es/iode’s Post

📃Scientific paper: Antimicrobial activity of D-amino acid in combination with photo-sonoactivated hypericin nanoparticles against Acinetobacter baumannii Abstract: Background The emergence of multidrug-resistant Acinetobacter baumannii strains is increasing worldwide. To overcome these life-threatening infections, the development of new treatment approaches is critical. For this purpose, this study was conducted to determine the antimicrobial photo-sonodynamic therapy (aPSDT) using hypericin nanoparticles (HypNP) in combination with D-Tryptophan (D-Trp) against A. baumannii . Materials and methods HypNP was synthesized and characterized, followed by the determination of the fractional inhibitory concentration (FIC) index of HypNP and D-Trp by checkerboard assay. Next, the antimicrobial and anti-biofilm potential of HypNP@D-Trp-mediated aPSDT against A. baumannii was evaluated. Finally, the anti-virulence activity of aPSDT using HypNP@D-Trp was accessed following the characterization of HypNP@D-Trp interaction with AbaI using in silico virtual screening and molecular docking. Results A synergistic activity in the combination of HypNP and D-Trp against A. baumannii was observed with a FIC index value of 0.5. There was a 5.10 log_10 CFU/mL reduction in the cell viability of A. baumannii when the bacterial cells were treated with 1/2 × MIC of HypNP@D-Trp and subsequently exposed to ultrasound waves and blue light ( P  < 0.05). Moreover, a significant biofilm degradation effect on biofilm-associated cells of A. baumannii was observed after treatment with aPSDT using 2 × MIC of HypNP@D-Trp in comparison with the control groups ( P  ... Continued on ES/IODE ➡️ https://etcse.fr/A34c ------- If you find this interesting, feel free to follow, comment and share. We need your help to enhance our visibility, so that our platform continues to serve you.

📃Scientific paper: Antimicrobial activity of D-amino acid in combination with photo-sonoactivated hypericin nanoparticles against Acinetobacter baumannii Abstract: Background The emergence of multidrug-resistant Acinetobacter baumannii strains is increasing worldwide. To overcome these life-threatening infections, the development of new treatment approaches is critical. For this purpose, this study was conducted to determine the antimicrobial photo-sonodynamic therapy (aPSDT) using hypericin nanoparticles (HypNP) in combination with D-Tryptophan (D-Trp) against A. baumannii . Materials and methods HypNP was synthesized and characterized, followed by the determination of the fractional inhibitory concentration (FIC) index of HypNP and D-Trp by checkerboard assay. Next, the antimicrobial and anti-biofilm potential of HypNP@D-Trp-mediated aPSDT against A. baumannii was evaluated. Finally, the anti-virulence activity of aPSDT using HypNP@D-Trp was accessed following the characterization of HypNP@D-Trp interaction with AbaI using in silico virtual screening and molecular docking. Results A synergistic activity in the combination of HypNP and D-Trp against A. baumannii was observed with a FIC index value of 0.5. There was a 5.10 log_10 CFU/mL reduction in the cell viability of A. baumannii when the bacterial cells were treated with 1/2 × MIC of HypNP@D-Trp and subsequently exposed to ultrasound waves and blue light ( P  < 0.05). Moreover, a significant biofilm degradation effect on biofilm-associated cells of A. baumannii was observed after treatment with aPSDT using 2 × MIC of HypNP@D-Trp in comparison with the control groups ( P  ... Continued on ES/IODE ➡️ https://etcse.fr/A34c ------- If you find this interesting, feel free to follow, comment and share. We need your help to enhance our visibility, so that our platform continues to serve you.

