Limitations in wound management have prompted scientists to introduce bioprinting techniques for creating constructs that can address clinical problems. The bioprinting approach is renowned for its ability to spatially control the three-dimensional (3D) placement of cells, molecules, and biomaterials. These features provide new possibilities to enhance homology to native skin and improve functional outcomes. However, for the clinical value, the development of hydrogel bioink with refined printability and bioactive properties is needed. In this study, we combined the outstanding viscoelastic behavior of nanofibrillated cellulose (NFC) with the fast cross-linking ability of alginate (ALG), carboxymethyl cellulose (CMC), and encapsulated human-derived skin fibroblasts (hSF) to create a bioink for the 3D bioprinting of a dermis layer. The shear thinning behavior of hSF-laden bioink enables construction of 3D scaffolds with high cell density and homogeneous cell distribution. The obtained results demonstrated that hSF-laden bioink supports cellular activity of hSF (up to 29 days) while offering proper printability in a biologically relevant 3D environment, making it a promising tool for skin tissue engineering and drug testing applications.
COBISS.SI-ID: 512974392
This work presents the development and validation of 8 new in situ bismuth-copper-film electrodes (BiCuFEs) for Zn(II), Cd(II), and Pb(II) trace analysis in 0.1 M acetate buffer. The BiCuFEs were compared with in situ copper-film (CuFE) electrodes – new electrodes that have recently been reported. The formation of every in situ electrode was performed at two different concentrations, i.e. 0.5 and 1.0 mg/L. All BiCuFEs were selective for Zn(II), Cd(II), and Pb(II) determination. By using different BiCuFEs, the lower limit of the linear concentration ranges for Zn(II), Cd(II), and Pb(II) was generally lower compared with those for the CuFEs. Moreover, the BiCuFEs were generally more sensitive and had lower limits of detection for Zn(II), Cd(II), and Pb(II) determination than the CuFEs. The precision of the methods and the precision of the systems were satisfactory for the vast majority of the electrodes tested (RSD ( 20.0%). For selected BiCuFEs a possible interference effect on the stripping signals of the analytes was checked in the presence of Fe(II), As(III), Na(I), K(I), Ca(II), Mg(II), Sn(II), Sb(III), and NO3– in water solution. Moreover, electrochemical impedance spectroscopy measurements were performed in order to determine if the electroanalytical system is under a kinetic-controlled or mixed kinetic- and diffusion-controlled process. Furthermore, the applicability of the selected BiCuFEs was confirmed by real water sample analysis.
COBISS.SI-ID: 22930454
The Centers for Disease Control and Prevention (CDC) provides extensive data that indicate our need for drugs to maintain human population health. Despite the substantial availability of drugs on the market, many patients lack specific drugs. New drugs are required to tackle this issue. Moreover, we need more reliable models for testing drug toxicity, as too many drug approval failures occur with the current models. This article briefly describes various approaches of the currently used models for toxicity screening, to justify the selection of in vitro cell-based models. Cell-based toxicity models have the best potential to reliably predict drug toxicity in humans, as they are developed using the cells of the target organism. However, currently, a large gap exists between in vitro cell-based approach to toxicity testing and the clinical approach, which may be contributing to drug approval failures. We propose improvements to in vitro cell-based toxicity models, which is often an insight approach, to better match this approach with the clinical homeostatic approach. This should enable a more accurate comparison of data between the preclinical as well as clinical models and provide a more comprehensive understanding of human physiology and biological effects of drugs.
COBISS.SI-ID: 512937272