Biology subjects

Migdal, P.

Publications and source records attributed to Migdal, P..

6 recordsLinked to original sources

bioRxiv2026

Surface functionalization of small extracellular vesicles derived from Caco-2 and HEK293T cells in the neutralization of Shiga toxin 1 subunit B

Shiga toxins (Stx) are key virulence factors of Shiga toxin-producing Escherichia coli (STEC), which are responsible for severe foodborne infections that can progress to hemolytic-uremic syndrome (HUS). Currently, no specific anti-toxin therapies are available. In this study, we devised a glycoengineering strategy utilizing Functional-Spacer-Lipid (FSL) conjugates to create small extracellular vesicles (sEVs)-based decoy receptors for Shiga toxin type 1 (Stx1). sEVs isolated from human Caco-2 and HEK293T cells were functionalized with Gb3 trisaccharide (Gal1[->]4Gal{beta}1[->]4Glc)-containing FSL conjugates, yielding Gb3-decorated vesicles, displaying the Gal1[->]4Gal epitope. Characterization of FSL-modified sEVs confirmed that FSL incorporation did not adversely affect sEV morphology, size distribution, or surface charge. Western blotting and bead-assisted flow cytometry verified the presence of exosomal markers (CD9 and CD63) and the Gb3 epitope on modified vesicles. Gb3-tagged sEVs from both cell types exhibited high specificity in binding Stx1B, while control vesicles carrying Galili epitope (Gal1[->]3Gal{beta}1[->]4GlcNAc), lacking Stx1B binding, demonstrated negligible binding. Gb3-expressing Caco-2 cell-based assays revealed that Gb3-decorated sEVs markedly reduced Stx1B binding to Caco-2 cells, indicating effective competition with cellular receptors. Furthermore, glycoengineered sEVs did not impair Caco-2 cell viability at concentrations sufficient for Stx1B sequestration. These findings establish FSL-mediated glycoengineering as a rapid and versatile approach for generating sEV-based decoy receptors that effectively bind Stx1B. Gb3-containing human sEVs may serve as an agent for neutralizing Stx1B and potentially other glycan-binding toxins, supporting the development of promising next-generation anti-toxin therapeutics.

bioengineering↗

bioRxiv2025

Extracellular vesicles as indicators of environmental stress response in Lactiplantibacillus plantarum: a multi-platform study

Extracellular vesicles (EVs) are key mediators of bacterial communication and adaptation to environmental stress. Their size, cargo, and surface charge are influenced by several factors, including environmental conditions, bacterial physiology, and isolation methods, and are highly strain-specific. Herein, we investigated how exposure to bile, a physiological component of the gut environment, affects the production and properties of EVs released by the probiotic strain Lactiplantibacillus plantarum NCIMB 8826. Through ultracentrifugation followed by size-exclusion chromatography (SEC), we isolated highly purified L. plantarum EVs (LpEVs) and characterized them according to the Minimal Information for Studies of Extracellular Vesicles guidelines. SEC purification significantly reduced the contents of contaminating proteins and peptidoglycans, improving the compositional purity of the isolated EVs. Compared with the parent bacteria, purified LpEVs exhibited distinct surface lipid profiles and zeta potential as well as remarkable stability across varying pH levels, elevated NaCl concentrations, and increasing detergent challenges. Under bile stress, the bacteria released larger LpEVs enriched in bile metabolism-related proteins, suggesting vesicle-mediated adaptation. Fourier-transform infrared spectroscopy further revealed bile-induced molecular alterations in LpEVs that differed from those in the parent bacteria. These findings highlight bacterial EVs as dynamic environmental communicators that respond to stress and may modulate host-microbe interactions before detectable changes occur in the bacterial cells.

microbiology↗

bioRxiv2024

No Miracle, Just a Mineral: The Not-So-Magical Antimicrobial World of Chlorine Dioxide

This study evaluates the in vitro antimicrobial efficacy and cytotoxicity of acidified sodium chlorite (ASC), a source of chlorine dioxide. Despite its controversial promotion in alternative medicine as a cure-all solution, known as "Miracle Mineral Solution" (MMS), the data on its factual medicinal activity is very limited. Therefore, we aimed to elucidate the activity of ASC against biofilms of Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis, Streptococcus mutans, Pseudomonas aeruginosa, Escherichia coli, and Lactobacillus sp. The study also investigated the in vitro cytotoxic effects of ASC towards eukaryotic fibroblasts and in in vivo model of Galleria mellonella larvae. Our findings demonstrate that these concentrations of ASC which can effectively eradicate biofilms, also pose potential health risks due to their in vitro and in vivo cytotoxicity. It implies that ASC applied in human can lead to damage to the mucous membrane of the gastrointestinal tract. This research contributes to the ongoing debate on the safety and efficacy of chlorine dioxide in clinical applications, highlighting the need for precise dosing to avoid mucosal damage in therapeutic contexts.

