Amount Of Adsorbed Bovine Serum Albumin Research Articles

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+].

Preparation And Characterizations Of Poly(vinyl butyral)/Caprolactam/Polyethylene Glycols Hydrophilic Flat‐sheet Membrane Through Thermally Induced Phase Separation

AbstractPoly(vinyl butyral)/caprolactam/polyethylene glycols hydrophilic flat‐sheet membranes were prepared via thermally induced phase separation (TIPS) for the first time. Poly(vinyl butyral) (PVB) was used as polymers,caprolactam (CPL) and polyethylene glycols (PEG) were used as mixed diluent. In all situations, the system occurs liquid‐liquid (L−L) phase separation to obtain asymmetric honeycomb structures. The effects of PVB concentration and molecular weight of PEG on the structure and performance of the flat‐sheet membranes were investigated in detail. Herein, the obtained PVB/CPL/PEG microporous membrane has some hydrophilicity and high BSA rejection ratio. Particularly, when the PVB concentration was 30 wt%, the PVB/CPL/PEG200 membrane achieved the highest bovine serum albumin (BSA) rejection of 85.36%. The prepared membrane had good antipollution performance, and the minimum adsorption amount of BSA was 4.94 g/m2. Those results show the PVB microporous membrane has great application prospects in the field of water treatment.

Model Protein Adsorption on Polymers Explained by Hansen Solubility Parameters

Hansen solubility parameters (HSP) theory has been successful in explaining the wettability of organic solvents on polymer surfaces and miscibility of different polymers. Here, we demonstrate that the amount of bovine serum albumin (BSA) protein adsorption on different polymer surfaces can also be explained by HSP. Interestingly, the HSP of the adsorbed BSA proteins calculated from the protein adsorption data is different than the HSP of native BSA protein itself. The HSP of the adsorbed BSA proteins are more hydrophobic than the native BSA protein. This observation suggested adsorbed BSA proteins are partially denatured and exposed their hydrophobic core toward the polymer surfaces. These results highlight a new strategic direction to understand interaction of protein with a surface: a theoretical approach that compliments experimental approach. The model in this study could be used to predict the amount of BSA adsorption on a polymer or any other solid surface, if the HSP of that surface is known. Further, the model can serve as a prescreen method to identify surfaces that are problematic at the outset and inform subsequent empirical studies to select packaging that will have the least adsorption for the specific biologic application.

Adsorption of BSA on carbon-coated Fe3O4 microspheres activated with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride

Carbon-coated Fe3O4 (Fe3O4/C) microspheres activated with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC) were prepared, characterized and applied to adsorb bovine serum albumin (BSA). The prepared magnetic microspheres had spherical core-shell structure with a uniform and continuous carbon coating coupled with activation by EDC, and possessed superparamagnetic characteristics. The experimental results showed that the adsorption amount of BSA on the EDC-activated Fe3O4/C (Fe3O4/C-EDC) microspheres was higher than that on the Fe3O4/C microspheres. The maximum adsorption of BSA on Fe3O4/C-EDC microspheres occurred at pH 4.7, which was the isoelectric point of BSA. At low concentrations (below 1.0 M), salt had no noticeable effect on BSA adsorption. The BSA adsorption of Fe3O4/C-EDC microspheres had a better fit to the Langmuir model than the Freundlich isotherm and Temkin isotherm model, and the kinetic data were well described by the pseudo-second-order model. The adsorption equilibrium could be reached within 20 min. High desorption efficiency (97.6%) of BSA from Fe3O4/C-EDC microspheres was obtained with 0.5 M Na2HPO4 (pH 9.4) as the desorbent.

