Multipatterned Chondrocytes' Scaffolds by FL-MOPL with a BSA-GMA Hydrogel to Regulate Chondrocytes' Morphology.

Repairing articular cartilage damage is challenging due to its low regenerative capacity. In vitro, cartilage regeneration is a potential strategy for the functional reconstruction of cartilage defects. A hydrogel is an advanced material for mimicking the extracellular matrix (ECM) due to its hydrophilicity and biocompatibility, which is known as an ideal scaffold for cartilage regeneration. However, chondrocyte culture in vitro tends to dedifferentiate, leading to fibrosis and reduced mechanical properties of the newly formed cartilage tissue. Therefore, it is necessary to understand the mechanism of modulating the chondrocytes' morphology. In this study, we synthesize photo-cross-linkable bovine serum albumin-glycidyl methacrylate (BSA-GMA) with 65% methacrylation. The scaffolds are found to be suitable for chondrocyte growth, which are fabricated by homemade femtosecond laser maskless optical projection lithography (FL-MOPL). The large-area chondrocyte scaffolds have holes with interior angles of triangle (T), quadrilateral (Q), pentagon (P), hexagonal (H), and round (R). The FL-MOPL polymerization mechanism, swelling, degradation, and biocompatibility of the BSA-GMA hydrogel have been investigated. Furthermore, cytoskeleton and nucleus staining reveals that the R-scaffold with larger interior angle is more effective in maintaining chondrocyte morphology and preventing dedifferentiation. The scaffold's ability to maintain the chondrocytes' morphology improves as its shape matches that of the chondrocytes. These results suggest that the BSA-GMA scaffold is a suitable candidate for preventing chondrocyte differentiation and supporting cartilage tissue repair and regeneration. The proposed method for chondrocyte in vitro culture by developing biocompatible materials and flexible fabrication techniques would broaden the potential application of chondrocyte transplants as a viable treatment for cartilage-related diseases.

Diosgenin protects against cationic bovine serum albumin-induced membranous glomerulonephritis by attenuating oxidative stress and renal inflammation via the NF-κB pathway.

CONTEXT: Membranous glomerulonephritis (MGN) is a leading cause of nephrotic syndrome in adults. Diosgenin (DG) has been reported to exert antioxidative and anti-inflammatory effects. OBJECTIVE: To investigate the renoprotective activity of DG in a cationic bovine serum albumin-induced rat model of MGN. MATERIALS AND METHODS: Fourty male Sprague-Dawley rats were randomized into four groups. The MGN model was established and treated with a DG dose (10 mg/kg) and a positive control (TPCA1, 10 mg/kg), while normal control and MGN groups received distilled water by gavage for four consecutive weeks. At the end of the experiment, 24 h urinary protein, biochemical indices, oxidation and antioxidant levels, inflammatory parameters, histopathological examination, immunohistochemistry and immunoblotting were evaluated. RESULTS: DG significantly ameliorated kidney dysfunction by decreasing urinary protein (0.56-fold), serum creatinine (SCr) (0.78-fold), BUN (0.71-fold), TC (0.66-fold) and TG (0.73-fold) levels, and increasing ALB (1.44-fold). DG also reduced MDA (0.82-fold) and NO (0.83-fold) levels while increasing the activity of SOD (1.56-fold), CAT (1.25-fold), glutathione peroxidase (GPx) (1.55-fold) and GSH (1.81-fold). Furthermore, DG reduced Keap1 (0.76-fold) expression, Nrf2 nuclear translocation (0.79-fold), and induced NQO1 (1.25-fold) and HO-1 (1.46-fold) expression. Additionally, DG decreased IL-2 (0.55-fold), TNF-α (0.80-fold) and IL-6 (0.75-fold) levels, and reduced protein expression of NF-κB p65 (0.80-fold), IKKß (0.93-fold), p-IKKß (0.89-fold), ICAM-1 (0.88-fold), VCAM-1 (0.91-fold), MCP-1 (0.88-fold) and E-selectin (0.87-fold), and also inhibited the nuclear translocation of NF-κB p65 (0.64-fold). DISCUSSION AND CONCLUSIONS: The results suggest a potential therapeutic benefit of DG against MGN due to the inhibition of the NF-κB pathway, supporting the need for further clinical trials.

