Tanning process is a polluting activity due to the release of toxic agents into the environment. One of the most important of those toxic chemicals is chromium. Different alternatives have been proposed for the removal of this metal from tanning waste water which include the optimization of the productive processes, physicochemical and biochemical waste water treatment. In this study, the biological adsorption process of trivalent chromium was carried out in synthetic water and tannery waste water through two types of native green microalgae, called Chlorella vulgaris and Scenedesmus acutus in Free State and immobilized in PVA state. This, considering that cellular wall of microalgae has functional groups like amines and carboxyl that might bind with trivalent chromium. Statistical significance of variables as pH temperature, chromium and algae concentrations was evaluated just like bio sorption capacity of different types of water and kind of bioadsorbent was calculated to determine if this process is a competitive solution comparing to other heavy metal removal processes.

Mesenchymal stromal cells (MSC) derived from human umbilical cord Wharton’s jelly (WJ) have a wide therapeutic potential in cell therapy and tissue engineering because of their multipotential capacity, which can be reinforced through gene therapy in order to modulate specific responses. However, reported methodologies to transfect WJ-MSC using cationic polymers are scarce. Here, WJ-MSC were transfected using 25 kDa branched- polyethylenimine (PEI) and a DNA plasmid encoding GFP. PEI/plasmid complexes were characterized to establish the best transfection efficiencies with lowest toxicity. Expression of MSC-related cell surface markers was evaluated. Likewise, immunomodulatory activity and multipotential capacity of transfected WJ-MSC were assessed by CD2/CD3/CD28-activated peripheral blood mononuclear cells (PBMC) cocultures and osteogenic and adipogenic differentiation assays, respectively. An association between cell number, PEI and DNA content, and transfection efficiency was observed. The highest transfection efficiency (15.3 ± 8.6%) at the lowest toxicity was achieved using 2 ng/μL DNA and 3.6 ng/μL PEI with 45,000 WJ-MSC in a 24-well plate format (200 μL). Under these conditions, there was no significant difference between the expression of MSC-identity markers, inhibitory effect on CD3+ T lymphocytes proliferation and osteogenic/adipogenic differentiation ability of transfected WJ-MSC, as compared with non-transfected cells. These results suggest that the functional properties of WJ-MSC were not altered after optimized transfection with PEI.

The maximization of lipid productivity in microalgae is crucial for the biofuel industry, and it can be achieved by manipulating their metabolism. However, little efforts have been made to apply metabolic models in a dynamic framework to predict possible outcomes to scenarios observed at an industrial scale. Here, we present a dynamic framework for the simulation of large-scale photobioreactors. The framework was generated by merging the genome-scale metabolic model of Chlorella vulgaris ( i CZ843) with reactor-scale parameters, thus yielding a multiscale model. This multiscale model was employed to predict the sensitivity of growth and composition variation of C. vulgaris on light and nitrogen levels. Simulations of lipid accumulation quantified the tradeoff between growth and lipid biosynthesis under nitrogen limitation. Moreover, our modeling approach quantitatively predicted the dependence of microalgal metabolism on light intensity and circadian oscillations. Finally, we use the model to design a reactor irradiance profile that maximized lipid accumulation, thus achieving a lipid productivity increase of 46% at a constant intensity of 966 μE m ⁻² s ⁻¹ . Our modeling framework elucidated how metabolism and external factors can be combined to predict optimized parameters for industrial applications.

Background Wharton’s Jelly-derived mesenchymal stromal cells (WJ-MSCs) present several advantages over other sources of multipotent stem cells, not only because they are obtained from neonatal umbilical cord, which is considered a biological waste, but also display higher proliferation rate and low senescence at later passages compared to stromal cells obtained from other sources. In the field of tissue engineering, WJ-MSCs have a wide therapeutic potential, due to their multipotential capacity, which can be reinforced if cells are genetically modified to direct their differentiation towards a specific lineage; unfortunately, as primary cells, WJ-MSC are difficult to transfect. Therefore, the objective of the present work was to standardize a protocol for the transfection of WJ-MSCs using a cationic polymer. Such protocol is important for future developments that contemplate the genetic modification of WJ-MSCs for therapeutic purposes. Methods In this work, WJ-MSCs were genetically modified using polyethylenimine (PEI) and a lentiviral plasmid that encodes for green fluorescent protein (pGFP). To achieve WJ-MSCs transfection, complexes between PEI and pGFP, varying its composition (N/P ratio), were evaluated and characterized by size, zeta potential and cytotoxicity. At the N/P ratio condition where the highest transfection efficiencies were obtained, immunophenotype, immunomodulation properties and multipotential capacity of WJ-MSCs were evaluated. Results Here, we present the standardization of the transfection conditions of the WJ-MSCs in a monolayer culture with PEI. The concentrations of plasmid and PEI that have the best transfection efficiencies were established Conclusions Transfection with PEI doesn’t affect immunophenotype, immunomodulatory properties and differentiation capacity of WJ-MSCs.