Fabrication of Mesoporous Silica Thin Film Platforms for Surface Reaction with Surface Plasmon Resonance

Mesoporous silica thin films were fabricated on gold substrates with a sol-gel method including a cationic surfactant. The interface of gold and silica thin films was fixed with a mercaptosilane. The surface roughness of the thin films and their grain sizes of silica were both increased with the elimination of the cationic surfactant and polyethylene glycol (PEG) modification on its surface. The surface reaction, adsorption of bovine serum albumin (BSA), was monitored with surface plasmon resonance (SPR). Although the adsorption amount of BSA at 1 mg/mL were 7.9 ng/cm2 on the mesoporous silica, the PEG modification can completely desorb BSA. The mesoporous silica thin films on gold substrates fabricated will be a good platform for analyzing surface reaction.

The Effect of Nano-ZnO Surface Wettability on Modulating Protein Adsorption

Although surface wettability plays a major role in regulating protein adsorption and nanostructured ZnO has shown great potential in various biomedical fields, few reports have examined the influence of nano-ZnO surface wettability on protein adsorption. Herein, we explored the adsorption behavior of bovine serum albumin (BSA) on the superhydrophilic, hydrophilic, hydrophobic and superhydrophobic nano-ZnO surfaces. The adsorption amount of BSA increased with increase of hydrophilicity because of increased adsorption sites on the hydrophilic surface. The protein adsorption was proved to occur along with the desorption and conformational changes by well-fitted kinetic adsorption curves with the Spreading Particle Model and Fourier transformation infrared spectral analysis. The rates of BSA adsorption and desorption increased with hydrophobicity of the ZnO surfaces, which was considered to be related with the energy barrier created by water bound to the ZnO surfaces via hydrogen bonding. The rate of conformational change varied in a complex way, which might be influenced by the surface wettability of ZnO and some other factors. The present work may open up a new avenue to design nano-bio interfacial materials for advanced biological study and clinical applications.

Adsorption of bovine serum albumin and urease by biochar

The application of biochar to soil improvement inevitably affects free soil enzymes. However, there is little information on the interaction of soil enzymes with biochar to our knowledge. We thus investigated the adsorption of bovine serum albumin (BSA) and urease onto two biochars from giant reed pyrolyzed at 300 and 600 °C (BCF300 and BCF600). The adsorption amount of BSA and urease on BCF300 and BCF600 was up to 45.6-209 mg/g and 75.3-808 mg/g, respectively, suggesting that the test proteins could be adsorbed onto the biochars effectively. The sorption rate of BSA and urease significantly decreased as the protein concentration increased, suggesting that their adsorption was nonlinear. For the same initial concentration (50 or 200 mg/L), the adsorption amount of BSA on the biochars was lower, only 25.9-60.5% of that of urease. The high specific surface area and hydrophobicity of the biochars may play important roles on the immobilization of the proteins by biochars. These findings will be helpful for better understanding the effects of biochar adding on the soil enzymes.

Molten salt synthesis of potassium-containing hydroxyapatite microparticles used as protein substrate

The bioactivity of a material may be favorably altered by exerting control over its protein sorption propensity. Spheroidal potassium-containing calcium phosphate bioceramic microparticles were manufactured by molten salt synthesis. The effects on particle characteristics and adsorption of bovine serum albumin (BSA) of different hydroxyapatite (HA, Ca10(PO4)6(OH)2) to salt flux (K2SO4) ratios were investigated. X-ray diffraction (XRD) patterns showed the emergence of minor phases in addition to the HA major phase with increased salt flux. Synthesized particles were found to increase in potassium content with increasing HA:K2SO4 ratio. Conversely, the amount of BSA adsorption onto microparticles, normalized for surface area, decreased with excess K2SO4. The results indicate that K2SO4 content can impact the morphology, composition, and BSA adsorption propensity of the resultant bioceramic microparticles.