The potential of Rhodobacter sphaeroides extract as an alternative supplement for cell culture systems.

It is essential to identify suitable supplements that enhance cell growth, viability, and functional development in cell culture systems. The use of fetal bovine serum (FBS) has been common, but it has limitations, such as batch-to-batch variability, ethical concerns, and risks of environmental contamination. In this study, we explore the potential of Rhodobacter sphaeroides extract, derived from a probiotic photosynthetic bacterium, as an alternative supplement. Our results demonstrate that the extract from R. sphaeroides significantly improves various aspects of cell behavior compared to serum-free conditions. It enhances cell growth and viability to a greater extent than FBS supplementation. Additionally, the extract alleviates oxidative stress by reducing intracellular levels of reactive oxygen species and stimulates lysosomal activity, contributing to cellular processes. The presence of abundant amino acids, glycine and arginine, in the extract may play a role in promoting cell growth. These findings emphasize the potential of R. sphaeroides extract as a valuable supplement for cell culture, offering advantages over the use of FBS.IMPORTANCEThe choice of supplements for cell culture is crucial in biomedical research, but the widely used fetal bovine serum (FBS) has limitations in terms of variability, ethics, and environmental risks. This study explores the potential of an extract from Rhodobacter sphaeroides, a probiotic bacterium, as an alternative supplement. The findings reveal that the R. sphaeroides extract surpasses FBS in enhancing cell growth, viability, and functionality. It also mitigates oxidative stress and stimulates lysosomal activity, critical for cellular health. The extract's abundance of glycine and arginine, amino acids with known growth-promoting effects, further highlights its potential. By providing a viable substitute for FBS, the R. sphaeroides extract addresses the need for consistent, ethical, and environmentally friendly cell culture supplements. This research paves the way for sustainable and reliable cell culture systems, revolutionizing biomedical research and applications in drug development and regenerative medicine.

Differential role of bovine serum albumin and HCO3- in the regulation of GSK3 alpha during mouse sperm capacitation.

To become fertile, mammalian sperm are required to undergo capacitation in the female tract or in vitro in defined media containing ions (e.g. HCO3 -, Ca2+, Na+, and Cl-), energy sources (e.g. glucose, pyruvate) and serum albumin (e.g. bovine serum albumin (BSA)). These different molecules initiate sequential and concomitant signaling pathways, leading to capacitation. Physiologically, capacitation induces changes in the sperm motility pattern (e.g. hyperactivation) and prepares sperm for the acrosomal reaction (AR), two events required for fertilization. Molecularly, HCO3 - activates the atypical adenylyl cyclase Adcy10 (aka sAC), increasing cAMP and downstream cAMP-dependent pathways. BSA, on the other hand, induces sperm cholesterol release as well as other signaling pathways. How these signaling events, occurring in different sperm compartments and with different kinetics, coordinate among themselves is not well established. Regarding the AR, recent work has proposed a role for glycogen synthase kinases (GSK3α and GSK3ß). GSK3α and GSK3ß are inactivated by phosphorylation of residues Ser21 and Ser9, respectively, in their N-terminal domain. Here, we present evidence that GSK3α (but not GSK3ß) is present in the anterior head and that it is regulated during capacitation. Interestingly, BSA and HCO3 - regulate GSK3α in opposite directions. While BSA induces a fast GSK3α Ser21 phosphorylation, HCO3 - and cAMP-dependent pathways dephosphorylate this residue. We also show that the HCO3--induced Ser21 dephosphorylation is mediated by hyperpolarization of the sperm plasma membrane potential (Em) and by intracellular pH alkalinization. Previous reports indicate that GSK3 kinases mediate the progesterone-induced AR. Here, we show that GSK3 inhibition also blocks the Ca2+ ionophore ionomycin-induced AR, suggesting a role for GSK3 kinases downstream of the increase in intracellular Ca2+ needed for this exocytotic event. Altogether, our data indicate a temporal and biphasic GSK3α regulation with opposite actions of BSA and HCO3 -. Our results also suggest that this regulation is needed to orchestrate the AR during sperm capacitation.

Radioactive gold nanoparticles coated with BSA: A promising approach for prostate cancer treatment.

