Bovine serum albumin (BSA) was firstly implemented as an effective sensitivity enhancer for a peptide-based amperometric biosensor for the ultrasensitive detection of prostate specific antigen (PSA). ...A porous and conductive substrate of chitosan-lead ferrocyanide-(poly(diallyldimethylammonium chloride)-graphene oxide) was in-situ generated on a glassy carbon electrode (GCE), in which Pb2Fe(CN)6 served as a novel redox species with strong current signal at −0.46 V (vs. Ag/AgCl). Poly(diallyldimethylammonium chloride)-graphene oxide was applied to improve conductivity of the substrate. After adsorbing Pb2+ for signal amplification, chitosan provided active sites to simultaneously immobilize peptides and 1-aminopropyl-3-methylimidazolium chloride by glutaraldehyde. To enhance the sensitivity, BSA was chemically linked to the immobilized peptide, behaving as a serious decrease of current signal for BSA hindering the electron transfer. The dramatic increase of current signal of the biosensor was obtained by PSA cleaving the immobilized BSA-peptide. The proposed biosensor exhibited a detection limit of 1fgmL−1 for PSA and its sensitivity was seven-fold higher than previous works.
•BSA was firstly implemented as an effective sensitivity enhancer for the peptide-based amperometric biosensor.•Multiple amplification strategies were developed for the amperometric biosensor for PSA.•Chitosan-Pb2Fe(CN)6-PDDA-GO as a new redox species was used as substrate.
Abstract Human serum albumin (HSA) is a biological nanocarrier that forms non-covalent complexes with a number of synthetic and biomolecules. Previously we demonstrated radiolabeled HSA-based ...nanoparticles can form non-covalent complexes with fluorescent cyanine dyes yielding imaging agents for surgical guidance towards tumor draining lymph nodes. Here the self-assembly approach enabled rapid clinical translation. Based on this experience we reasoned it would be interesting to expand this non-covalent technology to a targeted approach. Therefore, the ability of HSA to form non-covalent self-assembled complexes with peptides via near-infrared (NIR) cyanine dyes was explored. Föster resonance energy transfer (FRET) quenching interactions between HSA-Cy5 and the non-covalently bound fluorescent molecules indocyanine green (ICG), IR783–CO2 H and three IR783-labeled targeting peptides were used to monitor complex assembly and disassembly. The host-guest interactions between HSA and IR783-labeled peptides enabled the formation of (bio)nanoparticles that are coated with peptides, which may target αv β3 -integrins, the chemokine receptor 4 (CXCR4), or somatostatin receptors. The potential of CXCR4-targeted (bio)nanoparticles in sentinel lymph node procedures is demonstrated in vivo. By non-covalently binding NIR-dye labeled peptides to an already clinically approved HSA-scaffold, we have readily formed targeted bionanoparticles.
Purpose
This paper aims to investigate the immunoinhibitory properties of a lymph nodes-targeting suppressive oligonucleotide (ODN) for the potential treatment of autoimmune diseases or chronic ...inflammation.
Methods
Synthetic suppressive ODN engineered with an albumin-binding diacyl lipid at the 5′-terminal (lipo-ODN) was synthesized.
In vitro
and
in vivo
experiments were designed to compare the immune suppressive properties of lipo-ODN and unmodified ODN. Cellular uptake and distribution, inhibition of Toll-like receptor (TLR) activation, lymph nodes (LN) draining, and the suppression of antigen-specific immune responses in an ovalbumin protein model was investigated.
Results
Compared to unmodified ODN, lipid functionalized suppressive ODN demonstrated enhanced cellular uptake and TLR-9 specific immune suppression in TLR reporter cells. Additionally, injection of a low dose of lipid-modified suppressive ODN, but not the unconjugated ODN, accumulated in the draining LNs and exhibited potent inhibition of antigen-specific CD8
+
T cell and B cell responses
in vivo
.
Conclusions
Targeting suppressive ODN to antigen presenting cells (APCs) in the local LNs is an effective approach to amplify the immune modulation mediated by ODN containing repetitive TTAGGG motif. This approach might be broadly applicable to target molecular adjuvants to the key immune cells in the LNs draining from disease site, providing a simple strategy to improve the efficacy of many molecular immune modulators.
