Amount Of Bovine Serum Albumin Research Articles

Protein assay and immunoassay based on nematic thermotropic and lyotropic liquid crystals quantitated by haze measurement

Haze measurement is the cornerstone for assessing the transparency or opaqueness of liquid crystals (LCs) in applications such as smart windows and display technologies. In this study, we present a novel application of haze measurement as the quantitative approach for LC-based biosensing. Protein assay with bovine serum albumin (BSA) as the protein standard and immunoassay of the cancer biomarker CA125 were performed with the thermotropic LC 5CB and the nematic phase of the lyotropic chromonic LC sunset yellow. We observed that the brightness of LC optical texture increased with increasing analyte concentration due to enhanced light leakage caused by the attenuation of the vertical anchoring force of the surface alignment reagent coated on the glass surface. On the other hand, the haze value decreased as the amount of BSA or CA125 at the LC–glass interface increased, indicating that the scattering angle of the incident light was reduced. By calculating the percent difference in haze value, W (%), which gave rise to a positive correlation between the result of haze analysis and analyte concentration, a limit of detection (LOD) of 1.2 × 10−3 and 5.6 × 10−5 g/mL for BSA and CA125, respectively, was achieved by detection with 5CB, whereas the LOD values for BSA and CA125 were 1.0 × 10−12 and 1.9 × 10−9 g/mL, respectively, when detected with nematic sunset yellow. To the best of our knowledge, this study provides the first demonstration of the feasibility and simplicity of quantitative analysis by haze measurement in LC-based biosensing.

Versatile Bovine Serum Albumin as Ingenious Electron Operator-Enhanced Photoelectrochemical Biosensing for Ultrasensitive Detection of miRNA.

Bovine serum albumin (BSA) has been widely used in biosensors as a blocking agent. Herein, conformist BSA was first exploited as an ingenious operator to enhance the photocurrent response of (2Z,2'Z)-2,2'-(1,4-phenylene)bis(3-(4-(bis(4-methoxyphenyl)amino)phenyl)acrylonitrile) (TPDCN)-based photoelectrochemical (PEC) platform via manipulating the electron transfer process of the detection system. Concretely, the presence of target molecules triggered catalytic hairpin assembly reaction and subsequently powered terminal deoxynucleotidyl transferase-mediated signal amplification to produce the AgNP@BSA-DNA dendrimer nanostructure. After being treated with HNO3, a large amount of BSA could be released from the dendrimer nanostructure. When they were transferred to the TPDCN-based PEC platform, the photocurrent response of the biosensor was largely enhanced because BSA can manipulate the electrons of TPDCN via a well-matched energy level to form a new electron transfer track. Meanwhile, tryptophan (Trp) in BSA could be oxidized to quinone Trp-O under photoirradiation, which can facilitate the oxidation of ascorbate and generate more H+ to promote the migration of photogenerated electrons. As a result, the proposed PEC biosensor exhibits excellent analytical performance for detection of miRNA-21 (as a model target) over a wide linear range of 0.01 to 10,000 pM with detection limit as low as 4.7 fM. Overall, this strategy provides a new perspective on constructing efficient PEC biosensors, which expands the potential applications in bioanalysis and clinical diagnosis.

Anticancer and antibacterial potential of green synthesized BSA conjugated silver nanoparticles

In this study, silver nanoparticles (AgNPs) were synthesized by utilizing different volumes of silver nitrate (AgNO3) and a medicinally important protein, bovine serum albumin (BSA); subsequently, their anticancer and antibacterial activities were investigated. The volume of AgNO3 and BSA were varied to obtain physically and chemically stable NPs for better therapeutic effects. The synthesized BSA@AgNPs were characterized by spectroscopic and microscopic methods, such as FTIR, and UV–Vis spectroscopy, SEM/EDS, and TEM/SAED. The characterization results offer substantial proof for the successful preparation of non-aggregated stable BSA@AgNPs. The EDS analysis revealed the presence of Ag, C, and O, thus reaffirming the preparation of BSA-conjugated AgNPs. The anticancer efficacy of BSA@AgNPs was studied against colorectal (HCT-116) and HeLa cancerous cell lines. The anticancer results showed that the treatment of cancer cells with BSA@AgNPs decreased the number of cells compared with untreated cells. The NPs prepared with a moderate amount of BSA showed a better inhibiting property than the particles prepared with a high amount of BSA. The antibacterial activity of BSA@AgNPs was studied against gram-positive (S. aureus) and gram-negative (E. coli) bacteria. SEM and TEM analyses confirmed that S. aureus and E. coli cells were damaged upon exposure to BSA@AgNPs in the form of deep pits and cavities as opposed to untreated cells. The obtained results show that the green synthesized BSA@AgNPs could be used as potential anticancer and antibacterial drugs.