Background: Nanotechnology has revolutionized medicine, especially in oncological treatments. Gold nanoparticles (AuNPs) stand out as an innovative alternative due to their biocompatibility, potential for surface modification, and effectiveness in radiotherapeutic techniques. Given that prostate cancer ranks as one of the leading malignancies among men, there's a pressing need to investigate new therapeutic approaches. Methods: AuNPs coated with bovine serum albumin (BSA) were synthesized and their cytotoxicity was assessed against prostate tumor cell lines (LNCaP and PC-3), healthy prostate cells (RWPE-1), and endothelial control cells (HUVEC) using the MTS/PMS assay. For in vivo studies, BALB/C Nude mice were employed to gauge the therapeutic efficacy, biodistribution, and hematological implications post-treatment with BSA-coated AuNPs. Results: The BSA-coated AuNPs exhibited cytotoxic potential against PC-3 and LNCaP lines, while interactions with RWPE-1 and HUVEC remain subjects for further scrutiny. Within animal models, a diverse therapeutic response was observed, with certain instances indicating complete tumor regression. Biodistribution data emphasized the nanoparticles' affinity towards particular organs, and the majority of hematological indicators aligned with normative standards. Conclusions: BSA-coated AuNPs manifest substantial promise as therapeutic tools in treating prostate cancer. The present research not only accentuates the nanoparticles' efficacy but also stresses the imperative of optimization to ascertain both selectivity and safety. Such findings illuminate a promising trajectory for avant-garde therapeutic modalities, holding substantial implications for public health advancements.

Protective effects of l-cysteine and N-acetyl-l-cysteine on boar sperm quality during hypothermic liquid storage with bovine serum albumin as a protectant.

Hypothermic liquid storage at 4-5 °C has emerged as a novel approach for preserving boar semen, offering innovative possibilities for semen preservation. However, this method also presents challenges, including cold shock and excessive reactive oxygen species (ROS) production. Therefore, reducing oxidative damage induced by low temperatures becomes essential while supplementing appropriate protectants. In this study, we investigated the efficacy of Bovine Serum Albumin (BSA) compared to Polyvinylpyrrolidone (PVP) and Skim Milk Powder (SMP) in maintaining boar sperm motility and progressive motility using computer-assisted sperm analysis (CASA). Among the tested concentrations, 4 g/L of BSA exhibited the best protective effect. Subsequently, we supplemented different concentrations of l-cysteine (LC) and N-acetyl-l-cysteine (NAC) as additives in the presence of BSA as a protectant. Our results demonstrated that 1 mmol/L of LC and 0.5 mmol/L of NAC exhibited superior protection of sperm quality compared to other concentrations. Furthermore, the 1 mmol/L LC and 0.5 mmol/L NAC groups showed significantly improved plasma membrane integrity and acrosome integrity compared to the control group. These groups also exhibited enhanced antioxidant capacity, evidenced by increased mitochondrial membrane potential (MMP), ATP production, total superoxide dismutase (T-SOD) activity, total antioxidant capacity (T-AOC), glutathione (GSH), glutathione peroxidase (GSH-PX), and GPX-4 levels. Additionally, they demonstrated decreased reactive oxygen species (ROS) and malondialdehyde (MDA) levels, as well as reduced oxidized glutathione (GSSG) and glutathione reductase (GR) levels. Furthermore, LC and NAC treatment enhanced AMP-activated protein kinase (AMPK) phosphorylation. However, inhibiting AMPK using compound C did not inhibit the protective effects of LC and NAC on low-temperature preserved boar sperm. These findings suggest that 4 g/L BSA can serve as an effective protectant for hypothermic liquid storage of boar semen. Additionally, LC and NAC supplementation reduces oxidative damage by enhancing antioxidant capacity rather than through AMPK-mediated ATP supplementation. These results contribute to advancing the application of LC and NAC in hypothermic liquid storage of boar semen.

Platelet-Rich Plasma Lysate Enhances the Osteogenic Differentiation of Adipose-Derived Stem Cells.

