Pharmaceutical emulsions: a new approach for gene therapy

The concept of gene therapy involves the experimental transfer of a therapeutic gene into an individual's cells and tissues to replace an abnormal gene aiming to treat a disease, or to use the gene to treat a disease just like a medicine, improving the clinical status of a patient. The achievement of a foreigner nucleic acid into a population of cells requires its transfer to the target. Therefore, it is essential to create carriers (vectors) that transfer and protect the nucleic acid until it reaches the target. The obvious disadvantages of the use of viral vectors have directed the research for the development of a nonviral organized system such as emulsions. In fact, recently, there has been an increase of interest in its use in biotechnology as a nonviral vector for gene therapy. This review focuses on the progress of cationic emulsions and the improvement of the formulations, as a potential delivery system for gene therapy.</

Identification of plasmids from Brazilian Chromobacterium violaceum strains

Chromobacterium violaceum is an opportunistic pathogen found in tropical and subtropical regions worldwide. C. violaceum infections are difficult to treat, and many strains are resistant to antibiotics. Recently, a novel plasmid (pChV1) was discovered in the type strain ATCC 12472, suggesting that other C. violaceum strains may harbor extra-chromosomal DNA. The aim of the present study was to detect and compare new plasmids in Brazilian strains of C. violaceum using next generation sequencing techniques. We obtained draft genomes of six plasmids from strains isolated from the Amazon region and aligned them to pChV1. At least three plasmids, CVAC05, CVACO2, and CVT8, were similar to pChV1. Phylogenetic analysis suggested that these new extra-chromosomal DNA sequences have a common origin to pChV1, but have diverged. Many of the ORFs detected were related to plasmid segregation/maintenance, viral structural proteins, and proteins with unknown functions. These findings may enable better genetic manipulation of C. violaceum, which will enhance our ability to exploit this valuable microorganism in industrial and clinical applications.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Leads from Physical, Chemical, and Thermal Characterization on Cytotoxic Effects of Xylan-Based Microparticles

Interfacial cross-linking (ICL) has been considered a feasible technique to produce polysaccharide-based microparticles (PbMs), even though only a few studies have been concerned with their biocompatibility. In this work, PbMs were prepared by the ICL method and characterized in regard to their in vitro biocompatibility, chemical linkages, and physical and thermal properties. First, the cell viability assay revealed that PbMs toxicity was concentration-dependent. Then, it was observed that the toxicity may be related to the way in which the binding occurred, and not exclusively to the stoichiometry between the polymer and the cross-linking agent. Moreover, the PbMs biosafety was predicted by the use of physicochemical procedures, which were able to identify unbound cross-linking agent residues and also to reveal the improvement of their thermal stability. Accordingly, this work suggests a step-by-step physicochemical procedure able to predict potential toxicity from micro-structured devices produced by polysaccharides. Likewise, the use of PbMs as a drug carrier should be cautiously considered

A model for the RecA protein of Mycoplasma synoviae

In this work, we predict a structural model for the RecA protein from M. synoviae (MsRecA) by theoretical homology modeling and evaluate the occurrence of polymorphisms in this protein within several isolates of this species. The structural model suggested for MsRecA conserves the main domains present in MtRecA and EcRecA. The L1 and L2 regions showed six and three amino acid substitutions, respectively, which apparently do not affect the conformation and function of MsRecA. The C-terminal domain is shorter than that found in EcRecA and MtRecA, which may increase its capacity to bind dsDNA and displace SSB, compensating the absence of recombination initiation enzymes. The MS59 isolate RecA sequence showed one polymorphism which does not affect its functions since these belong to the same physical-chemical group