RNA-Based Therapy for Cryptosporidium parvum Infection: Proof-of-Concept Studies.

Cryptosporidium is a leading cause of moderate-to-severe diarrhea in children, which is one of the major causes of death in children under 5 years old. Nitazoxanide is the only FDA-approved treatment for cryptosporidiosis. However, it has limited efficacy in immunosuppressed patients and malnourished children. Therefore, it is urgent to develop novel therapies against this parasite. RNA interference-mediated therapies are emerging as novel approaches for the treatment of infectious diseases. We have developed a novel method to silence essential genes in Cryptosporidium using single-stranded RNA (ssRNA)/Argonaute (Ago) complexes. In this work we conducted proof-of-concept studies to test the anticryptosporidial activity of these complexes by silencing Cryptosporidium parvum nucleoside diphosphate kinase (NDK) using in vitro and in vivo models. We demonstrated that a 3-day treatment with anti-sense NDK ssRNA/Ago decreased parasite burden by ~98% on infected cells. In vivo studies showed that ssRNA/Ago complexes encapsulated in lipid nanoparticles can be delivered onto intestinal epithelial cells of mice treated orally. In addition a cryptosporidiosis-mouse model showed that treatment with NDK ssRNA/Ago complexes reduced oocyst shedding in 4/5 SCID/beige mice during the acute phase of the infection. Our findings highlight the potential use of antisense RNA-based therapy as an alternative approach to cryptosporidiosis treatment.

Combining TiO2-photocatalysis and wetland reactors for the efficient treatment of pesticides.

In the present work the photocatalytic and biological degradation of two commercial mixtures of pesticides (Folimat and Ronstar) and two fungicides (pyrimethanil and triadimenol) has been studied. The evolution of some components of these commercial products (dicofol, tetradifon and oxadiazon) and that of the two fungicides has been monitored by means of HPLC, GC-MS, TOC and toxicity (Lemna minor toxicity test) measurements. The photocatalytic method was able to degrade dicofol, tetradifon, pyrimethanil, triadimenol and the components of Ronstar with the exception of oxadiazon. In addition to this, the photocatalytic method eliminated pyrimethanil toxicity and reduced that of triadimenol by a 90%, Ronstar by a 78% and Folimat by an 87%. Nevertheless, the wetland reactors alone could reduce the toxicity of only the former. Finally, the proper dosage of the water containing the pesticides to a photocatalytic reactor followed by a wetland reactor resulted to be the most successful strategy for the detoxification of the studied compounds and their mixtures.