ABSTRACT: Adipose-derived stem cells (ADSCs) have become an accepted source of cells in bone tissue engineering. This study aimed to investigate whether platelet-rich plasma (PRP) lysate can replace traditional fetal bovine serum as a culture medium with the enhanced proliferation and osteogenic potential of ADSCs. We divided the experiment into 5 groups where the ADSCs were cultured in an osteogenic medium containing 2.5%, 5%, 7.5%, and 10% PRP lysate with 10% fetal bovine serum as the control group. The cell proliferation, alkaline phosphatase (ALP) activity, ALP stain, alizarin red stain, osteocalcin (OCN) protein expression, and osteogenic-specific gene expression were analyzed and compared among these groups. The outcome showed that all PRP lysate-treated groups had good ALP stain and ALP activity performance. Better alizarin red stains were found in the 2.5%, 5%, and 7.5% PRP lysate groups. The 2.5% and 5% PRP lysate groups showed superior results in OCN quantitative polymerase chain reaction, whereas the 5% and 7.5% PRP lysate groups showed higher OCN protein expressions. Early RUNX2 (Runt-related transcription factor 2 () genes were the most expressed in the 5% PRP lysate group, followed by the 2.5% PRP lysate group, and then the 7.5% PRP lysate group. Thus, we concluded that 5% PRP lysate seemed to provide the optimal effect on enhancing the osteogenic potential of ADSCs. Platelet-rich plasma lysate-treated ADSCs were considered to be a good cell source for application in treating nonunion or bone defects in the future.

Exploring the Impact of Nanoparticle Stealth Coatings in Cancer Models: From PEGylation to Cell Membrane-Coating Nanotechnology.

Nanotechnological platforms offer advantages over conventional therapeutic and diagnostic modalities. However, the efficient biointerfacing of nanomaterials for biomedical applications remains challenging. In recent years, nanoparticles (NPs) with different coatings have been developed to reduce nonspecific interactions, prolong circulation time, and improve therapeutic outcomes. This study aims to compare various NP coatings to enhance surface engineering for more effective nanomedicines. We prepared and characterized polystyrene NPs with different coatings of poly(ethylene glycol), bovine serum albumin, chitosan, and cell membranes from a human breast cancer cell line. The coating was found to affect the colloidal stability, adhesion, and elastic modulus of NPs. Protein corona formation and cellular uptake of NPs were also investigated, and a 3D tumor model was employed to provide a more realistic representation of the tumor microenvironment. The prepared NPs were found to reduce protein adsorption, and cell-membrane-coated NPs showed significantly higher cellular uptake. The secretion of proinflammatory cytokines in human monocytes after incubation with the prepared NPs was evaluated. Overall, the study demonstrates the importance of coatings in affecting the behavior and interaction of nanosystems with biological entities. The findings provide insight into bionano interactions and are important for the effective implementation of stealth surface engineering designs.

Polyethylene glycol precipitation is an efficient method to obtain extracellular vesicle-depleted fetal bovine serum.

Mesenchymal stromal/stem cell derived-extracellular vesicles (MSC-EVs) have gained interest as drug delivery nanoparticles, having immunoregulatory and potentiating tissue repair property. To maintain growth of MSCs and obtain pure MSC-derived EVs, the culture media should contain fetal bovine serum (FBS) devoid of EVs, as the presence of FBS EVs confounds the properties of MSC-EVs. Therefore, we tested three methods: 18h ultracentrifugation (UC) and ultrafiltration (UF), which are common FBS EV depletion methods in current MSC-EV research, and polyethylene glycol (PEG) precipitation to obtain three EV depleted FBS (EVdFBS) batches, and compared them to FBS and commercial (Com) EVdFBS on human adipose stem cell (hADSC) growth, differentiation, enrichment of EVs in hADSC supernatant and their biological function on collagen metabolism. Our comparative study showed UC and UF vary in terms of depletion efficiency and do not completely deplete EVs and affects the growth-promoting quality of FBS. Specifically, FBS EV depletion was comparable between PEG (95.6%) and UF (96.6%) but less by UC (82%), as compared to FBS. FBS protein loss was markedly different among PEG (47%), UF (87%), and UC (51%), implying the ratio of EV depletion over protein loss was PEG (2.03), UF (1.11), and UC (1.61). A significant decrease of TGFß/Smad signaling, involving in MSC growth and physiology, was observed by UF. After 96 hours of exposure to 5% FBS or 5% four different EVdFBS cell growth media, the osteogenesis ability of hADSCs was not impaired but slightly lower mRNA expression level of Col2a observed in EVdFBS media during chondrogenesis. In consistent with low confluency of hADSCs observed by optical microscope, cell proliferation in response to 5% UF EVdFBS media was inhibited significantly. Importantly, more and purer ADSCs EVs were obtained from ADSCs cultured in 5% PEG EVdFBS media, and they retained bioactive as they upregulated the expression of Col1a1, TIMP1 of human knee synovial fibroblast. Taken together, this study showed that PEG precipitation is the most efficient method to obtain EV depleted FBS for growth of MSCs, and to obtain MSC EVs with minimal FBS EV contamination.