Effect of band gap of graphene oxide on interaction with bovine serum albumin: Correlation of band gap with sensitivity

In the direction of developing new and reliable prognostic tools, metamaterial-based biosensor device is an emergent potential field. The special design of metamaterial provides signature frequency features of healthy or diseased tissues. In the current work we have studied the single split resonance device (SSR) using graphene oxide (GO) as probe for the accelerated and selective detection of bovine serum albumin (BSA). Further, we have used different band gap GO to interpret the structure-property relationship. Spectroscopy methods have been employed to further support the SSR results. 1 ppm solution of mGO-0.5 (band gap ∼1.35 eV) shows sequential increase in sensitivity on increasing amount of BSA. Figure-of-merit (FoM) of SSR biosensor also increased from 57 to 82 and highest Q-factor calculated for mGO-1 is ∼47 making it a good candidate as probe molecule. This work lays out a correlation of degree of GO functionalization with a physical parameter, i.e., band gap for activity towards protein molecules. Also, as the SSR devices use large wavelength radiation with high resolution and accuracy for quantitative estimation of analyte, these are potential non-invasive point-of-use portable diagnostic and early disease diagnosis devices.

Phase separation, aggregation, and complexation of triton-X100 and bovine serum albumin mixture: A combined cloud point and UV–visible spectroscopic approaches

Phase separation and aggregation behaviour of triton X-100 (TX-100) and bovine serum albumin (BSA) mixture were investigated using cloud point and UV–visible spectroscopic techniques. The effects of various hydrotropes (HYTs) - namely, sodium salicylate (SS), sodium benzoate (SB), glycerol (Glyc), and 4-aminobenzoic acid (4-ABA) - on the cloud point (CP) of TX-100 + BSA were determined. The obtained CP values for the mixed system in the presence of HYTs followed the order:CPH2O+4−ABA<CPH2O+Glyc<CPH2O+SB<CPH2O+SS. The measured critical micellization concentration (CMC) values of the TX-100 + BSA mixture were found to be significantly altered with varying amounts of BSA. The calculated free energy of clouding and micellization indicated the non-spontaneous nature of the phase transition and the spontaneous association of the TX-100 + BSA mixture. The non-spontaneity of phase separation decreased with increasing concentrations of HYTs. The enumerated values of ∆Hco and ∆Sco were consistently recorded as negative and positive magnitudes, respectively, in all aqueous HYTs media. The clouding process occurred due to a combination of hydrophobic and electrostatic interactions. The binding constant of the mixed system was determined employing the UV–vis spectroscopic method using the Benesi-Hildebrand equation.

Kinetic Study of the Esterase-like Activity of Albumin following Condensation by Macromolecular Crowding.

The ability of bovine serum albumin (BSA) to form condensates in crowded environments has been discovered only recently. Effects of this condensed state on the secondary structure of the protein have already been unraveled as some aging aspects, but the pseudo-enzymatic behavior of condensed BSA has never been reported yet. This article investigates the kinetic profile of para-nitrophenol acetate hydrolysis by BSA in its condensed state with poly(ethylene) glycol (PEG) as the crowding agent. Furthermore, the initial BSA concentration was varied between 0.25 and 1 mM which allowed us to modify the size distribution, the volume fraction, and the partition coefficient (varying from 136 to 180). Hence, the amount of BSA originally added was a simple way to modulate the size and density of the condensates. Compared with dilute BSA, the initial velocity (vi) with condensates was dramatically reduced. From the Michaelis-Menten fits, the extracted Michaelis constant Km and the maximum velocity Vmax decreased in control samples without condensates when the BSA concentration increased, which was attributed to BSA self-oligomerization. In samples containing condensates, the observed vi was interpreted as an effect of diluted BSA remaining in the supernatants and from the condensates. In supernatants, the crowding effect of PEG increased the kcat and catalytic efficiency. Last, Vmax was proportional to the volume fraction of the condensates, which could be controlled by varying its initial concentration. Hence, the major significance of this article is the control of the size and volume fraction of albumin condensates, along with their kinetic profile using liquid-liquid phase separation.

