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Current organ transplantation protocols require the rapid transport of freshly isolated donor tissue to the recipient patient at the site where the procedure is to be conducted. During transport, the tissue graft can quickly deteriorate as a result of oxygen starvation. In this study, we report the fabrication of oxygen-releasing coatings for improved tissue preservation. The coatings were prepared via the encapsulation of calcium peroxide or urea peroxide microparticles between layers of octadiene plasma polymer films. By varying the thickness of the plasma polymer coating and type of peroxide, formulations were obtained that generate oxygen upon contact with aqueous solutions, while at the same time limiting the amount of toxic reactive oxygen species produced. The optimized coatings were tested under hypoxic conditions using the MIN6 β-cell line, which resulted in a 3-fold increase in the viability of cultured cells. These thin oxygen-releasing coatings can be deposited on a wide range of surfaces, creating a platform for oxygen delivery with the potential to extend the viability of transported tissues and increase the time frame available for graft transport. Refereed/Peer-reviewed

When polymeric nanoparticles (NPs) are formed by nanoprecipitation, which is a nucleation−growth process, the control over size requires changing the polymer concentration or solvent composition. Here, we demonstrate that the NP size can be controlled independent of polymer variables by introducing a polyelectrolyte (PE) inthe aqueous phase. PEs that exhibit hydrogen bonding (H-bonding) yield a reduction in NP size, whereas PEs that do not possess this characteristic promote the formation of larger NPs. The observed effect can be attributed to the formation of a diffusional barrier around the NP in the form of a dense shell. This principle of controlling NP size is not limited to polymers and can also be employed in the production of lipid NPs. Refereed/Peer-reviewed