The effective removal of heavy metals and soluble microbial products from wastewater is crucial for ensuring a safe environment and good quality human health. The present work investigated the ...potential of eggshell (ES) waste as an adsorbent for removing heavy metals and soluble microbial products. ES was firstly used to capture heavy metal ions, and the eggshell–metal (ES-M) complex was then applied to remove soluble microbial products (e.g., proteins) from aqueous solution. In this study, bovine serum albumin (BSA) was selected as a model protein-based contaminant. The equilibrium and kinetic characteristics of soluble protein removed by ES were evaluated in batch mode involving parameters such as metal ions (Cu
2+
, Zn
2+
, Ni
2+
, Co
2+
), operating temperatures (277–323 K), and particle size of ES (100–700 µm). The isotherm curves were well-fitted by Langmuir–Freundlich model. As the temperature increased from 277 to 323 K, the maximum binding capacity for BSA increased from 25.22 to 34.28 (mg BSA/g ES-Zn). The negative values of Δ
G
° indicated the spontaneous nature of the protein adsorption, while the kinetic of protein adsorption followed the pseudo-second-order model. ES functionalized with heavy metal ions acted as an effective pseudo-chelating adsorbent for the removal of soluble protein from wastewater. Chelates of Zn–BSA found on the ES complexes were found to be highly stable, indicating a minimal possibility of secondary pollution caused by these Zn- and BSA-containing ES complexes. The ES-Zn complex can be potentially used as an adsorbent for removing soluble microbial products in wastewater prior to the membrane filtration.
Graphic abstract
Design of selective sensors for a specific analyte in blood serum, which contains a large number of proteins, small molecules, and ions, is important in clinical diagnostics. While metal and ...polymeric nanoparticle conjugates have been used as sensors, small molecular assemblies have rarely been exploited for the selective sensing of a protein in blood serum. Herein we demonstrate how a nonspecific small molecular fluorescent dye can be empowered to form a selective protein sensor as illustrated with a thiol-sensitive near-IR squaraine (Sq) dye (λabs= 670 nm, λem= 700 nm). The dye self-assembles to form nonfluorescent nanoparticles (D h = 200 nm) which selectively respond to human serum albumin (HSA) in the presence of other thiol-containing molecules and proteins by triggering a green fluorescence. This selective response of the dye nanoparticles allowed detection and quantification of HSA in blood serum with a sensitivity limit of 3 nM. Notably, the Sq dye in solution state is nonselective and responds to any thiol-containing proteins and small molecules. The sensing mechanism involves HSA specific controlled disassembly of the Sq nanoparticles to the molecular dye by a noncovalent binding process and its subsequent reaction with the thiol moiety of the protein, triggering the green emission of a dormant fluorophore present in the dye. This study demonstrates the power of a self-assembled small molecular fluorophore for protein sensing and is a simple chemical tool for the clinical diagnosis of blood serum.
Giriş: İnflamasyon kanser gelişimini kolaylaştırmanın yanı sıra birçok kanser tipinde kötü prognozla da ilişkilidir. Albümin ve globülin inflamasyonu yansıtan belirteçlerden ikisidir. Albüminin ...özellikle inflamasyon dışı birçok nedenden etkilenebileceği için albümin globülin oranının inflamasyonu yansıtmada daha başarılı olacağı gösterilmiştir. Biz bu çalışmada albümin globülin oranın (AGO) küçük hücreli akciğer kanserinde (KHAK) prognostik öneminin belirlenmesi ve diğer inflamatuar parametrelerle ilişkisinin saptanmasını amaçladık. Materyal ve Metot: Retrospektif olarak 2014-2018 yılları arasından tanı almış KHAK hastaları çalışmaya dâhil edildi. Tanı anındaki albümin globüline bölünerek AGO bulundu. Medyan değer olan 1,2 AGO için eşik değer olarak kabul edildi. Bulgular: Toplam 81 hasta çalışmaya dâhil edildi. Hastaların %40,30’ü AGO < 1,2 olarak saptanırken, % 59,30’ünün ise AGO ≥ 1,2 olarak bulundu. Her iki grup hasta özellikleri açısından benzerdi. AGO ile nötrofil lenfosit oranı ve platelet lenfosit oranı arasında istatistiksel anlamlı ters korelasyon saptandı. AGO ≥ 1,2 olan grupta hem progresyonsuz sağkalım hem de genel sağkalım istatistiksel olarak daha uzundu. Sonuç: AGO hem kolay uygulanabilir hem de ucuz bir belirteç olması nedeniyle KHAK’de prognostik belirteç olarak kullanılabilir.
Nonalcoholic fatty liver disease (NAFLD) is one of themajor causes of chronic liver injury. NAFLD includes awide range of clinical conditions from simple steatosisto nonalcoholic steatohepatitis ...(NASH), advancedfibrosis, and liver cirrhosis. The histological findingsof NASH indicate hepatic steatosis and inflammationwith characteristic hepatocyte injury (e.g. , ballooningdegeneration), as is observed in the patients withalcoholic liver disease. NASH is considered to be apotentially health-threatening disease that can progressto cirrhosis. A liver biopsy remains the most reliablediagnostic method to appropriately diagnose NASH,evaluate the severity of liver fibrosis, and determinethe prognosis and optimal treatment. However, thisinvasive technique is associated with several limitationsin routine use, and a number of biomarkers havebeen developed in order to predict the degree of liverfibrosis. In the present article, we review the currentstatus of noninvasive biomarkers available to estimateliver fibrosis in the patients with NASH. We also discussour recent findings on the use of the glycated albuminto-glycated hemoglobin ratio, which is a new index thatcorrelates to various chronic liver diseases, includingNASH.
