Recovery rate of multiple enteric viruses artificially seeded in water and concentrated by adsorption-elution with negatively charged membranes: interaction and interference between different virus species.

Viral concentration method by adsorption-elution with negative membranes has been widely employed for concentrating viruses from environmental samples. In order to provide an adequate assessment of its recovery efficiency, this study was conducted to assess viral recovery rates for viral species commonly found in water (HAdV-5, EV, RV, BAdV and CAV-2), quantifying viral genomes at the end of the five different steps of the process. Recovery rates were analyzed for several viruses combined in a single water sample and for each virus assayed separately. Ultrapure water samples were artificially contaminated and analyzed by real-time quantitative polymerase chain reaction (qPCR). High recovery rates were found after the final stage when assessed individually (89 to 125%) and combined in the same sample (23 to > 164%). HAdV-5 exhibited >100% recovery when assayed with human viruses and other AdVs, whereas BAdV and CAV-2 were not detected. These data suggest that recovery efficiency could be related to viral structural characteristics, their electric charges and other interactions, so that they are retained with greater or lesser efficiency when coupled. This protocol could be applied to environmental samples, since high recovery rates were observed and infectious viruses were detected at the end of the concentration process.

Evaluation of scaffolds based on α-tricalcium phosphate cements for tissue engineering applications.

Growth of cells in 3-D porous scaffolds has gained importance in the field of tissue engineering. The scaffolds guide cellular growth, synthesize extracellular matrix and other biological molecules, and make the formation of tissues and functional organs easier. The aim of this study is to use α-tricalcium phosphate cement in order to obtain new types of scaffolds with the aid of paraffin spheres as pore generators. The porosity of the scaffolds produced with paraffin spheres was analyzed and compared to the literature, and the study of scaffold permeability using the Forchheimer equation allowed the analysis of pore interconnectivity. In vitro tests showed the behavior of scaffolds in solutions of simulated body fluid, and viability and cell proliferation were also evaluated. The results show the potential use of the materials developed for scaffolds for use in tissue engineering applications.