Nickel chloride complexes with substituted 4'-phenyl-2',2':6',2″-terpyridine ligands: synthesis, characterization, anti-proliferation activity and biomolecule interactions.

A series of Ni(II) sandwich-like coordinated compounds were synthesized by the reaction of nickel dichloride and ten 4'-(4-substituent phenyl)-2',2':6',2″-terpyridine ligands, and their structures were confirmed by elemental analysis, FT-IR, ESI-MS, solid state ultraviolet spectroscopy and X-ray single crystal diffraction analysis. Three human cancer cell lines and a normal human cell line were used for anti-proliferation potential study: human lung cancer cell line (A549), human esophageal cancer cell line (Eca-109), human liver cancer cells (Bel-7402) and normal human liver cells (HL-7702). The results show that these nickel complexes possess good inhibitory effects on the cancer cells, outperforming the commonly used clinical chemotherapy drug cisplatin. Especially, complexes 3 (-methoxyl) and 7 (-fluoro) have strong inhibitory ability against Eca-109 cell line with IC50 values of 0.223 µM and 0.335 µM, complexes 4 and 6 showed certain cell selectivity, and complex 6 can inhibit cancer cells and slightly poison normal cells when the concentration was controlled. The ability of these complexes binding to CT-DNA was studied by UV titration and CD spectroscopy, and CD spectroscopy was also used to study the secondary structural change of BSA under the action of the complexes. The binding of these complexes with DNA, DNA-Topo I and bovine serum protein has been simulated by molecular docking software, and the docking results and optimal binding conformation data showed that they interacted with DNA in the mode of embedded binding, which is consistent with the experimental results. These complexes are more inclined to move to the cleavage site when docking with DNA-Topo I, so as to play a role of enzyme cleavage, while BSA promotes the action of the complexes by binding to effective binding sites.

Ga(III) pyridinecarboxylate complexes: potential analogues of the second generation of therapeutic Ga(III) complexes?

A series of novel Ga(III)-pyridine carboxylates ([Ga(Pic)3]·H2O (GaPic; HPic = picolinic acid), H3O[Ga(Dpic)2]·H2O (GaDpic; H2Dpic = dipicolinic acid), [Ga(Chel)(H2O)(OH)]2·4H2O (GaChel; H2Chel = chelidamic acid) and [Ga(Cldpic)(H2O)(OH)]2 (GaCldpic; H2Cldpic = 4-chlorodipicolinic acid)) have been synthesized by simple one-step procedure. Vibrational spectroscopy (mid-IR), elemental analysis, thermogravimetric analysis and X-ray diffraction confirmed complexes molecular structure, inter and intramolecular interactions and their influence to spectral and thermal properties. Moreover, complex species speciation was described in Ga(III)-HPic and Ga(III)-H2Dpic systems by potentiometry and 1H NMR spectroscopy and mononuclear complex species were determined; [Ga(Pic)2]+ (logß021 = 16.23(6)), [Ga(Pic)3] (logß031 = 20.86(2)), [Ga(Dpic)2]- (logß021 = 15.42(9)) and [Ga(Dpic)2(OH)]2- (logß-121 = 11.08(4)). To confirm the complexes stability in 1% DMSO (primary solvent for biological testing), timescale 1H NMR spectra were measured (immediately after dissolution up to 96 h). Antimicrobial activity evaluated by IC50 (0.05 mM) is significant for GaDpic and GaCldpic against difficult to treat and multi-resistant P. aeruginosa. On the other hand, the GaPic complex is most effective against Jurkat, MDA-MB-231 and A2058 cancer cell lines and significantly also decreases the HepG2 cancer cells viability at 75 and 100 µM concentrations in a relatively short time (up to 48 h). In addition, fluorescence measurements have been used to elucidate bovine serum albumin binding activity between ligands, Ga(III) complexes and bovine serum albumin.

Protein separation by sequential selective complex coacervation.

