoline) copolymers can effectively stabilize nanoscale droplets of hydrocarbon and perfluorocarbon in water. The living polymerization allows for the incorporation of chemical handles into the surfactants such that covalent modification of the emulsion surfaces can be performed. Through post-emulsion modification, we are able to access nanoemulsions with modified surface chemistries, yet consistent sizes. By decoupling size and surface charge, we explore structure-activity relationships involving the cellular uptake of nanoemulsions.

Fluorous Soluble Cyanine Dyes for Visualizing Perfluorocarbons in Living Systems

“…Previously, we have employed fluorous rhodamine 3 to track the cellular internalization and localization of 200 nm PFC nanoemulsions via confocal microscopy. 19,49 While this has been successful, only having one fluorophore available for imaging the nanoemulsions using common confocal laser lines (i.e., 405, 488, 532, or 635 nm) 50 limits the flexibility of multichannel experiments. Additionally, if the loading of rhodamine 3 into the nanoemulsions is too high, aggregation and leakage of the fluorophore is observed.…”

Therapeutic oxygen delivery by perfluorocarbon-based colloids

“…New binding techniques based on biorthogonal click chemistry are emerging [262,263]. Poly(2-oxazoline) amphiphiles were used to control PFC nanoemulsion surface chemistry [264]. Such additions authorize fluorescence, photoacoustic and sono-photoacoustic imaging, computed tomography (CT), X-ray phase contrast imaging, positron emission tomography (PET) or single-photon emission computed tomography (SPECT), or MR imaging or guidance, as well as labeling and tracking of circulating cells.…”

Regulating trained immunity with nanomedicine

“…Polymeric nanoparticles composed of amphiphilic block copolymers include polymeric vesicles called polymersomes 96 , nanostructures with a micellar morphology 97 , nanoemulsions consisting of a lipophilic matrix covered by a monolayer of block copolymers 98 , as well as polymeric nanoparticles for RNA delivery 99 . Lipoprotein-derived and -inspired nanomaterials include high-density lipoprotein 87 , low-density lipoprotein and microemulsion-like structures, as well as a apolipoprotein A1-based nanobiologic platform 56 .…”