Engineering in Life Sciences最新文献

Retraction: ‘Comparative molecular docking and molecular-dynamic simulation of wild-type- and mutant carboxylesterase with BTA-hydrolase for enhanced binding to plastic’, by Fatana Lameh, Abdul Qadeer Baseer, and Abubakar Garba Ashiru, Eng Life Sci. 2021; 13-29: The above article, published online on 15 November 2021 in Wiley Online Library (https://doi.org/10.1002/elsc.202100083), has been retracted by agreement between the authors, the journal's Editors in Chief, Prof. Dr. Ralf Takors and Prof. Dr. An-Ping Zeng, and Wiley-VCH GmbH.

The retraction has been agreed because the copyright owner, Universiti Teknologi Malaysia, does not consent to publication of the research.

We present a transient large eddy simulation (LES) modeling approach for simulating the interlinked physics describing free surface hydrodynamics, multiphase mixing, reaction kinetics, and mass transport in bioreactor systems. Presented case-studies include non-reacting and reacting bioreactor systems, modeled through the inclusion of uniform reaction rates and more complex biochemical reactions described using Contois type kinetics. It is shown that the presence of reactions can result in a non-uniform spatially varying species concentration field, the magnitude and extent of which is directly related to the reaction rates and the underlying variations in the local volumetric mass transfer coefficient.

The combined effect of surface topography and substrate rigidity in stem cell cultures is still under-investigated, especially when biodegradable polymers are used. Herein, we assessed human bone marrow stem cell response on aliphatic polyester substrates as a function of anisotropic grooved topography and rigidity (7 and 12 kPa). Planar tissue culture plastic (TCP, 3 GPa) and aliphatic polyester substrates were used as controls. Cell morphology analysis revealed that grooved substrates caused nuclei orientation/alignment in the direction of the grooves. After 21 days in osteogenic and chondrogenic media, the 3 GPa TCP and the grooved 12 kPa substrate induced significantly higher calcium deposition and alkaline phosphatase (ALP) activity and glycosaminoglycan (GAG) deposition, respectively, than the other groups. After 14 days in tenogenic media, the 3 GPa TCP upregulated four and downregulated four genes; the planar 7 kPa substrate upregulated seven genes and downregulated one gene; and the grooved 12 kPa substrate upregulated seven genes and downregulated one gene. After 21 days in adipogenic media, the softest (7 kPa) substrates induced significantly higher oil droplet deposition than the other substrates and the grooved substrate induced significantly higher droplet deposition than the planar. Our data pave the way for more rational design of bioinspired constructs.

Despite its widespread usage as a chemotherapy drug in cancer treatment, doxorubicin (DOX) has limitations such as short in vivo circulation time, low solubility, and poor permeability. In this regard, a pH-responsive chitosan (CS)- montmorillonite (MMT)- nitrogen-doped carbon quantum dots (NCQDs) nanocomposite was first developed, loaded with DOX, and then incorporated into a double emulsion to further develop the sustained release. The incorporated NCQDs into the CS-MMT hydrogel exhibited enhanced loading and entrapment efficiencies. The presence of NCQDs nanoparticles in the CS-MMT hydrogel also resulted in an extended pH-responsive release of DOX over a period of 96 h compared to that of CS-MMT-DOX nanocarriers at pH 5.4. Based on the Korsmeyer-Peppas model, there was a controlled DOX release at pH 5.4, while no diffusion was observed at pH 7.4, indicating fewer side effects. MTT assay showed that the cytotoxicity of DOX-loaded CS-MMT-NCQDs hydrogel nanocomposite was significantly higher than those of free DOX (p < 0.001) and CS-MMT-NCQDs (p < 0.001) on MCF-7 cells. Flow cytometry results demonstrated that a higher apoptosis induction achieved after incorporating NCQDs nanoparticles into CS-MMT-DOX nanocarrier. These findings suggest that the DOX-loaded nanocomposite is a promising candidate for the targeted treatment of cancer cells.