Glycative stress inhibits hypertrophy and impairs cell membrane integrity in overloaded mouse skeletal muscle.

Glycative stress, characterized by the formation and accumulation of advanced glycation end products (AGEs) associated with protein glycation reactions, has been implicated in inducing a decline of muscle function. Although the inverse correlation between glycative stress and muscle mass and strength has been demonstrated, the underlying molecular mechanisms are not fully understood. This study aimed to elucidate how glycative stress affects the skeletal muscle, particularly the adaptive muscle response to hypertrophic stimuli and its molecular mechanism. Male C57BL/6NCr mice were randomly divided into the following two groups: the bovine serum albumin (BSA)-treated and AGE-treated groups. Mice in the AGE-treated group were intraperitoneally administered AGEs (0.5mg/g) once daily, whereas those in the BSA-treated group received an equal amount of BSA (0.5mg/g) as the vehicle control. After 7days of continuous administration, the right leg plantaris muscle of mice in each group underwent functional overload treatment by synergist ablation for 7days to induce muscle hypertrophy. In in vitro studies, cultured C2C12 myocytes were treated with AGEs (1mg/mL) to examine cell adhesion and cell membrane permeability. Continuous AGE administration increased the levels of fluorescent AGEs, Nε-(carboxymethyl) lysine, and methylglyoxal-derived hydroimidazolone-1 in both plasma and skeletal muscle. Plantaris muscle weight, muscle fibre cross-sectional area, protein synthesis rate, and the number of myonuclei increased with functional overload in both groups; however, the increase was significantly reduced by AGE treatment. Some muscles of AGE-treated mice were destroyed by functional overload. Proteomic analysis was performed to explore the mechanisms of muscle hypertrophy suppression and myofibre destruction by AGEs. When principal component analysis was performed on 4659 data obtained by proteomic analysis, AGE treatment was observed to affect protein expression only in functionally overloaded muscles. Enrichment analysis of the 436 proteins extracted using the K-means method further identified a group of proteins involved in cell adhesion. Consistent with this finding, dystrophin-glycoprotein complex proteins and cell adhesion-related proteins were confirmed to increase with functional overload; however, this was attenuated by AGE treatment. Additionally, the treatment of C2C12 muscle cells with AGEs inhibited their ability to adhere and increased cell membrane permeability. This study indicates that glycative stress may be a novel pathogenic factor in skeletal muscle dysfunctions by causing loss of membrane integrity and preventing muscle mass gain.

Termostable and effective immobilized invertase for sucrose determination in fruit juices

In this study, immobilization of invertase enzyme was performed on a previously synthesized and characterized poly(N-vinylpyrrolidone-co-butylacrylate-co-N hydroxymethylacrylamide) terpolymer membranes by covalent bonding method. Glutaraldehyde(GA) was used as the crosslinker and Bovine Serum Albumin(BSA) was used as the binding agent. Optimum pH, temperature, amount of polymer, substrate concentration, amount of BSA and amount of GA values were determined for both free and immobilized enzyme. Optimum pH and temperature values were found as pH = 5.0, T = 55 °C, pH = 7.0 and T = 80 °C for free and immobilized enzyme, respectively. In particular, the optimum temperature of 80 °C for the immobilized enzyme provides its potential to be used commercially. The kinetic parameters of the free enzyme and the immobilized enzyme were determined using the well known Lineweaver-Burk method. The Vmax values for free (13.4 μM/min) and immobilized enzyme (12.2 μM/min) were found as close to each other, while the Km value of the immobilized enzyme (8.33 mM) was much lower than that of the free enzyme (29.41 mM). In reuse studies conducted with peach and orange juices, it was determined that the immobilized enzyme retained approximately 90% of its activity even after 30 reuses within 1 month.

Profiling Protein-Protein Interactions in the Human Brain by Refined Cofractionation Mass Spectrometry.

