Antileishmanial efficacy of amphotericin B bearing emulsomes against experimental visceral leishmaniasis

Abstract

Amphotericin B (AmB) was formulated in trilaurin-based emulsomes (nanosize lipid particles) stabilized by soya phosphatidylcholine (PC), as a new delivery system for macrophage targeting for the treatment of visceral leishmaniasis (VL). Emulsomes were modified by coating them with macrophage-specific ligand (O-palmitoyl mannan, OPM). The antileishmanial activity of AmB-deoxycholate (AmB-Doc) and emulsome entrapped AmB was tested in vitro in Leishmania donovani infected macrophage-amastigote system (J774A.1 cells), which showed higher efficacy of OPM grafted AmB emulsomes (TLEs-OPM) over plain AmB emulsomes (TLEs) and AmB-Doc. The in vivo antileishmanial activity of the AmB (0.5 mg/kg) was tested in AmB-Doc, TLEs and TLEs-OPM forms against VL in L. donovani infected hamsters. Formulation TLEs-OPM eliminated intracellular amastigotes of L. donovani within splenic macrophages more efficiently (73.7 +/- 6.7% parasite inhibition) than the formulation TLEs (51.7 +/- 5.4% parasite inhibition) (P < 0.01) or AmB-Doc (30.4 +/- 4.8% parasite inhibition) (P < 0.001). Our results suggest that these newer formulations (plain and ligand appended emulsomes) are a promising alternative to the conventional AmB-Doc formulation for the treatment of VL.

PLGA-based macrophage-mediated drug targeting for the treatment of visceral leishmaniasis

“…After washing, cells were fixed in 10% formalin in PBS and observed by CLSM (Olympus IX 81, Center Valley, PA, USA) equipped with a × 60 oil objective lens. Percent parasite inhibition in treated wells was calculated using the following formula reported and published by our associated group previously (2,6).…”

“…Studies on VL revealed that organs such as spleen and liver serve as safe havens for parasites residing inside the macrophages. Most of the antileishmanial drugs presently in use, fail to penetrate macrophages within which parasite creep and that derives researchers to pursue delivery systems and their engineered versions in order to be therapeutically effective (2). Currently surviving therapies for leishmaniasis are very toxic and also started exhibiting emergence of drug-resistant parasitic strains.…”

Development and evaluation of macrophage targeted multidrug therapy against visceral leishmaniasis

“…The Ex-vivo studies were performed by observing drug leaching and change in particle size following incubation of PCL-NPs with freshly pooled rat serum at 37 ± 1 0 C. The drug content of the PCL-NPs was determined by the method described previously with slight modifications (16). PCL-NPs formulations (1 mL) were incubated with 2 ml serum at 37 ± 1°C for 1, 2, 4, 6 and 24 hrs.…”

“…(2, 3, 4, 5 mg for AmB and 5, 10, 15, and 20 mg for DOX) in different formulations (Table 1) for determining optimum AmB and DOX content (15). Average particle size of different formulations was determined by particle size analyzer (Delsa Nano C, Beckman Coulter, USA) and percent drug entrapment in different formulations was also determined as described previously (16). PCL-NPs with optimum AmB and DOX to polymer content were optimized for optimum sonication time in terms of average particle size.…”

“…PCL-NPs were evaluated for percent drug entrapment and percent haemolysis. Percent haemolysis was determined by the method reported in literature (16). The optimization method for PCL-NPs was done to produce NPs of small size with high entrapment efficiency ( Figure 1).…”