In vitro model to compare the oxygen offloading behaviour of dodecafluoropentane emulsion (DDFPe)

Figures & data

Figure 1. Experimental set-up. In vitro oxygenation set-up used to simulate gas exchange and oxygen delivery from the lungs (fluid reservoir) to hypoxic tissues (gas exchange vessel).

Table 1. Table of assays.

Assay name	Sparging gas	Headspace gas	Fluid reservoir fluid
1. N2	N2	N2	0.9% Saline
2. PTB + sucrose blank	N2	N2	0.9% Saline
3. He	N2	He	0.9% Saline
4. He	He	He	0.9% Saline
5. CO2	CO2	CO2	0.9% Saline
6. Pre-oxygenation	CO2	CO2	0.9% Saline

Table of oxygen transport assays, describes the experimental components for each conducted assay. A control and an experimental test were run per assay.

Figure 2. Net oxygen offloading in sparging gas study. The net increase in oxygen concentration in the gas exchange vessel for assays 1–5 (Table 1). The number of trials for each assay (from left to right) is as follows: N₂ control (n = 4), N₂ DDFPe (n = 6), PTB + sucrose blank (n = 2), He control (sparged with N₂) (n = 4), He DDFPe (sparged with N₂) (n = 5), He control (sparged with He) (n = 3), He DDFPe (sparged with He) (n = 3), CO₂ control (n = 5) and CO₂ DDFPe (n = 3).

Figure 3. Effect of sparging gas selection on oxygen transport. The increase in oxygen concentration in the gas exchange vessel in assays 3 and 4 (Table 1), over the course of 45 min. Net increase of oxygen in the He DDFPe (sparged with N2) run compared to He DDFPe (sparged with He) run is statistically significant (p = .004).

Table 2. Sparging gas solubility and net oxygenation.

Solubility of gases in water at 25 °C (g of gas/kg of H2O)		Net oxygenation in 0.9% saline control (mg/l)
He	0.0015	4.42
N2	0.0175	4.15
O2	0.04	–
CO2	1.5	2.00

Solubility of gases in water at 25 °C and net oxygenation in control assay, compares the solubility of the utilized inert gases relative to molecular oxygen in water [25] to the net increase in oxygen concentration in the gas exchange vessel during the saline controls for each sparging gas (see assays 1, 4, and 5 in Table 1).

Figure 4. Oxygen offloading of pre-oxygenated DDFPe. The oxygen offloading behaviour of the pre-oxygenated DDPFe in assay 6 (Table 1).

Figure 5. Average oxygen offloading under pre-oxygenation and simultaneous oxygenation of DDFPe. Comparison of pre-oxygenated and simultaneously oxygenated DDFPe oxygen offloading. The graph depicts the oxygen offloading behaviour of pre-oxygenated DDFPe assay 6 (Table 1) in comparison to simultaneously oxygenated DDFPe assay 5 (Table 1).

Solubility of Gases in Water [online]. Engineering ToolBox; 2008 [cited 2018, July 6]. Available from:https://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html

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Data availability statement

All data supporting the results or analyses presented in the paper reside at NuvOx Pharma. For further information, contact the corresponding author. Meghna Jayaraman is a senior at the University of Arizona, majoring in biomedical engineering and minoring in mathematics and astronomy. She has been an intern at NuvOx Pharma for the past 2 years, where she has worked on refining an in vitro model of the human lung. As an undergraduate student researcher, she also has experience with biocompatible material characterization and pressure volume loop analysis in cardiac research. Kaitlin Graham (Harpel) is the Program Manager at NuvOx Pharma. She received her Master of Science degree in Biomedical Engineering at the University of Arizona. Her previous research experiences include oncology, microscopy, and cancer detection through the use of targeted perfluorocarbon microbubbles.