Proteins usually execute their biological functions through interactions with other proteins and by forming macromolecular complexes, but global profiling of protein complexes directly from human tissue samples has been limited. In this study, we utilized cofractionation mass spectrometry (CF-MS) to map protein complexes within the postmortem human brain with experimental replicates. First, we used concatenated anion and cation Ion Exchange Chromatography (IEX) to separate native protein complexes in 192 fractions and then proceeded with Data-Independent Acquisition (DIA) mass spectrometry to analyze the proteins in each fraction, quantifying a total of 4,804 proteins with 3,260 overlapping in both replicates. We improved the DIA's quantitative accuracy by implementing a constant amount of bovine serum albumin (BSA) in each fraction as an internal standard. Next, advanced computational pipelines, which integrate both a database-based complex analysis and an unbiased protein-protein interaction (PPI) search, were applied to identify protein complexes and construct protein-protein interaction networks in the human brain. Our study led to the identification of 486 protein complexes and 10054 binary protein-protein interactions, which represents the first global profiling of human brain PPIs using CF-MS. Overall, this study offers a resource and tool for a wide range of human brain research, including the identification of disease-specific protein complexes in the future.

Polydopamine modification of polydimethylsiloxane for multifunctional biomaterials: Immobilization and stability of albumin and fetuin-A on modified surfaces.

The surface of polydimethylsiloxane (PDMS) can be modified to immobilize proteins; however, most existing approaches are limited to complex reactions and achieving multifunctional modifications is challenging. This work applies a simple technique to modify PDMS using polydopamine (PDA) and investigates immobilization of multiple proteins. The surfaces were characterized in detail and stability was assessed, demonstrating that in a buffer solution, PDA modification was maintained without an effect on surface properties. Bovine serum albumin (BSA) and bovine fetuin-A (Fet-A) were used as model biomolecules for simultaneous or sequential immobilization and to understand their use for surface backfilling and functionalization. Based on 125I radiolabeling, amounts of BSA and Fet-A on PDA were determined to be close to double that were obtained on control PDMS surfaces. Following elution with sodium dodecyl sulfate, around 67% of BSA and 63% of Fet-A were retained on the surface. The amount of immobilized protein was influenced by the process (simultaneous or sequential) and surface affinity of the proteins. With simultaneous modification, a balanced level of both proteins could be achieved, whereas with the sequential process, the initially immobilized protein was more strongly attached. After incubation with plasma and fetal bovine serum, the PDA-modified surfaces maintained over 90% of the proteins immobilized. This demonstrates that the biological environments also play an important role in the binding and stability of conjugated proteins. This combination of PDA and surface immobilization methods provides fundamental knowledge for tailoring multifunctional PDMS-based biomaterials with applications in cell-material interactions, biosensing, and medical devices.

Determination of Hansen solubility parameters of water-soluble proteins using UV–vis spectrophotometry

Determination of solubility parameters by dissolution tests are difficult for some valuable molecules, such as proteins, where the quantities available are small, UV–vis spectroscopy can determine dissolved concentrations of even small amounts of material, but accurate determination of dissolution is difficult in relatively poor solvents, due to difficulty with constructing a reliable calibration curve. In this work we report a new simple procedure to determine the relative dissolution of proteins in various solvents using UV vis spectroscopy for the determination of Hansen solubility parameters (HSP) of proteins. This method allows qualitative determination of the amounts of BSA dissolved in various solvents. The amounts of BSA dissolved in each solvent, can then be used to rank solvents as good or bad for HSP calculation purpose, which gives more reliable ranking than observation alone in dissolution tests. To be able to evaluate the HSP of any solid material, the solubility of the tested material in a range of solvents needs to be determined. Solvents are then scored as good or bad based on observations and from the known properties of those solvents, the HSP of the solute molecule in question can be calculated. Here, bovine serum albumin (BSA) was used as a model protein, but the procedure reported here can be applied to any soluble protein or other macromolecule with a clear UV/vis adsorption peak. This procedure requires the tested material to be highly soluble in water, therefore eliminating the need for the preparation of many standard solutions of BSA in different solvents. Only a set of standard solutions of protein in water is required. UV–vis spectroscopy was used to analyze the remaining solid resuspended in water after centrifugation of solutions of BSA dissolved in other solvents to separate any undissolved protein. The HSP of BSA obtained via this procedure was compared to values previously obtained for BSA using other methods. A very good agreement between the HSP obtained in this work with the that reported by Houen et al. which used amino acid analysis for the estimation of the solubility of BSA in various organic solvents.