“Chemicals in the systemic circulation can undergo hepatic xenobiotic metabolism, generate metabolites, and exhibit altered toxicity compared with their parent compounds. This article describes a 2-chamber liver-organ coculture model in a higher-throughput 96-well format for the determination of toxicity on target tissues in the presence of physiologically relevant human liver metabolism. This 2-chamber system is a hydrogel formed within each well consisting of a central well (target tissue) and an outer ring-shaped trough (human liver tissue). The target tissue chamber can be configured to accommodate a three-dimensional (3D) spheroid-shaped microtissue or a 2-dimensional (2D) cell monolayer. Culture medium and compounds freely diffuse between the 2 chambers. Human-differentiated HepaRG liver cells are used to form the 3D human liver microtissues, which displayed robust protein expression of liver biomarkers (albumin, asialoglycoprotein receptor, Phase I cytochrome P450 [CYP3A4] enzyme, multidrug resistance-associated protein 2 transporter, and glycogen), and exhibited Phase I/II enzyme activities over the course of 17 days. Histological and ultrastructural analyses confirmed that the HepaRG microtissues presented a differentiated hepatocyte phenotype, including abundant mitochondria, endoplasmic reticulum, and bile canaliculi. Liver microtissue zonation characteristics could be easily modulated by maturation in different media supplements. Furthermore, our proof-of-concept study demonstrated the efficacy of this coculture model in evaluating testosterone-mediated androgen receptor responses in the presence of human liver metabolism. This liver-organ coculture system provides a practical, higher-throughput testing platform for metabolism-dependent bioactivity assessment of drugs/chemicals to better recapitulate the biological effects and potential toxicity of human exposures.”—From a #ToxSpotlight article by Blanche C. IP, Ph.D. et al. in the June 2024 issue of Toxicological Sciences. https://lnkd.in/ekNf3zSV #FreeToRead

I am happy to share that our systematic review on TiO2 nanoparticle lung carcinogenicity is now published open access in Nanotoxicology (Taylor & Francis Online). https://lnkd.in/ditdy7C9 Titanium dioxide (#TiO2) nanoparticles are among the most produced #nanomaterials worldwide, with increasing global use in many applications, e.g., inks and paints, photocatalysts, food and plastic colourants, drug delivery applications, sunscreens, and cosmetic products. However, the potential adverse health effects and carcinogenic potential of pulmonary #exposure to these nanoparticles is an ongoing matter of debate. #IARC classified TiO2 as possibly carcinogenic to humans (Group 2B) and #ECHA classified certain forms of TiO2 powder as a Carc 2, H351 (inhalation) category 2 suspected human carcinogen. Despite the classification from both #IARC and #ECHA, the mechanisms by which TiO2 causes carcinogenicity in the lung are not fully understood, and there are uncertainties regarding the carcinogenic potential of nano-sized TiO2 following inhalation. In our work, we systematically reviewed the existing in vitro and in vivo mechanistic evidence of TiO2 nanoparticle lung carcinogenicity using the 10 key characteristics of carcinogens for identifying and classifying carcinogens. Our main findings include: - Moderate to high confidence for the biological endpoints regarding genotoxicity, oxidative stress and chronic inflammation - A limited number of studies investigated other endpoints important to carcinogenesis, relating to proliferation and transformation, epigenetic alterations and receptor-mediated effects - Improvements in study quality and reliability are needed if mechanistic evidence is to be used in the evaluation of TiO2 NP carcinogenicity in the lung - Taking the challenges and limitations of the in vitro and in vivo studies into consideration, TiO2 NPs might possess the ability to induce chronic inflammation and oxidative stress - Given the limited number of high-quality and high-reliability studies identified in this review, there is a lack of good enough mechanistic evidence for TiO2 NP lung carcinogenicity - There is a need for more physiologically relevant, long-term studies using appropriate particle doses, particularly relevant for #occupational exposure Many thanks to all co-authors for their effort and contributions!

