Effect of Amphotericin B Nanodisks on Leishmania major Infected Mice

Lipid Systems for the Delivery of Amphotericin B in Antifungal Therapy

Amphotericin B (AmB), a broad-spectrum polyene antibiotic in the clinic for more than fifty years, remains the gold standard in the treatment of life-threatening invasive fungal infections and visceral leishmaniasis. Due to its poor water solubility and membrane permeability, AmB is conventionally formulated with deoxycholate as a micellar suspension for intravenous administration, but severe infusion-related side effects and nephrotoxicity hamper its therapeutic potential. Lipid-based formulations, such as liposomal AmB, have been developed which significantly reduce the toxic side effects of the drug. However, their high cost and the need for parenteral administration limit their widespread use. Therefore, delivery systems that can retain or even enhance antimicrobial efficacy while simultaneously reducing AmB adverse events are an active area of research. Among those, lipid systems have been extensively investigated due to the high affinity of AmB for binding lipids. The development of a safe and cost-effective oral formulation able to improve drug accessibility would be a major breakthrough, and several lipid systems for the oral delivery of AmB are currently under development. This review summarizes recent advances in lipid-based systems for targeted delivery of AmB focusing on non-parenteral nanoparticulate formulations mainly investigated over the last five years and highlighting those that are currently in clinical trials.

Comparative analysis between four model nanoformulations of amphotericin B-chitosan, amphotericin B-dendrimer, betulinic acid-chitosan and betulinic acid-dendrimer for treatment of Leishmania major: real-time PCR assay plus

Background

Amphotericin B (Amp) and Betulinic acid (BA) as antileishmanial agents have negligible water solubility and high toxicity. To solve these problems, for the first time, chitosan nanoparticles and Anionic Linear Globular Dendrimer (D) were synthesized for the treatment of Leishmania major (L. major).

Method

Chitosan and dendrimer nanoparticles were synthesized, and Amp and BA were loaded into the nanoparticles. The particles were then characterized using various methods and their efficacy was evaluated in vitro and in vivo environments (parasite burden was confirmed using pathological studies and real-time PCR methods).

Result

The results of docking showed that Amp and BA can be loaded into chitosan and dendrimer nanoparticles. The results of physically drug loading efficiency for AK (Amphotericin B-chitosan), BK (Betulinic acid-chitosan), AD (Amphotericin B-Dendrimer) and BD (Betulinic acid- Dendrimer) were 90, 93, 84 and 96 percent, respectively. The characterization results indicated that the drugs were loaded into nanoparticles physically. Moreover, the increased solubility rate for AD=478, BD=790, AK=80 and BK=300 folds. Furthermore, the results of the drug delivery system showed the slow controlled drug release pattern with cellular uptake of more than 90%. The treatment results showed a 100 percent decrease of toxicity for the all nanodrugs was observed in vivo and in vitro environments. Moreover, AK10 and BK20 mg/kg reduced parasite burden by 83 percent (P<0.001), while AD50 and BD40 mg/kg reduced it to a lesser extent compared to glucantime.

Conclusion

All the synthesized nanodrugs were completely succeeded by 100% to recovery the L. major induced pathological effects in the infected footpad. Also, the results of present study were confirmed with real-time PCR and the results showed that AK and BK were succeeded in a large extent to the treatment of L. major infection (P<0.001), therefore AK and BK could be considered as proper alternatives of choices drugs.

Monocyte subpopulations as important biomarkers of resistence and susceptibility during experimental infection with Leishmania (Leishmania) major

Visceral Leishmaniasis is a chronic and lethal, parasitic disease. In the later infection stages, it is known that expressive hematological disorders can be observed, including changes in the frequency and phenotype of certain leukocytes. There is a lack of good prognostic indicators to characterize the on-goin clinical status of the patient. In this study, we have analyzed the frequency of monocyte subpopulations in mice infected with Leishmania major (L. major). Our results show a significant correlation between increased blood monocyte frequency and lesion development in both BALB/c and in the C57BL/6 mice infected with L. major. In BALB/c mice we observed a significant correlation between the frequency of GR1⁺ monocytes and lesion size. Furthermore, treatment of infected BALB/c mice with Anfotericin B, to resolve lesions, resulted in a lower frequency of GR1⁺ monocytes compared to untreated infected BALB/c mice. C57BL/6 infected mice, which normally resolve infections, show decreased numbers of monocytes during the healing phase of infection. The results indicate that disease severity can be predicted by analyzing monocyte frequency. Thus, we propose that the frequency of monocytes, can be used to define the severity of the disease as well as the success of the treatment in experimental leishmaniasis.

Novel Nanosized Chitosan-Betulinic Acid Against Resistant Leishmania Major and First Clinical Observation of such parasite in Kidney

Regarding the antiparasitic effects of Betulinic acid (B) against Leishmaniasis, it was loaded into nanochitosan (K) for the first time in order to improve its therapeutic effects and decrease its side effects for the treatment of Leishmania major-infected Balb/c mice. Improvement the therapeutic efficacy of Bas an anti-leishmania agent through increasing the effective dose was achieved by using a novel solvent and phase separation method for K synthesis. The synthesized K with the size of 102 nm and Betulinic acid-nanochitosan (BK) with the size of 124 nm and drug loading efficiency of 93%, cellular uptake of 97.5% with the slow drug release pattern was prepared. To increase the therapeutic dose, a modified 10% acetic acid solvent was used. The in vitro and in vivo results showed that the nanodrug of BK was non toxic by 100% and BK20 mg/kg could completely performed the wound healing and inhibit the parasite in a large extent (P ˂ 0.001) compared to other groups. Therefore, BK could be considered as an alternative regimen for treatment of L. major.

Reduction toxicity of Amphotericin B through loading into a novel nanoformulation of anionic linear globular dendrimer for improve treatment of leishmania major

Amphotericin B (A) as an antileishmanial drug has limited clinical application owing to severe side-effects and low-water solubility. This is the first study reported using Anionic Linear Globular Dendrimer (ALGD) as A carrier for the increase of A solubility rate, decrease its toxicity, and improve its therapeutic effects. ALGD was synthesized and A was loaded into nanoparticles for the first time with the drug-loading efficiency of 82%. Drug loading was confirmed using characterization methods. The drug solubility rate was increased by 478-folds. The results of the study showed that the A toxicity was significantly decreased by 95% in vitro and in vivo environments, which was confirmed by pathology findings and enzymatic evaluation. Furthermore, the nanodrug caused that mortality rate was reached to zero. Moreover, the nanodrug was as potent as the free drug and glucantime (GUL) in reducing the parasite burden and parasite number. These findings indicated the potency of ALGD to decrease the drug side-effects, increase the drug solubility rate, and improve the drug efficacy. Moreover, the nanoformulation was a non-toxic and cost-effective formulation. The conformity between in vitro and in vivo results suggested that the A-loaded ALGD could be considered as a promising candidate in reducing the side-effects of A in leishmaniasis treatment.