Chiral organic-silica hybrid monolithic HPLC column with dynamic grafting BSA for the enantiomeric separation

BSA functionalized hybrid monolithic column prepared by in-situ dynamic grafting on traditional stainless steel column for enantiomeric separation. A hybrid silica monolithic column (HMC) was prepared using a single precursor (methytrimethoxysilane) in stainless steel HPLC column (50 mm × 4.6 mm) by sol–gel method. The chiral hybrid monolithic column (CHMC) was prepared by grafting 3-aminopropyl trimethoxysilane onto HMC, and then reacting bovine serum albumin (BSA) with Glutaraldehyde. The preparation conditions were optimized, and the maximum grafting amount of BSA was 48.6 mg g−1. The CHMC was characterized and its chromatographic performance was tested. The results showed that the CHMC has a homogeneous network skeleton structure, good stability and reproducibility. The CHMC was combined with HPLC, under optimized chromatographic conditions, the baseline separation of tryptophan and pidotimod enantiomers were successfully achieved.

Effect of Metal Ions on the Interaction of Condensed Tannins with Protein

A quantitative analysis of the precipitate effects of metal ions (Al3+, Fe2+, Cu2+, Zn2+) by bovine serum albumin (BSA) on two condensed tannins (CT) from sorghum and plum was presented in this study. The results showed that adding metal ions enhanced the precipitation of proteins by CT, depending on the type and concentration of the metal ions used in the reaction system. The presence of metal ions and precipitation results on the CT-protein complex showed that Al3+ and Fe2+ had a higher binding ability with CT and a weaker influence on the precipitation of the CT-protein complex than Cu2+ and Zn2+. However, when the initial reaction solution contained excessive amounts of BSA, the extra addition of metal ions had no significant effect on the amount of BSA precipitation. Reversely, adding Cu2+ or Zn2+ into the reaction solution increased the amount of precipitated BSA when the amount of CT was excessive. In addition, the amounts of CT from plum, rather than sorghum, generated more protein precipitate in the presence of Cu2+ or Zn2+, which may be due to the different binding modes between the metal ion and the CT-BSA complex. This study also proposed a model of the interaction between the metal ion and the CT-protein precipitate.

Implant surface physicochemistry affects keratinocyte hemidesmosome formation.

Previous studies have shown hydrophilic/hydrophobic implant surfaces stimulate/hinder osseointegration. An analogous concept was applied here using common biological functional groups on a model surface to promote oral keratinocytes (OKs) proliferation and hemidesmosomes (HD) to extend implant lifespans through increased soft tissue attachment. However, it is unclear what physicochemistry stimulates HDs. Thus, common biological functional groups (NH2 , OH, and CH3 ) were functionalized on glass using silanization. Non-functionalized plasma-cleaned glass and H silanization were controls. Surface modifications were confirmed with X-ray photoelectron spectroscopy and water contact angle. The amount of bovine serum albumin (BSA) and fibrinogen, and BSA thickness, were assessed to understand how adsorbed protein properties were influenced by physicochemistry and may influence HDs. OKs proliferation was measured, and HDs were quantified with immunofluorescence for collagen XVII and integrin β4. Plasma-cleaned surfaces were the most hydrophilic group overall, while CH3 was the most hydrophobic and OH was the most hydrophilic among functionalized groups. Modification with the OH chemical group showed the highest OKs proliferation and HD expression. The OKs response on OH surfaces appeared to not correlate to the amount or thickness of adsorbed model proteins. These results reveal relevant surface physicochemical features to favor HDs and improve implant soft tissue attachment.