Protein adsorption on single-crystal hydroxyapatite particles with preferred orientation to a(b)- and c-axes

Adsorption of bovine serum albumin (BSA) and lysozyme (LSZ) proteins with preferred orientation to a(b)- and c-axes of single-crystal hydroxyapatite (HAp) particles, was investigated. Fiber-like HAp single crystal particles (aHAp) and plate-like HAp single crystal particles (cHAp) were used as models for a(b)-plane and c-plane oriented HAps, respectively, together with randomly shaped HAp particles (iHAp) as a control. The selective adsorption behaviors of negatively charged BSA and positively charged LSZ on these HAp particles were examined in a phosphate buffered saline at pH 7.3 and 25°C for 48h. The amount of BSA adsorption, normalized for specific surface area, was in the order of aHAp>iHAp>cHAp; however, the order for LSZ was reversed as cHAp>iHAp ≒ aHAp. These results indicate that the a(b)- and c-planes of HAp crystal have high specificity for the adsorption of acidic or basic proteins.

Electrically Polarized Biphasic Calcium Phosphates: Adsorption and Release of Bovine Serum Albumin

In this study, we applied electrical polarization technique to increase adsorption and control protein release from biphasic calcium phosphate (BCP). Three different biphasic calcium phosphate (BCP) composites, with hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP), were processed and electrically polarized. Our study showed that stored charge was increased in the composites with the increase in HAp percentage. Adsorption of bovine serum albumin (BSA), as a model protein, on the poled as well as unpoled surfaces of the composites was studied. The highest amount of BSA adsorption was obtained on positively poled surfaces of each composite. Adsorption isotherm study suggested a multilayer adsorption of BSA on the BCP composites. The effect of electrical polarization on BSA release kinetics from positively charged BCP surfaces was studied. A gradual increase in percent BSA release from positively charged BCP surfaces with decreasing stored charge was observed. Our study showed that the BCP based composites have the potential to be used as a drug or growth factor delivery vehicle.

Characterisation of protein adsorption on different liquid crystal phthalocyaninethin films

Bovine serum albumin (BSA) protein adsorption on thin spun films of different metal octakishexylthiophthalocyanine [(C(6)S)(8)PcM, M=Cu, Ni] derivatives is investigated by using three independent spectroscopic measurements namely Raman spectroscopy, ellipsometry and surface plasmon resonance imaging. Thermally induced molecular self-reorganisations in the phthalocyanine films are found to have produced the changes in the surface energy which, in turn, control protein adsorption. The amount of BSA adsorption on [(C(6)S)(8)PcNi] is more limited than that on [(C(6)S)(8)PcCu] and this observation is consistent with the results on the surface wettability obtained from the contact angle measurements. The shift from the plasmonic resonance wavelength because of the BSA adsorption was significantly larger for the heat-treated [(C(6)S)(8)PcCu] than as-deposited film. Similar measurements on the [(C(6)S)(8)PcNi] films showed a limited BSA adsorption. The results of surface plasmon resonance experiments are consistent with those obtained from Raman spectroscopic and ellipsometric techniques.

EFFECTS OF IONIC SURFACTANTS ON THE ADSORPTION OF BOVINE SERUM ALBUMIN TO THE SURFACE OF HYDROXYAPATITE

The effects of ionic surfactants, dodecyltrimethylammonium chloride (DTMAC) and sodium dodecyl sulfate (SDS), on the adsorption amount of bovine serum albumin (BSA) onto the surface of hydroxyapatite (HAP) were studied. BSA was bound to HAP owing mainly to electrostatic interaction between opposite charges on HAP and BSA in the absence of an additive. The adsorption amount of BSA on HAP increased with a concentration of added DTMAC by virtue of hydrophobic interaction between hydrocarbon chains of DTMAC bound to BSA and those adsorbed on HAP in the range of a low concentration of DTMAC. The adsorption amount, however, decreased with the concentration in the region of a higher concentration of DTMAC. This is because the expansion/denaturation of BSA was caused after the binding of much amount of DTMAC, resulting in an increase in a molecular occupation area of BSA on the HAP surface. On the other hand, in the presence of SDS, the adsorption amount of BSA on HAP monotonously decreased with a concentration of SDS owing to the strong effect of SDS on the expansion and concomitant denaturation of BSA.