The present study reports the biological evaluation of vanadium(V) complexes (1–3) against three different proteins: tyrosinase, acetylcholinesterase (AChE), and human serum albumin (HSA), which were ...studied by spectroscopic techniques and molecular docking. Despite the synthesis and characterization of complexes 1 and 2 having already previously described, complex 3 is a novel dioxidovanadium(V) derivative. Complex 1 can activate both tyrosinase and AChE enzymes in about 11.5 and 47.0%, respectively. On the other hand, complexes 2 and 3 inhibited the same enzymes (1.30 and 46.0% for tyrosinase and 20.0 and 21.9% for AChE, respectively). Molecular docking calculations suggested that the presence of the hydroxyl group in complex 1 is essential to activate tyrosinase enzymes. According to theoretical analysis, hydrogen bonding, van der Waals, and hydrophobic forces are the main binding interactions for each V(V) complex and AChE. Moreover, the interaction between HSA and vanadium(V) complexes occurs via ground-state association, being only enthalpically driven for complexes 1 and 2 and entropically and enthalpically driven for complex 3. The interaction is spontaneous for all samples and the binding modes do not perturb significantly the secondary and surface structures of the albumin. As there are few reported cases in the literature that explore vanadium complexes against these three proteins, the present results may contribute to future studies by offering different scaffolds to design new vanadium(V) complexes in the hyperpigmentation process and Alzheimer's disease.
Display omitted
•Structural characterization analysis of vanadium(V) complexes;•Investigation of HSA-binding properties of vanadium(V) complexes;•Tyrosinase and acetylcholinesterase enzyme inhibition by vanadium(V) derivatives;
The current quantitative polymerase chain reaction (QPCR) assay of telomere length measures telomere (T) signals in experimental DNA samples in one set of reaction wells, and single copy gene (S) ...signals in separate wells, in comparison to a reference DNA, to yield relative T/S ratios that are proportional to average telomere length. Multiplexing this assay is desirable, because variation in the amount of DNA pipetted would no longer contribute to variation in T/S, since T and S would be collected within each reaction, from the same input DNA. Multiplexing also increases throughput and lowers costs, since half as many reactions are needed. Here, we present the first multiplexed QPCR method for telomere length measurement. Remarkably, a single fluorescent DNA-intercalating dye is sufficient in this system, because T signals can be collected in early cycles, before S signals rise above baseline, and S signals can be collected at a temperature that fully melts the telomere product, sending its signal to baseline. The correlation of T/S ratios with Terminal Restriction Fragment (TRF) lengths measured by Southern blot was stronger with this monochrome multiplex QPCR method (R² = 0.844) than with our original singleplex method (R² = 0.677). Multiplex T/S results from independent runs on different days were highly reproducible (R² = 0.91).
Background Although peanut oral immunotherapy (OIT) has been conclusively shown to cause desensitization, it is currently unknown whether clinical protection persists after stopping therapy. ...Objective Our primary objective was to determine whether peanut OIT can induce sustained unresponsiveness after withdrawal of OIT. Methods We conducted a pilot clinical trial of peanut OIT at 2 US centers. Subjects age 1 to 16 years were recruited and treated for up to 5 years with peanut OIT. The protocol was modified over time to permit dose increases to a maximum of 4000 mg/d peanut protein. Blood was collected at multiple time points. Clinical end points were measured with 5000-mg double-blinded, placebo-controlled food challenges once specific criteria were met. Results Of the 39 subjects originally enrolled, 24 completed the protocol and had evaluable outcomes. Twelve (50%) of 24 successfully passed a challenge 1 month after stopping OIT and achieved sustained unresponsiveness. Peanut was added to the diet. At baseline and the time of challenge, such subjects had smaller skin test results, as well as lower IgE levels specific for peanut, Ara h 1, and Ara h 2 and lower ratios of peanut-specific IgE/total IgE compared with subjects not passing. There were no differences in peanut IgG4 levels or functional activity at the end of the study. Conclusions This is the first demonstration of sustained unresponsiveness after peanut OIT, occurring in half of subjects treated for up to 5 years. OIT favorably modified the peanut-specific immune response in all subjects completing the protocol. Smaller skin test results and lower allergen-specific IgE levels were predictive of successful outcome.