Preserving the efficacy of probiotic bacteria exhibits paramount challenges that need to be addressed during the development of functional food products. Several factors have been claimed to be ...responsible for reducing the viability of probiotics including matrix acidity, level of oxygen in products, presence of other lactic acid bacteria, and sensitivity to metabolites produced by other competing bacteria. Several approaches are undertaken to improve and sustain microbial cell viability, like strain selection, immobilization technologies, synbiotics development etc. Among them, cell immobilization in various carriers, including composite carrier matrix systems has recently attracted interest targeting to protect probiotics from different types of environmental stress (e.g., pH and heat treatments). Likewise, to successfully deliver the probiotics in the large intestine, cells must survive food processing and storage, and withstand the stress conditions encountered in the upper gastrointestinal tract. Hence, the appropriate selection of probiotics and their effective delivery remains a technological challenge with special focus on sustaining the viability of the probiotic culture in the formulated product. Development of synbiotic combinations exhibits another approach of functional food to stimulate the growth of probiotics. The aim of the current review is to summarize the strategies and the novel techniques adopted to enhance the viability of probiotics.
Nanoscale spinel zinc ferrite (ZNF) was prepared by sol-gel auto-ignition route and subsequently its surface was modified by oleic-acid (OA) coating. The pristine and surface modified ZNF ...nanoparticles (UC-ZNF and OA-ZNF) were characterized by standard techniques. XRD patterns of both the samples ensured the nanocrystalline mono-phasic cubic-spinel lattice structure with ‘Fd-3m space-group’. FT-IR spectra revealed the presence of vibrational frequency-modes of spinel structure and successful coating of OA over ZNF. The nano-size spherical grains with some agglomeration and OA coating over ZNF were visualized in FE-SEM images. The hydrophobic-to-hydrophilic surface-transition of ZNF was confirmed by water contact-angle measurements. The BET surface-area and distribution of pore-radius was evaluated by recording N2-isotherms. The M − H plots confirmed the superparamagnetic nature of both the samples. Optical properties were studied by UV–Vis and PL spectroscopy techniques. The colloidal-stability and distribution of particle-sizes were estimated by zeta-potential and DLS measurements. Magnetic hyperthermia studies were carried out for different concentrations (2, 4, 6, 8 and 10 mg/mL) of both the samples. The biocompatible nature of both the samples was studied by cell-viability studies. All these results ensure the implementation of OA-ZNF nanoparticles with minimum dose rate (8 mg/mL) in magnetic hyperthermia therapies for cancer treatment.
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•Ca2+ electroporation (EP) is more efficient than Ca2+ sonoporation (SP).•Ca2+ SP elicits instant cell death starting (<15 min) – much faster than Ca2+ EP.•Ca2+ EP required 72 h to ...achieve the level of cytotoxicity of Ca2+ SP.•Ca2+ (5 mM) induces similar cell death as bleomycin (20 nM) during SP.
Ca2+, in combination with SP or EP, induces cell cytotoxicity much faster compared to BLM. The application of BLM in combination with, SP or EP, reaches the level of cell death, induced by similar combination with Ca2+, only after 72 h. The methods of SP and EP were calibrated according to the level of differential cytotoxicity, determined after 6 days (using cell clonogenic assay). The combination of Ca2+ SP induces cell death faster than Ca2+ EP – after Ca2+ SP it increases to a maximum level after 15 min and remains constant for up to 6 days, while the cytotoxic efficiency after Ca2+ EP increases to the level of Ca2+ SP only after 72 h. The combination of BLM SP shows a very similar dynamics to BLM EP – both reach maximal level of cytotoxicity after 48–72 h.
Ca2+ and BLM in combination with SP have shown similar levels of cytotoxicity at higher acoustic pressures (≥250 kPa); therefore, Ca2+ SP can be used to induce immediate and maximal level of cytotoxic effect. The faster cytotoxic efficiency of Ca2+ in combination with SP than EP was determined to be due to the involvement of microbubble inertial cavitation.
Design of biocompatible nano-heterostructure photocatalyst with broad UV–visible spectrum response and strong redox ability is a promising approach with potential application in micropollutant ...degradation and pathogen deactivation from aqueous sources. Herein, we have reported the facile fabrication of In2S3/Bi2Fe4O9 (ISxBFO) binary heterostructure by hydrothermally depositing In2S3 nanoparticles (20–40 nm) over Bi2Fe4O9 nanocuboids/nanoplates prepared by combustion synthesis route. In depth characterization study revealed broad spectrum UV–Vis absorption, large interfacial contact, improved charge carrier separation and mobility and a longer excited state life time (4.7 ns) for the ISxBFO heterostructure materials. The integration of In2S3 with Bi2Fe4O9 strongly boosts the optoelectrical and photocatalytic property of pristine Bi2Fe4O9. The ISxBFO heterostructure material exhibited enhanced photocatalytic efficiency for aqueous phase degradation of sulfamethoxazole antibiotics (kapp = 0.06 min−1) and phenyl urea herbicides (kapp = 0.028 min−1) with reaction rates 3–8 times higher than the pure BFO component. The MTT assay experiments confirmed non-cytotoxic nature of treated sulfamethoxazole and diuron solutions. The composite materials also displayed convincing antibacterial behavior towards toxigenic Vibrio cholerae pathogen. Haemagglutination assay study revealed excellent biocompatibility of the binary composite up to 200 mg L−1. Radical trapping study suggested expeditious generation of •OH and •O2− radicals over the ISxBFO surface which is nearly 3.8 and 2.3 times higher than pure BFO and In2S3 respectively. The occurrence of a direct Z-scheme mechanism is inferred from radical trapping and XPS study which accounted for the improved photocatalytic activity and strong radical generation property of the ISxBFO heterostructure material.