microbiology↗

bioRxiv2021

The processing of staphylococcal biofilm images from Fluorescence and Confocal Microscopy to assess in vitro efficacy of antiseptic molecules

The staphylococcal biofilms are major causative factors of non-healing wound infections. Their treatment algorithms recommend the use of locally applied antiseptic agents to counteract the spread of infection. The efficacy of antiseptics against biofilm is assessed in vitro by a set of standard quantitative and semi-quantitative methods. The development of software for image processing allowed to obtain quantitative data also from microscopic images of biofilm dyed with propidium iodine and SYTO-9 reagents, differentiating dead cells from the live ones. In this work, the method of assessment of the impact of antiseptic agents on staphylococcal biofilm in vitro, based on biofilms processed images, was proposed and scrutinized with regard to clinically-relevant antiseptics. Taking into account the fact that in vitro results of the efficacy of antiseptic agents against staphylococcal biofilm are frequently applied to back up their use in hospitals and ambulatory units, our work should be considered an important tool providing reliable, quantitative data with this regard.

microbiology↗

bioRxiv2021

Potato juice, a starch industry waste, as a cost-effective medium for the biosynthesis of bacterial cellulose

The unique properties of bacterial cellulose (BC) make it of great interest for numerous branches of industry. Nevertheless, the high cost of the dedicated, microbiological medium used for BC production significantly hinders possibility of widespread use. Searching for an alternative, we turned our attention to potato tuber juice (PJ), a major waste product of the potato starch industry. We verified the possibility of using PJ as a cost-effective, ecological-friendly medium that yielded BC with properties equivalent to those from conventional commercial Hestrin-Schramm medium. The BC yield from PJ medium (>4 g/L) was comparable, despite the lack of any pre-treatment. Likewise, the macro- and microstructure, physicochemical parameters, and chemical composition showed no significant differences between PJ and control BC. Importantly, BC obtained from PJ was not cytotoxic against fibroblast cell line L929 in vitro and did not contain any hard-to-remove impurities. These are very important aspects from an application standpoint, particularly in biomedicine. Therefore, we conclude that using PJ for BC biosynthesis is a path towards significant valorization of an environmentally problematic waste product of the starch industry and can help ultimately lower BC production costs. HighlightsO_LIPotato juice (PJ) was used as a culture medium for cellulose-synthesizing bacteria. C_LIO_LIPJ was suitable as source of nutrients and did not required any pre-treatment. C_LIO_LIYield of BC from PJ was equivalent to that obtained from conventional HS. C_LIO_LIPJ-BC did not differ from conventionally produced HS-BC in terms of its properties. C_LIO_LIPJ-BC can be used in the same applications as commercially produced BC. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/452442v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@5d10c1org.highwire.dtl.DTLVardef@1f71718org.highwire.dtl.DTLVardef@10d4976org.highwire.dtl.DTLVardef@1521f0a_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2020

Superabsorbent crosslinked bacterial cellulose biomaterials for chronic wound dressings

In this work, we present novel ex situ modification of bacterial cellulose (BC) polymer, that significantly improves its ability to absorb water after drying. The method involves a single inexpensive and easy-to-perform process of BC crosslinking, using citric acid along with catalysts, such as disodium phosphate, sodium bicarbonate, ammonium bicarbonate or their mixtures. In particular, the mixture of disodium phosphate and sodium bicarbonate was the most promising, yielding significantly greater water capacity (over 5 times higher as compared to the unmodified BC) and slower water release (over 6 times as compared to the unmodified BC). Further, our optimized crosslinked BC had over 1.5x higher water capacity than modern commercial dressings dedicated to highly exuding wounds, while exhibiting no cytotoxic effects against fibroblast cell line L929 in vitro. Therefore, our novel BC biomaterial may find application in super-absorbent dressings, designed for chronic wounds with imbalanced moisture level.Competing Interest StatementThe authors have declared no competing interest.AbbreviationsBCbacterial celluloseCATcatalystCAcitric acidM1modification with disodium phosphate as a catalyst (CAT)M2modification with sodium bicarbonate as a CATM3modification with mixture of disodium phosphate and sodium bicarbonate in the ratio 1:1 as a CATM4modification with ammonium bicarbonate as a CATM5modification with disodium phosphate and ammonium bicarbonate in the ratio 1:1 as a CATM6modification with sodium bicarbonate and ammonium bicarbonate in the ratio 1:1 as a CATM7modification with sodium hypophosphite as a CATSHPsodium hypophosphiteSRswelling ratioWHCwater holding capacityWPGweight percent gain.View Full Text

bioengineering↗