How to Avoid or Reduce High Background in Immunohistochemistry? High background staining in immunohistochemistry (IHC) can mask specific signals and affect the clarity of results. Fortunately, there are several strategies that can help reduce or eliminate unwanted background, thereby improving the accuracy of staining. 1. Proper Blocking One of the most common causes of high background is nonspecific binding of antibodies to tissue. To prevent this, a proper blocking step must be performed using serum or protein-based solutions such as bovine serum albumin (BSA), casein, or normal serum from the same species as the secondary antibody. The blocking solution covers the tissue sections and prevents nonspecific interactions between the antibody and the tissue. 2. Use Polyclonal or Monoclonal Antibodies Using monoclonal antibodies can reduce nonspecific binding because they are highly specific for one epitope. Polyclonal antibodies, while providing broader detection, can bind nonspecifically to off-target proteins, thereby increasing background noise. Choose antibodies that have been well characterized for use in IHC. 3. Optimize Antibody Concentration High concentrations of antibodies can lead to excessive binding, which can create background noise. It is important to titrate primary and secondary antibodies to find the optimal concentration that provides clear, specific staining without excessive background. 4. Proper Washing Inadequate or inadequate washing can lead to the accumulation of unbound antibody, which can cause high background. After applying the antibody, wash the sections thoroughly with an appropriate buffer such as PBS or TBS to remove any unbound antibody. 5. Block Endogenous Enzyme Activity If using enzyme-conjugated secondary antibodies, endogenous peroxidase or alkaline phosphatase activity in the tissue may cause background staining. Pre-treat sections with an enzyme inhibitor such as hydrogen peroxide (for peroxidase) or levamisole (for alkaline phosphatase) to block this activity. We believe that by optimizing blocking, antibody selection, concentration, and washing steps, you can significantly reduce high background in IHC, resulting in more reliable and specific staining results. Reference [1] So-Woon Kim et al., J Pathol Transl Med 2016 (doi: 10.4132/jptm.2016.08.08) #Immunohistochemistry #IHC #Antibodies #ResearchOptimization #BiomedicalResearch #ProteinDetection #Blocking #ScientificControls #TissueStaining

REPISTAT: AN EFFECTIVE HDAC INHIBITOR (HDAC-6 selective) IN RETINITIS PIGMENTOSA. Inherited retinal diseases, which include retinitis pigmentosa, are a family of genetic disorders characterized by gradual rod-cone degeneration and vision loss, without effective pharmacological treatments. Experimental approaches aim to delay disease progression, supporting consequences' survival, crucial for human vision. Histone deacetylases (HDACs) mediate the activation of epigenetic and nonepigenetic pathways that modulate cone degeneration in RP mouse models. In J Med Chem - to which he also dedicated the cover - Gabriele Carullo et al. present a new class of HDAC inhibitors, typified by a tetrahydro-γ-carboline scaffold, characterized by high HDAC6 inhibition potency. Compound 5d (REPISTAT, IC50 HDAC6 = 6.32 nM) increased the levels of acetylated α-tubulin compared to histone H3 in ARPE-19 and 661W cells. REPISTAT was designed and synthesized by a research group of pharmaceutical chemistry of the University of Siena in collaboration, for biological tests, with the Department of Pharmacy of the University of Pisa, and with the Institute of Neuroscience of the CNR - Pisa, the University College London and the University of Ferrara. Compound 5d (REPISTAT) promoted vision rescue in the atp6v0e1–/– zebrafish model of photoreceptor dysfunction. A single intravitreal injection of 5d in the rd10 mouse model of RP supported morphological and functional preservation of cone cells and maintenance of the retinal pigment epithelium array. #repistat #HDAC_I #retinitispigmentosa J. Med. Chem. 2024, 67, 17, 14946–14973 https://lnkd.in/d8vkRDyk

