(181f) Encapsulation of Salmon Hemoglobin in Silk Nanoparticles for Oxygen Delivery

Biological applications of microparticles and nanoparticles include the encapsulation and controlled release of bioactive molecules. Formation of these particles from silk fibroin is useful due to both the stabilization properties of the polymer, and its degradation into small peptides and amino acids in vivo (1-4). This work aims to leverage the unique properties of silk fibroin to encapsulate naturally-occurring oxygen carriers- specifically salmon hemoglobin. We aim to produce nanoparticles in the 200-500 nm range. The silk fibroin is isolated from Bombyx Mori cocoons and particles are then formed via phase separation with polyvinyl alcohol (PVA) (5, 6). The phase separation is induced via probe sonication. The amplitude of sonication, silk processing conditions, and relative concentrations of silk and PVA inform the final particle size. In order to establish a design space, we tested sonication amplitudes of 0, 8, 12, 16, 25, 40, and 50% as well as silk degumming times of 30, 60, and 90 minutes. Samples were analyzed via light microscopy, scanning electron microscopy (SEM) and dynamic light scattering (DLS) to assess particle size, stability and morphology. While changes in average size were observed as a function of these variables, high levels of polydispersity existed across all samples. In order to narrow the size distribution, the suspended particle solution was filtered. Following formation of a particle solution containing narrow polydispersity, we analyzed the incorporation of salmon hemoglobin into the particles and built a 2D Reaction-Diffusion COMSOL® model to predict oxygen dynamics within these particles as a function of the formulation parameters. On-going work aims to evaluate the oxygen delivery profiles using an in vitro perfusion flow system and PreSens® oxygen flow sensors.

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6.Solomun JI, Totten JD, Wongpinyochit T, Florence AJ, Seib FP. Manual Versus Microfluidic-Assisted Nanoparticle Manufacture: Impact of Silk Fibroin Stock on Nanoparticle Characteristics. ACS Biomaterials Science & Engineering. 2020;6(5):2796-804. doi: 10.1021/acsbiomaterials.0c00202.

This work is funded by the Department of Defense W81XWH2110199.