How and why does time matter - A comparison of fouling caused by organic substances on membranes over adsorption durations

This study investigated the effect of time on the severity of adsorptive fouling on polyvinylidene fluoride (PVDF) membrane surface. Sodium alginate (SA), bovine serum albumin (BSA), and humic acid (HA) were selected as representative membrane foulants. We examined the fouling behavior of these three selected model foulants over different adsorption durations (i.e., ~2300 and ~20,000 s). The fouling experiments were performed under conditions with and without the presence of Ca2+. For the SA-Ca2+ system, a longer adsorption duration slightly increased adsorption amount of SA but sharply reduced the reversibility (from 86.8 % to 12.9 %). For BSA-Ca2+, extended time did not change the deposition amount of BSA on the membrane surface, but led to more residual BSA after cleaning (reversibility decreased from 11.3 % to 4.5 %). Similarly, in the HA-Ca2+ system, adsorption duration barely influenced the adsorption amount of HA, while reduced its reversibility from 39.4 to 32.2 %. Therefore, time duration significantly influenced the amount and reversibility of membrane fouling depending on their chemical property. Corresponding results can be well reflected by a selected mathematical model. Further investigation on relevant mechanisms was conducted, quartz crystal microbalance with dissipation (QCM-D) and atomic force microscope (AFM) measurements indicated that longer adsorption duration resulted in more compacted fouling layer and stronger foulant-membrane interaction force. Our results suggest that time (adsorption duration) plays an important role in determining the reversibility of membrane fouling, while the severity is related to the inherent characteristics of foulants.

Improved sulfur autotrophic denitrification using supplementary bovine serum albumin

Excess nitrate presented in natural water body and drinking water has been a challenge for maintaining safe ecosystem and human health. Sulfur autotrophic denitrification is proved a feasible technology to remove nitrate from water environment. However, comparatively low rate of sulfur autotrophic denitrification needs to be addressed before wide application of this technology, which is a result of the low solubility of elemental sulfur. Therefore, this study employed bovine serum albumin (BSA) as a supplementary material to modify the elemental sulfur for improved sulfur autotrophic denitrification rate. Artificial biofilm of Thiobacillus denitrificans was prepared and employed in experiments. By testing different amount of BSA applied in both elemental sulfur and the biofilm, including 1 %, 2 % and 4 % mass ratios, it was found that larger employment of BSA had significant effect in increasing the denitrification rate. Particularly when 4 % BSA was added into elemental sulfur, the highest denitrification rate reached 26.8 mg-N/(L·d), 3.7 times of the control group. Meanwhile, the largest reaction rate constant was achieved, 4.13 mg0.5/(L0.5·d), 2.78 times of the control group. This effect was attributed to promoted conversion of elemental sulfur to polysulfide that was easily utilized by sulfur-oxidizing bacteria. A long-term operation (14 days) of packed bed reactor filled with sulfur particles and 1 % BSA delivered a much faster start-up than the control and outperformed it with better denitrification performance all-through the experiment. This result evidenced again that BSA could make a highly effective supplement in sulfur autotrophic denitrification.

Quantification of organic fluorophores in absorbing media by solid-phase fluorescence excitation–emission matrix (SPF-EEM) spectroscopy of modeled mixtures containing bovine serum albumin (BSA) and colorants

Solid-phase fluorescence excitation–emission matrix (SPF-EEM) spectroscopy is beneficial for investigating the characteristics of natural organic matter (NOM) in the solid phase without extraction procedures. However, inner filter effect (IFE) due to the presence of dark components in samples can make it difficult to quantify the fluorophore concentration. To establish a new method to determine unknown concentrations of a fluorescent material in a sample containing various absorbing materials by SPF spectroscopy, modeled mixtures containing bovine serum albumin (BSA) and colorants at different ratios were examined. Fluorescence intensities of BSA against various concentrations afforded different saturation curves for different colorants in the mixtures, suggesting that it is difficult to use the SPF intensity for quantifying the concentration of fluorescent samples in which IFE has occurred, because one cannot obtain a single calibration curve that does not depend on the absorbing medium that it is mixed in. However, products of the fluorescence intensity and Kubelka–Munk (KM) function at the excitation wavelength were proportional to the first order of BSA weight concentrations, regardless of the colorant type. By using this trend as a calibration curve, it may be possible to quantify the amount of BSA from its SPF-EEM spectrum. In this study, the KM function was obtained using an ultraviolet–visible (UV–Vis) spectrometer with an integrating sphere. To reduce the labor and equipment cost of UV–Vis spectroscopy, a substrate of the KM function also was obtained from the Rayleigh scattering in an SPF-EEM spectrum, which could be used as a parameter for calibration curves that quantify the BSA concentration. Although further studies are required, this study proposed that the product of the SPF intensity and KM function at the excitation wavelength can be partially used for an empirical formula to quantify a variety of fluorescent materials mechanically mixed with various absorbing materials.