EFFECT OF DODECYLTRIMETHYLAMMONIUM CHLORIDE ON THE ADSORPTION OF BOVINE SERUM ALBUMIN TO THE SURFACE OF HYDROXYAPATITE

The effect of a cationic surfactant, dodecyltrimethylammonium chloride (DTMAC), on the adsorption of bovine serum albumin (BSA) to the surface of hydroxyapatite (HAP) was studied. BSA was bound to HAP owing mainly to electrostatic interaction between opposite charges on HAP and BSA in the absence of an additive. On the other hand, the adsorption amount of BSA by HAP decreased after attaining a maximum with a concentration of DTMAC when a concentration of BSA was kept constant at 0.2w/v%. At a low concentration region of DTMAC, the adsorption amount of BSA on HAP increased with the concentration by virtue of hydrophobic interaction between hydrophobic groups of DTMAC bound to BSA and those adsorbed on HAP. The adsorption amount, however, decreased with the concentration at a high concentration region of DTMAC. This is because the expansion/denaturation of BSA molecule was caused by the binding of much amount of DTMAC, resulting in an increase in a molecular occupied area of BSA.

Ultrafiltration Behavior of Corynebacterium glutamicum Slurry with and without Bovine Serum Albumin

Ultrafiltration behavior of Corynebacterium glutamicum (C. glutamicum) slurry was investigated with and without bovine serum albumin (BSA). It was found that the average specific filtration resistance αav of C. glutamicum slurry depended on slurry pH without BSA: αav was much lower in the pH from 2.0 to 4.0 than in the pH from 4.5 to 8.0. The measurement of particle size distribution and zeta potential of cells indicated that the area mean diameter and the surface charge of cells were maximum and minimum at pH 3.0, respectively. Such a change in the state of aggregation due to the decrease of surface charge reduced αav. Furthermore the effect of the mass fraction sb of BSA on αav was investigated under a constant total mass fraction s of BSA and cells at pH 4.5, where cells and BSA were oppositely charged. The addition of a small amount of BSA was effective below 0.08 of sb/s for reducing αav via aggregation of cells where BSA worked as a binder between cells. Over 0.08 of sb/s, however, αav increased due to the increase of free BSA of which αav was much higher than that of cells. The interaction manner of BSA and cells was found mono-layer adsorption of BSA to cells, following the Langmuir isotherm, according to the measurement of the adsorption amount of BSA to cells.

Membrane properties of mixed dipalmitoylphosphatidylglycerol/ganglioside G M3 liposomes in the presence of bovine serum albumin

Liposomes composed of ganglioside G M3 (GM3), Gal β 1(3←2 α NANA)→4Glc β1→1Cer, and l-α-dipalmitoylphosphatidylglycerol (DPPG) were prepared by varying the amount of GM3, and the effects of GM3 on the membrane properties of liposomes in the presence of bovine serum albumin (BSA) were examined at pH 7.4 and 37 °C in terms of adsorption amount of BSA and permeability of the liposomal bilayer membranes. GM3 incorporated into DPPG liposomes inhibited the adsorption of BSA on the liposomes, and the leakage of calcein as an aqueous-space marker from liposomes through adsorption of BSA decreased. However, a large amount of GM3 incorporated into liposomes brought about a probable phase separation in the liposomal bilayer membranes, thereby increasing their permeability. The leakage of calcein from the liposomes in the presence of BSA showed a minimum value at 0.10 mole fraction of GM3.