In food manufacturing and particular biomedical products selected proteins are often required. Obtaining the desired proteins in a pure form from natural resources is therefore important, but often very challenging. Herein, we design a sequential coacervation process that allows to efficiently isolate and purify proteins with different isoelectric points (pIs) from a mixed solution, namely Bovine Serum Albumin (BSA, pI = 4.9) and Peroxidase from Horseradish (HRP, pI = 7.2). The key to separation is introducing a suitable polyelectrolyte that causes selective complex coacervation at appropriate pH and ionic strength. Specifically, polyethyleneimine (PEI), when added into the mixture at pH 6.0, produces a coacervation which exclusively contains BSA, leading to a supernatant solution containing 100 % HRP with a purity of 91 %. After separating the dilute and dense phases, BSA is recovered by adding poly(acrylic acid) (PAA) to the concentrated phase, which displaces BSA from the complex because it interacts more strongly with PEI. The supernatant phase after this step contains approximately 75 % of the initial amount of BSA with a purity of 99 %. Our results confirm that coacervation under well-defined conditions can be selective, enabling separation of proteins with adequate purity. Therefore, the established approach demonstrates a facile and sustainable strategy with potential for protein separation at industrial scale.

Extracellular Vesicle Depletion Protocols of Foetal Bovine Serum Influence Umbilical Cord Mesenchymal Stromal Cell Phenotype, Immunomodulation, and Particle Release.

The immunomodulatory properties of MSCs can be recreated using their extracellular vesicles (EVs). Yet, the true capabilities of the MSC EVs cannot be distinguished from contaminating bovine EVs and protein derived from supplemental foetal bovine serum (FBS). FBS EV depletion protocols can minimise this, but vary in terms of depletion efficiency, which can negatively impact the cell phenotype. We explore the impact of FBS EV depletion strategies, including ultracentrifugation, ultrafiltration, and serum-free, on umbilical cord MSC characteristics. Whilst a greater depletion efficiency, seen in the ultrafiltration and serum-free strategies, did not impact the MSC markers or viability, the MSCs did become more fibroblastic, had slower proliferation, and showed inferior immunomodulatory capabilities. Upon MSC EV enrichment, more particles, with a greater particle/protein ratio, were isolated upon increasing the FBS depletion efficiency, except for serum-free, which showed a decreased particle number. Whilst all conditions showed the presence of EV-associated markers (CD9, CD63, and CD81), serum-free was shown to represent a higher proportion of these markers when normalised by total protein. Thus, we caution MSC EV researchers on the use of highly efficient EV depletion protocols, showing that it can impact the MSC phenotype, including their immunomodulatory properties, and stress the importance of testing in consideration to downstream objectives.

Enhanced enzymatic activity and conformational stability of catalase in presence of tetrahedral DNA nanostructures: A biophysical and kinetic study.

The emergence of DNA nanotechnology has shown enormous potential in a vast array of applications, particularly in the medicinal and theranostics fields. Nevertheless, the knowledge on the biocompatibility between DNA nanostructures and cellular proteins is largely unknown. Herein, we report the biophysical interaction between proteins (circulatory protein bovine serum albumin, BSA, and the cellular enzyme bovine liver catalase, BLC) and tetrahedral DNA (tDNA), which are well-known nanocarriers for therapeutics. Interestingly, the secondary conformation of BSA or BLC was unaltered in the presence of tDNAs which supports the biocompatible property of tDNA. In addition, thermodynamic studies showed that the binding of tDNAs with BLC has a stable non-covalent interaction via hydrogen bond and van der Waals contact, which is indicative of a spontaneous reaction. Furthermore, the catalytic activity of BLC was increased in the presence of tDNAs after 24 h of incubation. These findings indicate that the presence of tDNA nanostructures not only ensures a steady secondary conformation of proteins, but also stabilize the intracellular proteins like BLC. Surprisingly, our investigation discovered that tDNAs have no effect on albumin proteins, either by interfering or by adhering to the extracellular proteins. These findings will aid in the design of future DNA nanostructures for biomedical applications by increasing the knowledge on the biocompatible interaction of tDNAs with biomacromolecules.

Formation of a Purple Product upon the Reaction of ABTS Radicals with Proteins.