HYDROGEN PEROXIDASE ENZYME ACTIVITY AT DIFFERENT CONCENTRATIONS OF BSA

Cross-linked enzymes are more stable at a certain temperature than free enzymes. Bovine serum albumin (BSA), which has a large number of amine groups, provides a strong binding between enzyme aggregates, thus leading to increased activity and stability of the bioactive layer. The enzyme-BSA mixture becomes more stable after covalent bonding with a crosslinking agent such as glutaraldehyde. The HRP enzyme was immobilized on the gold electrode together with BSA, gelatin and glutaraldehyde with the help of UV light. Four different electrodes were prepared using different amounts of BSA at 7.5 mg, 15 mg, 30 mg and 60 mg concentrations for each electrode Using four different electrodes prepared, 16 electrochemical measurements were performed with four different ferrous iron analytes. Glutaraldehyde binds to the BSA polymer, which has a higher affinity than the enzyme, reducing the tight covalent cross-links caused by BSA on the HRP and ensuring the continuation of the enzyme activity. It was observed that different BSA concentrations significantly affected the enzyme activity. The concentration of polymers to be used for crosslinking enzymes is an important factor in electrochemical studies.

Interactions of hydrophobically modified hyaluronan carrier with bovine serum albumin

The interactions of carrier systems with serum proteins complicate their performance in medical applications. Although interactions of proteins with native hyaluronan (HA) have been investigated, there is little known about the interactions of its derivatives. The interactions of the oleyl derivative of HA (oleyl-HA) with bovine serum albumin (BSA) were investigated using various physicochemical techniques to understand processes and structural changes at the molecular level. The response of used techniques could be divided into three regimes according to an interplay of hydrogen bonding, electrostatic, and hydrophobic interactions at certain BSA to oleyl-HA molar ratios. The hydrophobic interactions led to the incorporation of BSA into the carriers' structure resulting the formation of hybrid BSA-oleyl-HA nanostructures with increased curcumin loading. The structural changes were correlated with skin penetration experiments, which showed decreased penetration efficiency due to altered interfacial behavior of the hybrid nanostructures. The oleyl-HA carriers' ability to carry significant amounts of a hydrophobic active compound was preserved at both low and high amounts of BSA. The results provided important information about the complex behavior of hydrophobically modified HA derivatives in a biological environment. Acquired findings could accelerate the implementation of HA derivatives as drug delivery systems.

A durable Watasenia Scintillans-like luminescent hydrophilic coating for synergistic high-efficiency anti-biofouling

Marine bio-fouling has been a longstanding problem facing the marine industry, which affects the underwater facilities and causes serious economic losses. It is highly desirable to develop an effective antifouling coating currently. Here a novel antifouling coating inspired by Watasenia Scintillans is reported, which achieves excellent performance by synergism of highly hydrophilic surface and luminescence layer, where pentaerythritol triacrylate embedded in the acrylic resins provides active sites for the graft of poly (sulfobetaine methacrylate) (PSBMA) brush via UV-initiation. The antifouling test results show that the coating can effectively resist the adhesion of non-specific proteins, i.e. the adsorption amount of bovine serum albumin is decreased from 220.83 ng/cm2 of blank control to 40.01 ng/cm2, and the attachment amount of Phaeodyylum tricornutum is decreased to 67n/mm2, which is nearly one-sixth of the blank control (383n/mm2). After compounding fast rechargeable fluorescent particles with PSBMA coating, the adhesion amount of diatoms is further dropped to 4n/mm2, since long-lasting light can effectively interfere with the normal biorhythm of fouling organisms. The long-term underwater field tests results also proved the long-term durability and excellent performance of the hydrophilic luminescent coating in the complex actual aquatic environment. It is believed that the advantageous characteristics of the as-described composite eco-friendly coating and simplicity of the preparation process will be a pioneer for future marine anti-biofouling industry, since various biological fouling at different period underwater can be inhibited effectively.