Some interesting work by Yin et al deploys the use of  online size exclusion chromatography (SEC) to automate buffer exchange and sample introduction, which is hyphenated to Orbitrap-based Charge detection mass spectrometry (CDMS) 🎯 Summary: Yin et al observed CDMS histograms containing hundreds of individual ion signals can be obtained in as little as 5 min from single injections of <1 μg of sample. Using a model to test their SEC-CDMS application, real time digestion kinetic was performed on pentameric IgM with the protease IgMBRAZOR (Genovis). SEC-CDMS was able to mass-resolved and identified Several digestion intermediates, the loss F(ab’)2 subunits. SEC-CDMS can potentially be applied to a wide range of high mass macromolecules, such as antibodies, antibody-drug conjugates, virus-like particles, and protein complex Furthermore with new generation of SEC columns such as Waters Corporation  GTxResolve SEC Columns this application will expand #massspectrometry #massspec #adc #biotherapeutics #biotech #chemistry #cancer #drugconjugate #science #biopharmaceutical #anytical #lcms #mabs #scienceandtechnology #pharmaceutical https://lnkd.in/eg-tGVSk

Plasminogen Identified as a Key Ligand of ADAMTS13 through Optimized Plasma BioID • This study optimized the BioID proximity-dependent biotinylation technique for use in plasma to identify novel ligands of ADAMTS13, a metalloprotease crucial for regulating Von Willebrand Factor (VWF) activity and preventing thrombosis. • The optimized plasma BioID method, which addressed ATP instability in plasma by serial ATP supplementation, identified 108 proteins significantly interacting with ADAMTS13, including VWF (a positive control) and plasminogen. • Further investigation revealed that plasminogen, in its Glu- and Lys-forms, binds to ADAMTS13 with high affinity, specifically interacting with the C-terminus of ADAMTS13, involving the kringle domains of plasminogen and the Tsp-1 repeats or CUB domains of ADAMTS13. • The binding of plasminogen to ADAMTS13 was shown to be lysine-dependent, as it was attenuated by the lysine analogs tranexamic acid (TXA) and ε-aminocaproic acid (EACA). • Importantly, TXA also protected ADAMTS13 from degradation by plasmin, the active form of plasminogen, highlighting the role of this interaction in regulating ADAMTS13 activity. • Apolipoprotein(a) (apo(a)), sharing sequence homology with plasminogen, also bound to ADAMTS13 in a lysine-dependent manner, further supporting the significance of lysine residues in this interaction. • This research demonstrates the successful application of optimized plasma BioID to uncover crucial protein-protein interactions in the complex environment of plasma and provides valuable insights into the regulation of ADAMTS13 activity, which is crucial for maintaining hemostasis. https://lnkd.in/dTkWUmeJ

What are strategies to combat bacterial resistance other than outright discovering new #antibiotics? These researchers focused on using maleimide conjugated PEGylated #liposomes (Mal-PL-Ab) to individually encapsulate a variety of antibiotics and enhance their delivery against multi-drug resistant bacteria, such as E. coli and K. pneumoniae. 1. Compared to non-PEGylated liposomes (L-Ab), Mal-PL-Ab exhibited reduced toxicity in human dermal cells, emphasizing the importance of PEGylation in minimizing adverse effects. 2. Mal-PL-Ab significantly decreased the minimum inhibitory concentration (MIC) values against both E. coli and K. pneumoniae by 9.33-fold and eightfold reduction (compared to non-PEGylated liposomes with 2.33-fold and 2.33fold reduction), respectively, indicating enhanced efficacy against MDR strains. 3. in vitro scratch assay and gene expression analysis of human dermal fibroblast revealed that Mal-PL-Ab promoted cell proliferation, migration, and wound healing through upregulation of cell cycle, DNA repair, and angiogenesis-related genes. 4. Harnessing the power of encapsulation, Mal-PL-Ab presents a novel avenue for enhanced antibiotic delivery and wound healing, potentially transcending the limitations of traditional options. https://lnkd.in/e-N9Taki Pandit Deendayal Energy University #DDS #Liposome #LNP #LNPs #PNP #PEG #Lipids #Engineering #SyntheticBiology #LifeSciences #Innovation #DrugResistance #Nanotechnology

This review elucidates the structure of #LNPs, the mechanism for #mRNA delivery, and the targeted delivery of LNPs to various cells and tissues, including leukocytes, T-cells, dendritic cells, Kupffer cells, hepatic endothelial cells, and hepatic and extrahepatic tissues.