The reaction of the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) free radical (ABTS●) with proteins (bovine serum albumin, blood plasma, egg white, erythrocyte membranes, and Bacto Peptone) leads not only to a reduction of ABTS● but also to the appearance of a purple color (absorption maximum at 550-560 nm). The aim of this study was to characterize the formation and explain the nature of the product responsible for the appearance of this color. The purple color co-precipitated with protein, and was diminished by reducing agents. A similar color was generated by tyrosine upon reaction with ABTS●. The most feasible explanation for the color formation is the addiction of ABTS● to proteins' tyrosine residues. The product formation was decreased by nitration of the bovine serum albumin (BSA) tyrosine residues. The formation of the purple product of tyrosine was optimal at pH 6.5. A decrease in pH induced a bathochromic shift of the spectra of the product. The product was not a free radical, as demonstrated by electrom paramagnetic resonance (EPR) spectroscopy. Another byproduct of the reaction of ABTS● with tyrosine and proteins was dityrosine. These byproducts can contribute to the non-stoichiometry of the antioxidant assays with ABTS●. The formation of the purple ABTS adduct may be a useful index of radical addition reactions of protein tyrosine residues.

BSA modification of bacterial surface: a promising anti-cancer therapeutic strategy.

BACKGROUND: Attenuated live bacterial therapy and medical BSA materials have their own advantages in anti-cancer research, and their combination is expected to overcome some of the disadvantages of conventional anti-cancer therapeutics. METHODS AND OBJECTIVE: Utilizing the high affinity between biotin and streptavidin, BSA modification on the surface of Escherichia coli (E. coli) was achieved. Then, the adhesion and targeting abilities of BSA modified E. coli was explored on different bladder cancer cells, and the underlying mechanism was also investigated. RESULTS: BSA modification on the surface of E. coli enhances its ability to adhere and target cancer cells, and we speculate that these characteristics are related to the expression of SPARC in different bladder cancer cell lines. CONCLUSION: BSA and live bacteria have their own advantages in anti-cancer research. In this study, we found that E. coli surface-modified by BSA had stronger adhesion and targeting effects on bladder cancer cells with high expression of SPARC. These findings pave the way for the future studies exploring the combination of BSA combined with live bacteria for cancer therapy.

Biochemical and Biophysical in Vitro Studies and Systematic Literature Review on the Antioxidant and Antiglycation Activities of Trazodone.

BACKGROUND/AIMS: Trazodone is a selective serotonin reuptake inhibitor; however, other mechanisms of the drug's anti-depressive properties have also been postulated. Hence, the aim of the study was to perform a systematic review and assess antiglycoxidative properties of trazodone in in vitro models. METHODS: Trazodone's scavenging and chelating properties were measured with spectrophotometric method. The impact of the drug on carbonyl/oxidative stress was marked in the bovine serum albumin (BSA) model where sugars (glucose, fructose, galactose, ribose) and aldehydes (glyoxal and methylglyoxal) were used as glycation agents. Aminoguanidine and N-acetylcysteine (NAC) were applied as reference glycation/free radical inhibitors. Glycation biomarkers (kynurenine, N-formylkynurenine, dityrosine as well as advanced glycation end products contents) were assessed spectrofluorometrically. Concentrations of oxidation parameters (total thiols (TTs), protein carbonyls (PCs) and also advanced oxidation protein products (AOPPs) levels) were determined spectrophotometrically. RESULTS: We demonstrated that trazodone poorly scavenged radicals (hydroxyl radical, nitric oxide, hydrogen peroxide and 2,2-diphenyl-1-picrylhydrazyl radical) and showed low ferrous ion chelating, unlike aminoguanidine and NAC. Sugars/aldehydes caused enhancement of glycation parameters, as well as a decrease of TTs and an increase of PCs and AOPPs levels compared to BSA incubated alone. Trazodone did not reduce oxidation parameters to the baseline (BSA) and significantly exacerbated glycation markers in comparison with both BSA and BSA+glycators. The content of glycation products was markedly lower in aminoguanidine and NAC than in trazodone. The molecular docking of trazodone to BSA revealed its very low affinity, which may indicate non-specific binding of trazodone, facilitating the attachment of glycation factors. CONCLUSION: According to our findings, it may be concluded that trazodone poorly counteracts oxidation and intensifies glycation in vitro. A possible mechanism for antiglycoxidative effect of trazodone in vivo may be the enhancement of the body's adaptive response, as indicated by the results of our systematic review.

