title: Biodegradable microparticles containing crotamine isolated from Crotalus durissus terrificus display antileishmanial activity in vitro.
abstract: OBJECTIVE
  To evaluate antileishmanial activity of crotamine, a toxin isolated from Crotalus durissus terrificus, in solution form and encapsulated in biodegradable microparticles in vitro.
  
  
  METHODS
  Particles were analyzed on-chip by surface plasmon resonance and characterized by testing their diameters, zeta potential and encapsulation rate. The viability of promastigotes as well as murine macrophages was assessed. Furthermore, the phagocytic index was determined for macrophages, and cell supernatants were collected for the determination of TNF-α levels. An infection assay using Leishmania amazonensis-infected macrophages was also conducted.
  
  
  RESULTS
  The diameters and zeta potential of control particles (1.35 μm; -12.3 mV) and of those containing crotamine (3.09 μm; -20.9 mV) were adequate for the assays conducted. Crotamine-loaded particles were better captured by macrophages than control particles (increase of 12% in the phagocytic index), leading to increased TNF-α levels (196 pg/ml), and they also induced a significant decrease in the numbers of amastigotes compared to infected macrophages only.
  
  
  CONCLUSIONS
  The approach presented here opens the possibility of working with safe concentrations of encapsulated toxins to reach antileishmanial effects.
authors: Laboratório de Biotecnologia Aplicada à Saúde, Fundação Oswaldo Cruz, Fiocruz Rondônia, Porto Velho, RO, Brazil.
authors: Sharon Rose A
authors: SR
authors: Macedo
authors: Neuza B
authors: NB
authors: de Barros
authors: Amália S
authors: AS
authors: Ferreira
authors: Leandro S
authors: LS
authors: Moreira-Dill
authors: Leonardo A
authors: LA
authors: Calderon
authors: Andreimar M
authors: AM
authors: Soares
authors: Roberto
authors: R
authors: Nicolete
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000008:administration & dosage / Q000494:pharmacology*; D003435:Crotalid Venoms / Q000008:administration & dosage / Q000494:pharmacology*; D017839:Crotalus; D004337:Drug Carriers / Q000008:administration & dosage / Q000494:pharmacology; D019344:Lactic Acid / Q000737:chemistry; D007891:Leishmania / Q000187:drug effects*; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology; D008297:Male; D008807:Mice, Inbred BALB C; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000981:Antiprotozoal Agents; D003435:Crotalid Venoms; D004337:Drug Carriers; D014409:Tumor Necrosis Factor-alpha; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C010563:crotamine