engleski

Prevention of decompression illness: recently developed albumin-derived perfluorocarbon-based nanocapsules prove effectiveness on a clinical, biochemical and histological level

Decompression illness (DCI) is caused by the formation of nitrogen bubbles in blood and tissues. Perfluorocarbons with extraordinary gas dissolving capabilities failed in clinical routine because of side-effects associated with added emulsifiers. Albumin-derived perfluorocarbon-based nanocapsules (A-AOCs) combine good tolerability with the ability of transporting surplus nitrogen to the lung and improving oxygen supply in small vessels. The aim of this study was to assess whether A-AOCs could protect against DCI. Thirty seven Wistar rats were treated with A-AOCs (n=12), albumin nanocapsules filled with neutral oil (A-O-N, n=12) or serum albumin (A-0-0, n=13) before a simulated air dive in a hyperbaric chamber (Compression: 100 kPa/min up to 1, 000 kPa, maximum for 35min, decompression: 100 kPa/min pausing 5min at 200/160 kPa, 10min at 130 kPa). 11 rats injected with A-AOCs stayed at normal pressure. Up to 30 min after surfacing animals were supervised for clinical symptoms. Activity of lactate, transaminases, creatine kinase, myoglobin, D-dimer-levels, lactate dehydrogenase were measured in plasma samples. Histological assessment of spleen, kidney, heart, lung, liver was performed (hematoxylin-eosin). Statistical analysis: Chi square test, One-way ANOVA, Tukey's post hoc analysis (5% significance level).No toxic/allergic side-effects of A-AOCs were observed. The occurrence of the 3 levels of DCI depended on the treatment group (χ2 = 11.412, dl=4, p=0.022) [Fig.01]. A-AOCs significantly reduced DCI-appearance/mortality (χ2 = 10.17628, dl=4, p=0.006). A significant improvement of survival time was found (A-AOCs compared with A-0-0 treatments, p=0.001).Histological assessment of A-AOCs- compared with A-0-0-animals revealed significantly higher accumulation of macrophages but less blood congestion in the spleen ; significantly less circulatory disturbances, vacuolisation and cell damage in the liver. Compared to non-diving controls quickly responding plasma parameters lactate and myoglobin showed a significant increase after diving in the A- 0-0 and A-O-N group but not in the A-AOCs group. In conclusion the preventive intravenous application of A-AOCs proved to be well tolerated and effective in reducing the occurrence of DCI. Treated animals showed significantly higher survival rate and less symptoms compared to the group which received serum albumin only. These positive results were confirmed by analysis of histological examinations and plasma parameters.

decompression illness ; nanocapsules

nije evidentirano