Ternary Cobalt (II)-Metformin-Glycine/Histidine/Proline Complexes: Multispectroscopic DNA, HSA, and BSA Interaction and Cytotoxicity Studies.

The synthesized water-soluble ternary complexes [Co(met)(gly)(Cl)2] (1), [Co(met)(hist)(Cl)2] (2), and [Co(met)(pro)(Cl)2] (3), (met = metformin, gly = glycine, hist = histidine, and pro = proline) were evaluated using spectro-analytical techniques, and the stereochemistry of the complexes was determined to be octahedral. UV-Vis absorption, competitive DNA-binding experiments using ethidium bromide (EB) by fluorescence, fluorescence emission studies, viscosity studies, and gel electrophoresis techniques were all employed to explore the binding characteristics of the cobalt (II) complexes with CT-DNA and groove-binding mechanism established. The salt-dependent association of the complexes to CT-DNA was investigated using UV-Vis spectrophotometric analysis. The association of the cobalt (II) complexes with BSA and HSA was explored by utilizing UV-Vis absorption and fluorescence spectroscopy approaches. The findings show that the complexes exhibit adequate capacity to quench BSA and HSA fluorescence and that the binding response is mostly a static quenching mechanism. The cytotoxicity of the complexes has also been appraised with the human breast adenocarcinoma cell lines (MCF-7) and (MDA-MB-231) by utilizing the MTT assay. For each cell line, the IC50 values were computed. In both cell lines, all the complexes were active.

Comparison of pharmacokinetics, biodistribution, and excretion of free and bound Nε-carboxymethyllysine in rats by HPLC-MS/MS.

As a representative product of advanced glycation end products, Nɛ-carboxymethyllysine (CML) exists in free and bound forms in vivo and in food with different bioavailability. To thoroughly understand the bioavailability of free Nɛ-carboxymethyllysine (CML) and bovine serum albumin (BSA)-CML in vivo after intragastric administration, pharmacokinetics, biodistribution, and excretion of CML in rats were investigated by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Pharmacokinetics results revealed that free CML peaked at 1.83 h (1684.72 ± 78.08 ng/mL) and 1.33 h (1440.84 ± 72.48 ng/mL) in serum after intragastric administration of free CML and BSA-CML, demonstrating the higher absorption of free CML than BSA-CML. Besides, dietary free CML exhibited a relatively lower body clearance and tissue distribution than dietary BSA-CML based on the apparent volume of distribution and body clearance. Moreover, free CML was concentrated in the kidneys, indicating that kidneys were the target organ for the uptake of absorbed free CML. Additionally, the total excretion rate of CML in urine and feces were 37% and 60% after oral administration of free CML and BSA-CML. These results shed pivotal light on a better understanding of the biological effects of free and bound CML on health.

The impact of Zn doping on CdTe quantum dots-protein corona formation and the subsequent toxicity at the molecular and cellular level.

Understanding the formation of protein corona (PC) is of vital importance for exploring the toxicity of nanoparticles and promoting their safe applications. In this study, CdTe QDs doping with 0, 1%, 5% and 10% Zn were synthesized using one-pot hydrothermal methods. Afterwards, this study explored and compared the formation of pure and Zn doped-QDs PC as well as the subsequent molecular and cellular toxicity. Result found that Zn doping regulated the toxicity of Cd-QDs by controlling their ability to adsorb serum proteins. The adsorption to Cd-QDs induced the dispersion, unfolding, secondary structural changes and the activity loss of bovine serum albumin (BSA). Among the synthesized Cd-QDs, 10%Zn-QDs exhibited the highest fluorescence quantum yield and lowest molecular toxicity. The formations of pure QDs and 10%Zn-QDs with BSA corona are majorly driven by different forces with different patterns. The regulation of BSA on the cytotoxicity differences of pure QDs and 10%Zn-QDs was similar with fetal bovine serum, proving the significant contribution of BSA to the cytotoxicity of Cd-QDs PC. Compared with pure QDs PC, the higher cytotoxicity and oxidative stress level of 10%Zn-QDs PC were correlated with higher intracellular [Cd2+]. Both larger amount of BSA adsorption and higher level of intracellular reactive oxygen species could accelerate the dissolution rates of 10%Zn-QDs and thus result in higher intracellular [Cd2+].