Effect of adsorption of bovine serum albumin on liposomal membrane characteristics

The effect of adsorption of bovine serum albumin (BSA) on the membrane characteristics of liposomes at pH 7.4 was examined in terms of ζ potential, micropolarity, microfluidity and permeability of liposomal bilayer membranes, where negatively charged l-α-dipalmitoylphosphatidylglycerol (DPPG)/ l-α-dipalmitoylphosphatidylcholine (DPPC), negatively charged dicetylphosphate (DCP)/DPPC and positively charged stearylamine (SA)/DPPC mixed liposomes were used. BSA with negative charges adsorbed on negatively charged DPPG/DPPC mixed liposomes but did not adsorb on negatively charged DCP/DPPC and positively charged SA/DPPC mixed liposomes. Furthermore, the adsorption amount of BSA on the mixed DPPG/DPPC liposomes increased with increasing the mole fraction of DPPG in spite of a possible electrostatic repulsion between BSA and DPPG. Thus, the adsorption of BSA on liposomes was likely to be related to the hydrophobic interaction between BSA and liposomes. The microfluidity of liposomal bilayer membranes near the bilayer center decreased by the adsorption of BSA, while the permeability of liposomal bilayer membranes increased by the adsorption of BSA on liposomes. These results are considered to be due to that the adsorption of BSA brings about a phase separation in liposomes and that a temporary gap is consequently formed in the liposomal bilayer membranes, thereby the permeability of liposomal bilayer membranes increases by the adsorption of BSA.

Bovine serum albumin adsorption onto immobilized organotrichlorosilane surface: Influence of the phase separation on protein adsorption patterns

Octadecyltrichlorosilane (OTS) and [2-(perfluorooctyl)ethyl]trichlorosilane (FOETS) monolayers and their mixed monolayer were polymerized on a water subphase and subsequently immobilized onto a silicon wafer surface by covalent bonding. Atomic force microscopic (AFM) observation of the mixed (OTS/FOETS) monolayer revealed the formation of a phase-separated structure. Protein-adsorption behavior onto the monolayers was investigated in situ on the basis of an attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopic flow cell method and the morphology of the monolayer surface-adsorbed bovine serum albumin (BSA) was observed by AFM. Protein adsorption behavior observed by ATR-FT-IR flow cell method revealed that the amount of BSA adsorption onto the OTS and FOETS monolayers increased remarkably at an initial experimental stage and attained a steady state within a few minutes at pH 7.5. The amount of steady state adsorption was c. 0.18-0.2 μgcm-2. AFM observation of the monolayer after exposure to BSA solution suggested that BSA adsorbed in the end-on adsorption state on OTS monolayer and side-on one in the FOETS monolayer, respectively. However, in the case of the mixed (OTS/FOETS) monolayer, ATR-FT-IR flow cell experiment revealed that the amount of steady state adsorption of BSA was suppressed. Also, AFM observation revealed that at pH 7.5, BSA preferentially adsorbed onto the FOETS phase of the mixed (OTS/FOETS) monolayer, which had a higher interfacial free energy against water. On the other hand, BSA adsorbed homogeneously onto the OTS and FOETS phases at the isoelectric point of BSA (pH 4.7). These results indicate that the preferential adsorption of BSA onto the FOETS phase in the mixed (OTS/FOETS) monolayer system is due to: (1) the minimization of the interfacial free energy between a monolayer surface and an aqueous solution; and (2) the electrostatic repulsion between BSA molecules bearing negative charges.

Effect of electrochemical pretreatment on protein adsorption at glassy carbon electrodes protein

AbstractThree types of electrochemical, pretreatments (ECPs) were assessed as a means of reducing albumin adsorption at glassy carbon electrodes. The cyclic voltammetric and differential pulse responses of the probe analyte, ferrocenemonocarboxylic acid (FCA), in the absence and presence of 4 g L−1 bovine serum albumin (BSA) were used to monitor protein adsorption at pretreated electrodes. Severe dc pretreatment in acid increased BSA adsorption (compared to that at a polished electrode), whereas square‐wave pretreatment in aqueous NaCl and dc pretreatment in base both reduced the amount of BSA adsorption. The effects of the latter two ECPs on the response of acetaminophen in the presence of BSA were examined. The loss of sensitivity in the presence of BSA was reduced at electrodes which were pretreated. However, our results sugges: that ECP which leads to very strong accumulation of analyte may have a deleterious effect on electrode performance in the presence of protein.