novel carrier-mediated drug (steroid and anti-oxidant) formulations that have the ... The carriers are liposomes that have hyaluronan covalently-anchored to the.
Inhalational therapy post-exposure to toxic chemical materials applying novel targeted drug-carrier formulations, modeled in chlorine-exposed mice. Ilia Rivkin1, Yifat Galnoy-Glucksam1, Inbar Elron-Gross1, Amichay Afriat2, Arik Eisenkraft2,3,4 and Rimona Margalit1.1Department of Biochemistry and Molecular Biology, The 1George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel; 2NBC Protection Division, IMOD; 3Medical Corps Headquarters, IDF; 4The Institute for Research in Military Medicine, The Department of Military Medicine, The Hebrew University, Jerusalem, Israel.
Introduction
Objectives
3. Inhalational treatment of chlorine-exposed mice
1. The problem
To obtain proof of concept in chlorine-exposed mice, treated with aerosols of the drug-carrier formulations, testing single vs. dual drugs in the same liposome, and single vs. multiple dosings.
Typical weight changes as function of time and treatment, for days 2 and 15 from chlorine exposure (day 0) are shown in figure 4. The best doses were found to be 4 mg/ml NAC, 0.12 mg/ml Dex and 20 mg lipid/ml. Treating chlorineexposed mice with drug-free liposomes had no impact. The liposomal drugs were superior (up to 5 fold) to aerosols of the same doses of free drugs in both weight gain and reproducibility.
Materials and Methods
Toxic Industrial Materials (TICs), transported over railways and roads, are potential sources of accident-caused mass casualties, TICs are also chemical weapons. Currently, immediate and follow-up treatment for control of respiratory damage, by administration of free steroids and anti-oxidants is highly unsatisfactory. Free drugs lack targeting hence are distributed indiscriminately and are prone to dilution, inactivation and premature clearance – all of which undermine treatment efficacy. The indiscriminate distribution also leads to adverse effects and risks of toxicity.
1. Airways and lung deposition As shown in figure 3, good deposition of the liposomal aerosol was obtained, the liposomes reaching deep into the lungs.
Dex
NAC
Lung deposition
ACI stage
1
Cumulative Deposition: 69% of total
5 6
F 10
20
30
NAC
Figure 3: Left-hand side – the ACI device, right hand side - the different deposition localizations in human airways and lungs. Middle – the results of liposome deposition.
2. Behavioral response of mice exposed to chlorine in the inhalation chamber
Figure 2: The formulations of this project. NAC is the anti-oxidant N – Acetyl Cysteine and Dex is the anti-inflammatory corticosteroid Dexamethasone
The carriers are liposomes that have hyaluronan covalently-anchored to the liposomal surface, denoted HA-MLV. Figure 2A shows schemes of the three HA-MLV formulations: NAC alone, Dexamethasone (Dex) alone, NAC+Dex in the same liposome Figure 2B is an electron micrograph of an open liposome (MLV) illustrating the localizations proposed for Dexamethasone (within the lipid layer) and for NAC (within the water interior). In all three formulations there was good encapsulation, the systems performed as slow-release drug depots, the encapsulated drugs retained their therapeutic activities. The liposomal formulations were therapeutically-active in vitro, and were stable in the aerosols (by nebulization) retaining all pre-aerosolization properties.
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4 2
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*
0
Air Air
ClCl2 2
L-ND*1 L-ND*1
L-ND*3 L-ND*3
L-N*1 L-N*1
L-N*3 L-N*3
+ Cl2
Figure 4: The impact of liposomal treatment on chlorine-exposed mice at days 2 and 15. Air – control mice exposed to air only, in the inhalation chamber. Cl2 – mice exposed to chlorine only, without treatment. L-ND – hyaluronan liposomes (HA-MLV) encapsulating both NAC and Dex. L-N – hyaluronan liposomes encapsulating NAC alone. *1 indicates a single dose and *3 indicates three doses. Statistical significance is of control and each treatment compared to the group exposed to chlorine alone. * p