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•A broad spectrum visible light active Z-scheme In2S3/Bi2Fe4O9 composite fabricated.•Composite exhibited better photoelectrochemical feature and excited state life time.•Enhanced activity for sulfamethoxazole and phenyl urea herbicide photodegradation.•Convincing photocatalytic antibacterial property for toxigenic Vibrio cholera.•Haemagglutination assay study revealed biocompatible nature of the composite.
Cryopreservation is essential for the long‐term storage of primary cell samples and enables accessing primary cells anytime via a simple thawing process. However, low viability and cell fragmentation ...are the major issues for cryopreserved cell samples due to the toxicity of cryoprotective agents and crystallization of intracellular contents during cooling at low temperature. Human peripheral blood mononuclear cells (PBMCs) in high viability are critical for pathophysiological and therapeutic research of infectious diseases, especially for the current worldwide pandemic of coronavirus disease 2019. Conventional viability enrichment techniques for primary PBMC samples provoke either cryoinjury caused by cell sorting mechanism or substantial cell loss due to multiple sample preparation steps. Here, a label‐free viability assessment and on‐demand enrichment system for cryopreserved primary human PBMCs with validation by fluorescent label‐based flow cytometry, is demonstrated. It can provide consistent viability assays by discriminating viable PBMCs from apoptotic, DMSO toxicity‐induced dead cells and cell debris, and deliver over 90% viability of sorted samples in one step after thawing. This integrated cell viability assay and on‐demand enrichment of viable cells has broad applications in diverse cellular biology research and cell‐related biomedical diagnostics.
Low viability and cell fragmentation are major issues for cryopreserved cell samples. This work demonstrates a microfluidic label‐free viability assessment to discriminate viable cells from dead cells and cell debris. This viability assessment approach is further integrated with acoustic single‐cell sorting for on‐demand enrichment of viable cells, which has broad applications in diverse cellular biology research and cell‐related biomedical diagnostics.
The protocol described in this appendix allows for light microscopic quantitation of cell viability. Cells are suspended in PBS containing trypan blue and then examined to determine the percentage of ...cells that have clear cytoplasm (viable cells) versus cells that have blue cytoplasm (nonviable cells).
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A combination of nanostructured zinc oxide (ZnO) or graphene oxide or both of them with cellulose acetate (CA) enhances a new functionality of nanofibers aiming to improve ...bio-composite materials for wound healing application. The obtained nanofibers have been investigated using XRD, FTIR, and FESEM. It was observed that the maximum height of the roughness increased from 253 to 651.9 nm for both GO and ZnO/GO in the powdered phase, while it plunged from 613 to 482 nm and developed to 801 nm for ZnO@CA, GO@CA, and ZnO/GO@CA, receptively. Further, the mechanical properties of the obtained scaffolds have been tested and displayed a tremendous variation of tensile strength from 5.44 ± 0.81 to 12.87 ± 0.93 and 8.82 ± 1.2 MPa, while the toughness increased from 23.29 ± 1.4 to 68.95 ± 4.5 and 57.75 ± 3.6 MJ/m3 for ZnO@CA, GO@CA and ZnO/GO@CA, receptively. Moreover, the cell viability was investigated and showed a progression of 97.38 ± 3.9% for ZnO/GO@CA. Furthermore, the adhesion of human fibroblasts cell line towards the obtained nanofibrous scaffolds were examined and displayed that cells were proliferated and spread considerably through the scaffolds, whereas their filopodia have followed the morphology of the fibers.
Increasing evidence supports that ferroptosis plays an important role in tumor growth inhibition. Sorafenib, originally identified as an inhibitor of multiple oncogenic kinases, has been shown to ...induce ferroptosis in hepatocellular carcinoma (HCC). However, some hepatoma cell lines are less sensitive to sorafenib-induced ferroptotic cell death. Glutathione S-transferase zeta 1 (GSTZ1), an enzyme in the catabolism of phenylalanine, suppresses the expression of the master regulator of cellular redox homeostasis nuclear factor erythroid 2-related factor 2 (NRF2). This study aimed to investigate the role and underlying molecular mechanisms of GSTZ1 in sorafenib-induced ferroptosis in HCC. GSTZ1 was significantly downregulated in sorafenib-resistant hepatoma cells. Mechanistically, GSTZ1 depletion enhanced the activation of the NRF2 pathway and increased the glutathione peroxidase 4 (GPX4) level, thereby suppressing sorafenib-induced ferroptosis. The combination of sorafenib and RSL3, a GPX4 inhibitor, significantly inhibited GSTZ1-deficient cell viability and promoted ferroptosis and increased ectopic iron and lipid peroxides. In vivo, the combination of sorafenib and RSL3 had a synergic therapeutic effect on HCC progression in Gstz1
mice. In conclusion, this finding demonstrates that GSTZ1 enhanced sorafenib-induced ferroptosis by inhibiting the NRF2/GPX4 axis in HCC cells. Combination therapy of sorafenib and GPX4 inhibitor RSL3 may be a promising strategy in HCC treatment.
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